Becton Dickinson Directigen EZ Flu A+B assay in the diagnosis of pandemic influenza A H1N1 2009 virus infection in adult patients

To the editor: The recent emergence and spread of the pandemic influenza A H1N1 2009 virus demands the evaluation of rapid antigen assays for their ability to detect this novel subtype of influenza A virus. Data on the ability of BD Directigen EZ Flu A+B immunochromatographic (IC) assay (Beckton Dickinson and Company, Sparks, MD, USA) to detect the pandemic influenza A virus strain in fresh clinical samples have been recently published. 1 , 2 , 3 , 4 , 5 In these studies, the majority of specimens were collected from pediatric patients, and the sensitivities reported ranged from 46·8% to 76·6%. As viral shedding in the upper respiratory tract during influenza virus infection is of greater m…

SARS-CoV-2 antibodies, serum inflammatory biomarkers and clinical severity of hospitalized COVID-19 patients

Background The involvement of SARS-CoV-2 antibodies in mediating immunopathogenetic events in COVID-19 patients has been suggested. By using several experimental approaches, we investigated the potential association between SARS-CoV-2 IgGs recognizing the spike (S) protein receptor-binding domain (RBD), neutralizing antibodies (NtAb) targeting S, and COVID-19 severity. Patients and methods This unicenter, retrospective, observational study included 51 hospitalized patients (24 at the intensive care unit; ICU). A total of 93 sera from these patients collected at different time points from the onset of symptoms were analyzed. SARS-CoV-2 RBD IgGs were quantitated by ELISA and NtAb50 titers wer…

Optimal doses of caspofungin during continuous venovenous hemodiafiltration in critically ill patients

Spanish Society of Hematology and Hemotherapy expert consensus opinion for SARS-CoV-2 vaccination in onco-hematological patients.

Abstract In the midst of the COVID-19 pandemic, different vaccines in front of SARS-CoV-2 have been approved and administered in different vulnerable populations. As patients with cancer were excluded from pivotal trials of vaccination, little is known on their immunogenic response to these vaccines, particularly in patients with severely impaired immune system. In response to that uncertainty, the Spanish Society of Hematology and Hemotherapy launched an initiative aimed to provide recommendations for vaccination of the main hematological conditions. This document is based on the available information on COVID-19 outcomes, prior knowledge on vaccination in hematological patients, recent pu…

Diagnosis of systemic candidiasis by enzyme immunoassay detection of specific antibodies to mycelial phase cell wall and cytoplasmic candidal antigens

Diagnosis of systemic Candida infections was attempted by the use of an enzyme-linked immunosorbent assay (EIA) to detect IgG antibodies towards cell wall-bound and cytoplasmic candidal antigens. Cell wall antigens were sequentially solubilized by treatment of germinated blastoconidia of Candida albicans (ATCC 26555 strain) with beta-mercaptoethanol (beta ME extract) and digestion with Zymolyase 20T, a beta-glucanase preparation (Zymolyase extract). Protoplasts obtained after treatment with Zymolyase were osmotically lysed (cytoplasmic antigens). Sera were obtained from patients with systemic (n = 28) and superficial (n = 46) candidiasis. Control sera were obtained from normal healthy indiv…

Real-life evaluation of a rapid extraction-free SARS-CoV-2 RT-PCR assay (COVID-19 PCR Fast-L) for the diagnosis of COVID-19.

Comparative evaluation of molecular methods for the quantitative measure of torquetenovirus (TTV) viremia, the new surrogate marker of immune competence

Background Torquetenovirus (TTV) viremia is emerging as a promising tool to assess functional immune competence, to predict posttransplant immune-related complications, and eventually to customize immunosuppression. Methods In this study, 327 blood samples were tested using two real-time PCR (rtPCR) assays both targeted to the untranslated region of the TTV genome. The first assay was an in-house rtPCR developed by our group, the second one was the recently marketed TTV R-GENE assay. Results In the validation study, the TTV R-GENE showed good performances in precision and reproducibility, and sensitivity as low as 12 TTV DNA copies/mL, like previously reported for the in-house rtPCR. The Bl…

Assessment of human cytomegalovirus specific T cell immunity in human immunodeficiency virus infected patients in different disease stages following HAART and in long-term non-progressors.

T cell immunity to human cytomegalovirus (HCMV) was assessed in HAART-treated HIV-1 infected patients (9 asymptomatic, CDC group A; and 22 symptomatic, CDC group B), and in eight HIV-1 long term non-progressors. Patients were either prospectively or cross-sectionally examined for CD4(+) T cell counts, HIV RNA load, HCMV leukoDNAemia, HCMV DNA in urine, lymphoproliferative response (LPR) to HCMV and phytohemagglutinin (PHA), and cytokine secretion (IFN-gamma and IL-4) by HCMV-stimulated peripheral blood mononuclear cell (PBMC) cultures. No patient either progressed to clinical AIDS or developed HCMV active infection during the study period. Twenty-nine patients responded to HAART, though 12 …

How to best manage cytomegalovirus infection in the allogeneic stem cell transplant setting: future prospects

Active cytomegalovirus infection is not a risk factor for Epstein-Barr virus DNAemia in the allogeneic stem cell transplantation setting

Effect of cytomegalovirus (CMV) serostatus on the incidence and virological features of active CMV infection in allogeneic stem cell transplant recipients.

Surveillance for adenovirus DNAemia early after transplantation in adult recipients of unrelated-donor allogeneic stem cell transplants in the absence of clinically suspected infection

Surveillance for adenovirus DNAemia early after transplantation in adult recipients of unrelated-donor allogeneic stem cell transplants in the absence of clinically suspected infection

T cell–mediated response to SARS‐CoV‐2 in liver transplant recipients with prior COVID‐19

Abstract Whether immunosuppression impairs severe acute respiratory syndrome coronavirus 2‐specific T‐cell‐mediated immunity (SARS‐CoV‐2‐CMI) after liver transplantation (LT) remains unknown. We included 31 LT recipients in whom SARS‐CoV‐2‐CMI was assessed by intracellular cytokine staining (ICS) and interferon (IFN)‐γ FluoroSpot assay after a median of 103 days from COVID‐19 diagnosis. Serum SARS‐CoV‐2 IgG antibodies were measured by ELISA. A control group of non‐transplant immunocompetent patients were matched (1:1 ratio) by age and time from diagnosis. Post‐transplant SARS‐CoV‐2‐CMI was detected by ICS in 90.3% (28/31) of recipients, with higher proportions for IFN‐γ‐producing CD4+ than …

Plasma metabolomics profiling for the prediction of cytomegalovirus DNAemia and analysis of virus–host interaction in allogeneic stem cell transplant recipients.

Metabolomics analysis of biofluids is increasingly being recognized as a useful tool for the diagnosis and management of a number of infectious diseases. Here we showed that plasma metabolomics profiling by untargeted 1H nuclear magnetic resonance may allow the anticipation of the occurrence of cytomegalovirus (CMV) DNAemia in allogeneic stem cell transplant. For this purpose, key discriminatory metabolites were total glutathione, taurine, methylamine, trimethylamine N-oxide and lactate, all of which were upregulated in patients eventually developing CMV DNAemia. The overall classification accuracy (predictability) of the projection to latent structure discriminant analysis (PLS-DA) model i…

Assessment of prevalence and load of torquetenovirus viraemia in a large cohort of healthy blood donors.

OBJECTIVES: Torquetenovirus (TTV) is an emerging marker of functional immune competence with the potential to predict transplant-related adverse events. A large-scale epidemiological study was performed to understand how basal values vary in healthy individuals according to age and gender.; METHODS: We tested plasma from 1017 healthy blood donors aged 18-69years. The presence and load of TTV were determined by a real-time PCR assay. A sub-cohort of 384 donors was tested for anti-cytomegalovirus IgG antibodies, and 100 participants were also tested for TTV viraemia on a paired whole blood sample.; RESULTS: The overall prevalence of TTV was 65% (657/1017) with a mean (±SD) growth of 5±4% ever…

Seasonal Human Coronavirus Respiratory Tract Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

Abstract Background Little is known about characteristics of seasonal human coronaviruses (HCoVs) (NL63, 229E, OC43, and HKU1) after allogeneic stem cell transplantation (allo-HSCT). Methods This was a collaborative Spanish and European bone marrow transplantation retrospective multicenter study, which included allo-HSCT recipients (adults and children) with upper respiratory tract disease (URTD) and/or lower respiratory tract disease (LRTD) caused by seasonal HCoV diagnosed through multiplex polymerase chain reaction assays from January 2012 to January 2019. Results We included 402 allo-HSCT recipients who developed 449 HCoV URTD/LRTD episodes. Median age of recipients was 46 years (range,…

Epstein-Barr virus DNA load kinetics analysis in allogeneic hematopoietic stem cell transplant recipients: Is it of any clinical usefulness?

Abstract Background There is a lack of clinical information regarding the usefulness of plasma Epstein-Barr virus (EBV) DNA load kinetics analyses in the management of EBV infections in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Namely, it remains unknown whether this type of analysis can help physicians to anticipate the development of high-level EBV DNAemia episodes requiring rituximab treatment or predict the risk of recurrent EBV DNAemia or post-transplant lymphoproliferative disorders (PTLDs). Study design Unicentric, retrospective, observational study including 142 consecutive patients undergoing T-cell replete allo-HSCT. The plasma EBV DNA load was mon…

SARS‐CoV‐2 N‐antigenemia in critically ill adult COVID‐19 patients: Frequency and association with inflammatory and tissue‐damage biomarkers

Abstract The current study aimed at characterizing the dynamics of SARS‐CoV‐2 nucleocapsid (N) antigenemia in a cohort of critically ill adult COVID‐19 patients and assessing its potential association with plasma levels of biomarkers of clinical severity and mortality. Seventy‐three consecutive critically ill COVID‐19 patients (median age, 65 years) were recruited. Serial plasma (n = 340) specimens were collected. A lateral flow immunochromatography assay and reverse‐transcription polymerase chain reaction (RT‐PCR) were used for SARS‐CoV‐2 N protein detection and RNA quantitation and in plasma, respectively. Serum levels of inflammatory and tissue‐damage biomarkers in paired specimens were …

Community-acquired respiratory virus lower respiratory tract disease in allogeneic stem cell transplantation recipient: Risk factors and mortality from pulmonary virus-bacterial mixed infections.

Abstract Risk factors (RFs) and mortality data of community‐acquired respiratory virus (CARVs) lower respiratory tract disease (LRTD) with concurrent pulmonary co‐infections in the setting of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is scarce. From January 2011 to December 2017, we retrospectively compared the outcome of allo‐HSCT recipients diagnosed of CARVs LRTD mono‐infection (n = 52, group 1), to those with viral, bacterial, or fungal pulmonary CARVs LRTD co‐infections (n = 15, group 2; n = 20, group 3, and n = 11, group 4, respectively), and with those having bacterial pneumonia mono‐infection (n = 19, group 5). Overall survival (OS) at day 60 after bronchoalveol…

Field evaluation of a rapid antigen test (Panbio™ COVID-19 Ag Rapid Test Device) for the diagnosis of COVID-19 in primary healthcare centers

AbstractWe evaluated the Panbio™ COVID-19 AG Rapid Test Device (RAD) for the diagnosis of COVID-19 in symptomatic patients attended in primary healthcare centers (n=412). Overall specificity and sensitivity of RAD was 100% and 79.6%, respectively, taking RT-PCR as the reference. SARS-CoV-2 could not be cultured from specimens yielding RT-PCR+/RAD- results.

Evaluation of a rapid antigen detection test (Panbio™ COVID‐19 Ag Rapid Test Device) as a point‐of‐care diagnostic tool for COVID‐19 in a pediatric emergency department

Abstract We evaluated the Panbio™ COVID‐19 Ag Rapid Test Device as a point‐of‐care diagnostic tool for COVID‐19 in 357 patients at a pediatric emergency department. Thirty‐four patients tested positive by reverse transcription polymerase chain reaction, of which 24 were positive by the antigen assay. The sensitivity and specificity of the assay were 70.5% and 100%, respectively.

Optimizing ceftolozane-tazobactam dosage during continuous renal replacement therapy: some nuances

Natural populations of Spodoptera exigua are infected by multiple viruses that are transmitted to their offspring

Sublethal infections by baculoviruses (Baculoviridae) are believed to be common in Lepidoptera, including Spodoptera exigua. In addition, novel RNA viruses of the family Iflaviridae have been recently identified in a laboratory population of S. exigua (S. exigua iflavirus-1: SeIV-1; S. exigua iflavirus-2: SeIV-2) that showed no overt signs of disease. We determined the prevalence of these viruses in wild populations and the prevalence of co-infection by the different viruses in shared hosts. Infection by S. exigua multiple nucleopolyhedrovirus (SeMNPV) and iflaviruses in S. exigua adults (N= 130) from horticultural greenhouses in southern Spain was determined using qPCR and RT-PCR based tec…

Incidence and dynamics of active cytomegalovirus infection in allogeneic stem cell transplant patients according to single nucleotide polymorphisms in donor and recipient CCR5, MCP-1, IL-10, and TLR9 genes

Single nucleotide polymorphisms (SNPs) in genes involved in the activation or regulation of innate and adaptive immune responses may modulate the susceptibility to and the natural history of certain chronic viral infections. The current study aimed to investigate whether donor and recipient SNPs in the chemokine receptor 5 (rs1800023), monocyte chemoattractant protein 1 (rs13900), interleukin-10 (rs1878672), and Toll-like receptor 9 (rs352140) genes would exert any influence on the rate of incidence and features of CMV DNAemia in the allogeneic stem cell transplantation setting. This was a retrospective observational multicenter study. The cohort consisted of 102 non-consecutive allogeneic …

Efficacy and Safety of a Preemptive Antiviral Therapy Strategy Based on Combined Virological and Immunological Monitoring for Active Cytomegalovirus Infection in Allogeneic Stem Cell Transplant Recipients.

Preemptive antiviral therapy for active CMV infection in allogeneic stem cell transplant recipients guided by immunological and virological parameters minimizes the risk of recurrent viremia in a subset of patients.

