Prolactin and systemic lupus erythematosus.

Prolactin in a pituitary peptide hormone which is immunomodulatory. Increased serum prolactin concentrations accelerate autoimmunity in the NZB x NZW F1 mouse model of SLE. Some patients with SLE are hyperprolactinemic and, in cross-sectional and longitudinal studies, serum prolactin has been associated with or correlated to lupus disease activity. Suppression of physiologic levels of prolactin by bromocriptine administration was associated with improvement in SLE in a preliminary study. While specific mechanisms remain to be elucidated, prolactin appears to be immunostimulatory in patients with SLE. A better understanding of its role and its interactions with other immunoregulatory hormones in SLE may lead to novel therapies for the suppression of this hormonally sensitive autoimmune disease.