ЛАТЕНТНАЯ ФОРМА ИНФЕКЦИИ, ВЫЗВАННАЯ ВИРУСОМ ГЕПАТИТА B

Abstract

This paper reviews the literature on occult hepatitis B virus (HBV) infection (OBI), discussing its definition, pathogenesis, diagnosis and prevention. OBI is characterized by a low level of HBV replication, when the viral DNA is detected in the liver at low concentrations (< 200 IU/ml) and may be undetectable in serum, while antibodies to the HBV core protein (anti-HBc) and/or to its surface protein (anti-HBs) may be present. In most cases, OBI is caused by the virus whose genome is replicatively competent and comparable to the genomes isolated from individuals with HBsAgpositive infection. Host factors are strongly involved in the induction and maintenance of an occult form of infection. Clinical recovery from HBV infection does not imply complete eradication of the virus, but only the ability of the immune system to keep reproduction of the remaining virus in the liver under control. Numerous clinical studies have shown that any immunosuppressive factors may trigger HBV reactivation producing a typical serological profile of active infection. The clinical significance of OBI is summarized by the following three key points: 1) the “occult” virus can be transmitted, mainly with blood transfusions or liver transplantation, followed by development of acute hepatitis B in the recipient; 2) HBV can get reactivated during immunosuppression, and 3) latent HBV infection contributes to the progression of other chronic liver diseases and plays a role in hepatocarcinogenesis. Testing for anti-HBc is a simple precautionary measure to prevent transmission of HBV during blood transfusion, especially in immunocompromised patients. This review is based on 60 publications, 3 Russian and 57 foreign, retrieved from by the following databases: PubMed, Google Scholar, Scopus, Springer, Cochrane Library, Wiley Online Library, and Russian Science Citation Index.