Standardization of ELISA for the detection of anti-cardiolipin antibodies--effect of non-specific IgG binding.
Various frequencies of anti-cardiolipin antibodies reported in patients with systemic lupus erythematosus and other autoimmune and infectious diseases necessitates the need for standardization of the immunoassay. We report here the usefulness of "no-antigen" control for each serum in determining the actual value of the anti-phospholipid antibodies. This non-specific "no-antigen" binding was quite variable from serum to serum and in general was higher in the patient population than in healthy individuals which served as controls. This non-specific binding may be associated with the increased IgG content of the sera as shown by the linear association of the absorbance of the back-ground readings to increases in IgG concentration (correlation coefficient 0.98).
Kumar
V
V
Ernest Witebsky Center For Immunology, Department of Microbiology, SUNY, Buffalo.
Bartholomew
W
W
Shieh
M T
MT
Pierce
C
C
Kaul
N
N
D000937:Antigen-Antibody Reactions / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D001327:Autoimmune Diseases / Q000276:immunology; D002308:Cardiolipins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D013587:Syphilis / Q000276:immunology
D001323:Autoantibodies; D002308:Cardiolipins; D007074:Immunoglobulin G