title: The role of autoimmune testing in chronic idiopathic urticaria.
abstract: BACKGROUND
  The clinical implications of autoimmune testing in chronic idiopathic urticaria (CIU) are not well established.
  
  
  OBJECTIVE
  To identify the association of autoimmune biomarkers in CIU with disease severity.
  
  
  METHODS
  We retrospectively evaluated 195 patients with a diagnosis of CIU for the presence of antinuclear antibody (ANA), anti-thyroglobulin antibody (ATG), anti-thyroperoxidase antibody (ATPO), and Chronic Urticaria (CU) Index. The patients were categorized into controlled and refractory subgroups based on their response to antihistamines with or without a leukotriene receptor antagonist.
  
  
  RESULTS
  The percentage of patients with a positive test for ANA (titer>1:160), ATG, ATPO, and CU Index were 29%, 6%, 26%, and 38%, respectively. Among those tested, the percentage of patients categorized as refractory was significantly higher in those with a positive CU index (80% vs 46%; P = .01) or a positive ANA titer (50% vs 30%; P = .04) than those with negative test results; however, a similar relationship was not observed for ATPO or ATG antibodies. Odds ratios of individual or combinations of autoimmune biomarkers in CIU were examined for associations with refractoriness to antihistamines with or without a leukotriene receptor antagonist. The CU Index alone has an odds ratio of 4.5 (P = .005), whereas the combination of ANA, ATG, and ATPO has an odds ratio of 3.1 (P = .01) and ANA alone has an odds ratio of 2.3 (P = .04) for correlating with a refractory outcome.
  
  
  CONCLUSIONS
  Our data indicate the CU Index independently has the strongest correlation with disease severity followed by the combination of ANA, ATG, and ATPO and the ANA alone.
authors.affiliation: Division of Allergy, Pulmonary and Critical Care, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; Department of Medicine, William S. Middleton Veterans Hospital, Madison, Wisconsin.
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Viswanathan
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Biagtan
authors.forename: Sameer K
authors.initials: SK
authors.lastname: Mathur
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000097:blood*; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology; D015415:Biomarkers / Q000097:blood*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D014581:Urticaria / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D015415:Biomarkers; C006606:anti-thyroglobulin; D007073:Immunoglobulin E