Detection of hepatitis B virus DNA in serum is rare in the absence of hepatitis B surface antigen: impacts for detection and monitoring of chronic hepatitis B

摘要

Hepatitis B (HBV) is one of the most common infectious diseases worldwide, with 2 billion people having evidence of past or present infection worldwide and over 200,000 chronically infected in Australia alone.1'2 It has been estimated that in 2010 there were 312,400 deaths due to HBV-associated cirrhosis worldwide.Serological testing is the gold standard for diagnosis, with detection of hepatitis B surface (HBsAg) and envelope antigen (HBeAg) consistent with active replicating virus, and anti-hepatitis B surface antibody (anti-HBs Ab) found following successful immunisation or control of natural infection. Over time it has become clear that loss of HBsAg with or without the development of anti-HBs Ab does not represent 'clearance' of HBV as previously thought. In some patients, low level viral replication within the liver may persist associated with, or in the absence of, low level detectable HBV DNA in the serum.4 The prevalence of so called 'occult HBV varies geographically but was found in 5-10% of European blood donors with isolated anti-hepatitis B core Ab.5 The long-term clinical impacts have not yet been determined but these patients are at risk of HBV reactivation in the setting of immunosuppression.