EPIDEMIOLOGY AND PATHOGENESIS OF HEPATITIS B AND C VIRUSES

丙型肝炎病毒（HCV）在日本高度流行，这提供了 理想的学习环境。 在一项队列研究中， HCV和人嗜T淋巴细胞病毒I型（HTLV-I）在一个实验室中进行了研究。 两种病毒都流行的日本地区。 肝癌死亡率为 与HCV抗体（抗HCV）高度相关。 抗HTLV-I抗体 （抗HTLV-I）与HCV感染有一定相关性，但提供了 不会增加患肝癌的风险。 在一项相关的研究中，一组日本人 研究人员对夏威夷的美国人进行了研究，他们都是 在世纪中期HCV流行之前， 日本 肝细胞癌（HCC）与 在该人群中发现了B型肝炎病毒（HBV），但在HCC之间未发现 和HCV;这与日本今天的情况不同，日本80%的HCC 患者有丙型肝炎病毒感染。研究进行了肝癌从 美国确定DNA错配修复缺陷是否可以发挥作用 角色 10例HCC中有4例微卫星不稳定。 的 1例p53外显子多突变的HCC患者， 不稳定性; 5例患者的多个p53内含子改变， HCC（与其自身的非肿瘤性肝脏相比）没有微卫星 不稳定 错配修复缺陷导致微卫星 不稳定性可能在四个肝癌发生中起作用， 这些患者中，但其中3例与p53改变无关。

Hepatitis C virus (HCV) is highly prevalent in Japan, which provides an ideal situation for its study. In a cohort study, the interactions of HCV and human T lymphotropic virus type I (HTLV-I) were studied in an area of Japan where both viruses were endemic. Liver cancer death was highly associated with antibody to HCV (anti-HCV). Antibody to HTLV-I (anti-HTLV-I) was somewhat correlated with HCV infection, but provided no added risk for liver cancer. In a related study, a cohort of Japanese Americans in Hawaii was studied; all were descended from persons who had emigrated from Japan before the mid-twentieth century epidemic of HCV in Japan. A strong association between hepatocellular carcinoma (HCC) and hepatitis B virus (HBV) was found in this population, but not between HCC and HCV; this differs from the situation in Japan today, where 80% of HCC patients have HCV infection.Studies were conducted in HCCs from the United States to determine whether DNA mismatch repair defects could play a role. Microsatellite instability was detected in 4 of 10 HCCs. The one HCC patient with multiple p53 exon mutations had microsatellite instability; five patients with multiple p53 intron alterations in the HCC (compared to their own nontumorous livers) had no microsatellite instability. Mismatch repair defects resulting in microsatellite instability might have played a role in hepatocarcinogenesis in four of these patients, but it was unrelated to p53 alterations in three of them.