Comparative Evaluation of Three Automated Systems for DNA Extraction in Conjunction with Three Commercially Available Real-Time PCR Assays for Quantitation of Plasma Cytomegalovirus DNAemia in Allogeneic Stem Cell Transplant Recipients▿

ABSTRACT Limited data are available on the performance of different automated extraction platforms and commercially available quantitative real-time PCR (QRT-PCR) methods for the quantitation of cytomegalovirus (CMV) DNA in plasma. We compared the performance characteristics of the Abbott mSample preparation system DNA kit on the m24 SP instrument (Abbott), the High Pure viral nucleic acid kit on the COBAS AmpliPrep system (Roche), and the EZ1 Virus 2.0 kit on the BioRobot EZ1 extraction platform (Qiagen) coupled with the Abbott CMV PCR kit, the LightCycler CMV Quant kit (Roche), and the Q-CMV complete kit (Nanogen), for both plasma specimens from allogeneic stem cell transplant (Allo-SCT) …

Spontaneously‐resolving episodes of cytomegalovirus DNAemia in allogeneic hematopoietic stem cell transplant recipients: Virological features and clinical outcomes

It has been reported that low-plasma cytomegalovirus (CMV) DNA loads are associated with an increased risk of overall mortality in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Utilizing a conservative strategy for initiation of preemptive antiviral therapy (>1500 IU/mL), we characterized the virological features of spontaneously-resolving episodes of CMV DNAemia and assessed their impact on mortality through the first year after transplantation. We reviewed the CMV DNA polymerase chain reaction results and clinical charts of 230 consecutive adult patients who underwent T-cell replete allo-HSCT at our center. A total of 280 episodes of CMV DNAemia were registered in 164 pa…

Monitoring of Trough Plasma Ganciclovir Levels and Peripheral Blood Cytomegalovirus (CMV)-Specific CD8 + T Cells To Predict CMV DNAemia Clearance in Preemptively Treated Allogeneic Stem Cell Transplant Recipients

ABSTRACT It is uncertain whether monitoring plasma ganciclovir (GCV) levels is useful in predicting cytomegalovirus (CMV) DNAemia clearance in preemptively treated allogeneic stem cell transplant recipients. In this observational study, including 13 episodes of CMV DNAemia treated with intravenous (i.v.) GCV or oral valganciclovir, we showed that monitoring trough plasma GCV levels does not reliably predict response to therapy. Rather, immunological monitoring (pp65 and immediate-early [IE]-1-specific gamma interferon [IFN-γ]-producing CD8 + T cells) appeared to perform better for this purpose.

Early kinetics of Torque Teno virus DNA load and BK polyomavirus viremia after kidney transplantation

Performance Comparison of a Flow Cytometry-based and Two Commercial Chemiluminescent Immunoassays for Detection and Quantification of Antibodies Binding to SARS-CoV-2 Spike Protein

ABSTRACTThe performance of a laboratory-developed quantitative IgG/IgA flow cytometry-based immunoassay (FCI) using Jurkat T cells stably expressing full-length native S protein was compared against Elecsys® electrochemiluminiscent (ECLIA) Anti-SARS-CoV-2 S (Roche Diagnostics, Pleasanton, CA, USA), and LIAISON® SARS-CoV-2 TrimericS IgG chemiluminiscent assay (CLIA) (Diasorin S.p.a, Saluggia, IT) for detection and quantitation of SARS-CoV-2-specific antibodies. A total of 225 serum/plasma specimens from 120 acute or convalescent COVID-19 individuals were included. Overall, IgG/IgA-FCI yielded the highest number of positives (n=179), followed by IgA-FCI (n=177), Roche ECLIA (n=175), IgG-FCI (…

Pathogen safety of long-term treatments for bleeding disorders: still relevant to current practice

Hemophilia defines a group of hereditary bleeding disorders: hemophilia A (deficiency of Factor VIII, FVIII), hemophilia B (deficiency of FIX), and para-hemophilia (deficiency of FV). These result from mutations in clotting factor genes. As in the large majority of bleeding disorders ([Table 1][1

Point-of-care evaluation of a rapid antigen test (CLINITESTⓇ Rapid COVID-19 Antigen Test) for diagnosis of SARS-CoV-2 infection in symptomatic and asymptomatic individuals

AbstractRapid antigen assays (RAD) based on lateral flow immunochromatography (LFIC) technology have emerged as a valuable tool for the control of COVID-19 pandemic. Manufacturer□independent, real□world evaluation of these assays is crucial given the considerable heterogeneity reported in their clinical and analytical performances. Here, we report for the first time on the point-of-care performance of the CLINITEST® Rapid COVID-19 Antigen Test (Siemens, Healthineers, Erlangen, Germany) to detect SARS-CoV-2 infection in presumptive COVID-19 cases or asymptomatic close contacts of COVID-19 patients. When compared to RT-PCR, the overall sensitivity of the assay was 80.2 (95% CI, 70.9-87.1) for…

Kinetics of Torque Teno virus DNA in stools may predict occurrence of acute intestinal graft versus host disease early after allogeneic hematopoietic stem cell transplantation

Torque Teno virus (TTV) DNA load in blood may act as a marker of immune competence after allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). Conflicting data have been reported as to the value of this biomarker for anticipating acute Graft-versus-host disease (aGvHD) occurrence. Here, we hypothesized that quantitation of TTV DNA load in stool specimens early after allo-HSCT could be used to identify patients at high risk of acute intestinal graft-versus-host disease (aIGvHD). In this prospective two-center study we recruited a total of 83 non-consecutive adult patients undergoing allo-HSCT. The study period comprised the first 120 days after allo-HSCT. TTV DNA was quantita…

Cytomegalovirus infection management in solid organ transplant recipients across European centers in the time of molecular diagnostics: An ESGICH survey

Background Scant information is available about how transplant centers are managing their use of quantitative molecular testing (QNAT) assays for active cytomegalovirus (CMV) infection monitoring in solid organ transplant (SOT) recipients. The current study was aimed at gathering information on current practices in the management of CMV infection across European centers in the era of molecular testing assays. Methods A questionnaire-based cross-sectional survey study was conducted by the European Study Group of Infections in Immunocompromised Hosts (ESGICH) of the Society of Clinical Microbiology and Infectious Diseases (ESCMID). The invitation and a weekly reminder with a personal link to …

B and T cell immune responses elicited by the Comirnaty® COVID-19 vaccine in nursing home residents

Objectives The immunogenicity of the Comirnaty® COVID-19 vaccine is understudied in elderly people with comorbidities. SARS-CoV-2-S-targeted antibody and T cell responses following full vaccination were assessed in nursing home residents. Methods Sixty nursing home residents (44 female; age, 53-100 years), of whom 10 had previously been diagnosed of COVID-19, and 18 healthy controls (15 female; age, 27-54 years) were recruited. Pre- and post-vaccination blood specimens were available for quantitation of total antibodies binding SARS-CoV-2 S protein and enumeration of SARS-CoV-2-S-reactive IFN-γ CD4+ and CD8+ T cells by flow cytometry. Results The seroconversion rate in presumably SARS-CoV-2…

Would Kinetic Analyses of Plasma Cytomegalovirus DNA Load Help to Reach Consensus Criteria for Triggering the Initiation of Preemptive Antiviral Therapy in Transplant Recipients?: Table 1.

Amplification of human β-glucoronidase gene for appraising the accuracy of negative SARS-CoV-2 RT-PCR results in upper respiratory tract specimens

Real-time reverse transcription polymerase-chain reaction (RT-PCR) is the mainstay of Covid-19 diagnosis. False-negative RT-PCR results may hamper clinical management of patients and hinder the adoption of epidemiological measures to control the pandemic. The current study was aimed at assessing whether amplification of β-glucoronidase (GUSB) gene would help estimate the accuracy of SARS-CoV-2 RT-PCR negative results in upper respiratory tract (URT) specimens. URT specimens that tested negative by SARS-CoV-2 RT-PCR displayed higher GUSB RT-PCR cycle thresholds (CT) (P=0.070) than those testing positive (median, 30.7; range, 27.0-40.0, and median 29.7; range 25.5-36.8, respectively), this re…

The impact of virus population diversity on the dynamics of cytomegalovirus DNAemia in allogeneic stem cell transplant recipients

Mixed cytomegalovirus (CMV) infections are associated with delayed viral clearance in solid organ transplant recipients. We investigated whether this could be extrapolated to allogeneic stem cell transplant (allo-SCT) recipients. A total of 48 plasma specimens, obtained during 29 episodes of active CMV infection in 25 non-consecutive allo-SCT patients, were analysed. Baseline blood specimens, drawn shortly prior to the inception of pre-emptive antiviral therapy (pre-treatment specimen; n=29), as well as follow-up samples obtained either after the initiation of antiviral therapy (post-treatment specimen; n=15) or during recurrent episodes (n=4) were analysed. Plasma CMV DNA loads were quanti…

Diagnostic significance of SARS-CoV-2 IgM positive/IgG negative antibody profile in symptomatic patients with suspected COVID-19 testing negative by RT-PCR

An outbreak of new coronavirus SARS-CoV-2 was occurred in Wuhan, China and rapidly spread to other cities and nations. The standard diagnostic approach that widely adopted in the clinic is nucleic acid detection by real-time RT-PCR. However, the false-negative rate of the technique is unneglectable and serological methods are urgently warranted. Here, we presented the colloidal gold-based immunochromatographic (ICG) strip targeting viral IgM or IgG antibody and compared it with real-time RT-PCR. The sensitivity of ICG assay with IgM and IgG combinatorial detection in nucleic acid confirmed cases were 11.1%, 92.9% and 96.8% at the early stage (1-7 days after onset), intermediate stage (8-14 …

Assessment of immunodeficiency scoring index performance in enterovirus/rhinovirus respiratory infection after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Enterovirus/rhinoviruses (EvRh) are the most common cause of respiratory virus infections in recipients of allogeneic stem cell transplantation (allo-HSCT).; OBJECTIVE: We sought to analyze the value of the immunodeficiency scoring index (ISI) in predicting lower respiratory tract disease (LRTD) progression and mortality in a prospective cohort of consecutive adult (> 16 years) allo-HSCT recipients with EvRh infection from December 1 2013 to December 1 2019 at two Spanish transplant centers.; RESULTS: We included 234 allo-HSCT recipients with 383 EvRh episodes. Out of 383 EvRh episodes, 98 (25%) had LRTD. Multivariate logistic regression analysis identified three independent fac…

Need to evaluate the performance of real-time PCR assays for the quantitation of cytomegalovirus DNA load in lower respiratory tract specimens

There is an increasing appreciation for the potential clinical value of the quantitation of cytomegalovirus (CMV) DNA in the lower respiratory tract in critically ill patients lacking canonical immunosuppression, in view of the possible pathogenic role of CMV in these patients [1]. No data have been published on the analytical performance of real-time PCR assays for this purpose. We present our data on the performance of the COBAS® AmpliPrep/COBAS® TaqMan CMV PCR Assay (Roche Diagnostics, Mannheim, Germany) for the quantitation of CMV DNA in tracheal aspirates (TA). This CMV PCR assay has been approved recently by the US Food and Drug Administration for use with plasma specimens [2]. We cho…

A Continuous Time Pattern Recognition Retina

International audience; We present in this paper a pattern recognition retina operating in continuous time. During a programming phase, the reference image is acquired by the sensor. After thresholding, the resulting binary image is stored in the sensor's pixels. During the recognition phase, the retina calculates, in an analog way and in continuous time, the zero displacement intercorrelation of the current image with the binary reference image and its complement. These two intercorrelation values are output as currents. By comparing these currents to expected values, determined during the programming phase, a shift of the pattern or a difference between the observed and programmed pattern…

An investigation of the potential association between gastrointestinal viral and bacterial infection and development of intestinal acute graft versus host disease following allogeneic hematopoietic stem cell transplantation.

It is uncertain whether gastrointestinal (GI) infection caused by viral and bacterial pathogens may predispose to gastrointestinal acute Graft-versus-host disease (aGvHD-GI) in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). We investigated the potential association between detection of enteropathogenic viruses or bacteria in stools and subsequent occurrence of aGvHD-GI in a cohort of 121 allo-HSCT patients. Eighty-six out of 121 patients (71%) had acute diarrhea and underwent screening for primary GI pathogens by molecular diagnostic methods. One or more GI pathogens were detected in 27 out of the 86 patients with diarrhea (31.3%). Specifically, Clostridioides diffici…

Effect of Sirolimus Exposure on the Need for Preemptive Antiviral Therapy for Cytomeglovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation

The current study evaluates the clinical effect of sirolimus exposure on the occurrence of cytomegalovirus (CMV) DNAemia necessitating preemptive antiviral therapy. A total of 167 consecutive recipients of reduced-intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (allo-HSCT) who received sirolimus- and tacrolimus-based graft-versus-host disease (GVHD) prophylaxis and whose CMV serostatus was positive for donors and/or recipients were included in this multicenter retrospective study. A parametric model with consecutive sirolimus blood levels describing the time to CMV DNAemia-RAT was developed using NONMEM version 7.4. Overall, 122 of 167 patients (73%) were all…

Performance characteristics of the new Abbott Real Time MTB assay for detection of Mycobacterium tuberculosis complex in respiratory specimens

The performance of the Abbott Real Time MTB assay for detection of Mycobacterium tuberculosis complex in respiratory specimens was evaluated using a standard culture as the reference. The overall concordance between both methods was 0.95. The assay displayed an excellent sensitivity (100% for smear-positive/92.3% for smear-negative specimens) and specificity (100%).

Immunological response against SARS-CoV-2 following full-dose administration of Comirnaty® COVID-19 vaccine in nursing home residents

6 páginas, 2 figuras, 3 tablas. Se puede acceder al texto completo de este artículo desde PubMedCentral: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8490129 . Los datos de investigación utilizados en el mismo, se encuentran disponibles en: https://doi.org/10.1016/j.cmi.2021.09.031.

Epidemiologic and Clinical Characteristics of Coronavirus and Bocavirus Respiratory Infections after Allogeneic Stem Cell Transplantation: A Prospective Single-Center Study

Highlights • Human coronavirus are common after allogeneic stem cell transplantation and can progress to LRTDs, and in some cases this leads to hospitalization and requires supportive care. • Human bocavirus are quite rare after allogeneic stem cell transplantation and are commonly detected in conjunction with other viral co-pathogens.

Pulmonary cytomegalovirus (CMV) DNA shedding in allogeneic hematopoietic stem cell transplant recipients: Implications for the diagnosis of CMV pneumonia

Highlights • CMV DNA is frequently detected in BAL fluid specimens from allo-HSCT. • CMV DNA detection in BAL fluids is comparable across pneumonia etiologies. • CMV DNA loads in BAL fluids are comparable across pneumonia etiologies. • CMV DNA load in BAL may predict attributable-pneumonia mortality.

Plasma Torquetenovirus (TTV) DNA load as a surrogate marker of reconstitution of CMV-specific immunity in the allogeneic stem cell transplantation setting

Performance of the QuantiFERON-cytomegalovirus (CMV) assay for detection and estimation of the magnitude and functionality of the CMV-specific gamma interferon-producing CD8(+) T-cell response in allogeneic stem cell transplant recipients.

