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Persistence of hepatitis C virus (HCV) in patients who cleared HCV is still debated. Occult HCV infection is described as the presence of detectable HCV RNA in liver or peripheral blood mononuclear cells (PBMCs) of patients with undetectable plasma HCV-RNA by conventional PCR assays. We have assessed the persistence of HCV in 26 kidney-transplant patients, followed up for 10.5 years (range 2–16), after HCV elimination while on hemodialysis. If HCV really did persist, arising out of the loss of immune control caused by institution of the regimen of immunosuppressive drugs after kidney transplantation, HCV reactivation would have taken place. Their immunosuppression relied on calcineurin inhibitors (100%), and/or steroids (62%), and/or antimetabolites (94%). An induction therapy, given to 22 patients, relied on rabbit antithymocyte globulin (59%) or anti-IL2-receptor blockers (32%). All patients had undetectable HCV RNA as ascertained by several conventional tests. At the last follow-up, no residual HCV RNA was detected in the five liver biopsies, the 26 plasma, and in the 37 nonstimulated and 24 stimulated PBMCs tested with an ultrasensitive RT-PCR assay (detection limit, 2 IU/ml). No biochemical or virologic relapse was seen during follow-up. The absence of HCV relapse in formerly HCV-infected immunocompromised patients suggests the complete eradication of HCV after its elimination while on dialysis. [ABSTRACT FROM AUTHOR]

Abstract: Hepatitis C virus (HCV) infection in Cameroon is characterized by widespread seropositivity and great virus genetic diversity (3 genotypes and over 10 subtypes). A total of 244 HCV NS5B sequences of 382–405bp long (95 type 1, 58 type 2, and 91 type 4) were phylogenetically analyzed to estimate the history of the HCV epidemic in Cameroon. The newly developed Bayesian coalescent approach was used to infer the history of each HCV type. The estimated dates of the most recent common ancestors (MRCA) for genotypes 1 (1500; 95% confidence interval (95% CI): 1300–1650) and 4 (1500; 95% CI: 1350–1700) were in the same range, while the date for genotype 2 MRCA (1600; 95% CI: 1400–1750) was slightly more recent. The mean genetic distance between HCV genotype 1 sequences was greater than that of HCV type 4 sequences, itself greater than that of HCV type 2 sequences. The initial infected populations of all three genotypes did not grow until recently, when they grew exponentially. The growth rate has now begun to slow, with a less steep exponential growth curve. The period of exponential growth of all the three genotypes was between 1920 and 1960. These results (i) confirm that HCV genotypes 1 and 4 have produced long-term endemics, (ii) suggest that genotype 2 was introduced into Cameroon more recently, and (iii) indicate that the exponential spread of the three genotypes between 1920 and 1960 coincided with the mass campaign against trypanosomiasis and mass vaccinations in Cameroon. [Copyright &y& Elsevier]

Abstract: Conventional tests for antibody to Hepatitis C virus (HCV) and HCV RNA require considerable time before results are available, remain very expensive and are not adapted to many sub-Saharan African countries where HCV is endemic. The aim of this study was to evaluate the accuracy of an algorithm consisting of two HCV rapid tests to diagnose and predict HCV viremia in patients in Cameroon. Three hundred and twenty nine plasma samples were screened by two HCV rapid tests (ImmunoComb® II HCV, PBS Orgenics and Hexagon® HCV, Human). Previous evaluation of these samples for HCV antibodies (anti-HCV) by conventional third generation ELISA, considered as a reference test, indicated that 168 were anti-HCV negative and 161 positive. Among the 161 anti-HCV positive plasma, 114 (71%) were HCV RNA-positive by RT-PCR assay. The ImmunoComb® II HCV test provided the more sensitive detection of anti-HCV (sensitivity: 99.4% with a 95% CI=96–100%). Surprisingly, the second HCV rapid test, Hexagon® HCV, showed a high capacity to identify non-viremic subjects amongst anti-HCV positive cases (93.6% [95% CI: 82–99%]). These results suggest an algorithm using ImmunoComb® II HCV as a first test to screen anti-HCV positive subjects, and Hexagon® HCV as a second test to discriminate between viremic and non-viremic HCV seropositive subjects. [Copyright &y& Elsevier]

The double-stranded RNA-activated protein kinase-binding domain (PKRbd) of the NS5A gene of hepatitis C virus (HCV) was studied by the cloning and sequencing method, in HCV-infected patients who had a primary resistance to treatment with interferon (IFN)-α (early nonresponders). Patients whose virus load decreased by 0.5 log (early responders) were similarly analyzed. In the 2 groups, the PKRbd evolved similarly over the first 24 h. Selection of resistant HCV variants is unlikely to explain primary re- sistance to IFN-α. [ABSTRACT FROM AUTHOR]

Studies hepatitis C virus (HCV) replication and liver fibrosis progression in renal transplant recipients. Serum HCV RNA concentration; HCV genotype; Relationship between liver fibrosis progression and HCV quasi-species development.

A 9.2-kb sequence from a hepatitis C virus (HCV) strain found in southwest France was compared to sequences from reference strains in HCV sequence databases. We found a recombinant virus with genotype 2 at the 5′ end and genotype 5 at the 3′ end. The crossover point was located between genes NS2 and NS3. Recombination between HCV genotypes must now be considered in studies on HCV epidemiology and evolution and in predictions of the virus response to antiviral therapy. Knowing the location of the recombination point may also be useful for constructing infectious chimeric viruses. [ABSTRACT FROM AUTHOR]