Heterogeneous behavior of anti-beta2-glycoprotein I antibodies on various commercially available enzyme immunoassay plates coated with beta2-glycoprotein I

OBJECTIVE: To evaluate commercially available enzyme immunoassay (EIA) plates for the measurement of anti-beta2-glycoprotein I autoantibody (anti-beta2-GPI). METHODS: Sera from 10 patients with the antiphospholipid syndrome, and 3 monoclonal anti-beta2-GPI antibodies established from patients with antiphospholipid syndrome, were assayed for binding to solid phase beta2-GPI on 20 commercially available plates. RESULTS: Several commercially available EIA plates were found to be of potential value for the measurement of anti-beta2-GPI autoantibody. Some plates were unsuitable for anti-beta2-GPI detection, possibly due to less beta2-GPI on the plates, or to differences in the nature of conformational changes of beta2-GPI induced by the plates. CONCLUSION: Differences among EIA plates need to be considered when measuring beta2-GPI antibodies.