Tumor necrosis factor gene polymorphisms are associated with systemic lupus erythematosus susceptibility or lupus nephritis in Mexican patients

The TNF -238G/A (rs361525) and -308G/A (rs1800629) polymorphisms have consistently been associated with systemic lupus erythematosus (SLE) in several populations; however, these findings have not been verified in all populations. Here, we aimed to examine whether the TNF -238G/A, -308G/A, -376G/A (rs1800750), and -1031T/C (rs1799964) polymorphisms confer SLE or lupus nephritis (LN) susceptibility in a Mexican population. Our study included 442 patients with SLE and 495 controls. For genotyping, we used the TaqMan 5′ allele discrimination assay. The TNF -238G/A and -1031T/C polymorphisms were associated with SLE susceptibility (odds ratio (OR) 2.1, p = 0.0005 and OR 1.4, p = 0.003, respectively). Gender stratification showed a strong association between TNF -238G/A and SLE in women (OR 2.2, p = 0.00006), while TNF -1031T/C had an OR of 1.5 ( p = 0.007). With regard to the TNF -376G/A polymorphism, this also showed association with SLE susceptibility (OR 1.95, p = 0.036) and LN (OR 3.5, p = 0.01). In conclusion, our study provides the first demonstration of association between the TNF -376G/A polymorphism and SLE and LN susceptibility. In addition, our study is the second documenting an association of TNF -1031T/C with SLE susceptibility. We also observed a strong association between TNF -238G/A and SLE susceptibility. The TNF 308G/A polymorphism was not associated with SLE or LN.