ABSTRACTThe performance of the QuantiFERON-cytomegalovirus (CMV) assay was compared to that of a flow cytometry intracellular cytokine staining (ICS) method for the detection of CMV-specific gamma interferon (IFN-γ)-producing CD8+T-cell responses in allogeneic stem cell transplant (allo-SCT) recipients and for estimations of their magnitude and functionality. A total of 90 whole-blood specimens from 23 allo-SCT recipients was analyzed by both methods. Overall, the percentage of specimens that yielded concordant results by both methods was 68.8% (κ = 0.691; 95% confidence interval [CI], 0.548 to 0.835), and the sensitivity of the QuantiFERON-CMV assay for the detection of positive IFN-γ T-ce…

Fundamentos e implementación de Programas de Optimización de Diagnóstico Microbiológico

Resumen Los programas de optimizacion del diagnostico microbiologico (PRODIM) promueven actuaciones coordinadas orientadas a optimizar el uso de las tecnicas diagnosticas, propiciando la toma de decisiones terapeuticas, clinicas y preventivas adecuadas y «coste-efectivas». La implementacion de los PRODIM debe sustentarse en la creacion de comites multidisciplinares liderados por microbiologos clinicos para el diseno de algoritmos diagnosticos, la adecuacion del sistema informatico del laboratorio para el control de la pertinencia de las pruebas diagnosticas solicitadas, la puesta en marcha de un sistema de control de calidad, el diseno y realizacion de estudios de analisis de coste-efectivi…

Anidulafungin dosing in critically ill patients with continuous venovenous haemodiafiltration

Background Anidulafungin is indicated as a first-line treatment for invasive candidiasis in critically ill patients. In the intensive care unit, sepsis is the main cause of acute renal failure, and treatment with continuous renal replacement therapy (CRRT) has increased in recent years. Antimicrobial pharmacokinetics is affected by CRRT, but few studies have addressed the optimal dosage for anidulafungin during CRRT. Patients and methods We included 12 critically ill patients who received continuous venovenous haemodiafiltration to treat acute renal failure. Anidulafungin was infused on 3 consecutive days, starting with a loading dose (200 mg) on Day 1, and doses of 100 mg on Days 2 and 3. …

Identification of a large, fast-expanding HIV-1 subtype B transmission cluster among MSM in Valencia, Spain

We describe and characterize an exceptionally large HIV-1 subtype B transmission cluster occurring in the Comunidad Valenciana (CV, Spain). A total of 1806 HIV-1 protease-reverse transcriptase (PR/RT) sequences from different patients were obtained in the CV between 2004 and 2014. After subtyping and generating a phylogenetic tree with additional HIV-1 subtype B sequences, a very large transmission cluster which included almost exclusively sequences from the CV was detected (n = 143 patients). This cluster was then validated and characterized with further maximum-likelihood phylogenetic analyses and Bayesian coalescent reconstructions. With these analyses, the CV cluster was delimited to 11…

Qualitative assessment of SARS-CoV-2-specific antibody avidity by lateral flow immunochromatographic IgG/IgM antibody assay.

Abstract Knowledge of the precise timing of SARS‐CoV‐2 infection may be of clinical and epidemiological relevance. The presence of low‐avidity IgGs has conventionally been considered an indicator of recent infection. Here, we carried out qualitative assessment of SARS‐CoV‐2‐specific antibody avidity using an urea (6M) dissociation test performed on a lateral flow immunochromatographic IgG/IgM device. We included a total of 76 serum specimens collected from 57 COVID‐19 patients, of which 39 tested positive for both IgG and IgM and 37 only for IgG. Sera losing IgG reactivity after urea treatment (n = 28) were drawn significantly earlier (P = .04) after onset of symptoms than those which prese…

Active Cytomegalovirus Infection in Nonimmunosuppressed Patients in the ICU

Inference of SARS-CoV-2 spike-binding neutralizing antibody titers in sera from hospitalized COVID-19 patients by using commercial enzyme and chemiluminescent immunoassays

medRxiv: https://doi.org/10.1101/2020.09.07.20188151

Assessment of the association between cytomegalovirus DNAemia and subsequent acute graft-versus-host disease in allogeneic peripheral blood stem cell transplantation: A multicenter study from the Spanish hematopoietic transplantation and cell therapy group.

The potential role of active CMV infection in promoting acute Graft-versus-Host Disease (aGvHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a matter of debate. We further addressed this issue conducting a retrospective, observational, multicenter study of 632 patients subjected to allogeneic peripheral blood HSCT at 20 Spanish centers. Monitoring of CMV DNA load in plasma or whole blood was performed by real-time PCR assays. Cumulative incidence of CMV DNAemia was 48.9% (95% CI, 45%-52.9%), of any grade aGvHD, 45.6; 95% (CI, 41.3%-50.1%), and of grade II-IV aGvHD, 30.7 (95% CI, 24.9%-36.4%). Overall, development of CMV DNAemia at any level resulted in an increa…

Prevalence and prognostic implications of active cytomegalovirus infection in patients with acute heart failure

AHF (acute heart failure) causes significant morbidity and mortality. Recent studies have postulated that the expression of inflammatory mediators, such as cytokines and chemokines, plays an important role in the development and progression of heart failure. A pro-inflammatory state has been postulated as a key factor in triggering CMV (cytomegalovirus) reactivation. Therefore we sought to determine the prevalence of active CMV infection in immunocompetent patients admitted for AHF and to quantify the association with the risk of the combined end point of death or AHF readmission. A total of 132 consecutive patients admitted for AHF were enrolled in the present study. Plasma CMV DNAaemia wa…

Role of cytomegalovirus (CMV)-specific polyfunctional CD8+ T-cells and antibodies neutralizing virus epithelial infection in the control of CMV infection in an allogeneic stem-cell transplantation setting

The role of cytomegalovirus (CMV)-specific polyfunctional CD8+ T-cells and that of antibodies neutralizing virus epithelial infection (AbNEI) in the control of CMV DNAemia were investigated in 39 CMV-seropositive allogeneic stem-cell transplant (Allo-SCT) recipients with (n = 24) or without (n = 15) CMV DNAemia. AbNEI levels were monitored prospectively by means of a neutralization assay employing retinal epithelial cells (ARPE-19) and the recombinant CMV strain BADrUL131-Y4. Quantification of CMV-specific polyfunctional CD8+ T-cells (expressing two or three of the following markers: IFN-γγ, TNF-α and CD107a) in whole blood was performed by flow cytometry for intracellular cytokine staining…

The kinetics of torque teno virus plasma DNA load shortly after engraftment predicts the risk of high-level CMV DNAemia in allogeneic hematopoietic stem cell transplant recipients

Monitoring Torque teno virus (TTV) DNA load helps to estimate the risk of opportunistic infections in solid organ transplant recipients. We investigated whether the early kinetic pattern of plasma TTV DNA load after allogeneic hematopoietic stem cell transplantation (allo-HSCT) associates with subsequent CMV and EBV DNAemia. This study included 71 allo-HSCT patients. We found that the area under the curve (AUC) for log10 TTV DNA loads quantified by days 20 and 30 after transplantation (TTV DNA load AUC20-30), was significantly lower (P=0.036) in patients who subsequently developed CMV DNAemia requiring preemptive antiviral therapy (n=17) than in those who did not (n=8) or had no CMV DNAemia…

Pharmacokinetics of anidulafungin during venovenous extracorporeal membrane oxygenation

Echinocandins are currently considered the first-line treatment for invasive candidiasis (IC) in the intensive care unit (ICU) [1, 2]. However, extracorporeal membrane oxygenation (ECMO), a rescue therapy used in patients with severe acute respiratory distress syndrome (ARDS) [3], could alter the pharmacokinetics of certain drugs [4]. We prescribed anidulafungin for suspected IC in a patient with severe ARDS on ECMO and measured the plasma concentrations of the drug using high-performance liquid chromatography (HPLC).

Fundamentals and implementation of Microbiological Diagnostic Stewardship Programs.

Microbiological diagnostic stewardship programs promote coordinated measures aimed at optimizing the use of diagnostic techniques, thus favouring the adoption of adequate and cost-effective therapeutic, clinical and preventive decisions. The implementation of microbiological diagnostic stewardship relies upon the creation of multidisciplinary committees led by clinical microbiologists for the design of diagnostic algorithms, the adequacy of the laboratory computer system to monitor the relevance of the requested diagnostic tests, the implementation of a quality control system, the design and performance of studies of cost-effectiveness, the training of the petitioner and the technical and n…

Caveats in interpreting SARS‐CoV‐2 IgM + /IgG − antibody profile in asymptomatic health care workers

Serological testing is increasingly recognized as a useful tool for management of the COVID‐19 pandemic.1 Cross‐sectional serosurveys provide information on exposure levels in a target population, which is helpful for designing public health strategies to blunt community transmission.2 This article is protected by copyright. All rights reserved.

Human cytomegalovirus (HCMV)-specific CD4+ T lymphocyte response in AIDS patients with no past or current HCMV disease following HAART.

Abstract Background: The incidence of Human Cytomegalovirus (HCMV) end-organ disease has dramatically decreased since the implementation of highly active antiretroviral therapies (HAARTs), but the precise immune mechanism whereby HCMV is controlled remains to be elucidated. Objectives: To investigate the effect of (HAART) on CD4 + T-cell immunity to HCMV in AIDS patients with no past or current HCMV disease. Study design: Seventeen patients were prospectively examined for CD4 + (CD45RO + and CD45 RA + ) T-cell counts (flow cytometry), HIV RNA load (Amplicor HIV test), HCMV leukoDNAemia and HCMV DNA in urine (nested PCR), lymphoproliferative response (LPR) to HCMV, phytohemagglutinin (PHA) a…

SARS-CoV-2 RNA load in the lower respiratory tract, viral RNAemia and N-antigenemia in critically ill adult COVID-19 patients: relationship with biomarkers of disease severity

ABSTRACTBackgroundLittle is known about the comparative kinetics of SARS-CoV-RNA load in the lower respiratory tract and in blood compartment in patients admitted to the intensive care unit, and how these relate to biomarkers of COVID-19 severity.MethodsSeventy-three consecutive critically ill COVID-19 patients (median age, 65 years) were recruited. Serial lower respiratory tract (n=165) and plasma (n=340) specimens were collected. RT-PCR and lateral flow immunochromatography assay were used for SARS-CoV-2 RNA quantitation and N protein detection in plasma, respectively. Serum levels of inflammatory and tissue-damage biomarkers in paired specimens were analyzed.ResultsSARS-CoV-RNA was detec…

Multi-body-site colonization screening cultures for predicting multi-drug resistant Gram-negative and Gram-positive bacteremia in hematological patients

Abstract Background To investigate the multi-drug resistant bacteria (MDRB) colonization rate in hematological patients hospitalized for any cause using a multi-body-site surveillance approach, and determine the extent to which this screening strategy helped anticipate MDRB bloodstream infections (BSI). Methods Single-center retrospective observational study including 361 admissions documented in 250 adult patients. Surveillance cultures of nasal, pharyngeal, axillary and rectal specimens (the latter two combined) were performed at admission and subsequently on a weekly basis. Blood culture samples were incubated in an automated continuous monitoring blood culturing instrument (BACTEC FX). …

BD MAX Enteric Bacterial, Bacterial Plus, and Virus Panels for Diagnosis of Acute Infectious Gastroenteritis: a Cost-Benefit Analysis

Economic assessment is required to gauge the value of implementing PCR syndromic platforms in the microbiology laboratory for the diagnosis of community-acquired acute gastroenteritis (AGE) in pediatric and adult in- and outpatients. A cost-benefit analysis was conducted from a health care system perspective using BD MAX Enteric Bacterial, Bacterial Plus, and Virus panels. Two 6-month periods were selected, in which either conventional procedures (in 2017) or BD MAX PCR multiplex panels (in 2018) were used. We retrospectively reviewed medical records of all patients with positive results and a representative sample of negative ones. A Markov model was used to represent transition probabilit…

Antibody response to human cytomegalovirus (HCMV) glycoprotein B (gB) in AIDS patients with HCMV end-organ disease

Human cytomegalovirus (HCMV)-specific antibody responses in HIV-1 infected individuals either with or without HCMV end-organ disease were examined to determine the whether development of HCMV disease was associated with a particular deficit in the antibody response. Antiwhole HCMV, anti-glycoprotein B (gB), and neutralizing antibody levels were higher in HIV-1 infected individuals than in healthy immunocompetent subjects, particularly in patients with AIDS either with or without HCMV-associated disease. Irrespective of location and spread of HCMV disease, patients who had received anti-HCMV therapy prior to sampling exhibited significantly higher anti-gB and neutralizing antibody titers tha…

Susceptibility of Pseudomonas aeruginosa isolates to ceftazidime is unrelated to the expression of the outer membrane protein OprC.

Previously, it has been postulated that the porin OprC facilitates the diffusion of ceftazidime through the outer membrane of Pseudomonas aeruginosa. To further investigate this claim, the outer membrane protein (OMP) profiles of 22 ceftazidime-susceptible clinical isolates were analyzed. No correlation was found between MIC values and the level of expression of OprC. Further, OprC was either undetectable or expressed in reduced amounts in 12 isolates. In contrast, OprF and OprE were present in all isolates studied. This study suggests that OprC is dispensable for the permeation of ceftazidime through the outer membrane of P. aeruginosa.

Clinical effectiveness of influenza vaccination after allogeneic hematopoietic stem cell transplantation: A cross-sectional prospective observational study.

Abstract Background Vaccination is the primary method for preventing influenza respiratory virus infection (RVI). Although the influenza vaccine is able to achieve serological responses in some allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, its clinical benefits are still uncertain. Methods In this prospective, cross-sectional study, we retrospectively analyzed the effect of inactivated trivalent influenza vaccination on the prevalence of influenza RVI in a consecutive cohort of 136 allo-HSCT adult recipients who developed 161 RVI over 5 flu seasons (from 2013 to 2018). Respiratory viruses in upper– and/or lower–respiratory tract specimens were tested using multi…

Pharmacokinetics of anidulafungin during albumin dialysis

In the ICU setting, current guidelines recommend echi-nocandins as the first-line treatment for invasive candi-diasis [1]. Albumin dialysis (AD) has been used in theICU as supportive therapy for hepatic failure, but thistechnique can significantly enhance drug elimination [2].We prescribed anidulafungin for suspected invasivecandidiasis in a patient with severe liver failure treatedwith AD and measured the plasma concentrations of thedrug using high-performance liquid chromatography.This study (GEF-ANI-2010-02) was approved by thelocal ethics committee (INCLIVA, Institute of Research,Valencia, Spain) and written informed consent wasobtained from the patient’s next of kin. An adult patientwa…

Differences in cytomegalovirus plasma viral loads measured in allogeneic hematopoietic stem cell transplant recipients using two commercial real-time PCR assays.

5 páginas, 3 figuras.

Antibiotic susceptibility of Raoultella spp. in the Valencian Community: Results of Microbiological Surveillance Network for 4 years

SARS-CoV-2-specific Cell-mediated Immunity in Kidney Transplant Recipients Recovered From COVID-19.

BACKGROUND: The magnitude and kinetics of severe acute respiratory syndrome coronavirus 2-specific cell-mediated immunity (SARS-CoV-2-CMI) in kidney transplant (KT) recipients remain largely unknown. METHODS: We enumerated SARS-CoV-2-specific interferon-I³-producing CD69+ CD4+ and CD8+ T cells at months 4 and 6 from the diagnosis of coronavirus disease 2019 (COVID-19) in 21 KT recipients by intracellular cytokine staining. Overlapping peptides encompassing the SARS-CoV-2 spike (S) glycoprotein N-terminal 1- to 643-amino acid sequence and the membrane protein were used as stimulus. SARS-CoV-2 IgG antibodies targeting the S1 protein were assessed by ELISA at month 6. RESULTS: Detectable (≥0.1…

Reconstitution of CMV pp65 and IE-1-specific IFN-γ CD8+ and CD4+ T-cell responses affording protection from CMV DNAemia following allogeneic hematopoietic SCT

Threshold levels of CMV-specific T-cell populations presumably affording protection from active CMV infection in allo-SCT recipients have been proposed, but lack extensive validation. We quantified CMV pp65 and immediate-early 1-specific IFN-γ CD8(+) and CD4(+) T cell responses at days +30, +60 and +90 after transplantation in 133 patients, and established cutoff cell levels protecting from CMV DNAemia within the first 120 days after transplantation. No patients showing IFN-γ CD8(+) or IFN-γ CD4(+) T-cell counts1.0 and1.2 cells/μL, respectively, developed a subsequent episode of CMV DNAemia. Initial or recurrent episodes of CMV DNAemia occurred in the face of IFN-γ T-cell levels below defin…

Cytomegalovirus DNAemia Burden and Mortality Following Allogeneic Hematopoietic Stem Cell Transplantation: An Area Under a Curve-Based Investigational Approach.

