Hepatitis B surface antigen (HBsAg) level plays an important role in conjunction with other markers such as hepatitis B envelope antigen (HBeAg) and hepatitis B virus (HBV) deoxyribonucleic acid levels to predict disease activity in chronic Hepatitis B (CHB). Quantification of HBsAg is useful in differentiating carriers from active hepatitis in HBeAg negative patients, and current guidelines recommend monitoring of pegylated interferon alpha treatment in CHB infection. However, there are only few studies about the role of quantitative HBsAg (qHBsAg) monitoring in HIV-HBV coinfected patients. Studies have shown that tenofovir based antiretroviral therapy regimen leads to a very slow decline in HBsAg levels and a predicted time of 10-42 years to lose the HBsAg, in majority of patients. Rapid drop in HBsAg levels and gain in CD4 within the 1^st year of treatment and low baseline HBsAg level are associated with faster seroconversion. The reported rate of HBsAg loss in this population is < 15%. In this review, we discuss utility of qHBsAg in monitoring disease activity and treatment in HIV-HBV coinfected population.

中文翻译：

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乙肝表面抗原的定量：HIV-乙肝病毒合并感染中有作用吗？

乙型肝炎表面抗原（HBsAg）水平与其他标志物（例如乙型肝炎包膜抗原（HBeAg）和乙型肝炎病毒（HBV）脱氧核糖核酸水平）一起发挥重要作用，以预测慢性乙型肝炎（CHB）的疾病活动。HBsAg的定量可用于区分HBeAg阴性患者的活动性肝炎和活动性肝炎，目前的指南建议在CHB感染中监测聚乙二醇化干扰素α治疗。但是，关于定量HBsAg（qHBsAg）监测在HIV-HBV合并感染患者中的作用的研究很少。研究表明，对于大多数患者，基于替诺福韦的抗逆转录病毒疗法会导致HBsAg水平下降非常缓慢，预计失去HBsAg的时间为10-42年。1天内HBsAg水平快速下降，CD4增加^ST处理和低基线水平的HBsAg年与更快的血清转换有关。报告的该人群HBsAg丢失率<15％。在这篇综述中，我们讨论了qHBsAg在监测HIV-HBV合并感染人群的疾病活动和治疗中的效用。