Distribution of hepatitis C virus genotypes in Kayseri region, in Turkey: unexpected rate of genotype 4.

BACKGROUND: Hepatitis C virus (HCV) is an important cause of chronic liver disease. There are six genotypes and more than 80 subtypes of HCV. The aim of this study was to investigate the distribution of HCV genotypes in Middle Anatolia in Turkey, and the association of HCV genotypes with pre-treatment HCV RNA viral load, serum transaminase levels, and histopathological grade of liver fibrosis.

METHODS: A total of 160 patients (103 female, 57 male) with chronic hepatitis C were retrospectively evaluated. HCV RNA level was determined by commercial real time PCR method. HCV RNA positive sera were genotyped by the Abbott Real Time HCV Genotype II assay and sequenced by the ABI Prism 310 Genetic Analyzer. Gender, age, serum ALT, AST, HCV RNA viral load, and fibrosis staging of liver were determined in all patients.

RESULTS: Genotype 1b was the most frequent (64.7%) followed by genotype 4d (28.3%), 2 (4.4%), and la (2.5%). The HCV genotype results were found consistent with both methods. The gender distribution of the 160 HCV infected patients was 57 male/103 female. Log HCVRNA was significantly higher in genotype 1b compared to genotype 4 and 1a. Stage of liver fibrosis, histology activity index, serum ALT and AST levels did not differ between groups depending on genotypes. Advanced liver fibrosis (Group 2) was found in 36 (76.6%) patients with genotype 1b and in 10 (21.3%) patients with genotype 4 and only in 1 patient (2.1%) with genotype 1a.

CONCLUSIONS: HCV genotype 1b is the most frequent type (64.7%) in this region. Prevalence of genotype 4 in this region is higher than the national HCV genotype distribution. Serum transaminase levels and liver fibrosis scores are not associated with HCV genotypes.