Immune response to HBsAg differently interpreted by RIA and EIA.

Area of Science:

• Immunology
• Virology
• Clinical Chemistry

Background:

• Hepatitis B vaccination and infection elicit anti-HBs antibodies.
• Accurate quantification of anti-HBs is crucial for assessing immunity and vaccine efficacy.
• Different immunoassay methods may yield varying results.

Purpose of the Study:

• To compare the performance of radioimmunoassay (RIA) and enzyme immunoassays (EIAs) for detecting anti-HBs antibodies.
• To evaluate anti-HBs antibody levels following different vaccination schedules and natural infection.
• To assess the suitability of various reference panels for assay calibration.

Main Methods:

• Simultaneous testing of anti-HBs in sera from vaccinated and infected individuals using Ausab-RIA and Ausab-EIA.
• Comparison of RIA with two Organon Teknika EIAs (Hepanostika anti-HBs monoclonal and 'new').
• Determination of functional sensitivity and testing of multiple reference panels (in-house, Abbott, Organon).

Main Results:

• Geometric mean levels (GML) of anti-HBs by RIA/EIA showed ratios from 1.4 to 2.2 post-vaccination, differing from infection results (ratio 1.1).
• Differences in anti-HBs detection were observed between vaccine subgroups at early time points but not at later intervals.
• One EIA (HN) showed lower detection rates for anti-HBs >10 IU/l compared to RIA and another EIA (HM), with varying functional sensitivities.

Conclusions:

• The behavior of anti-HBs antibodies quantified using the Abbott reference panel differs from those obtained post-vaccination.
• The Organon Teknika EIAs demonstrated varying performance in detecting anti-HBs, with potential discrepancies compared to RIA.
• Standardized, test-system-independent reference sera are essential for accurate anti-HBs quantification across different assays.