Ethinylestradiol and diethylstilbestrol induced antibodies and vascular thrombosis

Antiethinylestradiol antibodies were demonstrated in several oral contraceptive users. The antibodies could be precipitated from serum immune complexes by 25% saturated ammonium sulfate. This test of serum precipitation was applied to a comparative study of 116 women on O.C and 65 men treated with diethylstilbestrol for a prostatic cancer. Controls without hormones were included in each group. The test was shown to discriminate among the estrogen users reactive and unreactive persons. 34% of women and 41% of men had high levels of precipitated immunoglobulins in 25% saturated ammonium sulphate. Study of the specificity of the Igs purified from the precipitates in reactive cases, showed that they were binding ethinylestradiol with an affinity constant consistent with an antigen antibody reaction. It is concluded that the oral ingestion of two different synthetic estrogen compounds may induce antiestrogen antibodies. The relation of these antibodies with the increased incidence of vascular thrombosis is considered.