Antibody to hepatitis B surface antigen in laboratory diagnostic sera

Thirty-four commercial blood-grouping sera were tested for the presence of HBsAg and anti-HBs by radioimmunoassay technic. One sample (2.9% of the total) was positive for HBsAg, a marked reduction from previous reports; however, 11 sera (32.4%) were found to contain anti-HBs, a previously unreported finding. There is still some dispute as to the risk of infection from samples containing anti-HBs, which the authors hope will be resolved when tests for anti-HBc are readily available. In the meantime, the high antibody rate reflects a high rate of exposure to HBsAg of donors of commercial antisera, and laboratory personnel should be reminded of the possible risk of this less obvious source of infection.