HLA class I allele associations with HCV genetic variants in patients with chronic HCV genotypes 1a or 1b infection

BACKGROUND & AIMS: The adaptive immune response against hepatitis C virus (HCV) is significantly shaped by the host's composition of HLA-alleles with the consequence that the HLA phenotype is a critical determinant of viral evolution during adaptive immune pressure. In the present study, we aimed to identify associations of HLA class I alleles with HCV subtypes 1a and 1b genetic variants. METHODS: The association between HCV genetic variants and specific HLA-alleles was investigated in a cohort of 159 patients with chronic HCV genotypes 1a- and 1b-infection who were treated with pegylated interferon-alfa 2b and ribavirin in a prospective controlled trial for 48 weeks by direct sequencing of the genes encoding the HCV proteins E2, NS3, and NS5B and by HLA class I-genotyping of patients. HCV genetic variants were associated with specific HLA-alleles and the binding strength of accordant amino acid sequences to the corresponding HLA-allele was assessed by using the SYFPEITHI-algorithm. RESULTS: Overall, associations between HLA class I alleles and HCV sequence variation were rare. Five unknown HLA class I-associated viral genetic variations were identified, which in part affected the binding of predicted HCV CD8+ T cell epitopes to the respective HLA-allele. In addition, different patterns of HLA class I-allele/HCV sequence associations between the two subtypes were observed. CONCLUSIONS: We identified several unknown HLA class I-restricted HCV variants which in part impair binding to predicted HCV CD8+ T cell epitopes with remarkable differences between HCV subtypes 1a and 1b quasispecies

Low-density lipoprotein receptor variants are associated with spontaneous and treatment-induced recovery from hepatitis C virus infection

Low-density lipoprotein receptor (LDLR) is involved in the entry of hepatitis C virus (HCV) in host cells. We investigated whether three single-nucleotide alterations within LDLR might be associated with the course of hepatitis C infection and response to antiviral therapy. We enrolled 651 individuals with chronic HCV infection who had received interferon-based combination therapy, 174 individuals with self-limited HCV infection, and 516 healthy controls. LDLR c.1171G > A, c.1413G > A, and c.*52G > A genotyping was performed by real-time PCR-based assays. HCV genotype 1-infected individuals who were homozygous for 3′UTR c.*52G were at increased risk for virologic non-response to antiviral therapy compared to virologic responders (66.3% vs. 51.0%, p = 0.001). Furthermore, compared to healthy controls, self-limited HCV genotype 1 infection was significantly associated with c.1171A (15.1% vs. 6.6%, p = 0.006) and negatively associated with c.1413G > A heterozygosity (33.0% vs. 46.1%, p = 0.023). The data indicate that LDLR alterations are correlated with response to interferon-based combination therapy and with self-limitation of HCV 1 infection