Association of IFI44L rs273259 polymorphism with the susceptibility and clinical characteristics of Systemic Lupus Erythematosus in a Chinese population

Background: Interferon (IFN)-inducible 44 like (<em>IFI44L</em>) is a newly discovered interferon-stimulated gene (ISG) which elevated in genes profile of many autoimmune diseases. The <em>IFI44L</em> rs273259 polymorphism has been reported to associate with the susceptibility of some infectious. In this present study, we aimed to evaluate the association of <em>IFI44L</em> gene polymorphism with the susceptibility and clinical characteristics of Systemic lupus erythematosus (SLE) in a Chinese population. Methods: A total of 576 SLE patients and 600 controls were recruited in this case-control study. Blood DNA was extracted using a genomic DNA isolation kit. The <em>IFI44L</em> rs273259 polymorphism was detected by TaqMan SNP Genotyping Assay Kit. Results: The frequencies of genotype AA (48.61% vs. 67.00%), AG (43.40% vs. 21.00%) and GG (7.99% vs. 12.00%) in SLE patients have a significantly difference compared to healthy controls (χ2 =67.985, <em>P</em>&lt;0.001). The genotype AG was associated with increased susceptibility of SLE when compared to the genotype AA (OR, 2.849; 95% CI, 2.190-3.705; <em>P</em>&lt;0.001). The frequencies of allele A (70.31% vs. 77.50%) and G (29.69% vs. 22.50%) in SLE patients have a significantly difference compared to healthy controls (χ2 =15.773, <em>P</em>&lt;0.001). The allele G was associated with increased susceptibility of SLE when compared to the allele A (OR, 1.454; 95% CI, 1.208-1.750; <em>P</em>&lt;0.001). The Genotype AG (AA vs. AG, OR, 1.81; 95% CI, 1.10-3.21; <em>P</em>=0.003) and GG (AA vs. GG, OR, 3.01; 95% CI, 0.92-5.76; <em>P</em>=0.036) was associated with increased susceptibility in female SLE patient and no significant difference was observed based on age. In addition, <em>IFI44L</em> gene polymorphism was associated with clinical characteristics of SLE including malar rash (χ2=105.837, <em>P</em>&lt;0.001), discoid rash (χ2=15.617, <em>P</em>&lt;0.001), lupus nephritis (χ2=58.860, <em>P</em>&lt;0.001) and Anti-Smith antibodies (χ2=44.256, <em>P</em>&lt;0.001). Conclusions: The genotype AG and allele G of <em>IFI44L</em> rs273259 increased the susceptibility to SLE in the Chinese population. <em>IFI44L</em> rs27325 polymorphism was associated with the presence of malar rash, discoid rash, lupus nephritis and anti-Smith antibodies in SLE patients.