Antisteroid immune complexes and vascular thrombosis during steroid hormone therapy

To test an immunological hypothesis proposed to explain the pathogenesis of cerebrovascular thrombosis in steroid users, circulating immune complexes were assayed in the sera from 6 control subjects, 14 ever users of oral contraceptive having developed a neurological ischaemic accident, and 7 patients with the same clinical history during use of other sex steroid not containing ethinylestradiol. Beaumont's ammonium sulfate and polyethylene glycol precipitation methods, together with a specific method of isolation of circulating immune complexes using affinity chromatography on Protein A, were used. Radioactivity from labeled ethinylestradiol added to the sera before precipitation was monitored in the precipitates to detect anti-ethinylestradiol antibodies. There were no significant differences for these parameters in the three groups. However, protein content and 3H-EE activity in the precipitates were equally and dramatically reduced after affinity chromatography in the three groups. These latter results do not support the presence of antibodies against ethinylestradiol in steroid users with cerebrovascular thrombosis. Moreover, our data suggest a lack of specificity of Beaumont's method for the isolation of immune complexes containing anti-ethinylestradiol antibodies.