Association of the polymorphisms rs179008 ( TLR7 ), rs2004640 ( IRF5 ), rs1800795 ( IL-6 ) and rs2280788 ( CCL5 ) with systemic lupus erythematosus in women of Mayan ethnicity from Yucatan.

Introduction: IFN-α is the main cytokine in SLE, and single nucleotide polymorphisms (SNP) in different genes could induce it. Aim: To determine the association of rs2004640 ( IRF5 ), rs179008 ( TLR7 ), rs1800795 ( IL-6 ) and rs2280788 ( CCL5 ) with SLE in Mexican women with Mayan ethnicity. Methods: DNA and RNA were isolated from the peripheral blood of 110 patients and 200 healthy control subjects. SNP genotyping and gene expression analysis of IRF5, TLR7, IL-6 and IFN-α were determined by real-time PCR and analyzed with SNP Stat, Stata 10.1 and Graph Pad Prism v5. Results: rs2004640, rs179008, and rs1800795 in both groups were according to Hardy-Weinberg equilibrium. Risk alleles rs179008T and rs2004640T frequencies were higher in controls ( p  = 0.015 and p  = 0.028, respectively), whereas rs179008A frequency was higher in patients ( p  = 0.015). Allelic combination AGT frequency was higher in patients ( p  = 0.001). IL-6 rs1800795C > G and CCL5 rs2280788G > C frequencies did not show significant differences ( p  > 0.05), being rs2280788G ( CCL5 ) monomorphic in controls. SLE patients showed higher TLR7, IRF5, IL6, and IFN-α mRNA levels. IRF5 expression was higher in SLE patients homozygous for rs2004640T ( IRF5 ). Conclusion: This work showed the contribution of TLR7 and IRF5 in SLE pathogenesis in Mayan females from Yucatan.