Serum prolactin levels in psoriasis and correlation with cutaneous disease activity

P>Background. Prolactin (PRL), a neuropeptide secreted by the anterior pituitary gland, possesses a variety of physiological actions. It has been implicated as an important immunomodulator and exerts a proliferative effect in cultured human keratinocytes via specific receptors. Some studies have indicated an increase in serum PRL levels in psoriasis and exacerbation of psoriasis when a prolactinoma is present. Aim. To evaluate the correlation between serum PRL levels and Psoriasis Area and Severity Index (PASI). Methods. Serum PRL levels were measured in 20 patients (10 mean, 10 women, age range 18-88 years) with plaque-type psoriasis before and after a 6-week period of topical treatment with tacalcitol ointment. Results were compared with a group of 20 healthy volunteers. Results. Serum PRL levels were significantly increased in the psoriatic group compared with the control group (P < 0.001) and were significantly reduced after treatment (P = 0.001). There was a correlation between pretreatment serum PRL levels and PASI (r = 0.33; P = 0.02). Conclusions. These results indicate that serum PRL levels may serve as a biological marker of psoriatic disease activity.