Alterations of estrogen metabolism in systemic lupus erythematosus.

Estradiol metabolism in 10 patients with systemic lupus erythematosus (SLE) and 29 normal controls was studied by measurement of urinary metabolites after injection of labeled 3H-estradiol. Patients with SLE manifested increased 16-hydroxylation of estrone. Diseases men differed from diseases women to the extent that only 16 alpha-hydroxyestrone was elevated in men, whereas women had elevations of both 16 alpha-hydroxyestrone and estriol. These data suggest that patients with SLE have abnormal patterns of estradiol metabolism, leading to increased estrogenic activity.