title: Differences between familial and sporadic early spondyloarthritis: results from the ESPERANZA cohort.
abstract: OBJECTIVE
  To describe and evaluate clinical and imaging differences between patients with familial and sporadic early spondyloarthritis (SpA).
  
  
  METHODS
  This was a cross-sectional study analysing the baseline dataset from ESPERANZA, a national programme developed for the early identification of patients with SpA. Patients fulfilling SpA ASAS classification criteria were included. Familial SpA was defined according to the ASAS/ESSG criteria as the presence in first- or second-degree relatives of any of the following: ankylosing spondylitis, psoriasis, uveitis, reactive arthritis, and inflammatory bowel disease. Socio-demographic and disease characteristics, disease activity, metrology and laboratory and imaging data were compared by descriptive and bivariate statistics.
  
  
  RESULTS
  A total of 377 patients were included - 64% men, mean age 32, and mean disease duration 12 months. Out of these, 132 (35%) patients (101 axial and 31 peripheral SpA) were familial forms. In patients with axial SpA, statistically significant differences (p<0.05) were found between familial and sporadic forms regarding age at symptoms onset (29.4±9.2 vs. 31.5±10 years), HLA B27 positivity (83% vs. 71%), BASMI (1.2± 13 vs. 1.6 1.2) and sacroiliitis on magnetic resonance imaging (36% vs. 47%), respectively. In patients with peripheral SpA, there were no significant differences for any of the variables analysed.
  
  
  CONCLUSIONS
  Familial axial SpA presents symptoms at a younger age, is more frequently HLA-B27 positive and shows better spinal mobility than sporadic axial SpA; this latter presenting sacroiliitis on MRI more frequently than familial axial SpA. Apparently, no differences exist in the expression of familial or sporadic peripheral SpA.
authors.affiliation: Rheumatology Unit, Hospital Universitario Fundación Alcorcón, Madrid, Spain. ralmodovar@fhalcorcon.es.
authors.forename: Raquel
authors.initials: R
authors.lastname: Almodóvar
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Navarro-Compán
authors.affiliation: Rheumatology Unit, Hospital Universitario de Elda, Alicante, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Fernández-Carballido
authors.affiliation: Rheumatology Unit, Hospital Universitario Virgen de la Salud, Toledo, Spain.
authors.forename: Azucena
authors.initials: A
authors.lastname: Hernández
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Eugenio
authors.initials: E
authors.lastname: De Miguel
authors.affiliation: Rheumatology Unit, Hospital Universitario Fundación Alcorcón, Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Zarco
mesh_terms: D000328:Adult; D017668:Age of Onset; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D042241:Early Diagnosis; D005260:Female; D005820:Genetic Testing; D015796:HLA-B27 Antigen / Q000276:immunology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010641:Phenotype; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D025241:Spondylarthritis / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics / Q000276:immunology
chemical_list: D015796:HLA-B27 Antigen