Association of the polymorphisms of TRAF1 (rs10818488) and TNFAIP3 (rs2230926) with rheumatoid arthritis and systemic lupus erythematosus and their relationship to disease activity among Egyptian patients

Aim of the study: Recent studies demonstrated the association of tumor necrosis factor á-induced protein 3 (TNFaiP3) (rs2230926) and tumor necrosis factor receptor associated factor 1 (TRaF1) (rs10818488) with rheumatoid arthritis (Ra) and systemic lupus erythematosus (SLe) in different populations. We aimed at determining whether they confer susceptibility to SLe and Ra in egyptian population and if there is any relation to disease activity and auto-antibodies profile. Material and methods: a case-control study involving 105 individuals with Ra, 90 with SLe and 75 healthy controls was performed using TaqMan genotyping assay for two SNPs that showed the best evidence of association in the previous Caucasian studies. Results: We detected significant differences in G allele frequency of TNFaiP3 (rs2230926) with SLe (p = 0.017∗) and Ra (oR = 2.333; 95% Ci: 1.103-4.935, p = 0.023∗) and association with Ra disease activity (< 0.001). The a allele of TRaF1 was significantly increased in Ra compared to controls (p = 0.049) and with Ra activity (p = 0.001), while TRaF1 polymorphism did not exhibit any significant difference in the frequencies of genotypes or alleles in SLe and control (p = 0.280). Conclusions: TNFaiP3 is a susceptibility gene to SLe and Ra in the egyptian population and is correlated to disease activity and the presence of autoantibodies while TRaF1 polymorphisms increase the risk of Ra but not to SLe in egyptian populations.