title: Decreased daily melatonin levels in women with systemic lupus erythematosus - a short report.
abstract: BACKGROUND
  The neuroendocrine system is known to influence immunity, but the precise interactions between different hormones and autoimmune disorders remain obscure.
  
  
  OBJECTIVE
  The present study aimed to investigate the role of daily serum melatonin concentrations in the development of systemic lupus erythematosus (SLE) in women.
  
  
  METHODS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Ralitsa
authors.initials: R
authors.lastname: Robeva
authors.affiliation: Clinic of Rheumatology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Dobromir
authors.initials: D
authors.lastname: Tanev
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Georgi
authors.initials: G
authors.lastname: Kirilov
authors.affiliation: Department of Social Medicine and Health Management, Medical University Sofia, Sofia, Bulgaria.
authors.forename: Milena
authors.initials: M
authors.lastname: Stoycheva
authors.affiliation: Clinic of Rheumatology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Analia
authors.initials: A
authors.lastname: Tomova
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Philip
authors.initials: P
authors.lastname: Kumanov
authors.affiliation: Clinic of Rheumatology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Rasho
authors.initials: R
authors.lastname: Rashkov
authors.affiliation: Clinic of Rheumatology, Medical University Sofia, Medical Faculty, Sofia, Bulgaria.
authors.forename: Zlatimir
authors.initials: Z
authors.lastname: Kolarov
keywords: Melatonin; SLEDAI; systemic lupus erythematosus; women