Dynamics of Torque Teno virus plasma DNAemia in allogeneic stem cell transplant recipients

Abstract Background Torque Teno virus (TTV) plasma DNA load directly correlate with the level of immunosuppresion in different clinical settings. It is uncertain whether this may be the case in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). Objectives We characterized the dynamics of TTV DNAemia in patients undergoing T-cell replete allo-SCT. Study design Retrospective single-center observational study including 72 allo-HSCT patients. Plasma TTV DNA loads were quantified before initiating the conditioning regimen and at different time-points after transplant by real-time PCR. White blood cells (WBC) and absolute lymphocyte counts (ALC) were measured by flow cytometry.…

Diversity and dynamic changes of anelloviruses in plasma following allogeneic hematopoietic stem cell transplantation.

Monitoring of alphatorquevirus (torque teno virus [TTV]) DNA in plasma may prove to be useful to assess the net state of immune competence following allogeneic hematopoietic stem cell transplantation (allo-HSCT). There are scarce data published on the prevalence of beta (torque teno mini virus [TTMV]) and gammatorqueviruses (torque teno midi virus [TTMDV]) and, in particular, on the dynamics of anelloviruses in allo-HSCT patients. Twenty-five allo-HSCT recipients with available plasma specimens obtained before conditioning and after engraftment were included. Degenerated primers targeting a highly conserved genomic sequence across all anelloviruses were designed for genomic amplification an…

Guidelines for the management of cytomegalovirus infection in patients with haematological malignancies and after stem cell transplantation from the 2017 European Conference on Infections in Leukaemia (ECIL 7).

Summary Cytomegalovirus is one of the most important infections to occur after allogeneic haematopoietic stem cell transplantation (HSCT), and an increasing number of reports indicate that cytomegalovirus is also a potentially important pathogen in patients treated with recently introduced drugs for hematological malignancies. Expert recommendations have been produced by the 2017 European Conference on Infections in Leukaemia (ECIL 7) after a review of the literature on the diagnosis and management of cytomegalovirus in patients after HSCT and in patients receiving other types of therapy for haematological malignancies. These recommendations cover diagnosis, preventive strategies such as pr…

Clinical significance of Pneumocystis jirovecii DNA detection by real-time PCR in hematological patient respiratory specimens

Type-Specific Antibodies to Pneumococcal Capsular Polysaccharide Acquired either Naturally or after Vaccination with Prevenar in Children with Underlying Chronic or Recurrent Lung Diseases

ABSTRACT The antibody response to capsular polysaccharides of pneumococcal serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F elicited either naturally or after vaccination with Prevenar was investigated in a cohort of children ( n = 163) with underlying chronic or recurrent lung diseases at risk of developing pneumococcal pneumonia and ultimately invasive disease. Serum concentrations of serotype-specific antibodies, as measured by enzyme-linked immunosorbent assay, in unvaccinated children ( n = 88) were higher in nasopharyngeal carriers ( n = 10) than in noncarriers ( n = 78) both at baseline and during follow-up. However, the antibody levels depended on the serotype and age of the children. Dur…

Are pathogenic intestinal bacteria present in stool specimens from patients with chronic heart failure?

It has been reported that patients with chronic heart failure exhibit an intestinal overgrowth of primary gut bacterial pathogens, such as Shigella spp., Salmonella spp., Campylobacter spp., and Yersinia enterocolitica. We failed to reproduce these findings in a cohort of 39 patients admitted to the hospital with decompensated heart failure by means of conventional stool bacterial cultures and a multiplexed polymerase chain reaction assay.

The clinical benefit of instituting a prospective clinical community-acquired respiratory virus surveillance program in allogeneic hematopoietic stem cell transplantation

Highlights • Rapid detection methods used as first diagnostic test for CARVs may delayed the start of antiviral therapy in a significant number of influenza and RSV cases. • Syndromic multiplex RT-PCR-based prospective clinical CARV survey in allo-HCT recipients translates into a lower mortality rate as compared to standard clinical practice based on RSV and influenza virus rapid detection test. • We found that donor/recipient HLA mismatch, CARV LRTD and high-risk ISI were also associated with higher mortality.

Evaluation of a rapid antigen test (Panbio™ COVID-19 Ag rapid test device) for SARS-CoV-2 detection in asymptomatic close contacts of COVID-19 patients

Objectives There is limited information on the performance of rapid antigen detection (RAD) tests to identify SARS-CoV-2-infected asymptomatic individuals. In this field study, we evaluated the Panbio™ COVID-19 Ag Rapid Test Device (Abbott Diagnostics, Jena, Germany) for this purpose. Methods A total of 634 individuals (355 female; median age, 37 years; range, 9–87) were enrolled. Two nasopharyngeal swabs were collected from household (n = 338) and non-household contacts (n = 296) of COVID-19 cases. RAD testing was carried out at the point of care. The RT-PCR test used was the TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, MA, USA). Results Household contacts were tested at a median …

A comparative study on cell wall antigens and cell surface hydrophobicity in clinical isolates ofCandida albicans

Characterization of common cell surface-bound antigens in Candida albicans strains, particularly those expressed in the walls of mycelial cells might be useful in the diagnosis of systemic candidiasis. Hence, antigenic similarities among wall proteins and mannoproteins from C. albicans clinical serotype A and B isolates, were studied using polyclonal (mPAbs) and monoclonal (MAb 4C12) antibodies raised against wall antigens from the mycelial form of a common C. albicans serotype A laboratory strain (ATCC 26555). Zymolyase digestion of walls isolated from cells of the different strains studied grown at 37 degrees C (germination conditions), released, in all cases, numerous protein and mannopr…

Primary prophylaxis of invasive fungal infections with posaconazole or itraconazole in patients with acute myeloid leukaemia or high-risk myelodysplastic syndromes undergoing intensive cytotoxic chemotherapy: A real-world comparison.

This is an observational-retrospective study comparing the real-world outcomes associated with posaconazole vs. itraconazole as prophylaxis treatments. Two hundred and ninety-three patient admissions attributable to 174 patients were included in the study. Patients were treated with itraconazole (n = 114 admissions; 39%) or posaconazole (n = 179; 61%). Antifungal prophylaxis failure (APF) due to treatment-related adverse events (in 34 out of 293 patient admissions; 11.6%) was more frequent in the posaconazole group (6.1% vs. 15.1%; P = 0.024). There were 9 patient admissions for episodes of APF due to probable/proven breakthrough fungal infection (primary endpoint): 6 and 3 in the itraconaz…

Human genetic polymorphisms and risk of viral infection after solid organ transplantation.

The immune system plays a key role in the host defense against viral pathogens. A signaling cascade is activated upon infection involving a variety of molecules such as pattern-recognition receptors (PRRs), interleukins or antiviral interferons. Long-term immunosuppression after solid organ transplantation (SOT) mainly abrogates adaptive T-cell-mediated responses, thus highlighting the relative contribution of innate immunity. Single-nucleotide polymorphisms (SNPs) within genes coding for PRRs or soluble mediators have been associated with differential susceptibility to viral infections among SOT recipients. A protective effect against cytomegalovirus (CMV) infection or disease has been att…

SARS‐CoV ‐2‐reactive antibody detection after SARS‐CoV ‐2 vaccination in hematopoietic stem cell transplant recipients: Prospective survey from the Spanish Hematopoietic Stem Cell Transplantation and Cell Therapy Group

This is a multicenter prospective observational study which included a large cohort (n = 397) of allogeneic (allo-HSCT) (n = 311) and autologous (ASCT) hematopoietic stem cell transplant (n = 86) recipients who were monitored for antibody detection within 3 to 6 weeks after complete SARS-CoV-2 vaccination from February 1st 2021 to July 20th 2021. Most patients (n = 387, 97.4%) received mRNA-based vaccines. Most of recipients (93%) were vaccinated more than 1 year after transplant. Detectable SARS-CoV-2-reactive antibodies were observed in 242 (78%) of allo-HSCT and in 73 (85%) of ASCT recipients. Multivariate analysis in allo-HSCT recipients identified lymphopenia <1x109 /mL [Odds ratio (OR…

Overcoming drug resistance in HSV, CMV, HBV and HCV infection.

Although vaccination has provided as a very efficient preventive tool, antiviral therapy is still needed to control viral infections not avoidable by prophylaxis with vaccines; those caused by viruses for which a vaccine is available, but vaccination is not universally implemented or does not result in complete, long-term protection; and in immunocompromised individuals with reduced immune control of viral replication. After more than 50 years of the first licensing for an antiherpetic drug, novel compounds for herpes-simplex viruses and human cytomegalovirus will open new strategies for better control and management of these two recurrent viral infections. Besides, the development and use…

Additional file 1 of SARS-CoV-2 vaccine response and rate of breakthrough infection in patients with hematological disorders

Additional file 1: Table S1. Characteristics of serological assays used in the study. Table S2. Commercial PCR test available in participating centers.

Early neutralizing and glycoprotein B (gB)-specific antibody responses to human cytomegalovirus (HCMV) in immunocompetent individuals with distinct clinical presentations of primary HCMV infection

Abstract Background: Antibodies with functional anti-Human Cytomegalovirus (HCMV) activity are likely to be involved in preventing virus dissemination and thus may contribute to minimize the clinical manifestations of infection. Objectives: To investigate the role of humoral immunity in modulating the clinical expression of primary Human Cytomegalovirus (HCMV) infection in immunocompetent persons. Study design: Neutralizing (NA) and glycoprotein B (gB)-specific antibodies were quantitated in acute-phase and late-convalescence phase sera from 19 individuals who developed either HCMV mononucleosis (12) or oligosymptomatic hepatitis (seven). Results: The levels of NA in sera drawn early after …

Consideraciones acerca de la ciencia como cultura

El presente trabajo consiste en una aproximación a la ciencia considerada como siendo en primera instancia un producto histórico y cultural. Dicha consideración no impide que la ciencia pueda ser también evaluada en su posición frente a otras formas culturales ofreciendo como resultado un serio cuestionamiento del relativismo cognitivo. En la línea de las tesis del pensador inglés Ernest Gellner realizamos una ponderación racionalista del conocimiento científico y su valor para la sociedad contemporánea.

Cytomegalovirus infection in solid organ transplantation.

Cytomegalovirus infection remains a serious threat to solid transplant recipients. Despite advances in this field, there are still difficulties in the diagnosis of the disease and there are questions about the best and most cost-effective strategy to prevent infection and its direct and indirect consequences in the short and long term. All these points are discussed and updated in this chapter.

Meropenem Permeation through the Outer Membrane of &lt;i&gt;Pseudomonas aeruginosa&lt;/i&gt; Can Involve Pathways Other than the OprD Porin Channel

The outer membrane protein (OMP) OprD is the major channel through which carbapenems permeate the outer membrane of Pseudomonas aeruginosa. In this study, we analyzed the OMP profiles of several P. aeruginosa clinical isolates showing diminished susceptibility to imipenem while remaining susceptible to meropenem. All these isolates lacked OprD or showed a reduced expression of this porin. Susceptibility to meropenem was thus independent of the level of OprD expression, indicating that the antimicrobial could be taken up via an alternative route. The level of expression of OprC (70 kD) was also unrelated to meropenem susceptibility. Nevertheless, OMPs OprF and OprE were expressed by all isol…

Comparison of two methods skipping cell lysis and protein extraction for identification of bacteria from blood cultures by matrix-assisted laser desorption/ ionization time-of-flight mass-spectrometry

ABSTRACT Objective Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) is widely used for fast identification of bacteria from blood cultures (BC). We compared the performance of two procedures, one including a pre-enrichment step in brain heart infusion and the other a direct method using vacutainer separator gel tubes (DI), for identification of bacteria from blood cultures by MALDI-TOF MS. Material and methods We first prepared a training set of 20 simulated bacteremia specimens, including 10 Gram-negative and 10 Gram-positive species. A total of 145 non-consecutive BCs flagged as positive (68 Gram-negative rods, and 77 Gram-positive cocci) were pr…

Early Post-Transplant Torquetenovirus Viremia Predicts Cytomegalovirus Reactivations In Solid Organ Transplant Recipients.

AbstractMonitoring the human virome has been recently suggested as a promising and novel area of research for identifying new biomarkers which would help physicians in the management of transplant patients. Imbalance of the immune system in transplant recipients has a significant impact on replication of Torquetenovirus (TTV), the most representative and abundant virus of human virome. TTV kinetic was studied by real-time PCR in 280 liver or kidney transplant recipients who underwent different drug regimens to maintain immunosuppression. During one-year post-transplant follow-up, TTV viremia fluctuated irrespective of transplanted organ type but consistent with the immunosuppression regimen…

Assessing the risk of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients by monitoring oxidative-stress markers in plasma

The level of antioxidants, such as thiol-containing tripeptide glutathione (GSH), in cytomegalovirus (CMV)-infected cells is notably increased. We previously showed that GSH levels in plasma, as measured by untargeted 1H nuclear magnetic resonance, are higher in allogeneic stem cell transplant (allo-SCT) recipients who subsequently develop CMV viraemia. We hypothesized that the net level of oxidative-stress markers present in plasma may be reduced in patients who develop CMV DNAaemia compared to those who do not. We serially monitored the levels of malondialdehyde (MDA) and carbonylated proteins (CPs) early after allo-SCT and assessed whether they could predict the occurrence of CMV DNAaemi…

Pooling of Nasopharyngeal Swab Specimens for SARS-CoV-2 detection by RT-PCR

ABSTRACTSystematic testing of large population groups by RT-PCR is mandatory to Covid-19 case identification and contact tracing in order to minimize the likelyhood of resurgence in contagion. Sample pooling for RT-PCR has been effectively used to detect community transmission of SARS CoV-2. Nevertheless, this procedure may decrease the sensitivity of RT-PCR assays due to specimen dilution. We evaluated the efficacy of this strategy for diagnosis of Covid-19 using a sensitive commercially-available RT-PCR targeting SARS CoV-2 E and RdRp genes in a single reaction. A total of 20 mini-pools containing either 5 (n=10) or 10 (n=10) nasopharyngeal exudates collected in universal transport medium…

Kinetics of torque teno virus DNA load in saliva and plasma following allogeneic hematopoietic stem cell transplantation

Plasma torque teno virus (TTV) DNA load directly correlates with the degree of T-cell immune reconstitution early after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, the kinetics of oral TTV DNA shedding was examined to assess whether quantitation of TTV DNA load in saliva may either replace or complement that in plasma for predicting lymphocyte (ALC) reconstitution after engraftment. This prospective observational study enrolled 38 nonconsecutive allo-HSCT recipients. Saliva and plasma specimens were collected at baseline (pretransplant) and at around days +30, +50, and +90 after allo-HSCT. TTV DNA was quantitated in both specimen types by real-time PCR. ALCs were m…

Performance of a Highly Sensitive Mycobacterium tuberculosis Complex Real-Time PCR Assay for Diagnosis of Pulmonary Tuberculosis in a Low-Prevalence Setting: a Prospective Intervention Study

ABSTRACT The potential impact of routine real-time PCR testing of respiratory specimens from patients with presumptive tuberculosis in terms of diagnostic accuracy and time to tuberculosis treatment inception in low-prevalence settings remains largely unexplored. We conducted a prospective intervention cohort study. Respiratory specimens from 1,020 patients were examined by acid-fast bacillus smear microscopy, tested by a real-time Mycobacterium tuberculosis complex PCR assay (Abbott RealTi me MTB PCR), and cultured in mycobacterial media. Seventeen patients tested positive by PCR (5 were acid-fast bacillus smear positive and 12 acid-fast bacillus smear negative), and Mycobacterium tubercul…

Kinetics of cytomegalovirus (CMV) pp65 and IE-1-specific IFNgamma CD8+ and CD4+ T cells during episodes of viral DNAemia in allogeneic stem cell transplant recipients: potential implications for the management of active CMV infection.

