Frequent presence of HBV in the sera of HBsAg-negative, anti-HBc-positive blood donors

BACKGROUND: Recent studies have revealed that HBV may not be cleared even a fter the disappearance of serum HBsAg. The purpose of this study was to inv estigate whether the replication of HBV persists in HBsAg-negative blood do nors who lack apparent liver disease. STUDY DESIGN AND METHODS: Serum HBV was examined by using PCR coupled with Southern blotting in 50 blood donors who were identified to be HBsAg negati ve but anti-HBc positive. RESULTS: HBV DNA was detected in the sera from 19 (38%) of 50 donors. In 11 of the 19, HBV existed exclusively as immune complexes, while HBV presumab ly did not exist as immune complexes in the remaining eight. The levels of HBV DNA were similar to those in patients who had recovered from acute HBV. Some nucleotide substitutions, which did not confer amino acid changes in the major epitope of HBsAg, were found in the preS-S regions. CONCLUSION: The replication of HBV is ongoing in a substantial proportion o f healthy blood donors who have anti-HBc. Blood from such donors may contai n very low levels of HBV free of immune complex formation and should be exc luded for transfusion. The fact that such blood donors apparently lacked li ver disease suggests no pathogenicity of such "occult" HBV.