Systemic lupus erythematosus associated with klinefelter's syndrome.

Studies in estrogen metabolism were carried out in 2 males with systemic lupus erythematosus (SLE) who also had Klinefelter's syndrome. Although these studies revealed elevated levels of urinary estrogens in 1 patient, abnormalities of estradiol metabolism suggesting persistent estrogen stimulation were detected in both. This report notes an association between SLE and Klinefelter's syndrome and suggests that chronic estrogenic stimulation may be significant in the development of SLE in these 2 patients.