title: Polyautoimmunity in a Greek cohort of multiple sclerosis.
abstract: OBJECTIVE
  The aim of this study was to assess the existence of polyautoimmunity in a Greek cohort of multiple sclerosis (MS), particularly multiple autoimmune syndrome (MAS), i.e., the presence of three or more distinct autoimmune disorders (ADs) in the same individual.
  
  
  METHODS
  Cross-sectional control study.
  
  
  RESULTS
  The overall prevalence of polyautoimmunity in 2140 MS patients (female to male ratio: 2.1:1) was 8.3% (vs 6.07% in 1580 matched control participants, P = 0.008) mainly due to differences in autoimmune thyroid disorders (AITD) and vitiligo. The prevalence of MAS was 1.0%. The most frequent diseases encountered in MS were organ-specific ADs. There was no statistical difference in the total rates of ADs between female and male MS patients. There were higher rates of AITD in women (P = 0.004) and higher rates of iritis (P = 0.039) and ankylosing spondylitis (P = 0.003) in men. MS was diagnosed in the same year with AD in 7.4% of patients with additional ADs, earlier than AD in 42.0% and later than AD in 50.6%.
  
  
  CONCLUSIONS
  Polyautoimmunity and particularly MAS occur more frequently in MS patients than in control participants indicating that MS may be part of a generalized susceptibility to autoimmunity. Therefore, polyautoimmunity may be implicated in the etiopathogenesis of MS-related ADs, with a potential impact on relative therapeutic strategies.
authors.affiliation: Department of Neurology, Multiple Sclerosis Unit, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Deretzi
authors.forename: J
authors.initials: J
authors.lastname: Kountouras
authors.forename: S A
authors.initials: SA
authors.lastname: Polyzos
authors.forename: E
authors.initials: E
authors.lastname: Koutlas
authors.forename: S-H
authors.initials: SH
authors.lastname: Pelidou
authors.forename: G
authors.initials: G
authors.lastname: Xeromerisiou
authors.forename: C
authors.initials: C
authors.lastname: Zavos
authors.forename: I
authors.initials: I
authors.lastname: Tsiptsios
mesh_terms: D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications* / Q000453:epidemiology*; D015551:Autoimmunity; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000276:immunology; D015995:Prevalence
keywords: autoimmune tautology; multiple autoimmune syndrome; multiple sclerosis; polyautoimmunity