title: Analysis of HLA-B15 and HLA-B27 in spondyloarthritis with peripheral and axial clinical patterns.
abstract: OBJECTIVE
  Human leucocyte antigen (HLA) B27 and HLA-B15 are associated with spondyloarthritis (SpA). Recent Assessment of SpondyloArthritis international Society (ASAS) criteria emphasise a distinction between SpA with axial and peripheral patterns. We analysed whether HLA-A, HLA-B and HLA-DRB1 alleles could associate with these patterns.
  
  
  METHODS
  We studied 100 healthy individuals and 178 patients with SpA according to European Spondyloarthropathy Study Group (ESSG) criteria. Patients were then classified according to ASAS criteria, the axial spondyloarthritis pattern (axSpA) being defined by ascertained sacroiliitis and the peripheral pattern (pSpA) by enthesitis and/or arthritis in extremities. A combined ax/p pattern was also considered.
  
  
  RESULTS
  Only HLA-B27 and HLA-B15 alleles were associated with SpA. ASAS criteria for axSpA were met in 152 patients (12 with isolated axSpA and 140 with a combined ax/p patterns). When the ASAS peripheral criteria were applied, 161 patients met these criteria (13 with isolated pSpA and 148 with a combined ax/p pattern). HLA-B27 was found in 83% of patients with axSpA and 43% of ax/pSpA patients according to axASAS. HLA-B27 occurred in 7% controls but not in any patient with isolated pSpA. HLA-B15 was encountered in 31% of patients with isolated pSpA and 20% of ax/pSpA patients according to pASAS criteria. Moreover, 2 healthy controls, but none of our patients with isolated axSpA were positive for HLA-B15.
  
  
  CONCLUSIONS
  Our data suggest that the presence of HLA-B15 favours the development of isolated/combined peripheral rather than isolated axSpA, while HLA-B27 promotes an isolated/combined axial disease and excludes a peripheral pattern. HLA-B15 should be considered in addition to HLA-B27 when diagnosing patients with SpA according to ASAS criteria.
authors.affiliation: Department of Rheumatology, University of La Sabana, Chia, Cundinamarca, Colombia.
authors.forename: John
authors.identifier: http://orcid.org/0000-0003-1074-644X
authors.initials: J
authors.lastname: Londono
authors.affiliation: Department of Rheumatology, University of La Sabana, Chia, Cundinamarca, Colombia.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Santos
authors.affiliation: Department of Rheumatology, University of La Sabana, Chia, Cundinamarca, Colombia.
authors.forename: Paola
authors.initials: P
authors.lastname: Peña
authors.affiliation: Department of Radiology, National University of Colombia, Bogota, Colombia.
authors.forename: Enrique
authors.initials: E
authors.lastname: Calvo
authors.affiliation: LSU Health Sciences Center, Louisiana State University, New Orleans, Louisiana, USA.
authors.forename: Luis R
authors.initials: LR
authors.lastname: Espinosa
authors.affiliation: Division of Rheumatology and Clinical Immunogenetics, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Reveille
authors.affiliation: Interventional Genetic Study Group in Cardiovascular Diseases, Department of Molecular Biology, National Institute of Cardiology Ignacio Chávez, Mexico DF, Mexico.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Vargas-Alarcon
authors.affiliation: Department of Biological Sciences, University of Los Andes, Bogota, Colombia.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Jaramillo
authors.affiliation: Rheumatology and Immunology Unit, Department of Internal Medicine, Hospital Militar Central, Bogota, Colombia.
authors.forename: Rafael
authors.initials: R
authors.lastname: Valle-Oñate
authors.affiliation: Department of Rheumatology, University of La Sabana, Chia, Cundinamarca, Colombia Rheumatology and Immunology Unit, Department of Internal Medicine, Hospital Militar Central, Bogota, Colombia.
authors.forename: Mabel
authors.initials: M
authors.lastname: Avila
authors.affiliation: Rheumatology and Immunology Unit, Department of Internal Medicine, Hospital Militar Central, Bogota, Colombia.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Romero
authors.affiliation: Department of Internal Medicine, School of Medicine, University of Navarra and Ciberehd, Pamplona, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Medina
mesh_terms: D000328:Adult; D005260:Female; D005838:Genotype; D059910:HLA-B15 Antigen / Q000235:genetics*; D015796:HLA-B27 Antigen / Q000235:genetics*; D006801:Humans; D008297:Male; D025241:Spondylarthritis / Q000145:classification* / Q000235:genetics*
chemical_list: D059910:HLA-B15 Antigen; D015796:HLA-B27 Antigen
keywords: GENETICS; IMMUNOLOGY; RHEUMATOLOGY