The dynamics of CMV pp65 and IE-1-specific IFNgamma-producing CD8(+) (IFNgamma CD8(+)) and CD4(+) (IFNgamma CD4(+)) T cells and CMV DNAemia were assessed in 19 pre-emptively treated episodes of active CMV infection. Peripheral counts of IFNgamma CD8(+) and IFNgamma CD4(+) T cells inversely correlated with CMV DNAemia levels (P = <0.001 and P = 0.003, respectively). A threshold value of 1.3 cells/microl predicting CMV DNAemia clearance was established for IFNgamma CD8(+) T cells (PPV, 100%; NPV, 93%) and for IFNgamma CD4(+) T cells (PPV, 100%; NPV, 75%). Undetectable T-cell responses were usually observed at the time of initiation of pre-emptive therapy. Either a rapid (within 7 days) or a d…

An investigation on the relationship between the occurrence of CMV DNAemia and the development of invasive aspergillosis in the allogeneic stem cell transplantation setting

Cytomegalovirus (CMV) infection might increase the risk of fungal superinfection in allogeneic stem cell transplant patients. The potential association between the occurrence of CMV DNAemia and the development of invasive aspergillosis in this clinical setting was investigated. The current retrospective observational study included 167 patients undergoing T cell-replete allogeneic stem cell transplantation. Virological monitoring of active CMV infection was performed by the pp65 antigenemia assay and/or by a plasma real-time PCR assay. A total of 109 out of 167 patients developed CMV DNAemia. Twenty-three patients had proven (n = 4) or probable (n = 19) invasive aspergillosis. The occurrenc…

SARS‐CoV‐2‐reactive interferon‐γ‐producing CD8+ T cells in patients hospitalized with coronavirus disease 2019

Abstract There is limited information on severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) T‐cell immune responses in patients with coronavirus disease 2019 (COVID‐19). Both CD4+ and CD8+ T cells may be instrumental in resolution of and protection from SARS‐CoV‐2 infection. Here, we tested 25 hospitalized patients either with microbiologically documented COVID‐19 (n = 19) or highly suspected of having the disease (n = 6) for presence of SARS‐CoV‐2‐reactive CD69+ expressing interferon‐γ (IFN‐γ) producing CD8+ T cells using flow‐cytometry for intracellular cytokine staining assay. Two sets of overlapping peptides encompassing the SARS‐CoV‐2 Spike glycoprotein N‐terminal 1 to 643 am…

Lack of association between the kinetics of human cytomegalovirus (HCMV) glycoprotein B (gB)-specific and neutralizing serum antibodies and development or recovery from HCMV active infection in patients undergoing allogeneic stem cell transplant

The kinetics of the gB-specific and neutralizing antibody responses to human cytomegalovirus (HCMV) were analyzed in 26 allogeneic stem-cell transplant recipients who either did (n = 20) or did not (n = 6) develop asymptomatic HCMV active infection during the study period. Antibody response profiles varied widely among individuals in both groups, irrespective of whether HCMV active infection did or did not occur. Development of HCMV active infection was not preceded by a decline in functional serum antibody levels. Neither the absence nor the presence of HCMV active infection correlated with either high or low serum levels of gB-specific and neutralizing antibodies, respectively. In most pa…

Cytomegalovirus‐specific T‐cell immunity and DNAemia in patients with chronic lymphocytic leukaemia undergoing treatment with ibrutinib

Evaluation of the Architect Epstein-Barr Virus (EBV) Viral Capsid Antigen (VCA) IgG, VCA IgM, and EBV Nuclear Antigen 1 IgG Chemiluminescent Immunoassays for Detection of EBV Antibodies and Categorization of EBV Infection Status Using Immunofluorescence Assays as the Reference Method

ABSTRACTCommercial immunoassays for detecting IgG and IgM antibodies against Epstein-Barr virus (EBV), viral capsid antigens (VCA), and IgGs toward EBV nuclear antigen-1 (EBNA-1) are routinely used in combination to categorize EBV infection status. In this study, we evaluated the performances of the Architect EBV VCA IgG, VCA IgM, and EBNA-1 IgG chemiluminescent microparticle assays (CMIAs) in EBV serological analyses using indirect immunofluorescence assays and anticomplement immunofluorescence assays as the reference methods for VCA IgG, VCA IgM, and EBNA-1 IgG antibody detection, respectively. A total of 365 serum samples representing different EBV serological profiles were included in t…

Combined kinetic analysis of SARS-CoV-2 RNAemia, N-antigenemia and virus-specific antibodies in critically ill adult COVID-19 patients

Combined kinetic analysis of plasma SARS-CoV-2 RNAemia, Nucleocapsid (N)-antigenemia and virus-specific antibodies may help ascertain the role of antibodies in preventing virus dissemination in COVID-19 patients. We performed this analysis in a cohort of 71 consecutive critically ill COVID-19 patients (49 male; median age, 65 years) using RT-PCR assay, lateral flow immunochromatography method and receptor binding domain (RBD) and N-based immunoassays. A total of 338 plasma specimens collected at a median of 12 days after symptoms onset were available for analyses. SARS-CoV-2 RNAemia and N-antigenemia were detected in 37 and 43 specimens from 26 (36.5%) and 30 (42.2%) patients, respectively.…

A risk-adapted approach to treating respiratory syncytial virus and human parainfluenza virus in allogeneic stem cell transplantation recipients with oral ribavirin therapy: A pilot study.

Here we report the applicability of a protocol based on clinical conditions and risk factors (RFs) for managing 35 allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients who developed a total of 52 episodes of respiratory viral infections (RVIs) caused by respiratory syncytial virus (RSV; n=19), human parainfluenza virus (HPIV; n=29), or both (n=4) over a 2-year study period. Risk categories were classified as high risk (cat-1) when the immunodeficiency scoring index was >= 3 and/or >= 3 RFs and/or >= 1 co-infective virus(es) were present; the remaining cases were classified as low risk (cat-0). The presence of two or more signs or symptoms including fever (T>38 degrees C…

Platinum chloride-based viability RT-qPCR for SARS-CoV-2 detection in complex samples.

Isolation, contact tracing and restrictions on social movement are being globally implemented to prevent and control onward spread of SARS-CoV-2, even though the infection risk modelled on RNA detection by RT-qPCR remains biased as viral shedding and infectivity are not discerned. Thus, we aimed to develop a rapid viability RT-qPCR procedure to infer SARS-CoV-2 infectivity in clinical specimens and environmental samples. We screened monoazide dyes and platinum compounds as viability molecular markers on five SARS-CoV-2 RNA targets. A platinum chloride-based viability RT-qPCR was then optimized using genomic RNA, and inactivated SARS-CoV-2 particles inoculated in buffer, stool, and urine. Ou…

Viability RT-PCR for SARS-CoV-2: a step forward to solve the infectivity quandary

Background Isolation, contact tracing and restrictions on social movement are being globally implemented to prevent and control onward spread of SARS-CoV-2, even though the infection risk modelled on RNA detection by RT-qPCR remains biased as viral shedding and infectivity are not discerned. Thus, we aimed to develop a rapid viability RT-qPCR procedure to infer SARS-CoV-2 infectivity in clinical specimens and environmental samples. Methods We screened monoazide dyes and platinum compounds as viability molecular markers on five SARS-CoV-2 RNA targets. A platinum chloride-based viability RT-qPCR was then optimized using genomic RNA, and inactivated SARS-CoV-2 particles inoculated in buffer, s…

B and T cell immune responses elicited by the BNT162b2 (Pfizer–BioNTech) COVID-19 vaccine in nursing home residents

ABSTRACTObjectivesThe immunogenicity of the BNT162b2 COVID-19 vaccine is understudied in elderly people with comorbidities. We assessed SARS-CoV-2-S-targeted antibody and T cell responses following full vaccination in nursing home residents (NHR).MethodsWe recruited 60 NHR (44 female; median age, 87.5 years), of whom 10 had previously had COVID-19, and 18 healthy controls (15 female; median age, 48.5 years). Pre- and post-vaccination blood specimens were available for quantitation of total antibodies binding RBD and enumeration of SARS-CoV-2-S-reactive IFN-γ CD4+ and CD8+ T cells by flow cytometry.ResultsThe seroconversion rate in presumably SARS-CoV-2 naïve NHR (95.3%), either with or with…

Comparison of the performance of 2 commercial multiplex PCR platforms for detection of respiratory viruses in upper and lower tract respiratory specimens

The performance of the CLART® PneumoVir system with that of the Luminex xTAG RVP Fast v1 assay for detection of most common respiratory viruses in upper and lower tract respiratory specimens (n = 183) from unique patients with influenza-like syndrome or lower tract respiratory infection. Nested PCR coupled to automated sequencing was used for resolution of discrepancies. Fully concordant results were obtained for a total of 122 specimens, whereas 56 specimens gave partially (n = 21) or fully discordant (n = 35) results (Kappa coefficient, 0.62). The overall specificity of the Luminex xTAG RVP Fast v1 assay was slightly higher than that of the CLART® PneumoVir assay for human bocavirus, infl…

Perfil de sensibilidad antibiótica de Raoultella spp. en la Comunidad Valenciana: resultados de la Red de Vigilancia Microbiológica durante un período de 4 años

Pre-emptive antiviral therapy for active CMV infection in adult allo-SCT patients guided by plasma CMV DNAemia quantitation using a real-time PCR assay: clinical experience at a single center

Pre-emptive antiviral therapy for active CMV infection in adult allo-SCT patients guided by plasma CMV DNAemia quantitation using a real-time PCR assay: clinical experience at a single center

An evaluation of the role of NKG2C+natural killer cells in protection from cytomegalovirus DNAemia early following allogeneic stem cell transplantation

The role of natural killer (NK) cells in affording protection against human cytomegalovirus (CMV) in allogeneic stem cell transplant recipients is largely unknown. The current study was aimed at determining whether NKG2C+ NK cells confer protection from CMV DNAemia early following transplantation in patients lacking mono and polyfunctional CMV pp65 and IE-1-specific CD4+ and CD8+ T-cell responses, as measured by flow cytometry for intracellular cytokine staining. Fourteen out of the 36 patients included in this study developed CMV DNAemia between days +30 and +60 after transplant. Three patients did so after day +60. Peripheral blood levels of CD56(bright) CD16(-/low) and CD56(dim) CD16+ NK…

Lack of prompt expansion of cytomegalovirus pp65 and IE-1-specific IFNγ CD8+ and CD4+ T cells is associated with rising levels of pp65 antigenemia and DNAemia during pre-emptive therapy in allogeneic hematopoietic stem cell transplant recipients

Rising levels of cytomegalovirus (CMV) DNAemia and/or pp65 antigenemia have been observed during pre-emptive ganciclovir therapy in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT). We assessed the incidence of this event in our series, and investigated whether its occurrence was associated with an impairment in the CMV-specific T-cell response. A total of 36 allo-SCT recipients experienced one or more episodes of active CMV infection (n=68) that were pre-emptively treated with val(ganciclovir). Rising levels of antigenemia and DNAemia, and an isolated increase in antigenemia, were observed in 39.7 and 2.9% of all episodes, respectively. Receipt of corticost…

Incidence, risk factors, and outcome of pulmonary invasive fungal disease after respiratory virus infection in allogeneic hematopoietic stem cell transplantation recipients

Abstract Background There is growing evidence that community‐acquired respiratory virus (CARV) increases the risk of pulmonary invasive fungal disease (IFD) in the allogeneic hematopoietic stem cell transplantation (allo‐HSCT) setting. To date, there is a lack of knowledge regarding the risk factors (RFs), as well as the most critical period for subsequent onset of IFD after CARV infections in allo‐HSCT recipients. Methods In this prospective longitudinal observational CARV survey, we analyzed the effect of CARV on subsequent IFD development in 287 adult allo‐HSCT recipients diagnosed with 597 CARV episodes from December 2013 to December 2018. Multiplex PCR panel assays were used to test CA…

Epidemiology of invasive candidiasis in a surgical intensive care unit: an observational study

Background: Invasive candidiasis (IC) is a frequent and life-threatening infection in critically ill patients. The aim of this study was to evaluate the epidemiology of IC and the antifungal susceptibility of etiological agents in patients admitted to our surgical intensive care unit (SICU) in Spain. Methods: We designed a prospective, observational, single center, population-based study in a SICU. We included all consecutive adult patients (≥18 years old) who had documented IC, either on admission or during their stay, between January 2012 and December 2013. Results: There were a total of 22 episodes of IC in the 1149 patients admitted during the 24-month study. The overall IC incidence wa…

Longitudinal analysis of human cytomegalovirus glycoprotein B (gB)-specific and neutralizing antibodies in AIDS patients either with or without cytomegalovirus end-organ disease

Serum neutralizing and glycoprotein B (gB)-specific antibody levels were monitored prospectively in AIDS patients who either did or did not develop human cytomegalovirus (HCMV) end-organ disease, to delineate further the role of antibodies in protecting against HCMV disease. Antibody levels declined substantially (at least 4-fold) only in patients who developed HCMV disease; this decline in turn occurred concurrently with antigenemia. Nevertheless, AIDS patients who remained free of HCMV disease and did not become antigenemic during the follow-up period maintained stable levels of serum antibodies, with only minor fluctuations. The impact of HAART on the levels of functional anti-HCMV antib…

Field evaluation of a rapid antigen test (Panbio™ COVID-19 Ag Rapid Test Device) for COVID-19 diagnosis in primary healthcare centres.

Abstract Objectives To our knowledge no previous study has assessed the performance of a rapid antigen diagnostic immunoassay (RAD) conducted at the point of care (POC). We evaluated the Panbio™ COVID-19 Ag Rapid Test Device for diagnosis of coronavirus 2019 disease (COVID-19) in symptomatic patients (n = 412) attending primary healthcare centres. Methods RAD was performed immediately after sampling following the manufacturer's instructions (reading at 15 min). RT-PCRs were carried out within 24 h of specimen collection. Samples displaying discordant results were processed for culture in Vero E6 cells. Presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cell cultures…

Cytomegalovirus Infection Management in Allogeneic Stem Cell Transplant Recipients: a National Survey in Spain.

ABSTRACT This study gathered information about current practices of cytomegalovirus (CMV) infection management in allogeneic stem cell transplant recipients at Spanish centers. A wide variety of preemptive antiviral therapy strategies for CMV infection guided by real-time PCR assays was found, yet the incidence of CMV disease was low (&lt;3%).

