Raimondo G, Pollicino T, Romanò L, Zanetti A R
Unit of clinical and molecular hepatology, department of internal medicine, Policlinico Universitario di Messina, Messina, Italy.
Pathol Biol (Paris). 2010 Aug;58(4):254-7. doi: 10.1016/j.patbio.2010.02.003. Epub 2010 Mar 19.
Occult hepatitis B virus infection is a challenging issue whose virological and clinical relevance has been a source of long-lasting debate. By definition, OBI is characterized by the persistence of HBV-DNA in the liver tissue (and in some cases also in the serum) in absence of HBsAg. According to the HBV serological profile, OBI may be antibody (anti-HBc alone or together with anti-HBs) positive (seropositive OBI) or antibody negative (seronegative OBI). OBI is a complex biological entity with possible relevant clinical implications, mainly related to the intrahepatic persistence of viral cccDNA and to a strong suppression of viral replication and gene expression. Clinical observations suggest that OBI carriers may be a source of HBV transmission through blood transfusion or orthotopic liver transplantation (OLT). The state of suppression of viral replication and gene expression may be discontinued when an immunosuppressive status occurs, leading to typical hepatitis B with severe - and some times - fulminant course. The long-lasting persistence of the virus in the liver may provoke a very mild but continuing necro-inflammation that (if other causes of liver damage cohexist) may contribute over time to the progression of the chronic liver damage towards cirrhosis. In addition, OBI is supposed to be an important risk factor to HCC development since it maintains the pro-oncogenic properties typical of the overt infection.
隐匿性乙型肝炎病毒感染是一个具有挑战性的问题，其病毒学和临床相关性一直是长期争论的焦点。根据定义，隐匿性乙型肝炎以在无乙肝表面抗原的情况下肝组织（某些情况下血清中也有）持续存在乙肝病毒DNA为特征。根据乙肝血清学特征，隐匿性乙型肝炎可能是抗体（单独抗-HBc或与抗-HBs同时存在）阳性（血清学阳性隐匿性乙型肝炎）或抗体阴性（血清学阴性隐匿性乙型肝炎）。隐匿性乙型肝炎是一个复杂的生物学实体，可能具有相关的临床意义，主要与病毒共价闭合环状DNA在肝内持续存在以及病毒复制和基因表达受到强烈抑制有关。临床观察表明，隐匿性乙型肝炎携带者可能是输血或原位肝移植（OLT）导致乙肝病毒传播的来源。当出现免疫抑制状态时，病毒复制和基因表达的抑制状态可能会终止，导致典型的乙型肝炎，病情严重，有时甚至呈暴发性病程。病毒在肝脏中长期持续存在可能引发非常轻微但持续的坏死性炎症（如果同时存在其他肝损伤原因），随着时间的推移可能会促使慢性肝损伤向肝硬化发展。此外，隐匿性乙型肝炎被认为是肝癌发生的一个重要危险因素，因为它保留了显性感染典型的促癌特性。
