Transforming growth factor-beta-1 genetic polymorphism in Japanese patients with chronic hepatitis C virus infection

BACKGROUND AND AIM: Transforming growth factor beta-1 (TGF-beta1) is one of the most dominant fibrogenic cytokines in hepatic fibrosis. The aim of the present study was to examine the effects of TGF-beta1 polymorphisms in Japanese patients with chronic hepatitis C virus (HCV) infection and in healthy control subjects. METHODS: The TGF-beta1 genotypes at codon 10 and codon 25 were determined in 206 Japanese patients with chronic HCV infection and in 101 Japanese healthy control subjects. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for the detection of these polymorphisms. The degree of hepatic fibrosis was assessed by liver biopsy and graded according to the New Inuyama Classification for chronic hepatitis graded F0-4. RESULTS: The authors found no significant differences in genotype distributions and allele frequency between the HCV patients and the healthy control subjects. The frequencies of the TT, TC, and CC genotypes of codon 10 were 24%, 42% and 35%, respectively, among the patients of the F0-2 group, and 31%, 40% and 29%, respectively, among those of the F3-4 group. No significant differences were shown between the TGF-beta1 polymorphism at codon 10 and the stage of hepatic fibrosis. In contrast, no genetic alteration of codon 25 was found in healthy controls and patients with chronic HCV infection. CONCLUSION: These results suggest that there may not be a significant relationship between polymorphism at codon 10 and the development of progressive hepatic fibrosis in the Japanese population.