Clinical significance of serum TNFα and -308 G/A promoter polymorphism in rheumatoid arthritis

To evaluate the clinical significance of serum levels of tumor necrosis factor alpha (TNFα) and -308 G/A promoter polymorphism in rheumatoid arthritis (RA) patients. We studied 43 RA patients and 30 controls. Demographic, clinical and serological data were prospectively evaluated. Disease activity score (DAS28) and the Health Assessment Questionnaire (HAQ) were assessed. Serum TNF-α level was measured and promoter (-308 G/A) genotyped. Serum TNF-α level was significantly higher in the RA patients compared to controls (p = 0.036) and was significantly higher in those with AA promoter polymorphism who had a significantly younger age at disease onset. In the multivariate analysis, disease duration would predict the TNFα level (p = 0.006) while age at disease onset, DAS28 and HAQ would predict the TNFα polymorphism (p = 0.004, p = 0.04 and p = 0.03 respectively). A significant negative correlation was present between TNFα level with age (p = 0.001) and age at disease onset (p < 0.0001) while in those with GA genotype a significant negative correlation was present with DAS28 (r = −0.66, p = 0.038). Serum TNFα levels and -308 G/A promoter polymorphism were higher in RA patients than in controls and could be predicted by disease activity and HAQ.