Objectives: To determine if a tumour necrosis factor (TNF +489) polymorphism is associated with susceptibility to rheumatoid arthritis (RA).
Methods: Two European populations were studied: 217 controls and 238 patients from the north of England and 145 controls and 179 patients from Spain. HLA-DRB1 and TNF +489 markers were typed using polymerase chain reaction based methods.
Results: Strong associations were demonstrated with shared epitope (SE) encoding HLA-DRB1 alleles in the English (OR = 2.9 [2.2-3.9]) and Spanish (OR = 2.3 [1.6-3.3]) populations, however no association was found with TNF +489 alleles. Furthermore carriage of TNF +489A was not associated with the presence of radiological erosions, rheumatoid nodules or rheumatoid factor.
Conclusion: The role of the TNF locus in the genetic background of RA is unclear, however, our data does not support the previous reported association of the TNF +489A allele with RA susceptibility or severity.