title: Both baseline clinical factors and genetic polymorphisms influence the development of severe functional status in ankylosing spondylitis.
abstract: Functional severity in ankylosing spondylitis (AS) patients is variable and difficult to predict early. The aim of our study was to assess whether a combination of baseline clinical factors and genetic markers may predict the development of severe functional status in AS. We performed a cross-sectional association study on AS patients included in the Spanish National Registry of Spondyloarthropathies--REGISPONSER. Bath Ankylosing Spondylitis Functional Index (BASFI) was standardized by adjusting for disease duration since the first symptoms (BASFI/t). We considered as severe functional status the values of BASFI/t in the top of the 60th (p60), 65th (p65), 70th (p70), and 75th (p75) percentile. We selected 384 single nucleotide polymorphisms (SNPs) distributed in 190 genes to be analyzed. The study cohort included 456 patients with mean age 50.8(± 10.5) years and with mean disease duration since first symptoms 24.7 (± 10.1) years. Older age at disease onset and neck pain at baseline showed statistical significant association with severe BASFI/t. Polymorphisms associated in the allele frequencies test with severe BASFI/t in all classifications were: rs2542151 (p60 [P = .04], p65 [P = .04], p70 [P = .001] and p75 [P = .001]) and rs2254441 (p60 [P = .004], p65 [P = .02], p70 [P = .01] and p75 [P<.001]).. Genotype association, after adjustment for covariates, found an association in three of the four patients' classifications for rs2542151 and in two of the classifications for rs2254441.Forward logistic regression did not identify any model with a good predictive power for severe functional development.In our study we identified clinical factors and 24 polymorphisms associated with development of severe functional status in AS patients. Validation of these results in other cohorts is required.
authors.affiliation: Department of Pharmacology, Iuliu Hatieganu University of Medicine and Pharmacy and SCBI- Rheumatology Department, Cluj-Napoca, Romania.
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Schiotis
authors.forename: Nerea
authors.initials: N
authors.lastname: Bartolomé
authors.forename: Alejandra
authors.initials: A
authors.lastname: Sánchez
authors.forename: Magdalena
authors.initials: M
authors.lastname: Szczypiorska
authors.forename: Jesús
authors.initials: J
authors.lastname: Sanz
authors.forename: Eduardo
authors.initials: E
authors.lastname: Cuende
authors.forename: Eduardo
authors.initials: E
authors.lastname: Collantes Estevez
authors.forename: Antonio
authors.initials: A
authors.lastname: Martínez
authors.forename: Diego
authors.initials: D
authors.lastname: Tejedor
authors.forename: Marta
authors.initials: M
authors.lastname: Artieda
authors.forename: Anca
authors.initials: A
authors.lastname: Buzoianu
authors.forename: Juan
authors.initials: J
authors.lastname: Mulero
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D013030:Spain; D013167:Spondylitis, Ankylosing / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*