Specific antiphospholipid antibodies as a predictive variable in patients with recurrent pregnancy loss

Antiphospholipid antibodies (APLs) consist of very heterogenous autoantibodies. It has not been fully explored what kind of specificities are most relevant to recurrent pregnancy loss. Thus, we investigated the effects of specific APLs on recurrent aborters.

IgG and IgM antibodies against PE (treated with 1% acetic acid) and five negatively-charged phospholipids were measured by ELISA among 334 recurrent aborters without autoimmune disease. The relationships between APL specificities and subsequent pregnancy outcome were prospectively investigated in 38 recurrent aborters with positive APL who did not receive treatment with prednisolone and aspirin. Antibody levels exceeding the 99th percentile of 280 healthy women were considered positive.

Positive IgG and/or IgM APLs were detected in 14%, IgG APLs in 12%, and IgG antibodies against PA, PG, PI, PS, CL and PE, respectively, in 9%, 7%, 7%, 7%, 8%, and 8%. In a prospective study of the 38 untreated patients, fetal loss recurred in 82% of the 33 IgG APL-positive patients, but in 40% of the five patients positive for only IgM APLs. The incidence of fetal loss in the next pregnancy of patients with IgG specific APL-positive against PE, PI, PS, or Cl was even higher at 90% and over, and fetal loss recurred in all of 21 patients with two or more IgG APL-positive against PE, PI, PS, or CL.

These results suggest the possibility that two or more IgG APL-positive value against treated PE, PI, PS, or CL, may be more accurate as a predictive variable than that of only one IgG APL-positive in patients with recurrent pregnancy loss.