Comparison of nine commercially available assays for quantification of antibody response to hepatitis B virus surface antigen.

Quantitative measurement of anti-HBs is used to evaluate the response to hepatitis B vaccination in health care workers and to optimize postexposure management. The different guidelines for hepatitis B vaccination and booster policy imply that the measurement of anti-HBs levels by different assays is accurate and consistent, yielding comparable quantitative results. We measured anti-HBs levels in 200 serum samples from patients and health care professionals by nine different anti-HBs assays and compared the quantitative results and the performance characteristics of the different test systems. The assay specificity ranged between 96.8 and 100% when sera from individuals without a vaccination history and with negative anti-HBc status were defined as true negatives. Sensitivity ranged between 93.5 and 100%. A high number of sera showed discrepancies between measurements by the different systems. The mean coefficient of variation between the different measurements was 47.1% (range, 15.0 to 201.0%), and the factors of multiplication ranged from 2.8 to 105. Hemolysis or lipemia did not seem to influence the measurement, and there was no difference between anti-HBc-positive and -negative individuals. The classical enzyme immunoassays tend to find lower anti-HBs levels than the automated systems, with higher values by the Abbott AXSYM assay. The serial dilution of the international standard preparation was measured accurately by most of the assays. In conclusion, the quantitative measurement of anti-HBs levels is not reliable, even though an international standard is used for the calibration of the systems. Some systems showed specific problems that should be addressed by the manufacturers.