Published online Jun 27, 2014. doi: 10.4254/wjh.v6.i6.384
Revised: March 16, 2014
Accepted: May 31, 2014
Published online: June 27, 2014
Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.
Core tip: In occult Hepatitis B infection (OBI), hepatitis B virus reactivation is more common in anti-HIV-positive subjects, in those in onco-hematological settings, in patients who undergo hemopoietic stem cell transplantation and in those treated with anti-CD20 or anti-CD52 monoclonal antibody. Reactivation may be severe and in nearly 20% of cases it may take a life-threatening course. The use of nucleot(s)ide analogues to prevent this reactivation is mandatory in hepatitis B surface antigen-negative/anti-hepatitis B core-positive patients in all conditions of strong and/or prolonged immunosuppression. We describe the characteristics of OBI in onco-hematological and rheumatological diseases, in solid cancers and in HIV infection.