Decreased daily melatonin levels in women with systemic lupus erythematosus - a short report.

Background: The neuroendocrine system is known to influence immunity, but the precise interactions between different hormones and autoimmune disorders remain obscure.

Aims: The present study aimed to investigate the role of daily serum melatonin concentrations in the development of systemic lupus erythematosus (SLE) in women.

Study Design: Case-control study.

Methods: One-hundred and eleven SLE female patients and 46 healthy women were included in the study. Daily serum melatonin levels were investigated in all participants.

Results: SLE patients showed significantly lower daily melatonin levels in comparison to healthy women during the short photoperiod (17.75±7.13 pg/mL [16.05] vs. 21.63±6.60 pg/mL [20.10], p=0.012). Hormone concentrations were inversely related to the SLE activity index (SLEDAI) (r= -0.268, p=0.004), but they did not correlate to any particular American College Rheumatology (ACR) criterion (p>0.05 for all).

Conclusion: Daily melatonin levels were decreased in women with systemic lupus erythematosus and correlated inversely to the activity of the autoimmune disease. Further studies are needed to clarify the importance of the pineal and extrapineal melatonin secretion in patients with systemic lupus erythematosus as well as the interrelations between hormones and autoimmunity.