Measurement of anti-phospholipid antibodies by ELISA using beta 2-glycoprotein I as an antigen.
The requirement of plasma cofactor beta 2-glycoprotein I for binding autoantibodies against anionic phospholipids has been reported. We describe the development of an enzyme-linked immunosorbent assay (ELISA) for anti-phospholipid antibodies using highly purified beta 2-glycoprotein I for coating microtitre plates. Intra- and interassay coefficients of variation, determined with serum pools of low, medium and high positivity, ranged between 3% and 18%. 54 sera from patients with systemic lupus erythematosus and related autoimmune disorders were analyzed by this assay; the results correlated well to those obtained in an ELISA using anionic phospholipids on the solid phase (r = 0.85, P less than 0.001). The two ELISA systems showed similar sensitivities although 8/31 positive sera scored negative in the beta 2-glycoprotein I ELISA. The latter group of eight sera showed significantly higher anti-phosphatidylcholine/anti-phosphatidylserine binding ratios than the group of 23 sera which scored positive in both assays. This new assay should permit accurate measurement of most of the clinically relevant anti-phospholipid antibodies and avoid inconsistencies likely to arise from secondary interactions that characterize lipid-based ELISA.
Laboratoires d'Immunologie, Centre Hospitalier Universitaire, Grenoble, France.
J
J
Arvieux
B
B
Roussel
M C
MC
Jacob
M G
MG
Colomb
D000595:Amino Acid Sequence; D016736:Antiphospholipid Syndrome / Q000276:immunology; D001053:Apolipoproteins / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D002308:Cardiolipins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053482:beta 2-Glycoprotein I
D001053:Apolipoproteins; D001323:Autoantibodies; D002308:Cardiolipins; D006023:Glycoproteins; D007074:Immunoglobulin G; D010743:Phospholipids; D053482:beta 2-Glycoprotein I