1Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan.
2Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan. Electronic address: firstname.lastname@example.org.
Hepatitis B flare, defined as an event with abrupt rise of alanine aminotransferase (ALT) to > 5 times upper limit of normal during chronic hepatitis B virus (HBV) infection, is considered to be the results of human leukocyte antigen-I restricted, cytotoxic T lymphocyte mediated immune response against HBV and its downstream mechanisms. It may occur spontaneously, during or after antiviral therapy and in the setting of immunosuppression and/or chemotherapy. The clinical spectrum of hepatitis B flares varies from asymptomatic to symptomatic and typical overt acute hepatitis, even with hepatic decompensation or failure. Flares may also occur in viremic patients with cirrhosis with higher incidence of decompensation/mortality, hence require immediate antiviral therapy. An upsurge of serum HBV DNA and hepatitis B surface antigen levels usually precedes the abrupt rise of ALT. Rising or stable and high HBV DNA during flares represent ineffective immune clearance that further hepatocytolysis, even hepatic decompensation, may occur. Such patients require immediate antiviral therapy. In contrast, bridging hepatic necrosis and/or alphafetoprotein > 100 ng/mL or with decreasing HBV DNA during flares represent more effective immune clearance, frequently lead to seroclearance of HBV DNA and/or hepatitis B e antigen with remission. If non-cirrhotic and no concern of developing decompensation, patients may be observed for 3-6 months before deciding the need of antiviral therapy. Severe and repeated flares are prone to develop decompensation or lead to cirrhosis development, thus timely treatment to prevent hepatitis B flare is better than to contend with the flare. Screening, monitoring and prophylactic or preemptive antiviral therapy is mandatory for patients who are going to receive immunosuppression or chemotherapy.