Gherlan George Sebastian
Department of Infectious Diseases, "Carol Davila" University of Medicine and Pharmacy, Bucharest 030303, Romania.
World J Clin Cases. 2022 Jun 16;10(17):5518-5530. doi: 10.12998/wjcc.v10.i17.5518.
With over 40 years of history, occult hepatitis B infection (OBI) continues to remain an important and challenging public health problem. Defined as the presence of replication-competent hepatitis B virus (HBV) DNA (, episomal HBV covalently closed circular DNA) in the liver and/or HBV DNA in the blood of people who test negative for hepatitis B surface antigen (HBsAg) in currently available assays, OBI is currently diagnosed using polymerase chain reaction (PCR) and real-time PCR assays. However, all efforts should be made to exclude a false negative HBsAg in order to completely follow the definition of OBI. In recent years, significant advances have been made in understanding the HBV lifecycle and the molecular mechanisms that lead to the persistence of the virus in the occult form. These factors are mainly related to the host immune system and, to a smaller proportion, to the virus. Both innate and adaptive immune responses are important in HBV infection management, and epigenetic changes driven by host mechanisms (acetylation, methylation, and microRNA implication) are added to such actions. Although greater genetic variability in the gene of HBV isolated from OBIs was found compared with overt infection, the mechanisms of OBI are not mainly viral mutations.
隐匿性乙型肝炎感染（OBI）已有40多年的历史，仍然是一个重要且具有挑战性的公共卫生问题。OBI的定义是，在目前可用检测中乙肝表面抗原（HBsAg）检测呈阴性的人的肝脏中存在具有复制能力的乙型肝炎病毒（HBV）DNA（即游离型HBV共价闭合环状DNA）和/或血液中存在HBV DNA，目前通过聚合酶链反应（PCR）和实时PCR检测来诊断OBI。然而，应尽一切努力排除假阴性HBsAg，以便完全符合OBI的定义。近年来，在了解HBV生命周期以及导致病毒以隐匿形式持续存在的分子机制方面取得了重大进展。这些因素主要与宿主免疫系统有关，其次与病毒有关。先天性和适应性免疫反应在HBV感染管理中都很重要，宿主机制（乙酰化、甲基化和微小RNA参与）驱动的表观遗传变化也参与其中。尽管与显性感染相比，从OBI分离出的HBV基因具有更大的遗传变异性，但OBI的机制主要不是病毒突变。
