title: TNFalpha polymorphisms and risk of psoriatic arthritis.
abstract: BACKGROUND
  Tumour necrosis factor alpha (TNFalpha) is a cytokine of critical importance in psoriatic arthritis.
  
  
  OBJECTIVE
  (1) To examine the association between TNFalpha promoter gene polymorphisms and psoriatic arthritis in two well characterised Canadian populations with the disease; (2) to carry out a meta-analysis of all TNFalpha association studies in white psoriatic arthritis populations.
  
  
  METHODS
  DNA samples were genotyped for five TNF variants by time of flight mass spectrometry using the Sequenom platform. All five single nucleotide polymorphisms were in the 5' flanking region of TNFalpha gene at the following positions: -1031 (T-->C), -863 (C-->A), -857 (C-->T), -308 (G-->A), and -238 (G-->A). Primary analyses were based on logistic regression. Summary estimates of disease/genotype relations from several studies were derived from random effects meta-analyses.
  
  
  RESULTS
  237 psoriatic arthritis subjects and 103 controls from Newfoundland and 203 psoriatic arthritis subjects and 101 controls from Toronto were studied. A combined analysis of data from both populations, showed a significant association between disease status and the -238(A) variant (p=0.01). The meta-analysis estimate for the -238(A) TNFalpha variant in eight psoriatic arthritis populations was also significant (odds ratio=2.29 (95% confidence interval, 1.48 to 3.55)).
  
  
  CONCLUSIONS
  Analysis of TNFalpha variants in psoriatic arthritis populations shows that the -238 (A) variant is a significant risk factor for this disease.
authors.affiliation: St Clare's Mercy Hospital, Memorial University of Newfoundland, 1 South-154 LeMarchant Rd, St John's, Newfoundland, Canada A1C-5B8. prahman@mun.ca
authors.forename: P
authors.initials: P
authors.lastname: Rahman
authors.forename: F
authors.initials: F
authors.lastname: Siannis
authors.forename: C
authors.initials: C
authors.lastname: Butt
authors.forename: V
authors.initials: V
authors.lastname: Farewell
authors.forename: L
authors.initials: L
authors.lastname: Peddle
authors.forename: F
authors.initials: F
authors.lastname: Pellett
authors.forename: D
authors.initials: D
authors.lastname: Gladman
mesh_terms: D015535:Arthritis, Psoriatic / Q000235:genetics*; D002170:Canada; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D015810:Linkage Disequilibrium; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha