Do Prolactin and its Receptor Play a Role in Alopecia Areata?

CONTEXT: Studying the link between prolactin and autoimmunity has gained much ground over the past years. Its role played in alopecia areata (AA) is not clear yet, as previous reports yielded controversial results. AIMS: This study aimed to measure the serum level of prolactin and to detect the expression of its receptor in AA, in an attempt to highlight its possible role in the pathogenesis of this disease. SUBJECTS AND METHODS: A case-control study of 30 AA patients and 20 controls from outpatient clinic were undertaken. Every patient was subjected to history taking and clinical examination to determine the severity of alopecia tool (SALT) score. Blood samples were taken from patients and controls to determine the serum prolactin level. Scalp biopsies were obtained from the lesional skin of patients and normal skin of controls for assessment of the prolactin receptor. STATISTICAL ANALYSIS: Depending upon the type of data, t-test, analysis of variance test, Chi-square, receiver operator characteristic curve were undertaken. RESULTS: On comparing the serum prolactin level between patients and controls, no significant difference was found, while the mean tissue level of prolactin receptor was significantly higher in patients than in controls. In patients, a significant positive correlation was found between the prolactin receptor and the SALT score. CONCLUSIONS: Prolactin plays a role in AA, and this role is probably through the prolactin receptors rather than the serum prolactin level.