Grob P J, Frei P C
Abteilung für Klinische Immunologie, Universitätsspital, Zürich.
Soz Praventivmed. 1998;43 Suppl 1:S5-9, S79-83. doi: 10.1007/BF02042164.
The hepatitis B virus belongs to the hepadna viruses family. Its genome consists of an incompletely double stranded DNA. The preS/S domain encodes proteins which make up the outer viral coat containing the HBs surface antigen (HBsAg). Other viral genes programme for structures inside the virus and for various regulatory enzymes. HBV mainly infects hepatocytes. The virus replicates in the cytoplasm and is primarily non-cytopathogenic. HBV can also integrate into the host cell. Various stable genotypes and subtypes are known, which have a characteristic geographic distribution. They all share a common HBsAg epitop, which has allowed the development of a vaccine which is efficient world-wide. The protective principle consists of inducing protective anti-HBs. The infected cell has to be destroyed to eliminate the virus. Cellular immune defence mechanisms are mainly relevant, the principle effectors being cytotoxic T lymphocytes, activated monocytes/macrophages and cytokines such as interferon-gamma. The natural course of infection is highly variable, comprising viral elimination with or without acute hepatitis and chronic infection which might lead to chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. This is due to the balance respectively to the inbalance between the viral replication capacity and the immune defence mechanisms.
乙型肝炎病毒属于嗜肝DNA病毒科。其基因组由一条不完全双链DNA组成。前S/S结构域编码构成含有乙肝表面抗原（HBsAg）的病毒外衣壳的蛋白质。其他病毒基因编码病毒内部结构和各种调节酶。乙肝病毒主要感染肝细胞。该病毒在细胞质中复制，主要无细胞病变作用。乙肝病毒也可整合到宿主细胞中。已知有多种稳定的基因型和亚型，具有特征性的地理分布。它们都有一个共同的乙肝表面抗原表位，这使得一种在全球范围内有效的疫苗得以研发。其保护原理是诱导产生保护性抗-HBs。必须破坏被感染的细胞以清除病毒。细胞免疫防御机制主要起作用，主要效应细胞是细胞毒性T淋巴细胞、活化的单核细胞/巨噬细胞以及细胞因子，如干扰素-γ。感染的自然病程变化很大，包括伴有或不伴有急性肝炎的病毒清除以及可能导致慢性肝炎、肝硬化和肝细胞癌的慢性感染。这分别是由于病毒复制能力与免疫防御机制之间的平衡或失衡所致。
