<Emphasis Type="Italic">EPSTI1</Emphasis> polymorphisms are associated with systemic lupus erythematosus

Epithelial stromal interaction 1 (EPSTI1) is an interferon (IFN) response gene, which was originally identified as a stromal fibroblast-induced gene in breast cancer. Our previous study using a customized SNP chip found evidence of an association between EPSTI1 and susceptibility to the chronic inflammatory disease, systematic lupus erythematosus (SLE). This study aimed to validate whether polymorphisms in EPSTI1 are associated with susceptibility to SLE. We analyzed genotype and allele frequencies of SNPs at EPSTI1 using genomic DNA from 119 patients with SLE and 512 healthy controls. We found that the genotype frequencies of rs1044856 and rs1359184 in patients with SLE were significantly different from those found in the control group (P?=?0.03 and P?=?0.01, respectively). In addition, we found that genotype and allele frequencies of rs1359184 in female patients with SLE were significantly different from those found in female controls (P?=?0.02 and P?=?0.04, respectively). We identified two major haplotypes in EPSTI1 that were significantly different between patients with SLE and healthy controls (P?=?0.01 and P?=?0.05, respectively). Furthermore, we found that rs1359184 and rs1044856 in EPSTI1 were associated with antinuclear antibody (ANA) and erythrocyte sedimentation rate (ESR) levels in patients with SLE (P?=?0.0035 and P?=?0.021, respectively). Our findings indicate that polymorphisms in EPSTI1 are associated with susceptibility to SLE and that haplotypes at EPSTI1 may be useful genetic markers for SLE.