Comparison of an ELISA system for the quantification of hepatitis B antibody with an automated and a semi-automated system.

In order to manage the increased workload resulting from post vaccination hepatitis antibody testing of health care workers, the anti-hepatitis B ELISA assay ETI-AB-AUK (Sorin Biomedica), adapted for quantification using standards available as an addition to the qualitative kit assay (ABAU-STD-SET, (Sorin Biomedica)) and a sample pre-dilution step, was compared with a fully automated microparticle enzyme immunoassay IMX AUSAB (Abbott Laboratories), and a semi-automated enhanced luminescence system (Amerlite Amersham, now Kodak). Seventy-eight samples were concurrently tested and analysed statistically using a Regression Coefficient computer package (Apple Mackintosh Cricket). Good quantitative agreement was observed with ELISA vs IMX giving a linear correlation coefficient (r = 0.96). The linear correlation coefficient for ELISA vs Amerlite was r = 0.77. This study validates the use of the automated IMX system and allows the comparison of IMX results with previous 'semi-quantitative' ELISA results when longitudinally assessing patients response to a recombinant hepatitis B vaccine.