Search results for "Viral Load"
showing 10 items of 232 documents
A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts
2020
Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in‐house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV…
Future Perspectives in NNRTI-Based Therapy: Bases for Understanding Their Toxicity
2011
Continuous administration of the drugs included under the term Highly Active Antiretroviral Therapy (HAART) has turned AIDS into a chronic disease, at least in developed countries (Panos et al., 2008). The initial development of these drugs was particularly rapid and focused on clinical efficacy before all other considerations. However, as the disease has come under control, there has been growing emphasis on the long-term adverse effects associated with this therapy. The first drug for the treatment of HIV infection, zidovudine (AZT), was approved in 1987. The number of other antiretroviral drugs already approved for use or under development continues to grow, and the primary aim of resear…
Kinetics of cytomegalovirus (CMV) pp65 and IE-1-specific IFNgamma CD8+ and CD4+ T cells during episodes of viral DNAemia in allogeneic stem cell tran…
2010
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…
DI-032 Study of effectiveness and safety of foscarnet in cytomegalovirus treatment in haematopoietic stem cell transplantation recipients
2016
Background Cytomegalovirus disease is an important cause of morbidity and mortality in haematopoietic stem cell transplantation (HSCT) recipients. Foscarnet, an intravenous drug active against cytomegalovirus, represents an increasingly widespread alternative when there is resistance or intolerance to conventional treatments (ganciclovir/valganciclovir, acyclovir). More data about its use, effectiveness and safety in the clinical practice are necessary. Purpose To analyse the effectiveness and safety of the use of foscarnet against cytomegalovirus in HSCT recipients, and its adaptation to clinical practice guidelines and expert recommendations in order to optimise future treatment strategie…
Immunological insights into the pathogenesis of active CMV infection in non-immunosuppressed critically ill patients.
2011
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)…
Preemptive CD8 T-Cell Immunotherapy of Acute Cytomegalovirus Infection Prevents Lethal Disease, Limits the Burden of Latent Viral Genomes, and Reduce…
1998
ABSTRACT In the immunocompetent host, primary cytomegalovirus (CMV) infection is resolved by the immune response without causing overt disease. The viral genome, however, is not cleared but is maintained in a latent state that entails a risk of virus recurrence and consequent organ disease. By using murine CMV as a model, we have shown previously that multiple organs harbor latent CMV and that reactivation occurs with an incidence that is determined by the viral DNA load in the respective organ (M. J. Reddehase, M. Balthesen, M. Rapp, S. Jonjic, I. Pavic, and U. H. Koszinowski. J. Exp. Med. 179:185–193, 1994). This predicts that a therapeutic intervention capable of limiting the load of lat…
Heterogeneity of HVR-1 quasispecies is predictive of early but not sustained virological response in genotype 1b-infected patients undergoing combine…
2003
ISDR mutation pattern and HVR-1 quasispecies were analyzed in HCV genotype 1b-infected patients treated with either PEG- or STD-IFN plus ribavirin, in order to find virological correlates of therapy outcome. ISDR region analysis, performed at baseline (T0) and at 4 weeks of therapy (T1), indicated that ISDR mutation pattern was not predictive of response to treatment. Moreover, no selection of putative resistant strains in the first month of therapy was observed. Viral load was not correlated with any parameter of HVR-1 heterogeneity. Among the HVR-1 heterogeneity parameters considered, complexity was inversely correlated to viral load decline at T1. In univariate analysis, complexity, prop…
Immune activation promotes evolutionary conservation of T-cell epitopes in HIV-1.
2013
The immune system should constitute a strong selective pressure promoting viral genetic diversity and evolution. However, HIV shows lower sequence variability at T-cell epitopes than elsewhere in the genome, in contrast with other human RNA viruses. Here, we propose that epitope conservation is a consequence of the particular interactions established between HIV and the immune system. On one hand, epitope recognition triggers an anti-HIV response mediated by cytotoxic T-lymphocytes (CTLs), but on the other hand, activation of CD4(+) helper T lymphocytes (TH cells) promotes HIV replication. Mathematical modeling of these opposite selective forces revealed that selection at the intrapatient l…
Chronic hepatitis B: Do we know everything or is there still something to learn?
2009
Chronic hepatitis B is a dynamic process with different phases. The progression of liver damage is related to time of infection, linked to the persistence of viral replication, and based on the virus–host interaction. [1]. The course of liver disease can be modified by virological events related to the kinetics of HBV replication and influenced by the host immune system. Knowledge of the natural history of HBV infection and of its viral replication mechanisms suggest the treatment end points and guide the choice of antiviral drugs [2–4]. The key points for the management of chronic hepatitis Ba re: Evaluation of viral status (HBeAg positive or HBeAg negative), staging of liver disease (chro…
The presence of high amounts of HBV-DNA in serum is associated with suppressed costimulatory effects of interleukin 12 on HBV-induced immune response
1999
Abstract Background/Aims: The aim of this study was to examine the influence of the viral load on costimulatory effects of rhIL-12 on the hepatitis B virus (HBV)-induced immune response. Methods: Peripheral blood mononuclear cells of HBsAg positive patients without cirrhosis were stimulated with HBsAg, HBcAg, preSlAg and tetanus toxoid in the absence or presence of IL-12 (0.01, 0.1 and 1 ng/ml). Stimulation by α-CD3+α-CD28, pokeweed mitogen (PWM) and lipopolysaccharide (LPS) were used as controls. Then, proliferation and cytokine production were determined by 3 H-thymidine uptake and ELISA after 72 h. The patients were divided into group 1 ( n =21): HBV-DNA: not detectable, group 2 ( n =13)…