Search results for "chronic infection"
showing 10 items of 35 documents
HCV genotype 5: an orphan virus
2013
HCV genotype 5 (HCV-5) is the least known HCV genotype. It is found mainly in South Africa and in restricted areas of Belgium, Spain, France, Syria and Greece. Sporadic cases are reported worldwide. The main modes of transmission are blood transfusion and iatrogenic causes. Little is known about its origin, but various studies have elucidated its spread worldwide. In endemic areas, patients infected with HCV-5 are on average older and have a higher viral load and more advanced fibrosis than those infected with non-HCV-5 genotypes. The current standard of care for HCV-5 chronic infection is 48 weeks of dual therapy with pegylated interferon plus ribavirin. ‘Favourable’ Il28B polymorphisms a…
Gamma interferon blocks gammaherpesvirus reactivation from latency in a cell type-specific manner
2007
Gammaherpesviruses are important pathogens whose lifelong survival in the host depends critically on their capacity to establish and reactivate from latency, processes regulated by both viral genes and the host immune response. Previous work has demonstrated that gamma interferon (IFN-gamma) is a key regulator of chronic infection with murine gammaherpesvirus 68 (gammaHV68), a virus that establishes latent infection in B lymphocytes, macrophages, and dendritic cells. In mice deficient in IFN-gamma or the IFN-gamma receptor, gammaHV68 gene expression is altered during chronic infection, and peritoneal cells explanted from these mice reactivate more efficiently ex vivo than cells derived from…
Genetic similarity of hepatitis C virus and fibrosis progression in chronic and recurrent infection after liver transplantation
2006
SUMMARY. The effect of hepatitis C virus (HCV) genetic heterogeneity on clinical features of post-transplantation hepatitis C is controversial. Different regions of the HCV genome have been associated with apoptosis, fibrosis, and other pathways leading to liver damage in chronic HCV infection. Besides, differences in immunodominant regions, such as NS3, may influence HCV-specific immune responses and disease outcome. In the liver transplant setting, a recent study has reported a positive association between HCV-1b Core region genetic relatedness 5-year post-transplantation and histological severity of recurrent hepatitis C. We have compared nucleotide sequences of HCV Core, NS3 and NS5b re…
Forecasting Hepatitis C liver disease burden on real-life data. Does the hidden iceberg matter to reach the elimination goals?
2018
Abstract Background & Aims Advances in direct‐acting antiviral treatment of HCV have reinvigorated public health initiatives aimed at identifying affected individuals. We evaluated the possible impact of only diagnosed and linked‐to‐care individuals on overall HCV burden estimates and identified a possible strategy to achieve the WHO targets by 2030. Methods Using a modelling approach grounded in Italian real‐life data of diagnosed and treated patients, different linkage‐to‐care scenarios were built to evaluate potential strategies in achieving the HCV elimination goals. Results Under the 40% linked‐to‐care scenario, viraemic burden would decline (60%); however, eligible patients to treat w…
An Outbreak of Hepatitis C Virus Infection Among Transfused Thalassemia Patients: Root Cause Analysis, Phylogenetic Epidemiology and Antiviral Therapy
2021
Background: Occurrence of HCV infection is reduced by effective risk management procedures, but patient-to-patient transmission continues to be reported in healthcare settings. We report an outbreak of 11 patients with HCV acute hepatitis (seven new infections and four re-infections) among 128 thalassemia patients followed at a Hospital in Sicily. Methods All patients with acute hepatitis and known chronic infection were tested for HCV-RNA, HCV genotyping, and NS3, NS5A and NS5B HCV-genomic regions sequencing. To identify transmission clusters we built phylogenetic trees for each gene employing Bayesian methods. Findings All patients with acute hepatitis were infected with HCV genotype 1b…
Hepatitis E seroprevalence and viremia rate in immunocompromised patients: a systematic review and meta‐analysis
2020
Background and aims Hepatitis E is an infectious disease of the liver caused by the hepatitis E virus (HEV). Immunocompromised patients present a particular risk group, as chronification of hepatitis E leading to life-threatening cirrhosis occurs when these patients are infected. Therefore, this study aims to estimate and compare the anti-HEV seroprevalence and the rate of HEV RNA positivity in transplant recipients and patients with human immunodeficiency virus (HIV). Methods This systematic review and meta-analysis involved a literature search (PubMed, Scopus; 1,138 studies) including 120 studies from 1996 to 2019, reporting anti-HEV seroprevalence and/or HEV-RNA positivity. Statistical a…
Intrahepatic myeloid-cell aggregates enable local proliferation of CD8+T cells and successful immunotherapy against chronic viral liver infection
2013
Chronic infection is difficult to overcome because of exhaustion or depletion of cytotoxic effector CD8(+) T cells (cytotoxic T lymphoytes (CTLs)). Here we report that signaling via Toll-like receptors (TLRs) induced intrahepatic aggregates of myeloid cells that enabled the population expansion of CTLs (iMATEs: 'intrahepatic myeloid-cell aggregates for T cell population expansion') without causing immunopathology. In the liver, CTL proliferation was restricted to iMATEs that were composed of inflammatory monocyte-derived CD11b(+) cells. Signaling via tumor-necrosis factor (TNF) caused iMATE formation that facilitated costimulation dependent on the receptor OX40 for expansion of the CTL popu…
Risk Factors and Outcome among a Large Patient Cohort with Community-Acquired Acute Hepatitis C in Italy
2006
Background The epidemiology of acute hepatitis C has changed during the past decade in Western countries. Acute HCV infection has a high rate of chronicity, but it is unclear when patients with acute infection should be treated. Methods To evaluate current sources of hepatitis C virus (HCV) transmission in Italy and to assess the rate of and factors associated with chronic infection, we enrolled 214 consecutive patients with newly acquired hepatitis C during 1999-2004. The patients were from 12 health care centers throughout the country, and they were followed up for a mean (+/- SD) period of 14+/-15.8 months. Biochemical liver tests were performed, and HCV RNA levels were monitored. Result…
Serum BLyS/BAFF predicts the outcome of acute hepatitis C virus infection.
2009
Summary. B-lymphocyte stimulator/B activating factor (BLyS/BAFF) is a tumour necrosis factor-family cytokine that plays a key role in generating and maintaining the mature B-cell pool. BLyS/BAFF expression by macrophages is stimulated by interferon-γ and interleukin-10, and its serum levels are increased in chronic hepatitis C (CHC). The aim of this study was to assess serum levels of BLyS/BAFF in patients with acute hepatitis C (AHC) and correlate them with disease outcome. We studied 28 patients with AHC (14 males, mean age 59.3 ± 15 years), followed for at least 7 months since onset, comparing them with 86 CHC patients and 25 healthy blood donors (HBD). BLyS/BAFF levels were assessed at…
Differential alterations in the small intestine epithelial cell turnover during acute and chronic infection with Echinostoma caproni (Trematoda)
2015
Background The intestinal epithelium plays a multifactorial role in mucosal defense. In this sense, augmented epithelial cell turnover appears as a potential effector mechanism for the rejection of intestinal-dwelling helminths. Methods A BrdU pulse-chase experiment was conducted to investigate the infection-induced alterations on epithelial cell kinetics in hosts of high (mouse) and low (rat) compatibility with the intestinal trematode Echinostoma caproni. Results High levels of crypt-cell proliferation and tissue hyperplasia were observed in the ileum of infected mice, coinciding with the establishment of chronic infections. In contrast, the cell migration rate was about two times higher …