Antibodies to phospholipids and nuclear antigens in non-pregnant women with unexplained spontaneous recurrent abortions.

In a collaborative study of 73 non-pregnant Kuwaiti women with unexplained spontaneous recurrent abortion (RSA), 30 control healthy non-pregnant multiparous Kuwaiti women and 20 North American women who received elective abortion(s), autoantibodies to 6 phospholipids and 9 nuclear antigens were measured. Women with recurrent spontaneous abortions demonstrated 3 times higher incidence of antibodies to phospholipids (30.1%) than controls (10% each) (P = 0.029). The incidence of both IgM and IgA class antiphospholipid antibodies were significantly higher than those of controls. The incidence of antibodies to cardiolipin in women with recurrent spontaneous abortions (12.3%) was significantly higher than those of controls (P = 0.035) and incidence of IgM but not IgG anticardiolipin antibody was significantly higher in women with RSAs than in controls (P = 0.053). The incidences of anti-polyinosinic acid (P = 0.035) and anti-histone 1 antibody (P = 0.052) were significantly higher in women with recurrent spontaneous abortions than controls. There was no significant difference in the incidence of autoantibodies between primary and secondary aborters. However, women with a history of second trimester abortions showed a higher incidence of antiphospholipid antibodies than women with first trimester abortions only. Recurrent spontaneous abortion is associated with autoantibodies to phospholipid epitopes including IgA antiphospholipid antibodies.