title: Variation in the TNF gene promoter and risk of osteolysis after total hip arthroplasty.
abstract: Genetic factors may influence implant failure caused by osteolysis after THA. In an association study of 481 subjects after THA, we found that carriage of the TNF-238A allele was associated with an increased incidence of osteolysis versus noncarriage (odds ratio, 1.7) and was independent of other risk factors. Genetic and environmental factors influence implant survival after THA.
  
  
  BACKGROUND
  Tumor necrosis factor (TNF) is thought to play a role in osteolysis, the major cause of implant failure after total hip arthroplasty (THA). Natural sequence variations at -238 and -308 in the TNF gene promoter are associated with differences in susceptibility to several TNF-mediated diseases. We tested whether these polymorphisms are associated with osteolysis after THA.
  
  
  METHODS
  A total of 481 whites (214 with failed versus 267 with intact implants) were recruited 11.7 +/- 4 years after cemented THA. Genomic DNA was extracted from peripheral blood and genotyped for the -238 and -308 polymorphisms using the Taqman 5' nuclease method. Healthy controls (n = 500) from the background population were also genotyped to establish the local prevalence of these alleles.
  
  
  RESULTS
  The carriage of -238A was 8.8% in the background population and 10.9% in the THA controls (p > 0.05). Carriage of -238A in the osteolysis group was 17.3% (odds ratio, 1.7; 95% CI, 1.0-2.9). Carriage was highest (20.5%) in patients with more widespread osteolysis (OR, 2.1; 1.2-3.8). The association of -238A with osteolysis was independent of other risk factors for osteolysis (logistic regression analysis: OR, 1.8; 1.0-3.2). Carriage of -308A was not associated with osteolysis.
  
  
  CONCLUSIONS
  Genetic, as well as environmental factors, influence implant failure after THA. Whether the TNF-238 polymorphism causes a biological change that predisposes to loosening or is in linkage disequilibrium with such a locus is not yet known.
authors: Division of Clinical Sciences, Bone Metabolism Group, University of Sheffield, Northern General Hospital, Sheffield, United Kingdom. wilkomark@aol.com
authors: J Mark
authors: JM
authors: Wilkinson
authors: A Gerard
authors: AG
authors: Wilson
authors: Ian
authors: I
authors: Stockley
authors: Ian R
authors: IR
authors: Scott
authors: David A
authors: DA
authors: Macdonald
authors: Andrew J
authors: AJ
authors: Hamer
authors: Gordon W
authors: GW
authors: Duff
authors: Richard
authors: R
authors: Eastell
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D004777:Environment; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D006085:Graft Survival / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010014:Osteolysis / Q000209:etiology / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha