Management of occult hepatitis B virus infection:An update for the clinician

Occult hepatitis B virus(HBV) infection(OBI) is defined by the presence of HBV DNA in the liver tissue of individuals who test negative for hepatitis B surface antigen(HBsAg).Patients who have recovered from acute hepatitis B can carry HBV genomes for a long time and show histological patterns of mild necro-inflammation,even fibrosis,years after the resolution of acute hepatitis,without showing any clinical or biochemical evidence of liver disease.At least in conditions of immunocompetence,OBI is inoffensive itself,but when other relevant causes of liver damage are present it might make the course of the liver disease worse.The risk of HBV transmission through transfusion is related to blood donations negative for HBsAg that have been collected during the pre-seroconversion period or during chronic OBI.Use of HBV nucleic acid amplification testing and multivalent anti-HBs antibodies in the HBsAg assays is recommended for detection of true and false OBI,respectively.It is not known if prior hepatitis B immunization with an optimal anti-HBs response in cases of HBV transmission through organ transplantation can effectively modulate or abort the infection.Use of anti-viral agents as prophylaxis in patients with serological evidence of past HBV infection prevents reactivation of OBI after transplantation in most cases.Reactivation of OBI has been observed in other conditions that cause immunosuppression,in which antiviral therapy could be delayed until the HBV DNA or HBsAg becomes detectable.OBI might contribute to the progression of liver fibrosis and hepatocellular carcinoma development in patients with chronic liver disease.

Hepatitis B and immunosuppressive therapies for chronic inflammatory diseases: When and how to apply prophylaxis, with a special focus on corticosteroid therapy

Currently immunosuppressive and biological agentsare used in a more extensive and earlier way in patients with inflammatory bowel disease, rheumatic or dermatologic diseases. Although these drugs have shown a significant clinical benefit, the safety of these treatments is a challenge. Hepatitis B virus(HBV) reactivations have been reported widely, even including liver failure and death, and it represents a deep concern in these patients. Current guidelines recommend to preemptive therapy in patients with immunosuppressants in general, but preventive measures focused in patients with corticosteroids and inflammatory diseases are scarce. Screening for HBV infection should be done at diagnosis. The patients who test positive for hepatitis B surface antigen, but do not meet criteria for antiviral treatment must receive prophylaxis before undergoing immunosuppression, including corticosteroids at higher doses than prednisone 20 mg/d during more than two weeks. Tenofovir and entecavir are preferred than lamivudine because of their better resistance profile in long-term immunosuppressant treatments. There is not a strong evidence, to make a general recommendation on the necessity of prophylaxis therapy in patients with inflammatory diseases that are taking low doses of corticosteroids in short term basis or low systemic bioavailability corticosteroids such as budesonide or beclomethasone dipropionate. In these cases regularly HBV DNA monitoring is recommended, starting early antiviral therapy if DNA levels begin to rise. In patients with occult or resolved hepatitis the risk of reactivation is much lower, and excepting for Rituximab treatment, the prophylaxis is not necessary.