Prolactin modulates the disease activity of systemic lupus erythematosus accompanied by prolactinoma

We present a 31-year-old female patient with systemic lupus erythematosus (SLE) which was accompanied by prolactinoma. Her SLE flared when the plasma levels of prolactin (PRL) increased, and subsided when these levels decreased following the administration of bromocriptine, irrespective of the glucocorticoid dosage. For the 29 plasma samples obtained during the clinical course, PRL levels were significantly correlated to the serum anti-DNA antibody titers (r = 0.55, p < 0.05) and inversely to the serum complement activity (r = -0.33, p < 0.05). This result suggests that PRL may play a role in the pathogenesis of SLE in some patients.