title: [Frequency of HLA alleles class I and II in a cohort of northwestern Colombian patients with spondyloarthritis].
abstract: BACKGROUND
  Spondyloarthritis is a chronic rheumatic disease that affect the axial skeleton and peripheral joints, along with several extra-articular manifestations. The association with HLA-B27 remains one of the strongest known links between these entities and the major histocompatibility complex. However, the global distribution of HLA-B27 varies considerably and furthermore, associations with non-HLA-B27 genes have been described.
  
  
  OBJECTIVE
  The frequency of HLA class I and II was determined in a population of patients with spondyloarthritis with respect to detection in the clinical setting and by radiology.
  
  
  METHODS
  A descriptive, observational, cross-sectional, retrospective and prospective study was conducted in 56 patients from northwestern Colombia. Each was diagnosed with spondyloarthritis between 2005 and 2008. In each case, alleles were identified for the loci HLA class I and II (HLA-B; HLADQB1 and HLADRB). The frequency of these alleles in the axial, peripheral, extraarticular and radiological manifestations.
  
  
  RESULTS
  The frequency of HLA-B27 was 50% overall, and it was the most frequent allele. The two other alleles were HLA.DRB4*01 at 35.7% and HLA-DQB1*0501 at 28.6%, as detected in each of the clinical and radiological manifestations. A high frequency of HLA-B27 and HLA-DRB4*01 (64.3%) was noted in patients with dactylitis.
  
  
  CONCLUSIONS
  The alleles HLA-B27, HLA-DRB4*01 and HLA-DQB1*0501 were common in the different subtypes of spondyloarthritis and were frequent in the specific clinical axial, peripheral and extraarticular clinical manifestations, as well as radiological sacroiliitis.
authors.affiliation: Sección de Ingeniería Biológica, Laboratorio de Microbiología Industrial, Laboratorio de Microbiología Industrial, Universidad Nacional de Colombia, Medellín, Colombia.
authors.forename: Eliana Patricia
authors.initials: EP
authors.lastname: Velásquez
authors.forename: Julio César
authors.initials: JC
authors.lastname: Quintero
authors.forename: Beatriz Helena
authors.initials: BH
authors.lastname: Aristizábal
authors.forename: Olga Lucía
authors.initials: OL
authors.lastname: Rincón
authors.forename: Carlos Jaime
authors.initials: CJ
authors.lastname: Velásquez
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Pinto
authors.forename: Javier Darío
authors.initials: JD
authors.lastname: Márquez
mesh_terms: D000328:Adult; D000483:Alleles; D015331:Cohort Studies; D003105:Colombia / Q000453:epidemiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004751:Enteritis / Q000453:epidemiology / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005805:Genes, MHC Class I; D005802:Genes, MHC Class II; D020022:Genetic Predisposition to Disease; D015796:HLA-B27 Antigen / Q000235:genetics; D059866:HLA-DQ beta-Chains / Q000235:genetics; D059811:HLA-DRB1 Chains / Q000235:genetics; D059845:HLA-DRB4 Chains / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012189:Retrospective Studies; D058566:Sacroiliitis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000235:genetics; D017422:Sequence Analysis, DNA; D025241:Spondylarthritis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000235:genetics*; D013167:Spondylitis, Ankylosing / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000235:genetics; D014605:Uveitis / Q000453:epidemiology / Q000235:genetics
chemical_list: D015796:HLA-B27 Antigen; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains; D059845:HLA-DRB4 Chains