乙型肝炎表面抗原(HBsAg)是乙型肝炎(乙肝)病毒(HBV)的外膜蛋白,主要存在于患者的血液及体液中,不具有传染性,但它在HBV感染中起主要作用,人感染HBV 4~7 d后,血清中出现HBsAg且常伴HBV存在,因此,在临床诊断中可作为HBV感染的标志。既往临床通过检测HBV标志物HBsAg、乙型肝炎e抗原(HBeAg)、HBV DNA来判断HBV的复制情况,特别是在抗HBV感染治疗中HBeAg、HBV DNA作为评估和预测疗效及停药的重 Hepatitis B surface antigen (HBsAg) is an outer membrane protein of Hepatitis B virus (HBV), mainly present in the patient’s blood and body fluids, not infectious, but it plays a major role in HBV infection. Human Infected with HBV 4 ~ 7 d after the serum HBsAg and often accompanied by the presence of HBV, therefore, in clinical diagnosis can be used as a marker of HBV infection. Past clinical detection of HBV markers HBsAg, hepatitis B e antigen (HBeAg), HBV DNA to determine the replication of HBV, especially in the treatment of anti-HBV infection HBeAg, HBV DNA as the assessment and prediction of efficacy and withdrawal of heavy