20. 2. HBV 基因组结构 pre-s1 pre-s2 S P pre-C X HBV DNA 3.2 kb pre-S1 pre-S1 蛋白 pre-S2 pre-S2 蛋白 S HBsAg P DNA P X HBxAg C HBcAg Pre-C+C HBeAg 编码 C pre-S1 pre-S2 S P X
39. Natural History of HCV Infection Exposure (Acute phase) Resolved Chronic Cirrhosis Stable Slowly Progressive End stage disease: Cancer Transplant Death 15-40% 60-85% 10-20 years 2-30 (average 20) % Years
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45. H A 抗 HAV IgM ：感染后数天产生，持续 3 ～ 6 m ， 早期诊断 IgG ： 出现晚，持续多年或终身 保护性抗体
46. H B HBsAg 抗 -HBs HBeAg 抗 -HBe 抗 -HBc 抗 -HBcIgM Pre-S1 抗 -pre-S1 Pre-S2 抗 -pre-S2
47. H C 抗 HCV IgM ：现症感染，临床未常规检测 IgG ：现症感染或既往感染， 低滴度，病毒静止 高滴度，病毒复制 非保护性抗体
75. 各型病毒性肝炎的病理特点 肝实质病变 汇管区炎症细胞浸润 纤维组织增生 坏死 增生 急性肝炎 Y Y 淋巴细胞 无 慢性肝炎 Y Y 同上 有 重型肝炎 急性 Y ＞ 2/3 N 同上 无 亚急 Y 亚大块 Y 同上 无 慢重 Y 亚大块 Y 同上 有 淤胆型肝炎 肝细胞病变轻， 同上 有或无 但有肝细胞内胆色素滞留 毛细胆管内胆栓形成
Key messages Hepatitis B is one of the most common infectious diseases in the world. There are 350 million chronic carriers of the hepatitis B virus worldwide. Hepatitis B is the ninth leading cause of death worldwide. Geographical prevalence varies widely throughout the world. Nearly 75% of HBV chronic carriers are Asian. Points of explanation The geographical prevalence of hepatitis B varies from a highly endemic disease in Asia and Africa to a disease of low prevalence in North America and Western Europe. Additional information More than 2 billion people worldwide have been infected with HBV though not all of these have become chronically infected. The majority of hepatocellular carcinoma in Asia results from hepatitis B virus infection References Margolis HS, Alter JH, Habler SC. Hepatitis B: evolving epidemiology and implications for control. Sem Liver Dis 1991;11:84-92 Mast EE, Alter JH. Epidemology of viral hepatitis: an overview. Sem Viral 1993;4:273-283 World Health Organisation Data
This slide depicts the different phases of chronic HBV infection Not all patients go through all phases During the Immune tolerant phase patients are HBeAg+, HBV DNA level is high but ALT is normal The Immune clearance phase is characterized by elevated ALT In some patients this is followed by spon HBeAg seroconversion and Patients enter into inactive carrier state with normal ALT and very low HBV DNA In other patients, the immune clearance phase is protracted with recurrent hepatitis flares leading to severe hepatitis and cirrhosis Not all patients who enter the inactive carrier state stay that way Some develop reactivation of HBV replication but remain HBeAg- Many of these patients have precore or core promoter HBV variants that prevent or decrease HBeAg production These patients have e-CHB
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