title: HLA-B27 frequency in a group of patients with psoriatic arthritis.
abstract: BACKGROUND
  HLA-B27 is associated with spondyloarthritis, a group of diseases that includes psoriatic arthritis.
  
  
  OBJECTIVE
  To describe the HLA-B27 frequency in a group of Brazilian patients with psoriatic arthritis and correlate its presence or absence with their clinical manifestations.
  
  
  METHODS
  Cross-sectional study with 44 psoriatic arthritis patients of a Rheumatology clinic. Demographic and social data were recorded, as were skin and joints clinical examination. HLA-B27 was tested. All data were processed descriptively and comparatively by appropriate software. Parametric and non parametric tests were used with 5% statistical significance.
  
  
  RESULTS
  HLA-B27 was negative in 32 of the 44 patients (72,7%). Most of them were male, Caucasian, living in Rio de Janeiro, with plaque type psoriasis and average age of 52,9 years. There was statistical significant correlation between positive HLA-B27 and male gender (p=0,004). Negative HLA-B27 had a tendency to correlate with hands and wrists arthritis (p=0,07). There was an inverse significant correlation between HLA values and Schöber's test (p=0,02).
  
  
  CONCLUSIONS
  Although HLA-B27 is negative in most of patients, it is significantly associated to male gender and inversely correlated with Schöber's test.
authors.affiliation: Federal University of Rio de Janeiro (UFRJ) - Porto Nacional (TO), Brazil. danilogruiz@hotmail.com
authors.forename: Danilo Garcia
authors.initials: DG
authors.lastname: Ruiz
authors.forename: Mário Newton Leitão de
authors.initials: MN
authors.lastname: Azevedo
authors.forename: Omar
authors.initials: O
authors.lastname: Lupi
mesh_terms: D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D003430:Cross-Sectional Studies; D005260:Female; D015796:HLA-B27 Antigen / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012959:Socioeconomic Factors
chemical_list: D015415:Biomarkers; D015796:HLA-B27 Antigen