Incidence, features, and outcomes of cytomegalovirus DNAemia in unmanipulated haploidentical allogeneic hematopoietic stem cell transplantation with post‐transplantation cyclophosphamide

Background Conflicting data have been published as to the risk of cytomegalovirus (CMV) DNAemia and CMV disease in patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplantation cyclophosphamide. Methods We conducted a multicenter retrospective study including 118 patients subjected to unmanipulated haplo-HSCT to further clarify this issue. An historic cohort comprising 165 patients undergoing other transplant modalities (HLA-matched related, matched unrelated or mismatched) was built for comparison purposes. Plasma CMV DNA monitoring was performed using two highly sensitive real-time PCR assays. Results Overall, the cumulative incidence of…

Initial viral load and decay kinetics of SARS-CoV-2 lineage B.1.1.7 in the upper respiratory tract of adults and children

We read with interest the systematic review published by Walsh et al. in the Journal of Infection,1 focusing on the dynamics of SARS-CoV-2 RNA at the upper respiratory tract (URT). In this context, a novel SARS-CoV-2 variant lineage (B.1.1.7), first detected in the UK at the end of 2020 has transmission advantage over other lineages.2 Increased transmissibility of the B.1.1.7 variant has been linked to enhanced ACE2 affinity3 allegedly resulting in higher viral loads in URT, an observation that has been reported in some,3, 4, 5, 6 but not all7 large series published to date. In addition, longer duration of SARS-CoV-2 RNA shedding in URT has been reported in individuals infected by the B.1.1…

Early detection of SARS-CoV-2 infection cases or outbreaks at nursing homes by targeted wastewater tracking

Objectives Near-source tracking of SARS-CoV-2 RNA in the sewage drains serving particular buildings may allow rapid identification of SARS-CoV-2 infection cases or local outbreaks. In this pilot study, we investigated whether this was the case for nursing homes (NH). Methods The study involved five NH (from A to E) affiliated to the Clínico-Malvarrosa Health Department, Valencia (Spain). These were nursing or mixed nursing/care homes of different sizes, altogether providing care for 472 residents attended by a staff of 309. Near-source sewage samples were screened for presence of SARS-CoV-2 RNA by RT-qPCR at least 5 days per week during the study period. SARS-CoV-2 RNA testing in nasopharyn…

Field performance of the Abbott RealTime MTB assay for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting

Introduction: The sensitivities of conventional mycobacterial culture in solid or liquid media and acid-fast bacilli (AFB) smear microscopy for Mycobacterium tuberculosis complex (MTBC) detection in extrapulmonary specimens are suboptimal. We evaluated the field performance of the Abbott RealTime MTB assay for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting. Methods: The total number of extrapulmonary specimens with mycobacterial culture and PCR results was 566: sterile fluids (n = 278), non-sterile fluids (n = 147), lymph node material (n = 69) tissue biopsies (n = 63), and abscess aspirates (n = 9). A composite standard consisting of mycobacterial culture results,…

Comparison of the new Abbott Real Time CMV assay and the Abbott CMV PCR Kit for the quantitation of plasma cytomegalovirus DNAemia

CMV DNA loads measured by the new Abbott RealTime CMV PCR were significantly higher than those quantitated by the Abbott CMV PCR kit (approximately 1 log(10)), and provided a better estimate of the actual CMV load present in plasma specimens as inferred by the use of the WHO standard.

The Culpability of Respiratory Viruses in Pneumonia-Related Acute Respiratory Failure

Monitoring of alphatorquevirus DNA levels for the prediction of immunosuppression-related complications after kidney transplantation

The replication kinetics of nonpathogenic anelloviruses belonging to the Alphatorquevirus genus (such as torque teno virus) might reflect the overall state of posttransplant immunosuppression. We analyzed 221 kidney transplant (KT) recipients in whom plasma alphatorquevirus DNA load was quantified by real-time polymerase chain reaction at baseline and regularly through the first 12 posttransplant months. Study outcomes included posttransplant infection and a composite of opportunistic infection and/or de novo malignancy (immunosuppression-related adverse event [iRAE]). Alphatorquevirus DNA loads at month 1 were higher among patients who subsequently developed posttransplant infection (P  = …

Concurrent detection of human herpesvirus type 6 and measles-specific IgMs during acute exanthematic human parvovirus B19 infection

A familial outbreak of human parvovirus B19 infection is described in which serological tests carried out routinely for determining the causal agent of febrile rashes of viral etiology failed to yield a definitive diagnosis. Concurrent detection of serum IgMs to parvovirus B19 and to heterologous viruses such as human herpesvirus type 6 (HHV-6) and measles virus complicated interpretation of the data. IgG avidity tests and investigation and testing for the presence of viral DNA in sera by PCR were required to confirm parvovirus B19. The study stresses the importance of avidity and PCR tests to obtain a firm diagnosis of febrile exanthematic viral diseases.

Effect of the IL28B Rs12979860 C/T polymorphism on the incidence and features of active cytomegalovirus infection in allogeneic stem cell transplant patients

The current study was aimed at investigating whether the single nucleotide polymorphism (SNP) (rs12979860), upstream of the IL28B gene, had any effect on the incidence rate and the features of active CMV infection in the Allogeneic stem cell transplantation setting. This was a retrospective observational study including 151 patients undergoing T cell-replete Allo-SCT. Donor and recipient IL28 SNP genotype was determined by allele-specific real-time PCR. The incidence rate of active CMV infection was not significantly associated with either the donor or the recipient IL28B SNP genotype. Nevertheless, a trend towards a lower incidence of active CMV infection was noted in the donor T/T populat…

Re-examining the relationship between active cytomegalovirus (CMV) infection and acute graft-versus-host disease in allogeneic stem cell transplant recipients in the era of real-time PCR CMV assays.

Missing Cases of Herpes Simplex Virus (HSV) Infection of the Central Nervous System When the Reller Criteria Are Applied for HSV PCR Testing: a Multicenter Study

ABSTRACT Previous studies suggested that herpes simplex virus (HSV) PCR testing can be safely deferred in patients with normal cerebrospinal fluid (CSF) white blood cell (WBC) counts and protein levels as long as they are older than 2 years of age and are not immunocompromised, the so-called Reller criteria. In this multicenter study, we retrospectively assessed the validity of these screening criteria in our setting. A total of 4,404 CSF specimens submitted for HSV PCR testing to the respective microbiology laboratories at the participating hospitals between 2012 and 2018 were included. Six commercially available HSV PCR assays were used across the participating centers. Ninety-one of the …

Assessing the potential association between SARS-CoV-2 RNA load in the respiratory tract and COVID-19 mortality.

Special Issue on New coronavirus (2019‐nCoV or SARS‐CoV‐2) and the outbreak of the respiratory illness (COVID‐19): Part‐XI

Applying lessons learned from cytomegalovirus infection in transplant patients to vaccine design

Studies in transplant recipients over the past decade aiming to characterize the immune response to cytomegalovirus (CMV) replication have provided insights that can be used to guide CMV vaccine development. These studies have characterized multiple aspects of the immune response to virus infection in humans, and have identified immunologic variables that correlate with the ability to control virus replication. These findings can be used to guide vaccine development by informing decisions regarding antigen selection and the type of immune response that must be elicited by these antigens to promote protective immunity. In addition, these studies have provided information that could aid in th…

Factors influencing cytomegalovirus DNA load measurements in whole blood and plasma specimens from allogeneic hematopoietic stem cell transplant recipients

We assessed the impact of several parameters, including the nature of the episode of Cytomegalovirus (CMV) DNAemia, the use of preemptive antiviral therapy, and the blood cell content in CMV DNA loads measured in whole blood (WB) and plasma (PL). CMV DNA load was quantified in 245 paired specimens collected within 43 postengraftment episodes of CMV DNAemia by using the CMV RealTime CMV PCR (Abbott Molecular). Concordant categorical results were obtained for 78.4% of paired specimens (Kappa index, 0.385; P = 0.001). Overall, CMV DNA loads in PL were higher than those in WB (mean bias, +0.115 log IU/mL) in both initial and recurrent episodes; this was so in post-antiviral treatment but not in…

Validation of a plasma metabolomics model that allows anticipation of the occurrence of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients.

A plasma metabolomic model obtained by means of untargeted 1H nuclear magnetic resonance, to which taurine, choline, methylamine, total glutathione, trimethylamine N-oxide, lactate, lysine, isoleucine, total fatty acids and unsaturated fatty acids contributed, was validated for the prediction of first episodes of cytomegalovirus (CMV) DNAaemia in a cohort of 79 allogeneic stem haematopoietic stem cell transplant (allo-HSCT) recipients. The predictive success rate was nearly 65 % for patients at both low and high risk of CMV-related complications according to their baseline characteristics. Plasma metabolomics profiling shortly after engraftment (day 21 after transplantation) allowed the ant…

Guidelines from the 2017 European Conference on Infections in Leukaemia for management of HHV-6 infection in patients with hematologic malignancies and after hematopoietic stem cell transplantation

Of the two human herpesvirus 6 (HHV-6) species, human herpesvirus 6B (HHV-6B) encephalitis is an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplant. Guidelines for the management of HHV-6 infections in patients with hematologic malignancies or post-transplant were prepared a decade ago but there have been no other guidelines since then despite significant advances in the understanding of HHV-6 encephalitis, its therapy, and other aspects of HHV-6 disease in this patient population. Revised guidelines prepared at the 2017 European Conference on Infections in Leukaemia covering diagnosis, preventative strategies and management of HHV-6 disease are n…

Co-detection of respiratory pathogens in patients hospitalized with Coronavirus viral disease-2019 pneumonia.

ABSTRACTThere is scarce information on the frequency of co-detection of respiratory pathogens (RP) in patients with Covid-19. Documentation of coinfections in Covid-19 pneumonia patients may be relevant for appropriate clinical and therapeutic management of patients. Between March 4th and March 28th, 2020, a total of 183 adult patients testing positive by SARS CoV-2 RT-PCR on respiratory specimens were hospitalized with interstitial pneumonia at our center, of whom 103 were tested for other RP by a multiplexed PCR assay. Three patients had a positive result for either one (n=2; Coronavirus HKU1 or Mycoplasma pneumoniae) or two targets (n=1; Influenza virus A (H3) and Respiratory syncytial v…

Prophylaxis of early bacterial infections after autologous peripheral blood stem cell transplantation (PBSCT): a matched-pair study comparing oral fluoroquinolones and intravenous piperacillin-tazobactam.

The safety and efficacy of early bacterial prophylaxis with piperacillin-tazobactam were prospectively evaluated in 51 autologous peripheral blood stem cell transplantation (PBSCT) recipients. The results were compared with those obtained in 51 control patients receiving oral fluoroquinolones in a retrospective matched-pair control study. Overall, 76% of the study group and 98% of the control group developed at least one febrile episode during neutropenia (P=0.002). Time from neutropenia to the first febrile episode (FFE) was significantly longer in the study group than in the control group (P=0.04). Once a febrile episode appeared, the duration of fever was significantly longer in cases th…

Performance of an automated human immunodeficiency virus (HIV) antigen/antibody combined assay for prenatal screening for HIV infection in pregnant women

Adaptive immune responses to SARS-CoV-2 in recovered severe COVID-19 patients

ABSTRACTObjectivesThere is an imperative need to determine the durability of adaptive immunity to SARS-CoV-2. We enumerated SARS-CoV-2-reactive CD4+ and CD8+ T cells targeting S1 and M proteins and measured RBD-specific serum IgG over a period of 2-6 months after symptoms onset in a cohort of subjects who had recovered from severe clinical forms of COVID-19.MethodsWe recruited 58 patients (38 males and 20 females; median age, 62.5 years), who had been hospitalized with bilateral pneumonia, 60% with one or more comorbidities. IgG antibodies binding to SARS-CoV-2 RBD were measured by ELISA. SARS-CoV-2-reactive CD69+-expressing-IFNγ-producing-CD4+ and CD8+ T cells were enumerated in heparinize…

A New Clinical and Immunovirological Score for Predicting the Risk of Late Severe Infection in Solid Organ Transplant Recipients: The CLIV Score

Abstract Background We aimed at constructing a composite score based on Epstein-Barr virus DNAemia (EBVd) and simple clinical and immunological parameters to predict late severe infection (LI) beyond month 6 in solid organ transplantation (SOT) recipients. Methods Kidney and liver transplant recipients between May 2014 and August 2016 at 4 participating centers were included. Serum immunoglobulins and complement factors, peripheral blood lymphocyte subpopulations, and whole blood EBVd were determined at months 1, 3, and 6. Cox regression analyses were performed to generate a weighted score for the prediction of LI. Results Overall, 309 SOT recipients were followed-up for a median of 1000 da…

One-year breakthrough SARS-CoV-2 infection and correlates of protection in fully vaccinated hematological patients

AbstractThe long-term clinical efficacy of SARS-CoV-2 vaccines according to antibody response in immunosuppressed patients such as hematological patients has been little explored. A prospective multicenter registry-based cohort study conducted from December 2020 to July 2022 by the Spanish Transplant and Cell Therapy group, was used to analyze the relationship of antibody response over time after full vaccination (at 3–6 weeks, 3, 6 and 12 months) (2 doses) and of booster doses with breakthrough SARS-CoV-2 infection in 1551 patients with hematological disorders. At a median follow-up of 388 days after complete immunization, 266 out of 1551 (17%) developed breakthrough SARS-CoV-2 infection a…

Failure of Cytomegalovirus-Specific CD8+ T Cell Levels at Viral DNAemia Onset to Predict the Eventual Need for Preemptive Antiviral Therapy in Allogeneic Hematopoietic Stem Cell Transplant Recipients

Suitability of two rapid lateral flow immunochromatographic assays for predicting SARS‐CoV‐2 neutralizing activity of sera

Purpose: Assessment of commercial SARS-CoV-2 immunoassays for their capacity to provide reliable information on sera neutralizing activity is an emerging need. We evaluated the performance of two commercially-available lateral flow immunochromatographic assays (LFIC) (Wondfo SARS-CoV-2 Antibody test and the INNOVITA 2019-nCoV Ab test) in comparison with a SARS-CoV-2 neutralization pseudotyped assay for COVID-19 diagnosis in hospitalized patients, and investigate whether the intensity of the test band in LFIC associates with neutralizing antibody (NtAb) titers. Patients and Methods: Ninety sera were included from 51 patients with moderate to severe COVID-19. A green fluorescent protein (GFP)…

Real-life evaluation of a rapid antigen test (Panbio™ COVID-19 Ag Rapid Test Device) for SARS-CoV-2 detection in asymptomatic close contacts of COVID-19 patients

ABSTRACTObjectivesThere is limited information on the performance of rapid antigen detection (RAD) tests to identify SARS-CoV-2-infected asymptomatic individuals. In this field study, we evaluated the Panbio™ COVID-19 Ag Rapid Test Device (Abbott Diagnostics, Jena, Germany) for the purpose.MethodsA total of 634 individuals (355 female; median age, 37 years; range, 9-87) were enrolled. Household (n=338) contacts were tested at a median of 2 days (range, 1-7) after diagnosis of the index case and non-household contacts (n=296) at a median of 6 days (range, 1-7) after exposure. RAD testing was carried out at the point of care. The RT-PCR test used was the TaqPath COVID-19 Combo Kit (Thermo Fis…

Virological and immunological features of active cytomegalovirus infection in nonimmunosuppressed patients in a surgical and trauma intensive care unit.

