Hepatitis C virus 5' untranslated region variability correlates with treatment outcome

The influence of anti-HBc status on the sustained virological response rate in HCV-infected patients treated with pegylated interferon alfa 2 and ribavirin

Aim of the study

To determine the influence of HBsAg and HBeAg negative but anti-HBc positive status on the sustained virological response (SVR) rate in HCV-infected patients treated with pegylated interferon alfa 2 (Peg-IFNα-2) and ribavirin (RBV).

Material and methods

The study was based on the retrospective analysis of medical records of HCV-infected patients who started Peg-IFNα and RBV treatment between 1 January 2011 and 31 December 2013 at the 1^st and 2^nd Department of Infectious Diseases of the Regional Hospital in Wrocław, Poland.

Results

Among 240 patients included in the analysis 99 were anti-HBc positive and 141 anti-HBc negative. In the genotype 1, anti-HBc positive group the SVR rate was 47% and in the anti-HBc negative group it was 42.7% (p = 0.591). In the genotype 3, anti-HBc positive group the SVR rate was 60% and in anti-HBc negative patients it was 63.2% (p = 0.79). Differences in SVR rates between anti-HBc positive and negative groups were not statistically significant. None of the anti-HBc positive patients developed reactivation of HBV infection during or in the 24 weeks following the end of treatment.

Conclusions

Anti-HBc determination does not seem to be useful in predicting treatment outcome of conventional Peg-IFNα/RBV therapy in patients infected with HCV genotypes 1 and 3.

Genetic Variability of Hepatitis C Virus (HCV) 5' Untranslated Region in HIV/HCV Coinfected Patients Treated with Pegylated Interferon and Ribavirin

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.

IL28B polymorphism (rs12979860) associated with clearance of HCV infection in Poland: systematic review of its prevalence in chronic hepatitis C patients and general population frequency

BACKGROUND

A common single nucleotide polymorphism (rs12979860) of the interleukin-28B (IL28B) gene is strongly associated with spontaneous and treatment-related eradication of HCV infection. In this study we estimated rs12979860 genotypes distribution among chronic hepatitis C patients in Poland using a systematic review of published studies and compared this data with the prevalence of rs12979860 variants of IL28B in representative sample of the Southern Poland population.

METHODS

Systematic review on rs12979860 variant prevalence in the Polish chronic HCV subjects was performed. Additionally, age- and gender-stratified population sample was recruited from inhabitants of Kraków using a randomized municipal census data, DNA samples available for 538 individuals were genotyped using a real-time PCR method.

RESULTS

The frequency of homozygotes TT was from 15 to 27% and carriers of unfavorable T alleles (genotypes CT and TT) were present in 70-80% of chronic HCV subjects. In the general population, 47% individuals were CC homozygous, 42% CT heterozygous and 11% TT homozygous. The population frequency of T allele was 0.318 (95% CI: 0.291-0.347) and the variant was in Hardy-Weinberg equilibrium. Distributions of IL28B genotypes in chronic HCV patients were characterized by a departure from the genetic equilibrium and differed significantly from the random population sample.

CONCLUSIONS

Events of spontaneous viral clearance can fully explain differences between genotype distributions in general population and chronic HCV subjects and a departure from the genetic equilibrium. This is the first study estimating the prevalence of IL28B rs12979860 SNP in the Southern Poland population based on a random representative sample.

Analysis of genotype 1b hepatitis C virus IRES in serum and peripheral blood mononuclear cells in patients treated with interferon and ribavirin

Hepatitis C virus (HCV) highly conserved IRES (internal ribosome entry site) sequence, localized within the 5(')-untranslated region (5(')UTR), may determine viral properties like replication efficiency and cell tropism. The aim of the present study was to characterize newly emerging 5(')UTR variants in serum and peripheral blood mononuclear cells (PBMC) in chronic hepatitis C patients treated with interferon (IFN) and ribavirin and to identify their effect on IRES secondary structures. The study group consisted of 87 patients infected with genotype 1b from whom serum and PBMC samples were collected at 9 time points (before, during, and after treatment). New 5(')UTR variants developed in 9 patients. Out of the overall 14 new variants, 9 (64%) were found in PBMC. HCV variants with decreased thermodynamic stability were identified only in PBMC and C183U mutation was the most common one in this compartment. In conclusion, antiviral treatment may favor emergence of new 5(')UTR variants both in blood and in PBMC compartments. However, variants developing in the latter compartment were predicted to have lower thermodynamic stability of the IRES secondary structures compared to serum strains. C-U change in position 183, which has not been described previously, might indicate viral adaptation to lymphoid cells.