Quasispecies evolution in NS5A region of hepatitis C virus genotype 1b during interferon or combined interferon-ribavirin therapy.

AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA-dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by cloning and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-alpha2b for 3 mo followed by IFN-alpha2b alone or combined IFN-R therapy for 9 additional months. Patients were categorized into two groups based on their response to the treatments: 7 with sustained virological response (SVR) (quasispecies = 150) and 3 non-responders (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispecies during therapy. Analysis of amino acids substitutions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate the two groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed molecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.

Prevalence and impact of GBV-C, SEN-V and HBV occult infections in HIV-HCV co-infected patients on HCV therapy.

BACKGROUND/AIMS: It has been suggested that, in HIV-HCV co-infected patients, co-infections with other viruses may affect the response to HCV therapy. We aimed to assess the prevalence of GBV-C, SEN-V and occult HBV infections, their impact on HCV and HIV infections and on the response to HCV therapy in HIV-HCV co-infected patients. METHODS: Three-hundred and sixty eight patients were tested before starting interferon-ribavirin for the presence of occult hepatitis B DNA, GBV-C RNA and SEN-V DNA by using real time PCR. Clinical, immunological, virological, histological characteristics and response to HCV therapy were compared according to the presence or not of each viral co-infection. RESULTS: HBV DNA, GBV-C RNA and SEN-V DNA were found in 5 (1.4%, CI95%: 0.2-2.4%), 104 (29.9%, CI95%: 25.1-34.7%) and 209 patients (57.9%, CI95%: 52.8-63.0%), respectively. GBV-C positive patients had significantly higher CD4 count at baseline, during and after HCV therapy, even after stratification on antiretroviral treatment. No other significant difference was observed according to the presence or not of GBV-C or SEN-V co-infection, in particular regarding virological responses to HCV combination therapy. CONCLUSIONS: There is no reason to withhold HCV therapy in HIV infected patients who have access to HAART, because of occult HBV, GBV-C or SEN-V co-infections.

Rapid and early virological response to chronic hepatitis C treatment with IFN alpha2b or PEG-IFN alpha2b plus ribavirin in HIV/HCV co-infected patients.

BACKGROUND AND AIMS: An algorithm based on a 2 log(10) decline in hepatitis C virus (HCV) RNA at week (W) 12 has been proposed in US and European recommendations for the management of patients with chronic hepatitis C treated with pegylated-interferon and ribavirin. METHODS: We examined rapid virological response (RVR; at W2 and W4 after the initiation of therapy) in HIV/HCV co-infected patients. Using HCV RNA measurements (Versant HCV RNA 3.0, Cobas Amplicor HCV 2.0), RVR was studied in 323 patients from the ANRS HC02 RIBAVIC trial, comparing interferon alpha2b 3 MU x3/week with pegylated interferon alpha2b 1.5 microg/kg/week, each combined with ribavirin 800 mg/day over 48 weeks. RESULTS: The best positive and negative predictive values of sustained virological response (SVR) were obtained with an undetectable HCV RNA at W4 (97%) and with more than a 2 log(10) decrease at W12 (99%), respectively. Prediction of non-SVR was obtained in all patients by using HCV RNA cut-off levels above 460,000 IU/ml at W4 and above 39,000 UI/ml at W12 irrespective of the HCV genotype and arm of treatment. CONCLUSION: We propose a new algorithm based on RVR thresholds using HCV RNA that allows for excellent prediction of non-SVR as early as W4.

Mucosal humoral immune response to hepatitis C virus E1/E2 surface glycoproteins and HCV shedding in saliva and cervicovaginal fluids from chronically HCV-infected patients.

BACKGROUND/AIMS: We herein focused on identifying biological factors possibly involved in non-parenteral transmission of hepatitis C virus (HCV), such as HCV excretion patterns and antibody-based immunity to the virus in saliva and/or cervicovaginal secretions (CVS). METHODS: Paired blood, saliva and cervicovaginal lavage samples were obtained from HCV-RNA plasma-positive hemoglobin (Hb) antigen and HIV-seronegative, HCV-seropositive males (n=13) and females (n=21). HCV-specific antibodies were detected by ELISA in paired samples, and HCV-RNA was detected in cell-free and cell-associated body fluids. RESULTS: Antibodies to E1 HCV surface glycoprotein of the IgG and IgA isotypes showed similar, but less pronounced, profiles as IgG and IgA to E2. HCV-specific IgG and IgA in mucosal fluids likely originated predominantly from the systemic compartment, because HCV-specific mucosal immunoglobulins involved primarily monomeric antibodies, including monomeric IgA, and because their specific activities for HCV antigens in corporeal fluids were similar to those in paired serum (Se). Viral shedding in saliva or CVS was restricted to cell-associated, non-replicating strand((+)) HCV-RNA in 42% (12 out of 28) of saliva and in 19% (four out of 21) of cervicovaginal fluids. CONCLUSIONS: The association in body fluids of HCV-specific IgG, and to a lesser extent IgA, directed to E1/E2 surface glycoproteins (which may block critical steps of virus-cell interactions), of undetectable free viral RNA, and of occasional non-replicating cell-associated HCV, suggests a resulting poor infectivity of saliva or cervicovaginal fluid in chronically HCV-infected individuals. Taken together, these observations provide the basis for the low risk of non-parenteral transmission of HCV infection.