Genetic polymorphisms modifying oxidative stress are associated with disease activity in rheumatoid arthritis patients

Reactive oxygen and nitrogen species are involved in the pathology of rheumatoid arthritis (RA). Polymorphisms in genes coding for superoxide dismutases (SOD2 and SOD3), catalase (CAT), tumor necrosis factor-alpha (TNFA) and inducible NO synthase (NOS2A) may influence RA activity. We determined SOD2 Ala-9Val, SOD3 Arg213Gly, CAT C-262T, TNFA G-308A, TNFA C-857T and NOS2A (CCTTT)(n) polymorphisms in 327 RA patients. Carriers of CAT -262T and TNFA -308A allele had lower mean disease activity score of 28 joint count (DAS28) values than patients with CAT -262CC and TNFA -308GG genotypes (p = 0.014 and p = 0.046, respectively). Patients with the combination of CAT -262T and TNFA -308A allele had lower mean DAS28 values and a higher probability for low disease activity than non-carriers (p = 0.003, OR = 3.585, 95% CI = 1.538-8.357). Our results suggest that CAT and TNFA polymorphisms alone and in combination influence the activity of RA.