Relative Etiologic Role of Hepatitis B Virus and Hepatitis C Virus in Chronic Liver Diseases and Hepatocellular Carc inoma among Age-Spec i f ic Groups in Ko rea: the Poss ib Ie Presence of Non-B, Non-C Agents

= Abstract =Korea is one of the endemic areas of chronic hepatitis B virus (HBV) infection. To investigate the relative etiologic role of HBV and hepatitis C virus (HCV) in chronic liver diseases (CLD) including hepatocellular carcinoma (HCC) among age-specific groups in Korea, we enrolled consecutively 673 patients with chronic active hepatitis (CAH), 677 patients with liver cirrhosis (LC) and patients with HCC who had been diagnosed in the liver unit at Seoul National University Hospital. HBsAg and anti-HCV were tested using commercially available radioimmunoassay and enzyme immunoassay kits, respectively. From this study, we were reached at suggestion for the possible presence of non-B, non-C type CLD agent(s) by exclusion method. The prevalence rates of HBsAg were 45.3%, 62.5% and 69.3% in patients with CAH, LC and HCC, respectively. The general prevalence rates of anti-HCV in patients with CAH, LC and HCC were 27.3%, 19. 6% and 17%, respectively, and, however, in HBsAg-negative patients with CAH, LC and HCC those were 48.1%, 46.1% and 42.7%, respectively. The coinfection rates of HBV and HCV in patients with CAH, LC and HCC were 1%, 2.4% and 3. 9%, respectively. The rates of CAH, LC and HCC patients who were negative for both HBsAg and anti-HCV and therefore, serologically classified as non-B, non-C type were 28.4%, 20.2% and 17.6%, respectively. There was a significant differeence in mean age between B- and C-type, and B and non-B, non-C type patients with CAH (41.7 vs 54.5 and 50.4 years), LC (48.5 vs 60.1 and 54.9 years) and HCC (5 1.6 vs 60.4 and 56.1 years) (p < 0.001, respectively). Before the age of 50, the etiology of CAH and LC was almost exclusively HBV, while over the age of 50, the etiologic role of HCV and non-B, non-C was more predominant than that of HBV. In elderly (older than 60 years of age) patients even with HCC, HCV played an etiologic role as important as HBV.