PREVALENCE AND CLINICAL-FEATURES OF HEPATITIS-DELTA VIRUS-INFECTION IN THE MIYAKO ISLANDS, OKINAWA, JAPAN

The aims of this study were twofold: (1) to determine the prevalence a nd clinical features of hepatitis delta virus (HDV) infection among su bjects positive for hepatitis B surface antigen (HBsAg) living in the Miyako islands, Okinawa Prefecture, Japan, and (2) to clarify the rela tionship between KDV-RNA level and severity of HDV-related liver disea se. One hundred and ninety-nine HBsAg-positive subjects (123 asymptoma tic carriers [ASCs], 3 patients with acute hepatitis [AH], 50 patients with chronic hepatitis [CH], 15 patients with liver cirrhosis [LC], a nd 8 patients with hepatocellular carcinoma [HCC], were tested for ant ibody to HDV (anti-HDV) by radioimmunoassay. Anti-HDV-positive individ uals were examined to determine semi-quantified HDV-RNA level by polym erase chain reaction (PCR). The overall prevalence of anti-HDV among t he 199 subjects was 21.1%. The positivity rate tended to increase with age or the severity of the underlying liver disease: anti-HDV-positiv e rates were 10.6% (13/123) in ASCs, 32.0% (16/50) in patients with CH , 40.0% (6/15) in patients with LC, and 87.5% (7/8) in patients with H CC. None of the patients with AH were positive for anti-HDV. There was no correlation between semi-quantified serum HDV-RNA levels and the s everity of chronic liver disease in patients positive for anti-HDV. Th e present study showed the local spread of HDV infection in the Miyako Islands, Okinawa, Japan. Although the anti-HDV positivity rate tended to increase with the severity of the underlying liver disease, the se verity of HDV-related liver disease did not correlate with the semi-qu antified serum HDV-RNA level.