Plasma sex hormones and aromatase activity in tissues of patients with systemic lupus erythematosus.

Clinical observations and experimental data suggest that sex hormones influence the development of systemic lupus erythematosus (SLE). An imbalance between androgen and estrogen plasma levels may suggest an abnormality in the aromatase activity involved in estradiol synthesis. Aromatase activity in skin and subcutaneous tissue and plasma sex-hormone levels (testosterone, androstenedione, estrone, estradiol, dehydrosterone sulfate, cortisol) were measured in 15 SLE patients (nine female, six male) who had never received corticosteroid treatment and in eight (four female, four male) healthy control subjects. There was a tendency toward an increase in aromatase activity in SLE patients when compared to control subjects. Among SLE patients the aromatase activity varied inversely with disease activity. Patients with SLE had decreased androgen and increased estrogen levels. Aromatase activity in SLE patients had significant direct correlation with estrogen levels. These data suggest that abnormal regulation of aromatase activity may partially explain the abnormalities of estrogen synthesis in SLE.