Screening for heterozygous 1 -antitrypsin deficiency. 3. A provocative test with diethylstilbestrol and effect of oral contraceptives.

Abstract

Diethylstilbestrol caused serum trypsin-inhibitory capacity (STIC) values to rise into the low-normal range in most studied heterozygotes with α 1 -antitrypsin deficiency, but never above 1.20 units; in control subjects, the stimulated STIC values exceeded 1.30 units. Subjects with homozygous antitrypsin deficiency did not respond to diethylstilbestrol. Lack of response to 3 mg of diethylstilbestrol daily for two weeks in a patient with 1.20 units or less of antitrypsin activity indicates that the patient's antitrypsin level is already maximally stimulated by his disease, and confirms a dagnosis of heterozygous α 1 -antitrypsin deficiency. Women receiving oral contraceptive medication or other estrogenic hormones whose random antitrypsin assay shows a level of 1.20 units or less should be suspected of carrying the abnormal gene for antitrypsin deficiency.