title: Association of the IL4R single-nucleotide polymorphism I50V with rapidly erosive rheumatoid arthritis.
abstract: OBJECTIVE
  To examine whether single-nucleotide polymorphisms (SNPs) of the interleukin-4 receptor gene IL4R influence susceptibility to, or radiographic progression in, rheumatoid arthritis (RA).
  
  
  METHODS
  The contribution of 2 SNPs (I50V and Q551R) in the coding region of IL4R to RA susceptibility was analyzed by allele-specific polymerase chain reaction in a case-control study of 471 RA patients and 371 healthy controls. Patients with available radiographs of the hands and feet obtained 2 years after disease onset (n = 302) were stratified retrospectively according to radiologic outcome into an erosive and a nonerosive group to evaluate the association between IL4R SNPs and disease progression.
  
  
  RESULTS
  No differences in the genotype and allele frequencies of the I50V or Q551R SNPs were identified between the RA patients and healthy controls. In contrast, significant differences in the distribution of I50V IL4R SNP genotypes between patients with erosive and nonerosive disease were observed (chi2 = 15.68, P = 0.0004). Bone erosions at 2 years after disease onset were present in 68.1% of patients homozygous for the V50 allele compared with 37.0% of patients homozygous for the I50 allele (odds ratio 3.86, P < 0.0001). This association was independent of individual factors previously associated with severe disease, such as rheumatoid factor or the HLA-DR shared epitope. On a cellular level, the V50 allele conferred significantly reduced responsiveness to interleukin-4, providing a possible mechanism for the association of the I50V IL4R polymorphism with early erosions in RA.
  
  
  CONCLUSIONS
  Our data identify the I50V IL4R SNP as a novel genetic marker in RA, showing high predictive value for early joint destruction.
authors.affiliation: Nikolaus Fiebiger Center for Molecular Medicine, Clinical Research Group III, University of Erlangen-Nuremberg, Germany.
authors.forename: Iryna
authors.initials: I
authors.lastname: Prots
authors.forename: Alla
authors.initials: A
authors.lastname: Skapenko
authors.forename: Jörg
authors.initials: J
authors.lastname: Wendler
authors.forename: Stefan
authors.initials: S
authors.lastname: Mattyasovszky
authors.forename: Clarisse L
authors.initials: CL
authors.lastname: Yoné
authors.forename: Bernd
authors.initials: B
authors.lastname: Spriewald
authors.forename: Harald
authors.initials: H
authors.lastname: Burkhardt
authors.forename: Rolf
authors.initials: R
authors.lastname: Rau
authors.forename: Joachim R
authors.initials: JR
authors.lastname: Kalden
authors.forename: Peter E
authors.initials: PE
authors.lastname: Lipsky
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schulze-Koops
mesh_terms: D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D053662:Interleukin-4 Receptor alpha Subunit; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D019948:Receptors, Interleukin-4 / Q000235:genetics*; D013997:Time Factors
chemical_list: C504000:IL4R protein, human; D053662:Interleukin-4 Receptor alpha Subunit; D019948:Receptors, Interleukin-4