Association of interleukin-10 gene single nucleotide polymorphisms with susceptibility to systemic lupus erythematosus in a Chinese population

The aim of this study was to investigate the association of interleukin (IL)-10 gene single nucleotide polymorphisms (SNPs) with susceptibility to systemic lupus erythematosus (SLE) in a Chinese population. 848 SLE patients and 461 normal controls were recruited in this study. Nine SNPs in IL-10 gene (rs1518110, rs1518111, rs1554286, rs1800890, rs1800893, rs3024493, rs3024495, rs3024498 and rs6667202) were genotyped using TaqMan genotyping assays on Fluidigm 192.24 system. The frequency of IL-10 rs3024498-C allele was significantly higher in patient group compared with control subjects (OR = 5.118, 95% CI = 1.819-14.405, P = 0.002). No significant differences were detected for the distribution of allele and genotype frequencies of other eight SNPs between patients with SLE and controls after Bonferroni correction (all P > 0.0056). Interestingly, significant differences were detected both in the allele and genotype frequencies of rs3024498 between SLE patients with and without arthritis (P = 0.002, P = 0.022, respectively).There was significant difference in genotype frequency at rs3024498 between SLE patients with and without malar rash (P = 0.040). And, there was significant difference in allele frequency at rs3024498 between SLE patients with and without anti-double-stranded DNA (P = 0.032). Meanwhile, significant difference in genotype frequency at rs1518110 and rs1518111 were found in patients with and without lupus headache (P = 0.025, P = 0.038, respectively). There were significant difference in allele and genotype frequency at rs1800890 and rs6667202 between SLE patients with and without thrombocytopenia (rs1800890: P = 0.016, P = 0.026, respectively; rs6667202: P = 0.007, P = 0.007, respectively). Further, significant difference were observed both in allele frequency and in genotype distribution of rs1800893 between patients with and without tubular urine and proteinuria (tubular urine: P < 0.001, P = 0.003, respectively; proteinuria: P = 0.001, P = 0.018, respectively). In summary, IL-10 rs3024498 polymorphism might contribute to SLE susceptibility and several clinical phenotypes.