Hepatitis C virus genotypes in chronic dialysis patients

Background. Hepatitis C virus (HCV) infection is highly prevalent in dialysis patients. To further characterize HCV infection in this patient population, we studied the distribution of viral genotypes in 55 patients undergoing chronic dialysis treatment with seropositivity for HCV markers. Methods. Thirty-two of 55 (58%) patients showed HCV RNA in the serum using reverse transcription polymerase chain reaction (RT-PCR) in the 5'-untranslated region (UTR) of the viral genome. HCV genotyping was performed using biotinylated type-specific oligonucleotide probes after hybridization with amplified sample material. Results. HCV subtype 2a was dominant (56%), followed by HCV subtype 1b (31%), type 3 (3%) and 4 (3%). There was no association between demographic or clinical features of this cohort and HCV genotype. Genotype dependence was observed for antibody response toward the NS4 (c 100-3 and 5-1-1) proteins, which was infrequent in genotype 2a carriers compared with genotype 1b (P=0.004). Conclusions, HCV subtype 2a was dominant in our cohort of anti-HCV-positive dialysis patients; there was no association between HCV genotypes and demographic or clinical features of patients; the absence of antibody response toward the NS4-related antigens was frequent in genotype 2a carriers and may serve to predict responses to interferon therapy. The relative homogeneity of the viral population in dialysis patients attending our unit suggests a nosocomial transmission of HCV in this clinical setting.