Antibody to the hepatitis C virus in acute hepatitis and chronic liver diseases in Japan.

In a 6-month follow-up study of acute hepatitis in Japan, 31 out of 41 (75.6%) cases of post-transfusion non-A and non-B hepatitis (NANB-PTH) and 14 out of 40 (35.0%) cases of sporadic non-A non-B hepatitis (NANB-SPO) were found to be positive for antibody to the hepatitis C virus (HCVAb). After 12 months of follow-up, 30 cases (81.1%) became chronic among 37 HCVAb positive acute NANB hepatitis cases. This figure shows a significantly higher rate of chronicity as compared with HCVAb negative acute NANB hepatitis. The prevalences of HCVAb in hepatitis B surface antigen (HBsAg) negative cases of chronic hepatitis and liver cirrhosis were 76.3% (200/262) and 66.7% (106/159), respectively, which were significantly different from the values of 5.1% (13/255) and 10.6% (13/123) observed in HBsAg positive cases. Of chronic liver disease cases positive for HCVAb, 45.8% (152/332) had a history of blood transfusion, in contrast to the value of 3.7% (13/352) observed in HBsAg positive cases of chronic liver disease that were negative for HCVAb.