HBV DNA in anti-HBc-positive first-time blood donors

Purpose: The objective of our work was to investigate whether anti-HBc screening of blood donations could reduce the residual risk of post-transfusion HBV infection. Background is the low-level viremia in HBV infection which complicates NAT screening of blood donations for HBV DNA. Methods: 12,105 first-time blood donors were tested for anti-HBc using a microparticle enzyme immunoassay (AxSYM core, Abbott GmbH, Wiesbaden, Germany). Positive results were confirmed by a second ELISA (Enzygnost Anti-HBc monoclonal, Dade Behring GmbH, Liederbach, Germany). DNA was prepared from l-2ml plasma by means of the NucliSens™ Extractor (Organon Teknika, Boxtel, The Netherlands). For amplification and simultaneous detection of PCR products we developed a novel approach based on the TaqMan® Universal PCR Master Mix on the ABI Prism 7700 SDS (PE Applied Biosystems, Weiterstadt, Germany). The detection limit of the method amounted to approximately 10 lU/ml related to the WHO international standard for HBV DNA (NIBSC code 97/746). A human ?-actin DNA sequence was coamplified separately as external positive control to avoid false negative results. Results: 162 blood donors (1.34%) were tested anti-HBc-positive in both tests. 151 of them (11 HBsAg+,140 HBsAg-) were tested for HBV DNA. In 9 (81.82%) of the HBsAg-positive blood donors HBV-DNA was repeatedly detected, and in 3 (2.14%) of the HBsAg-negative blood donors HBV DNA was also repeatedly found. In the 3 cases HBV DNA-positive/ HBsAg-negative, anti-HBe as well as anti-HBs (>100 IU/1) were also detectable. Even in HBsAg-positive samples viral load was seen at a low level. Conclusions: There is no serological evidence of a complete recovery from HBV infection. HBV DNA is rarely found in HBsAg-negative/anti-HBcpositive blood donors. Look back studies on regular blood donors are necessary to determine the infection rate due to those blood donations.