title: The influence of a TNF gene polymorphism on the severity of rheumatoid arthritis in the Brazilian Amazon.
abstract: OBJECTIVE
  The aim of this study was to investigate the influence of the TNF -308 G/A polymorphism in the promoter region of the tumor necrosis factor-α gene on the susceptibility and severity of rheumatoid arthritis (RA) in individuals from the Brazilian Amazon.
  
  
  METHODS
  A total of 323 individuals-192 healthy controls without arthritis and 131 individuals suffering from arthritis-were genotyped for this polymorphism using a methodology based on PCR-RFLP.
  
  
  RESULTS
  The frequency of the A allele (TNF2) in rheumatoid arthritis sufferers was not significantly higher than in the controls (p=0.926; OR=0.97; confidence interval 0.54-1.76). However, using a logistic regression model, when the patients were stratified according to whether the manifestations were preponderantly articular or systemic, there was a strong association between the TNF2 allele and systemic arthritis (p=0.001; OR=5.89; confidence interval=1.98-17.5) as well as the use of anti-TNF immunotherapy (p=0.023; OR=1.10; confidence interval=1.00-1.14). The main factors that were found to influence the risk of extra-articular disease were age greater than or equal to 60 years (p=0.008; OR=4.06; confidence interval=1.45-11.38), disease duration greater than 10 years (p=0.031; OR=3.10; confidence interval=1.11-8.63) and positive rheumatoid factor (p=0.035; OR=2.07; confidence interval=1.05-4.09).
  
  
  CONCLUSIONS
  These results suggest that the TNF2 allele is associated with the more serious forms of the disease in individuals from the Brazilian Amazon but not with a risk for developing RA.
authors.affiliation: Clínica de Artrite Reumatoide, Hospital Adriano Jorge, Manaus, Brazil. alboechat@ufam.edu.br
authors.forename: Antonio Luiz
authors.initials: AL
authors.lastname: Boechat
authors.forename: Narjara de Oliveira
authors.initials: Nde O
authors.lastname: Boechat
authors.forename: Mauricio Morishi
authors.initials: MM
authors.lastname: Ogusku
authors.forename: Mariana Raposo
authors.initials: MR
authors.lastname: Alencar
authors.forename: Themis da Costa
authors.initials: Tda C
authors.lastname: Abensur
authors.forename: José
authors.initials: J
authors.lastname: Cardoso Neto
authors.forename: Leilian de Souza
authors.initials: Lde S
authors.lastname: Amorim
authors.forename: Lívia Moura
authors.initials: LM
authors.lastname: de Oliveira
authors.forename: Aya
authors.initials: A
authors.lastname: Sadahiro
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Dos-Santos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000473:pathology*; D001938:Brazil; D016022:Case-Control Studies; D003710:Demography; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007596:Joints / Q000473:pathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012372:ROC Curve; D015203:Reproducibility of Results; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D055815:Young Adult
chemical_list: C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha