Detection of antiphospholipid autoantibody in systemic lupus erythematosus is temperature-dependent.
Non-reactive SLE sera in an ELISA for anticardiolipin antibody (aCL) retested positive in the immunoassay when the sera were first heat-inactivated at 56 degrees C for 30 minutes. This was not a false positive phenomenon since the positive ELISA reactivity of the heated SLE sera was markedly reduced by inhibition with the cardiolipin antigen. Furthermore, the heat-potentiated ELISA reaction was abolished by prior IgG depletion of the SLE sera with Protein A preparation. The unmasked aCL in the heat-treated SLE sera also exhibited selective binding in ELISA to other negatively-charged phospholipids, namely phosphatidylserine and phosphatidic acid but not against either phosphatidylcholine or phosphatidyl-ethanolamine. The data strongly indicate an interaction between antiphospholipid antibodies and heat-sensitive serum component(s), a reduction of the latter resulting in the ELISA detection of the autoantibody.
Cheng
H M
HM
Department of Physiology and Medicine, University of Malaya, Kuala Lumpur.
Wang
F
F
D001323:Autoantibodies / Q000032:analysis*; D002308:Cardiolipins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006358:Hot Temperature; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D010743:Phospholipids / Q000276:immunology*
D001323:Autoantibodies; D002308:Cardiolipins; D010743:Phospholipids