各型乙型肝炎HLA-Ⅰ、Ⅱ类抗原免疫组织化学研究

IMMUNOHISTOCHEMICAL STUDY OF HLA- CLASS Ⅰ AND Ⅱ ANTIGENS IN VARIOUS TYPES OF HEPATITIS B

用免疫组织化学桥联酶标APAAP法和PAP法对各型乙型肝炎113例检测了肝内的HLA-Ⅰ、Ⅱ类抗原、T细胞亚群、HBsAg和HBcAg,同时测定血清HBV DNA(斑点杂交)和β_2微球蛋白(RIA)。结果表明;急性肝炎、慢性活动性肝炎、重症肝炎患者的肝细胞HLA-Ⅰ、Ⅱ类抗原表达增强,尤以Ⅰ类抗原明显,慢性迁延性肝炎则几乎无表达。肝细胞HLA-Ⅰ类抗原表达与肝内炎症反应、肝细胞膜型HBSAg和浆膜型HBcAg关系密切,肝内活动性病变主要浸润细胞为CD_2^+细胞,CD_0^+细胞构成主要的细胞亚群。认为抗原依赖的、HLA限制的细胞毒性T细胞效应是构成乙型肝炎免疫损害的主要机制。

HLA-class Ⅰ and Ⅱ antigens, T cell subsets, HBsAg, HBcAg of the liver were srudied by the APAAP and PAP methods of immunohistochemical technique in 113 cases of acute, chronic and severe types of hepatitis B. Serum HBV DNA and β2-microglobulin were simultaneously assayed by dot blot hybridization and radial immunoassay respectively. The expressions of HLA- class Ⅰ and Ⅱ antigens on the hepatocyte membrane were increased in acute, chronic active and severe hepatitis B, especially for the HLA-class Ⅰ antigens. Whereas there was almost no expression in chronic persistent hepatitis B. There existed close relationship between the hepatocyte expression of HLA-class Ⅰ antigens and the inflammatory activity as well as the membrane expressions of HBsAg and HBcAg. It was found that the major infiltrating cells in the hepatic damage area were CD2+ lymphocytes, of which CD8+ cells constituted the major subpopulations. The attack and lysis of hepato-cytes by the antigen-dependent, HLA-restricted cytotoxic T lymphocyte is considered as the main mechanism of the immunopathologic damage in hepatitis B.