Objective: To determine whether a polymorphism within the tumour necrosis factor alpha (TNF alpha) gene is associated with susceptibility to, or severity of, rheumatoid arthritis (RA).
Methods: Consecutive patients with recent onset RA were enrolled in a prospective trial. DNA was collected, disease activity was measured at presentation, and radiographic progression at three years was assessed. Typing of TNF alpha was by polymerase chain reaction and single stranded conformation polymorphism analysis.
Results: No association of TNF alpha alleles and susceptibility to, or severity of, RA was demonstrated.
Conclusions: These results indicate that this TNF alpha polymorphism does not play a part in the genetic background of RA.