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Association between hepatitis C virus (HCV) quasispecies and treatment outcome among patients with chronic hepatitis C has been the subject of many studies. However, these studies focused mainly on viral variable regions (E1 and E2) and usually did not include human immunodeficiency virus (HIV)-positive patients. The aim of the present study was to analyze heterogeneity of the 5' untranslated region (5'UTR) in HCV/HIV coinfected patients treated with interferon and ribavirin. The HCV 5'UTR was amplified from serum and peripheral blood mononuclear cells (PBMC) samples in 37 HCV/HIV coinfected patients treated for chronic hepatitis C. Samples were collected right before treatment, and at 2, 4, 6, 8, 12, 20, 24, 36, 44, 48, 60, and 72 weeks. Heterogeneity of the 5'UTR was analyzed by single strand conformational polymorphism (SSCP), cloning and sequencing. Sustained virological response (SVR) was achieved in 46% of analyzed HCV/HIV co-infected patients. Stable SSCP band pattern was observed in 22 patients (62.9%) and SVR rate among these patients was 23%. Decline in the number of bands and/or shift in band positions were found in 6 patients (17.1%), 5 (83%) of whom achieved SVR (p=0.009). A novel viral genotype was identified in all but one of these patients. In 5 of these 6 patients a new genotype was dominant. 5'UTR heterogeneity may correlate with interferon and ribavirin treatment outcome. In the analyzed group of HCV/HIV coinfected patients, viral quasispecies stability during treatment favored viral persistence, whereas decrease in the number of variants and/or emergence of new variants was associated with SVR. Among injection drug users (IDU) patients, a new genotype may become dominant during treatment, probably due to the presence of mixed infections with various strains, which have different susceptibility to treatment.

Genetic heterogeneity is a characteristic feature of hepatitis C virus (HCV) and it reflects selection mechanisms affecting the virus. It is considered a major factor contributing the viral persistence and drug resistance. The following work presents the preliminary results of 5'UTR and E2/HVR1 genetic variation analysis and comparison in serum and peripheral blood mononuclear cells (PBMC) of 7 patients before and during the early phase of pegylated interferon alfa (PEG-IFN-alpha) and ribavirin therapy. Single strand conformational polymorphism (SSCP) analysis revealed genetic stability of 5'UTR in all but one patient who did not respond to treatment (SVR-), where new genetic variants appeared. E2/HVR1 genetic changes were characteristic in patients displaying treatment failure (SVR-) and usually reflected fluctuations in complexity and appearance of new genetic HCV variants. Genetic changes (reduction in complexity) were found in one of three sustained virological responders (SVR+ patients). Comparatory analysis of the HCV quasispecies present in serum and PBMC showed differences in at least one analysed region in all non-responders. Presented results suggest the independent forces driving genetic changes in analysed regions. They also point out the presence of genetic compartmentalization possibly having an impact on antiviral treatment result.

Purpose: Genetic variability of hepatitis C virus (HCV) is considered to be an important factor defining viral pathogenesis, [persistence and resistance to treatment. The aim of the present study was to characterize HCV genetic heterogeneity within a hypervariable region 1 (HVR-1) before and during the early period of pegylated interferon alfa (PEG-IFN-α) and ribavirin treatment in correlation with treatment outcome. Material and Methods: The study involved 24 patients treated with PEG-IFN-α and ribavirin whose sera were collected before (baseline) and at 7,14, 21 28 and 56 day of treatment. HCV HVR-1 region was amplified by nested RT-PCR and subjected to SSCP (single strand conformational polymorphism) analysis. SSCP changes of HCV HVR-1 over time in each patient were : compared to treatment outcome results. Results: In 2/11 (18%) SVR+ and 8/13 (62%) SVR- treated patients, HVR-1 genetic changes manifested by new SSCP bands (new genetic variants) and were significantly more frequent in nonresponders (P <0.05). Conclusions: Our results indicate that HCV HVR-1 variability during the early phase of PEG-IFN-α and ribavirin therapy may be predictive of treatment outcome. [ABSTRACT FROM AUTHOR]