Anti-phosphatidylserine, anti-cardiolipin, anti-β2 glycoprotein I and anti-prothrombin antibodies in recurrent miscarriage at 8–12 gestational weeks

Abstract

Objective To investigate the association of antibodies to β2-glycoprotein I (anti-β2GPI), cardiolipin (ACA), phosphatidylserine (anti-PS) and prothrombin (anti-PT) with recurrent spontaneous miscarriage (RSM).

Study design Case–control study involving 277 RSM cases and 288 controls: autoantibody levels were measured by ELISA. Differences between cases and controls were analyzed by nonparametric Mann–Whitney test, and logistic regression was used in analyzing the association of autoantibodies with RSM.

Results Anti-PS IgG, ACA IgM and IgG, and anti-PT IgM were significantly associated with RSM risk, and differential antibody association was noted according to BMI and primary and secondary RSM. Higher prevalence of elevated anti-PS IgG was seen in cases, with the strongest risk above the 99th percentile. For ACA IgM, 28 cases (10.1%) and 5 controls (1.7%) were positive, with increasing OR for increasing cut-off points, which was significant at antibody titers >99th percentile. For ACA IgG, 101 cases (36.5%) and 13 controls (4.5%) were positive, with graded increase in OR for increasing cut-off points, which was significant at titers >90th percentile (maximal at titers >99th percentile). For anti-PT, 23 cases (12.0%) and 9 controls (6.1%) were positive, with increased OR at titers >90th percentile. Regression analyses confirmed the independent association of anti-PS IgG, ACA IgM and IgG with RSM, and significant RSM risk was associated with high anti-PS IgG (P < 0.001) and ACA IgM (P < 0.001) titers, and a dose-dependent increase in RSM risk was seen with progressively increased ACA IgG titers. No significant association existed between anti-PT IgM and RSM.