EPIDEMIOLOGY OF GENOTYPES OF HEPATITIS-C VIRUS IN JAPANESE PATIENTS WITH TYPE-C CHRONIC LIVER-DISEASES - A MULTI-INSTITUTION ANALYSIS

Sixteen medical institutions in Japan collaborated in this study of th e epidemiology of hepatitis C virus (HCV) genotypes. A total of 4176 p atients with type C chronic liver disease, from the four main islands of Japan, were evaluated. Of those evaluated, 2794 had chronic hepatit is, 727 had liver cirrhosis and 655 had hepatocellular carcinoma. The HCV genotype of the patients was determined by an enzyme-linked immuno sorbent assay based on serological genotype 1- and 2-specific recombin ant peptides (SG-1 and SG-2, respectively) of the NS4 region. The prev alence of SG-1 and SG-2 HCV was similar in the four main islands of Ja pan. SG-1 HCV predominated in each disease category (69-76%). The perc entage of patients with SG-1 HCV increased by 7%, while that of patien ts with SG-2 HCV decreased by 7%, as liver disease progressed in sever ity from chronic hepatitis to carcinoma (P < 0.001). Patients with eit her SG-1 or SG-2 had a similar mean age and history of blood transfusi on. In conclusion, SG-1 HCV was found to predominate in Japan, and the HCV genotype was found to be related to the stage of hepatitis C dise ase.