Division of Medicine and Hepatology, University Hospital of Messina, 98124 Messina, Italy.
Department of Clinical and Experimental Medicine, University of Messina, 98124 Messina, Italy.
Viruses. 2022 Jul 8;14(7):1504. doi: 10.3390/v14071504.
Occult hepatitis B virus (HBV) infection (OBI) refers to a condition in which replication-competent viral DNA is present in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing negative for the HBV surface antigen (HBsAg). In this peculiar phase of HBV infection, the covalently closed circular DNA (cccDNA) is in a low state of replication. Many advances have been made in clarifying the mechanisms involved in such a suppression of viral activity, which seems to be mainly related to the host's immune control and epigenetic factors. OBI is diffused worldwide, but its prevalence is highly variable among patient populations. This depends on different geographic areas, risk factors for parenteral infections, and assays used for HBsAg and HBV DNA detection. OBI has an impact in several clinical contexts: (a) it can be transmitted, causing a classic form of hepatitis B, through blood transfusion or liver transplantation; (b) it may reactivate in the case of immunosuppression, leading to the possible development of even fulminant hepatitis; (c) it may accelerate the progression of chronic liver disease due to different causes toward cirrhosis; (d) it maintains the pro-oncogenic properties of the "overt" infection, favoring the development of hepatocellular carcinoma.
隐匿性乙型肝炎病毒 (HBV) 感染 (OBI) 是指在乙型肝炎表面抗原 (HBsAg) 检测阴性的个体肝脏中存在复制型病毒 DNA（血清中可检测到或检测不到 HBV DNA）的情况。在这种 HBV 感染的特殊阶段，共价闭合环状 DNA (cccDNA) 的复制处于低水平。人们在阐明这种病毒活性抑制的机制方面取得了许多进展，这似乎主要与宿主的免疫控制和表观遗传因素有关。OBI 广泛存在于世界各地，但在不同患者群体中的流行率差异很大。这取决于不同的地理区域、与血源感染相关的危险因素，以及用于检测 HBsAg 和 HBV DNA 的检测方法。OBI 在几种临床情况下有影响：(a) 它可以通过输血或肝移植传播，引起典型的乙型肝炎；(b) 在免疫抑制的情况下可能会重新激活，导致甚至暴发性肝炎的发生；(c) 它可能会由于不同的原因加速慢性肝病向肝硬化的进展；(d) 它保持了“显性”感染的致癌特性，有利于肝细胞癌的发展。
