CLINICAL-SIGNIFICANCE OF BETA(2)-GLYCOPROTEIN I-DEPENDENT ANTICARDIOLIPIN ANTIBODIES IN THE REPRODUCTIVE AUTOIMMUNE FAILURE SYNDROME - CORRELATION WITH CONVENTIONAL ANTIPHOSPHOLIPID ANTIBODY DETECTION SYSTEMS

OBJECTIVE: Our purpose was to determine whether beta(2)-glycoprotein I -dependent anticardiolipin antibodies may represent a superior marker of reproductive risk than do conventional antiphospholipid antibodies. STUDY DESIGN: The incidence of beta(2)-glycoprotein I-dependent and b eta(2)-glycoprotein I-independent anticardiolipin antibodies and of si x conventional antiphospholipid antibodies was statistically compared between study groups with and without autoantibody-associated features of reproductive failure. Sera from 356 women were randomly selected f rom the frozen sera bank at the Center for Human Reproduction, Chicago . They included sera from 259 patients with autoantibody-associated fe atures of reproductive failure such as unexplained infertility, endome triosis, and repeated pregnancy loss and 97 infertile controls. Autoan tibody levels by a modified enzyme-linked immunosorbent assay for beta (2)-glycoprotein I-dependent and beta(2)-glycoprotein I-independent an ticardiolipin antibodies and a standard enzyme-linked immunosorbent as say for anticardiolipin antibody and five other antiphospholipid antib odies were then compared, RESULTS: Patients demonstrated a significant ly higher incidence of beta(2)-glycoprotein I-dependent anticardiolipi n antibodies (5.4%) than did controls (0%) in a modified enzyme-linked immunosorbent assay (p = 0.01). No such difference was, however, note d for p,beta(2)-glycoprotein I-independent anticardiolipin antibodies or any one of six antiphospholipid antibodies. Two or more among six a ntiphospholipid antibodies, especially if involving anticardiolipin an tibodies, antiphosphatidylserine and antiphosphatidylinositol, as assa yed by standard enzyme-linked immunosorbent assay, were significantly more often (p = 0.02) positive in the patients (5.0%) than in the cont rols (0%). Moreover, positivity in two of those three antiphospholipid antibodies correlated in 59% of cases to positivity in the beta(2)-gl ycoprotein I-dependent anticardiolipin antibody. CONCLUSIONS: As a sin gle test beta(2)-glycoprotein I-dependent anticardiolipin antibody app ears to be superior to cofactor-independent anticardiolipin antibody o r any other single conventional antiphospholipid antibody for the dete ction of autoantibody-associated conditions of reproductive failure. A broadly based panel of conventional antiphospholipid antibodies, espe cially if inclusive of anticardiolipid antibody, antiphosphatidylserin e, and antiphosphatidylinositol, may, however, achieve similar results .