[Contraceptive hormones, vascular risk and abnormal precipitation of serum gamma-globulins (author's transl)].

The monoclonal anti-ethinyl-estradiol antibody previously found in the serum of a woman on oral contraceptives, was precipitated by 25% saturated ammonium sulfate à 22 degrees C. This simple test has been used to investigate the possible relationship between abnormally precipitating gamma-globulins (GAP) and the vascular risk of the pill. Four groups of women were studied: --50 women who had never used the pill; --100 women on oral contraceptives; --30 women who had stopped the pill; --17 women who had experienced venous or arterial thrombosis during oral contraception. The results obtained indicate: 1) that a GAP increase is nearly always associated with the thrombotic events (90% of the cases in group 4); 2) that the presence of GAP is seen only in part of the women population on oral contraceptives representing approximately 30% of the total population investigated as indicated by a bimodal distribution; 3) that the GAP remain increased for months and even years after the pill was discontinued. The significance of this test is discussed. It is proposed that the presence of GAP in the serum appears to be related to the presence of ethinyl-estradiol binding antibodies. This hypothesis is verified by experiments in progress.