RP 9-92

Study of liver diseases in the Adult Health Study sample: Relationship between radiation dose and infection by B and C hepatitis virus


The relationship between liver diseases and atomic-bomb-radiation dose found in the previous studies at the Atomic Bomb Casualty Commission/Radiation Effects Research Foundation (ABCC/RERF) can, at least partially, be explained by the increased prevalence of hepatitis-B virus (HBV) carriers in highly exposed survivors, although the mechanisms involved in the increased prevalence of the carriers are yet to be elucidated. With the availability of the serum assay of hepatitis-C virus (HCV), the role of its infection in the natural history of hepatitis and other liver disorders has recently become the focus of attention. It is suspected that the HCV infection may assume a major role in the development of liver diseases in Japanese. In the proposed study, HCV and HBV serum assays will be done for Adult Health Study (AHS) participants in both Hiroshima and Nagasaki 1) to determine the HCV infection rate as a function of atomic-bomb-radiation dose and 2) to identify HBV carriers and then to determine their HBV envelope (HBe) antigen levels. Also proposed in this protocol is the follow-up of HCV-antibody-positive subjects and HBV carriers to improve our understanding of the natural history of HCV- and HBV-related liver disorders in the atomic-bomb (A-bomb) survivors. The HBV data to be obtained will help clarify the association of radiation dose with the HBe antigen level, which is considered to be related to hepatitis-B activity, and will help as well determine the seroconversion rate among the HBV carriers identified during this study or past RERF HBV studies. Data from this study will also enable us to analyze the risk of liver disorders associated with HCV and HBV infection among the A-bomb survivors.