Cytomegalovirus (CMV) reactivation occurs frequently in critically ill patients. The natural course of CMV infection and the interaction between CMV and the adaptive immune system in this setting remain poorly defined. Fifty-three CMV-seropositive patients in a surgical and trauma intensive care unit were included in this study. The CMV DNA load in tracheal aspirates (TA) and plasma (PL) was monitored by qPCR. CMV-specific T-cell immunity was assessed by intracellular cytokine staining. Plasma TNF-alpha levels were determined by ELISA. CMV reactivation occurred in 39.7% of patients (23% had CMV DNA detected only in TA). The analysis of TA allowed an earlier diagnosis in 28% of patients. Cle…

Low rate of detection of active cytomegalovirus (CMV) infection early following acute myocardial infarction

When should preemptive antiviral therapy for active CMV infection be withdrawn from allogeneic stem cell transplant recipients?

When should preemptive antiviral therapy for active CMV infection be withdrawn from allogeneic stem cell transplant recipients?

Expanding role of cytomegalovirus as a human pathogen

Cytomegalovirus (CMV) continues to be a leading cause of morbidity and mortality in transplant recipients, despite major advancements in preventative strategies. Antiviral prophylaxis and pre-emptive antiviral therapeutic regimens are associated with a high incidence of late-onset end-organ disease and cause drug-related toxicity when overused. Therefore, the identification of risk factors for CMV replication is required. Genetic and immunological factors that predispose individuals to CMV-related clinical complications have been identified and may be instrumental for optimizing CMV treatment in the future. Evidence suggests a causal pathogenetic link between CMV-related complications and i…

Clinical virology of cytomegalovirus infection following hematopoietic transplantation

Cytomegalovirus (CMV) causes significant morbidity and mortality in allogeneic stem cell transplant recipients. The incidence of early CMV disease has been dramatically reduced by use of preemptive therapeutic strategies. Nevertheless, a trend toward a later appearance of CMV disease is being increasingly recognized. Currently, quantitative real-time PCR assays are the first-line choice for monitoring active CMV infection. However, no threshold DNAemia levels for triggering the initiation of preemptive therapy have been clinically validated in large studies. Although more time limited than universal prophylaxis, preemptive therapy strategies may also result in over treatment. Combined viro…

Expansion of the CRF19_cpx Variant in Spain

Abstract Background HIV-1 CRF19_cpx, is a recombinant variant found almost exclusively in Cuba and recently associated to a faster AIDS onset. Infection with this variant leads to higher viral loads and levels of RANTES and CXCR4 co-receptor use. Objectives The goal of this study was to assess the presence of CRF19_cpx in the Spanish province of Valencia, given its high pathogenicity. Study design 1294 HIV-1 protease-reverse transcriptase (PR/RT) sequences were obtained in Valencia (Spain), between 2005 and 2014. After subtyping, the detected CRF19_cpx sequences were aligned with 201 CRF19_cpx and 66 subtype D sequences retrieved from LANL, and subjected to maximum-likelihood phylogenetic a…

SARS-CoV-2-reactive interferon-γ-producing CD8+ T cells in patients hospitalized with Coronavirus viral disease-2019

There is limited information on SARS-CoV-2 T-cell immune responses in patients with Covid-19. Both CD4+ and CD8+ T cells may be instrumental in the resolution of and protection from SARS-CoV-2 infection. Here, we tested 25 hospitalized patients with either microbiologically documented Covid-19 (n=19) or highly suspected of having the disease (n=6) for the presence of SARS-CoV-2-reactive- CD69+-expressing interferon-gamma;-producing-(IFN-gamma;) CD8+ T cells by a flow-cytometry for intracelular cytokine staining assay. Two sets of overlapping peptides encompassing the SARS-CoV-2 Spike glycoprotein N-terminal 1-643 amino acid sequence and the entire sequence of SARS-CoV-2 M protein were used …

Early adjustment of empirical antibiotic therapy of bloodstream infections on the basis of direct identification of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and Gram staining results

Abstract Introduction To assess the potential added value of rapid MALDI-TOF MS-based identification of bacteria in positive blood cultures to the information provided by Gram staining for adequate empirical antibiotic treatment adjustments in patients with bloodstream infections (BSI). Methods We conducted a retrospective, single-center, pre-post quasi-experimental study. In the pre-MALDI-TOF MS phase of the study antibiotic adjustments were made on the basis of Gram stain results, whereas in the MALDI-TOF MS phase they were based on information provided by Gram staining and MALDI-TOF MS results. No antimicrobial stewardship program for BSI was in place within the study period. Antibiotic …

Enumeration of NKG2C+natural killer cells early following allogeneic stem cell transplant recipients does not allow prediction of the occurrence of cytomegalovirus DNAemia

The role of Natural killer (NK) cells in the control of cytomegalovirus (CMV) infection in allogeneic stem cell transplant recipients has not been precisely characterized. The current study is aimed at investigating the potential role of NK cells expressing the activating receptor NKG2C in affording protection against the development of CMV DNAemia in patients exhibiting detectable CMV-specific CD8+ T-cell responses early following transplantation. A total of 61 nonconsecutive patients were included in the study. Peripheral levels of CD56brightCD16−/low and CD56dimCD16+ NKG2C+ NK cells and CMV pp65/IE-1-specific IFN-γ-producing CD8+ T-cells were enumerated by flow cytometry at days +30 and …

An Assessment of the Effect of Human Herpesvirus-6 Replication on Active Cytomegalovirus Infection after Allogeneic Stem Cell Transplantation

Human herpesvirus-6 (HHV-6) may enhance cytomegalovirus (CMV) replication in allogeneic stem cell transplant (allo-SCT) recipients either through direct or indirect mechanisms. Definitive evidence supporting this hypothesis are lacking. We investigated the effect of HHV-6 replication on active CMV infection in 68 allo-SCT recipients. Analysis of plasma HHV-6 and CMV DNAemia was performed by real-time PCR. Enumeration of pp65 and IE-1 CMV-specific IFNgamma CD8(+) and CD4(+)T cells was performed by intracellular cytokine staining. HHV-6 DNAemia occurred in 39.8% of patients, and was significantly associated with subsequent CMV DNAemia in univariate (P=.01), but not in multivariate analysis (P…

Hydrogen- and Methane-Based Breath Testing and Outcomes in Patients With Heart Failure

Background: Recent evidence endorses gut microbiota dysregulation in the pathophysiology of heart failure (HF). Small intestinal bacterial overgrowth (SIBO) might be present in HF and associated with poor clinical outcomes. Lactulose breath testing is a simple noninvasive test that has been advocated as a reliable indicator of SIBO. In patients with HF, we aimed to evaluate the association with clinical outcomes of the exhaled hydrogen (H-2) and methane (CH4) concentrations through the lactulose breath test. Methods and Results: We included 102 patients with HF in which lactulose SIBO breath tests were assessed. Cumulative gas was quantified by the area under the receiver operating characte…

Effect of long-term prophylaxis in the development of cytomegalovirus-specific T-cell immunity in D+/R- solid organ transplant recipients.

Background This study aimed to characterize the dynamics of acquisition of cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) in CMV donor positive/recipient negative solid organ transplant (SOT) patients receiving long-term antiviral prophylaxis, and to determine whether development of CMI confers protection against CMV disease. Methods A prospective multicenter study was conducted in Spain from September 2009 to September 2012. Whole blood specimens were prospectively collected at 30, 90, 120, 200, and 365 days after SOT, and CMI was determined by enumeration of CMV pp65 and IE-1-specific CD69+/interferon-γ-producing CD8+ and CD4+ T cells by flow cytometry for intracellular cytok…

Immunological insights into the pathogenesis of active CMV infection in non-immunosuppressed critically ill patients.

Dissociation of cytomegalovirus (CMV) DNA loads between the lower respiratory tract and blood, with high levels in the former compartment and low or undetectable levels in the latter, commonly occurs during active CMV infection in critically ill patients despite the presence of high frequencies of CMV-specific IFN-γ-producing CD8+ and CD4+ T cells in blood. Data presented in this case report suggest that inter-compartmental differences in interleukin-10 (IL-10) levels may, in part, explain the pathobiology of this phenomenon. In the absence of ganciclovir treatment, a significant correlation was observed between IL-10 levels and CMV DNA loads in lower respiratory tract specimens (P = 0.016)…

Reconstitution of lymphocyte populations and cytomegalovirus viremia or disease after allogeneic peripheral blood stem cell transplantation

Early reconstitution of lymphoid populations was monitored by immunophenotyping in 57 allogeneic peripheral blood stem cell (allo-PBSC) transplant patients either with or without cytomegalovirus (CMV) viremia or disease. Cell counts for total lymphocytes and CD4(+) T cells above the percentile 60th at day 14 postransplant were associated significantly with CMV viremia-free survival within 120 days after transplant. Recovery of total lymphocyte, CD3(+), and CD8(+) T-cell counts proceeded at a more rapid rate in CMV viremic patients than in nonviremic patients, irrespective of whether preemptive treatment with ganciclovir had been prescribed. Significant expansion of CD8(+) and CD8(+) CD57(+)…

Becton Dickinson Directigen EZ Flu A+B assay in the diagnosis of pandemic influenza A H1N1 2009 virus infection in adult patients

Lack of evidence for a reciprocal interaction between bacterial and cytomegalovirus infection in the allogeneic stem cell transplantation setting

Summary Pathogenic interactions between bacteria and cytomegalovirus (CMV) may potentially occur early after allogeneic stem cell transplantation (Allo-SCT). This possibility nevertheless has not been investigated in depth. This was a retrospective study that included 170 consecutive patients who underwent 173 Allo-SCTs. Both bacterial infection (most of which were bacteremic) and CMV DNAemia were detected in 78 Allo-SCTs (62.9%). In total, 51 and 32 episodes of bacterial infection preceded or occurred after CMV DNAemia detection, respectively. Both events were diagnosed concurrently in four Allo-SCTs. The cumulative incidence of bacterial infection (of any type) over the study period was c…

Comparison of the artus Epstein-Barr virus (EBV) PCR kit and the Abbott RealTime EBV assay for measuring plasma EBV DNA loads in allogeneic stem cell transplant recipients.

The ability of the artus Epstein-Barr virus (EBV) PCR kit and the Abbott RealTime EBV PCR assay to detect and quantify plasma EBV DNAemia was compared. The agreement between these assays was 95.8%. The EBV DNA loads measured by the two assays significantly correlated (P=< 0.0001).

Proteins of Human Cytomegalovirus that Elicit Humoral Immunity

Several of the cytomegalovirus (CMV) genes encoding glycoproteins, structural proteins, and infected-cell proteins that elicit an immune response in human infection have been mapped. Human sera and monoclonal antibodies react with these viral polypeptides made as native molecules in CMV-infected cells, as genetically engineered proteins, as truncated derivatives expressed in eukaryotic cells, and as bacterial fusion proteins from portions of the reading frames cloned into prokaryotic expression vectors. Synthetic oligopeptides from immunodominant regions of these molecules have also been used as antibody targets. Studies on proteins encoded by reading frames UL55, UL32, and UL44, on glycopr…

The effect of timing on community acquired respiratory virus infection mortality during the first year after allogeneic hematopoietic stem cell transplantation: a prospective epidemiological survey.

The effect of timing of community acquired respiratory virus (CARV) infection after allogeneic hematopoietic stem cell transplant (allo-HCT) is an as yet unsettled issue. We evaluate this issue by including all consecutive allo-HCT recipients with molecularly-documented CARV infection during the first year after transplant. The study cohort was drawn from a prospective longitudinal survey of CARV in allo-HCT recipient having respiratory symptoms conducted from December 2013 to December 2018 at two Spanish transplant centers. Respiratory viruses in upper and/or lower respiratory specimens were tested using multiplex PCR panel assays. The study cohort comprised 233 allo-HCT recipients with 37…

High vancomycin MICs within the susceptible range in Staphylococcus aureus bacteraemia isolates are associated with increased cell wall thickness and reduced intracellular killing by human phagocytes

Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thic…

Features of Cytomegalovirus DNAemia Blips in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Implications for Optimization of Preemptive Antiviral Therapy Strategies.

Cytomegalovirus (CMV) DNAemia occurs frequently in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). There is limited information about the incidence, features, and clinical impact of CMV DNAemia blips (episodes defined by an isolated positive PCR result) in this setting. In this retrospective study, 225 consecutive adult patients undergoing any modality of allo-HSCT at our center between May 2012 and July 2019 were included. Plasma CMV DNA load was monitored using a highly sensitive real-time PCR assay. In all, 187 of 225 patients had CMV DNAemia through day 365 after allo-HSCT (total number of episodes, n = 379). Eighty-three of the 187 patients had 1 or more blips (n …

COVID-19 infodemics: the role of mainstream and social media

Dynamics of cytomegalovirus (CMV) plasma DNAemia in initial and recurrent episodes of active CMV infection in the allogeneic stem cell transplantation setting: implications for designing preemptive antiviral therapy strategies.

Preemptive antiviral therapy strategies for active cytomegalovirus (CMV) infection occurring in allogeneic stem cell transplant recipients should be optimized to avoid overtreatment. The current study was aimed at determining whether the analysis of the kinetics of CMV DNA load in plasma may provide useful information for the therapeutic management of active CMV infection in this setting. A total of 59 consecutive patients were included in the study, of which 40 (67.8%) developed 1 (n = 21) or more (n = 19) episodes of CMV DNAemia. The need for antiviral therapy for initial or secondary episodes of CMV DNAemia could not be predicted on the basis of the CMV DNA load value in the first plasma…

Quantification of DNA in Plasma by an Automated Real-Time PCR Assay (Cytomegalovirus PCR Kit) for Surveillance of Active Cytomegalovirus Infection and Guidance of Preemptive Therapy for Allogeneic Hematopoietic Stem Cell Transplant Recipients

ABSTRACT The performance of a plasma real-time PCR (cytomegalovirus [CMV] PCR kit; Abbott Diagnostics) was compared with that of the antigenemia assay for the surveillance of active CMV infection in 42 allogeneic hematopoietic stem cell transplantation (Allo-SCT) recipients. A total of 1,156 samples were analyzed by the two assays. Concordance between the two assays was 82.2%. Plasma DNA levels correlated with the number of pp65-positive cells, particularly prior to the initiation of preemptive therapy. Fifty-seven episodes of active CMV infection were detected in 37 patients: 18 were defined solely by the PCR assay and four were defined on the basis of the antigenemia assay. Either a cutof…

Functional profile of cytomegalovirus (CMV)-specific CD8+ T cells and kinetics of NKG2C+ NK Cells associated with the resolution of CMV DNAemia in allogeneic stem cell transplant recipients

Immune mechanisms involved in control of cytomegalovirus (CMV) infection in the allogeneic stem cell transplantation setting have not been fully disclosed. CMV pp65 and IE-1-specific CD8(+) T cells expressing IFN-γ, TNF-α, and CD107a, alone or in combination, and NKG2C(+) NK cells were prospectively enumerated during 13 episodes of CMV DNAemia. The expansion of monofunctional and polyfunctional CD8(+) T cells was associated with CMV DNAemia clearance. The size and functional diversity of the expanding CD8(+) T-cell population was greater in self-resolved episodes than in episodes treated with antivirals. These differences were related to the magnitude of expansion of cognate antigen IFN-γ C…

Effect of highly active anti-retroviral therapy and hepatitis C virus co-infection on serum levels of pro-inflammatory and immunoregulatory cytokines in human immunodeficiency virus-1-infected individuals

ABSTRACTThis study aimed to determine the effect of highly active anti-retroviral therapy (HAART) and hepatitis C virus (HCV) co-infection on peripheral levels of interleukin (IL)-2, IL-10, IL-12 (p70), IL-18 and soluble tumour necrosis factor receptor type II (sTNFRII). Serum levels were monitored for a 1-year period in 25 patients infected with human immunodeficiency virus-1 (HIV-1) who were naive for HAART at the initiation of the study, and in four HIV-1-infected long-term non-progressors. Serum levels of both IL-18 and sTNFRII at baseline were significantly higher in HIV-1-infected patients than in controls. Baseline levels of IL-18 and sTNFRII were not significantly different in long-…

Impact of cytomegalovirus DNAemia on overall and non-relapse mortality in allogeneic stem cell transplant recipients.

