EPIDEMIOLOGY AND PATHOGENESIS OF HEPATITIS B AND C VIRUS

丙型肝炎病毒（HCV）是美国慢性肝病的重要病因，也是确保血液供应安全的持续监管挑战。Miyazaki队列研究是一项正在进行的研究，在日本HCV和人类T淋巴细胞嗜型病毒I型（HTLV-I）高度流行的地区对973人进行研究。在1985-1995年期间，该人群中有14例HCV抗体（抗HCV）血清转化者（在以前血清阴性的人中，每1000人年有3.6例血清转化者）。在10例血清转化者中检测到HCV-RNA，其中8例在一年以上的时间内仍可检测到HCV-RNA。在一些患者中，丙型肝炎病毒和乙型肝炎病毒都可能导致肝细胞癌（HCC）的发展，通常与p53肿瘤抑制基因突变有关。通过直接测序检测突变比免疫组织化学（IH）染色提供了更多的信息，但是所需的设备和所需的时间使其在大规模研究或发展中国家的研究中不太实用。在一项对28例hcc的研究中，19例（68%）有50%至95%的细胞被染色。直接测序在17例（61%）中发现p53外显子5-8突变，表明与直接测序检测hbv感染的HCC患者中p53突变体相比，IH具有较高的敏感性和特异性。

Hepatitis C virus (HCV) is an important cause of chronic liver disease in the United States and a continuing regulatory challenge for ensuring the safety of the blood supply. The Miyazaki Cohort Study is an ongoing study of 973 people in an area of Japan where both HCV and the human T lymphotropic virus type I (HTLV-I) are highly prevalent. Between 1985-1995, there were 14 seroconverters to antibody to HCV (anti-HCV) in this population (3.6 seroconverters per 1,000 person-years in previously seronegative persons). HCV-RNA was detectable in 10 of the seroconverters, and it remained detectable for greater than one year in eight of them. Both HCV and the hepatitis B virus may lead to the development of hepatocellular carcinoma HCC) in some patients, often in association with mutations in the p53 tumor suppressor gene. Detection of mutations by direct sequencing provides more information than immunohistochemical (IH) staining, but the equipment needed and the time required make it less practical for use in large-scale studies or in studies in developing countries. In a study of 28 HCCs, 19 (68%) had 50 to 95% of cells stained. Mutations in p53 exons 5-8 were found by direct sequencing in 17 (61%), indicating a high level of sensitivity and specificity of IH compared to direct sequencing to detect mutant p53 in HBV-infected patients with HCC.