Methodological approach for the detection of IgM anticardiolipin antibodies.
The effects of 10% fetal calf serum (10% FCS), 10% adult bovine serum (10% ABS) and 1% bovine serum albumin (1% BSA) buffers on the reactivity of samples with or without IgM anticardiolipin antibodies (ACA IgM) were studied on cardiolipin-coated wells (target wells) and cardiolipin-free wells (control wells) in an ELISA test. With 1% BSA, target well reactivity was very low for samples containing ACA IgM. The 10% FCS induced a moderate but significant binding of polyclonal IgM on target wells particularly in the case of IgM hypergammaglobulinemia. With 10% ABS, whatever the IgM serum level, this non-specific binding did not occur on the solid phase either in the presence or in the absence of cardiolipin. Using 10% ABS, the study of 35 SLE sera showed that non-specific binding of IgM on control-wells occurred only with ACA IgM positive samples. Thus with the use of 10% ABS, we propose that subtraction of control well from target well values must not be performed for the detection of ACA IgM. The significance of cardiolipin-free well IgM reactivity of ACA IgM positive sera is discussed.
Rupin
A
A
Department of Immunology, Faculté de Médecine, Tours, France.
Gruel
Y
Y
Leroy
J
J
Bardos
P
P
D000328:Adult; D001323:Autoantibodies / Q000302:isolation & purification*; D002021:Buffers; D002308:Cardiolipins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000302:isolation & purification*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D008875:Middle Aged
D001323:Autoantibodies; D002021:Buffers; D002308:Cardiolipins; D007075:Immunoglobulin M