title: Prevalence of spondyloarthritis in reference to HLA-B27 in the French population: results of the GAZEL cohort.
abstract: OBJECTIVE
  To estimate the prevalence of spondyloarthritis (SpA) in reference to HLA-B27 in the French population.
  
  
  METHODS
  In 1989, 20 625 employees of the French national gas and electricity company aged 35-50 years were enrolled in the GAZEL cohort. In 2010, 18 757 still active participants were screened by a questionnaire validated for the detection of SpA. Responders with available DNA were retained for further studies. Pelvic radiograph and HLA-B27 typing were performed in all the self-reported cases of SpA or psoriatic arthritis. Self-reported diagnosis was verified by a qualified rheumatologist. HLA-B27 determination was also performed in subjects without any SpA feature.
  
  
  RESULTS
  The target population consisted of 6556 responders with available DNA. Their male:female ratio was 3.6 and their mean age was 65.5±3.3 years. A diagnosis of SpA was confirmed in 32 of the 72 self-reported cases, 75% of them being HLA-B27 positive. Estimated SpA prevalence adjusted for sex was 0.43% (95% CI 0.26% to 0.70%). HLA-B27 positivity rate in 2466 healthy controls was 6.9% (95% CI 5.9% to 7.9%). The relative risk of SpA in HLA-B27 positive individuals was 39 (95% CI 17 to 86).
  
  
  CONCLUSIONS
  We estimated the prevalence of SpA in the French population in 2010 to 0.43%. With an estimated prevalence of 75.0% in SpA and 6.9% in healthy controls, HLA-B27 increased the disease risk 39-fold, as compared with HLA-B27 negative subjects.
authors.affiliation: Institut Cochin, Université Paris Descartes, Paris, France INSERM U1016, Paris, France.
authors.forename: Félicie
authors.initials: F
authors.lastname: Costantino
authors.affiliation: Institut Cochin, Université Paris Descartes, Paris, France INSERM U1016, Paris, France.
authors.forename: Alice
authors.initials: A
authors.lastname: Talpin
authors.affiliation: Rheumatology Division, Ambroise Paré Hospital (AP-HP), Boulogne-Billancourt, France.
authors.forename: Roula
authors.initials: R
authors.lastname: Said-Nahal
authors.affiliation: Population-Based Epidemiological Cohorts, Research Platform, UMRS 1018, Centre for Research in Epidemiology and Population Health, Villejuif, France UFR des Sciences de la Santé, Simone Veil, Versailles Saint Quentin en Yvelines University, Montigny-Le-Bretonneux, France.
authors.forename: Marcel
authors.initials: M
authors.lastname: Goldberg
authors.affiliation: Population-Based Epidemiological Cohorts, Research Platform, UMRS 1018, Centre for Research in Epidemiology and Population Health, Villejuif, France UFR des Sciences de la Santé, Simone Veil, Versailles Saint Quentin en Yvelines University, Montigny-Le-Bretonneux, France.
authors.forename: Joseph
authors.initials: J
authors.lastname: Henny
authors.affiliation: Institut Cochin, Université Paris Descartes, Paris, France INSERM U1016, Paris, France UFR des Sciences de la Santé, Simone Veil, Versailles Saint Quentin en Yvelines University, Montigny-Le-Bretonneux, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Chiocchia
authors.affiliation: Institut Cochin, Université Paris Descartes, Paris, France INSERM U1016, Paris, France UFR des Sciences de la Santé, Simone Veil, Versailles Saint Quentin en Yvelines University, Montigny-Le-Bretonneux, France Genetics Division, Ambroise Paré Hospital (AP-HP) Boulogne-Billancourt, France.
authors.forename: Henri-Jean
authors.initials: HJ
authors.lastname: Garchon
authors.affiliation: Population-Based Epidemiological Cohorts, Research Platform, UMRS 1018, Centre for Research in Epidemiology and Population Health, Villejuif, France UFR des Sciences de la Santé, Simone Veil, Versailles Saint Quentin en Yvelines University, Montigny-Le-Bretonneux, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Zins
authors.affiliation: Institut Cochin, Université Paris Descartes, Paris, France INSERM U1016, Paris, France Rheumatology Division, Ambroise Paré Hospital (AP-HP), Boulogne-Billancourt, France UFR des Sciences de la Santé, Simone Veil, Versailles Saint Quentin en Yvelines University, Montigny-Le-Bretonneux, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Breban
mesh_terms: D000368:Aged; D015535:Arthritis, Psoriatic / Q000453:epidemiology / Q000235:genetics; D015331:Cohort Studies; D005260:Female; D005602:France / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D015796:HLA-B27 Antigen / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D025241:Spondylarthritis / Q000453:epidemiology / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D015796:HLA-B27 Antigen
keywords: Ankylosing Spondylitis; Epidemiology; Spondyloarthritis