Background We conducted a retrospective single-center study to investigate the potential impact of cytomegalovirus (CMV) DNAemia on mortality in allogeneic stem cell transplant recipients (allo-SCT). Methods A total of 151 consecutive patients who underwent T-cell replete allo-SCT were included in the study. Patients with CMV DNAemia were treated pre-emptively with antivirals upon detection of plasma CMV DNA loads >1500 IU/mL. Results At least one episode of CMV DNAemia occurred in 109 (72.2%), and 67 of these patients (61.5%) required one or more courses of antiviral therapy. The cumulative incidence of 1-year overall and non-relapse mortality (NRM) was 28.5% (95% confidence interval [CI],…

An update on the management and prevention of cytomegalovirus infection following allogeneic hematopoietic stem cell transplantation

ABSTRACT  A significant progress has been made in deciphering critical aspects of the biology and immunology of CMV infection in the allogeneic stem cell transplantation setting. Genetic traits predisposing to active CMV infection and CMV end-organ disease have begun to be delineated. Reliable molecular assays for CMV DNA load quantitation in body fluids have been developed. Elucidation of immune mechanisms affording control of CMV infection will help to improve the management of active CMV infection. Finally, the advent of new CMV-specific antivirals and promising vaccine prototypes as well as the development of fine procedures for large-scale ex vivo generation of functional CMV-specific…

Management of cytomegalovirus infection in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations.

Cytomegalovirus (CMV) infection remains a major complication of solid organ transplantation. Because of management of CMV is variable among transplant centers, in 2011 the Spanish Transplantation Infection Study Group (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) developed consensus guidelines for the prevention and treatment of CMV infection in solid organ transplant recipients. Since then, new publications have clarified or questioned the aspects covered in the previous document. For that reason, a panel of experts revised the evidence on CMV management, including immunological monitoring, diagnostics, prevention, vaccines, indirect effects, tre…

Sirolimus exposure and the occurrence of cytomegalovirus DNAemia after allogeneic hematopoietic stem cell transplantation

Sirolimus appears to protect against cytomegalovirus (CMV) in organ transplant recipients. The effect of this drug in allogeneic hematopoietic stem cell transplantation recipients remains unexplored. By means of multivariate continuous-time Markov model analyses, we identified 3 independent covariates that significantly impacted the risk of CMV DNAemia: recipient/donor CMV serostatus, tacrolimus exposure, and sirolimus exposure. CMV-seropositive recipients with CMV-seronegative donors had a significantly higher probability of having detectable CMV DNAemia. Increasing the tacrolimus trough concentration from 0 to 16 ng/mL increased the probability of patients having detectable CMV DNAemia by…

Frequent detection of cytomegalovirus (CMV) DNA in the lower respiratory tract in CMV-seropositive pediatric patients with underlying chronic bronchopulmonary diseases lacking canonical immunosuppression

Abstract Cytomegalovirus (CMV) may be a relevant cause of morbidity in patients displaying various inflammatory diseases. In this study, it was investigated whether CMV DNA is detected in the lower respiratory tract and the systemic compartment in pediatric patients with chronic or recurrent bronchopulmonary diseases. A total of 42 lower respiratory tract specimens and 11 paired plasma samples from 42 patients were analyzed for the presence of CMV DNA by real‐time PCR. The respiratory specimens were also screened for the presence of respiratory viruses and human herpesvirus 6 (HHV‐6) and 7 (HHV‐7) by PCR methods. Quantitative bacterial and fungal cultures were performed. IL‐6 levels in the …

Cytomegalovirus DNA load monitoring in stool specimens for anticipating the occurrence of intestinal acute graft‐versus‐host disease following allogeneic hematopoietic stem cell transplantation: Is it of any value?

Background Data have been published suggesting a bidirectional interaction between cytomegalovirus (CMV) infection and acute graft-versus-host disease (aGvHD) in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. Here, we hypothesized that prospective CMV DNA monitoring in stool specimens may be useful for predicting subsequent occurrence of intestinal aGvHD (IaGvHD). Methods This two-center study enrolled 121 consecutive adult patients undergoing any modality of allo-HSCT. A total of 1,009 stool specimens were collected (a median of 7 specimens/patient; range, 1-18). CMV DNA monitoring in stools and plasma was performed using real-time PCR assays. Results CMV DNA was det…

Neutralizing antibodies against SARS-CoV-2 variants of concern elicited by the comirnaty COVID-19 vaccine in nursing home residents.

Immunosenescence may impact the functionality and breadth of vaccine-elicited humoral immune responses. The ability of sera to neutralize the SARS-CoV-2 spike protein (S) from Beta, Gamma, Delta, and Epsilon variants of concern (VOCs) relative to the ancestral Wuhan-Hu-1 strain was compared in Comirnaty COVID-19-vaccinated elderly nursing home residents, either SARS-CoV-2 naïve (n = 22) or experienced (n = 8), or SARS-CoV-2 naïve younger individuals (n = 18) and non-vaccinated individuals who recovered from severe COVID-19 (n = 19). In all groups, except that including SARS-CoV-2-experienced nursing home residents, some participants lacked NtAb against one or more VOCs, mainly the Beta vari…

The first wave of the Spanish COVID-19 epidemic was associated with early introductions and fast spread of a dominating genetic variant

The COVID-19 pandemic has shaken the world since the beginning of 2020. Spain is among the European countries with the highest incidence of the disease during the first pandemic wave. We established a multidisciplinar consortium to monitor and study the evolution of the epidemic, with the aim of contributing to decision making and stopping rapid spreading across the country. We present the results for 2170 sequences from the first wave of the SARS-Cov-2 epidemic in Spain and representing 12% of diagnosed cases until 14th March. This effort allows us to document at least 500 initial introductions, between early February-March from multiple international sources. Importantly, we document the …

Intra- and Interinstitutional Evaluation of an Etest for Vancomycin Minimum Inhibitory Concentration Measurement inStaphylococcus aureusBlood Isolates: Figure 1.

Diagnostic accuracy and potential clinical value of the LightCycler SeptiFast assay in the management of bloodstream infections occurring in neutropenic and critically ill patients

Summary Objectives The objectives of this study were to compare the performance of the LightCycler SeptiFast Test MGRADE and conventional blood culture in the etiological diagnosis of febrile episodes occurring in neutropenic and critically ill patients (in the intensive care unit; ICU), and to assess the potential clinical value of the SeptiFast test in patient management. Methods A total of 86 febrile episodes occurring in 33 neutropenic patients and 53 ICU patients were analyzed. Blood samples for blood culture and SeptiFast testing were obtained at the onset of fever, before the implementation of empirical antimicrobial therapy. Results The overall microorganism-to-isolate agreement bet…

Pathogen safety of long-term treatments for bleeding disorders: (un)predictable risks and evolving threats.

Substantial improvements in the safety of blood and plasma products for the management of bleeding disorders have been achieved in recent decades. This has led some clinicians to believe that the infectious threat is over and that inhibitor formation is the foremost complication of hemophilia therapy. On the contrary, elimination of all microbes from blood is difficult, potentially impossible, and there are always threats from emerging pathogens. The risk of infection transmission is also increasing due to greater exposure to products, increasing prophylaxis and high-dose regimens for immune tolerance, and longevity of hemophilia patients. Current products can be considered "reasonably safe…

Evolution of SARS-CoV-2 immune responses in nursing home residents following full dose of the Comirnaty® COVID-19 vaccine

ABSTRACTObjectivesThere is scarce information as to the durability of immune responses elicited by the Comirnaty® COVID-19 vaccine in nursing home residents. Here, we assessed SARS-CoV-2-Spike (S)-targeted antibody and functional T cell responses at around 6 months after complete vaccination.MethodsThe sample comprised 46 residents (34 females; age, 60-100 years), of whom 10 had COVID-19 prior to vaccination. Baseline (median of 17.5 days after vaccination) and follow-up (median, 195 days) plasma specimens were available for quantitation of SARS-CoV-2-S antibodies and enumeration of SARS-CoV-2-S-reactive IFN-γ CD4+ and CD8+ T cells by flow cytometry.ResultsIn total, 44/45 participants had d…

Application of a 5-bromo-2′-deoxyuridine ELISA for measuring the lymphoproliferative response to human cytomegalovirus in HIV-1-infected patients

Assessment of the lymphoproliferative response to human cytomegalovirus (HCMV) may help to identify human immunodeficiency virus (HIV)-1-infected patients at high risk of developing HCMV end-organ disease. The tritiated thymidine ([3H]-TdR)-incorporation assay is the gold standard for measuring lymphoproliferative responses, though it is unsuitable as a routine laboratory procedure. An alternative non-radioactive technique, a 5-bromo-2'-deoxyuridine (BrdU) enzyme-linked immunosorbent assay, was applied for measuring T-cell proliferation in response to HCMV. Stimulation of either 1 x 10(5) or 5 x 10(4) peripheral blood mononuclear cells (PBMCs)/well with 10 PFU/well (before inactivation) of …

Preemptive antiviral therapy for CMV infection in allogeneic stem cell transplant recipients guided by the viral doubling time in the blood

Preemptive antiviral therapy for CMV infection in allogeneic stem cell transplant recipients guided by the viral doubling time in the blood

The molecular epidemiology of HIV-1 in the Comunidad Valenciana (Spain): analysis of transmission clusters

AbstractHIV infections are still a very serious concern for public heath worldwide. We have applied molecular evolution methods to study the HIV-1 epidemics in the Comunidad Valenciana (CV, Spain) from a public health surveillance perspective. For this, we analysed 1804 HIV-1 sequences comprising protease and reverse transcriptase (PR/RT) coding regions, sampled between 2004 and 2014. These sequences were subtyped and subjected to phylogenetic analyses in order to detect transmission clusters. In addition, univariate and multinomial comparisons were performed to detect epidemiological differences between HIV-1 subtypes, and risk groups. The HIV epidemic in the CV is dominated by subtype B i…

Serum Heat Shock Protein 60 in Acute Heart Failure: A New Biomarker?

Heat shock protein 60 (HSP60) is a mitochondrial protein constitutively expressed in the majority of cells, and its expression is up-regulated by a variety of stressors. In heart failure, HSP60 is released from cardiomyocytes. The authors speculate that increased serum HSP60 (sHSP60) may be related to the severity of heart failure. This investigation sought to assess the association between sHSP60 and the composite end point of death ⁄ readmission in patients with acute heart failure (AHF). A total of 132 consecutive patients were admitted for AHF. The independent association between sHSP60 and the end point was assessed with Cox regression. During a median follow-up of 7 months (interquart…

Sirolimus versus cyclosporine in haploidentical stem cell transplantation with posttransplant cyclophosphamide and mycophenolate mofetil as graft‐versus‐host disease prophylaxis

Sirolimus has emerged as an alternative to calcineurin inhibitors-based (CNI) graft-versus-host disease (GVHD) prophylaxis. This retrospective study compares the outcome of 133 consecutive adult patients with haematological malignancies undergoing haploidentical stem cell transplantation with posttransplant cyclophosphamide (PTCy) and mycophenolate mofetil (MMF), combined with cyclosporine A (PTCy-CsA-MMF,

Functional patterns of cytomegalovirus (CMV) pp65 and immediate early-1-specific CD8+T cells that are associated with protection from and control of CMV DNAemia after allogeneic stem cell transplantation

Background The functional profile of cytomegalovirus (CMV)-specific CD8+ T cells that associate with protection from and control of CMV DNAemia in allogeneic stem cell transplant (allo-SCT) recipients remains incompletely characterized. Methods We enumerated pp65 and immediate early (IE)-1-specific CD8+ T cells expressing interferon-gamma, tumor necrosis factor-alpha, and CD107a, by flow cytometry in 94 patients at days +30 and +60 after allo-SCT. Results Fifty of 94 patients had CMV DNAemia within the first 100 days after transplant. CMV-specific CD8+ T-cell responses (of any functional type) were more likely to be detected in patients who did not display CMV DNAemia than in those who did …

Cytomegalovirus DNAemia in patients with de novo acute myeloid leukemia undergoing cytotoxic chemotherapy

There is evidence suggesting that cytomegalovirus (CMV) reactivation following allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be associated with a lower relapse incidence in acu...

Whole-genome sequencing of Mycobacterium tuberculosis directly from clinical samples for high-resolution genomic epidemiology and drug resistance surveillance: an observational study

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Looking for biological factors to predict the risk of active cytomegalovirus infection in non-immunosuppressed critically ill patients

The identification of non-immunosuppressed critically ill patients most at risk for developing cytomegalovirus (CMV) reactivation is potentially of great clinical relevance. The current study was aimed at determining (i) whether single nucleotide polymorphisms in the genes coding for chemokine receptor 5 (CCR5), interleukin-10 IL-10), and monocyte chemoattractant protein-1 (MCP-1) have an impact on the incidence rate of active CMV infection, (ii) whether serum levels of CMV-specific IgGs are associated with the risk of CMV reactivation, and (iii) whether detection of CMV DNA in saliva precedes that in the lower respiratory tract or the blood compartment. A total of 36 out of 78 patients (46…

Regular monitoring of cytomegalovirus-specific cell-mediated immunity in intermediate-risk kidney transplant recipients: predictive value of the immediate post-transplant assessment

Abstract Objective Previous studies on monitoring of post-transplant cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) are limited by single-centre designs and disparate risk categories. We aimed to assess the clinical value of a regular monitoring strategy in a large multicentre cohort of intermediate-risk kidney transplant (KT) recipients. Methods We recruited 124 CMV-seropositive KT recipients with no T-cell-depleting induction pre-emptively managed at four Spanish institutions. CMV-specific interferon-γ-producing CD4+ and CD8+ T cells were counted through the first post-transplant year by intracellular cytokine staining after stimulation with pp65 and immediate early-1 peptide…

Current concepts in the prevention of pathogen transmission via blood/plasma-derived products for bleeding disorders

The pathogen safety of blood/plasma-derived products has historically been a subject of significant concern to the medical community, Measures such as donor selection and blood screening have contributed to increase the safety of these products, but pathogen transmission does still occur. Reasons for this include lack of sensitivity/specificity of current screening methods, lack of reliable screening tests for some pathogens (e.g. prions) and the fact that many potentially harmful infectious agents are not routinely screened for. Methods for the purification/inactivation of blood/plasma-derived products have been developed in order to further reduce the residual risk, but low concentrations…