title: Chronic spontaneous urticaria: epidemiological characteristics focusing on the histocompatibility profile and presence of antibodies.
abstract: BACKGROUND
  Understanding the etiopathogenesis of chronic spontaneous urticaria (CSU) remains a challenge. The clinical and laboratory characteristics relating to its histocompatibility profile and autoimmunity are constant research topics.
  
  
  OBJECTIVE
  To analyze the clinical and laboratory characteristics of patients with CSU by means of a cross-sectional study, focusing on the histocompatibility profile, presence of antinuclear antibodies (ANA) and presence of antithyroperoxidase antibodies (anti-TPO).
  
  
  METHODS
  Sixty-seven adults with CSU were analyzed. The autologous serum skin test (ASST), ANA and anti-TPO were performed in all cases and MHC classes I and II (loci A, B and DR) were evaluated in 49 patients.
  
  
  RESULTS
  The factors that worsened urticaria included use of non-steroid anti-inflammatory drugs, emotional stress and physical stimuli, reported by 27%, 16% and 15% of these patients, respectively. The ASST test was positive in 49 patients (73%) and anti-TPO and ANA were present in 15 (22.4%) and 7 (10.5%), respectively. The OR (with 95% CI) for the association between ANA and anti-TPO was 5.94 (1.16-30.42), and thus statistically significant. There was a favorable association (with statistical significance) between HLA B*50 and patients with CSU, with OR (95% CI) of 2.96 (1.17- 7.48).
  
  
  CONCLUSIONS
  A significant favorable association was found between these patients and HLA B*50, and between the presence of anti-TPO and ANA. The greater prevalence of HLA B*50 in these patients and the association between ANA and anti-TPO reinforce the possibility that an immunogenic mechanism may be the triggering factor for CSU.
authors.affiliation: Division of Allergy and Clinical Immunology of Marília Medical School (FAMEMA), Marília, São Paulo, Brazil. calamita@unimedmarilia.com.br
authors.forename: Zamir
authors.initials: Z
authors.lastname: Calamita
authors.forename: Andrea Bronhara
authors.initials: AB
authors.lastname: Pelá Calamita
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000974:Antibodies, Antinuclear / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D001938:Brazil; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D015235:HLA-B Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006648:Histocompatibility / Q000235:genetics; D006650:Histocompatibility Testing; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012882:Skin Tests; D013315:Stress, Psychological; D014581:Urticaria / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000974:Antibodies, Antinuclear; D001324:Autoantigens; D015235:HLA-B Antigens; D033862:Iron-Binding Proteins; C056658:TPO protein, human; D007453:Iodide Peroxidase