title: Preferential association of interferon regulatory factor 5 gene variants with seronegative rheumatoid arthritis in 2 Swedish case-control studies.
abstract: OBJECTIVE
  Two interferon regulatory factor 5 (IRF5) gene variants were examined for association with rheumatoid arthritis (RA).
  
  
  METHODS
  A total of 2300 patients with RA and 1836 controls were recruited from 2 independent RA studies in Sweden. One insertion-deletion polymorphism (CGGGG indel) and one single-nucleotide polymorphism (rs10488631) in the IRF5 gene were genotyped and analyzed within RA subgroups stratified by rheumatoid factor (RF) and anticitrullinated peptide antibodies (ACPA).
  
  
  RESULTS
  The CGGGG indel was preferentially associated with the RF-negative (OR 1.29, p = 7.9 × 10(-5)) and ACPA-negative (OR 1.27, p = 7.3 × 10(-5)) RA subgroups compared to the seropositive counterparts. rs10488631 was exclusively associated within the seronegative RA subgroups (RF-negative: OR 1.24, p = 0.016; ACPA-negative: OR 1.27, p = 4.1 × 10(-3)).
  
  
  CONCLUSIONS
  Both the CGGGG indel and rs10488631 are relevant for RA susceptibility, especially for seronegative RA.
authors.affiliation: Department of Medical Sciences, Uppsala University, Molecular Medicine, Research Department II, Entrance 70, 3rd Floor, Academic Hospital, SE-75185 Uppsala, Sweden.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.forename: Heidi
authors.initials: H
authors.lastname: Kokkonen
authors.forename: Johanna K
authors.initials: JK
authors.lastname: Sandling
authors.forename: Martin
authors.initials: M
authors.lastname: Johansson
authors.forename: Maria
authors.initials: M
authors.lastname: Seddighzadeh
authors.forename: Leonid
authors.initials: L
authors.lastname: Padyukov
authors.forename: Solbritt
authors.initials: S
authors.lastname: Rantapää-Dahlqvist
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Syvänen
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D050835:Interferon Regulatory Factors / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D013548:Sweden
chemical_list: C431713:IRF5 protein, human; D050835:Interferon Regulatory Factors