title: Familial autoimmunity and polyautoimmunity in 60 Brazilian Midwest patients with systemic sclerosis.
abstract: BACKGROUND
  Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology, characterized by a triad of vascular injury, autoimmunity and tissue fibrosis. It is known that a positive family history is the greatest risk factor already identified for the development of SSc in a given individual. Preliminary observation of a high prevalence of polyautoimmunity and of familial autoimmunity in SSc patients support the idea that different autoimmune phenotypes may share common susceptibility variants.
  
  
  OBJECTIVE
  To describe the frequency of familial autoimmunity and polyautoimmunity in 60 SSc patients in the Midwest region of Brazil, as well as to report the main autoimmune diseases observed in this association of comorbidities.
  
  
  METHODS
  A cross-sectional study with recruitment of 60 consecutive patients selected at the Rheumatology Department, University Hospital, Medicine School, Federal University of Mato Grosso do Sul (FMUFMS), as well as interviews of their relatives during the period from February 2013 to March 2014.
  
  
  RESULTS
  A frequency of 43.3% of polyautoimmunity and of 51.7% of familial autoimmunity in SSc patients was found. Patients with the presence of polyautoimmunity and familial autoimmunity presented primarily the diffuse form of SSc, but this indicator did not reach statistical significance. The autoimmune diseases most frequently observed in polyautoimmunity patients were: Hashimoto's thyroiditis (53.8%), Sjögren's syndrome (38.5%), and inflammatory myopathy (11.5%). The main autoimmune diseases observed in SSc patients' relatives were: Hashimoto's thyroiditis (32.3%), rheumatoid arthritis (22.6%), and SLE (22.6%). The presence of more than one autoimmune disease in SSc patients did not correlate with disease severity or activity.
  
  
  CONCLUSIONS
  From the high prevalence of coexisting autoimmune diseases found in SSc patients, we stress the importance of the concept of shared autoimmunity, in order to promote a continued vigilance and promptly diagnose other possible autoimmune disease in patients, or in their kin.
authors.affiliation: Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil; Service of Rheumatology, Hospital Regional de Mato Grosso do Sul, Campo Grande, MS, Brazil; Program of Medical Residence in Rheumatology, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil. Electronic address: clinicaactivite@gmail.com.
authors.forename: Alex Magno Coelho
authors.initials: AM
authors.lastname: Horimoto
authors.affiliation: Program of Medical Residence in Rheumatology, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Aida Freitas do Carmo
authors.initials: AF
authors.lastname: Silveira
authors.affiliation: Program of Medical Residence in Rheumatology, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil; Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Department of Internal Medicine, Faculdade de Medicina, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil; Service of Rheumatology, Hospital Universitário, Hospital Maria Aparecida Pedrossian, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Izaias Pereira
authors.initials: IP
authors.lastname: da Costa
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D001323:Autoantibodies; D015551:Autoimmunity; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D012595:Scleroderma, Systemic / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D012859:Sjogren's Syndrome / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D013967:Thyroiditis, Autoimmune / Q000150:complications / Q000453:epidemiology / Q000276:immunology
chemical_list: D001323:Autoantibodies
keywords: Autoantibodies; Autoanticorpos; Autoimmune disease; Autoimunidade familiar; Doença autoimune; Esclerose sistêmica; Familial autoimmunity; Poliautoimunidade; Polyautoimmunity; Systemic sclerosis