Among eight SSc-associated susceptibility polymorphisms which were applied for meta-analysis, IRF5 rs2004640 polymorphism (OR 1.12; 95% CI 1.02-1.22, P = 1.39 × 10<sup>-2</sup>), STAT4 rs7574865 polymorphism (OR 1.25; 95% CI 1.07-1.47, P = 5.3 × 10<sup>-3</sup>), IRAK1 rs1059702 polymorphism (OR 1.20; 95% CI 1.05-1.37, P = 0.007), and CTGF G-945C polymorphism (OR 1.42; 95% CI 1.18-1.71, P = 0.002) are associated with PF status in SSc, while TNFAIP3 rs5029939, CD226 rs763361, CD247 rs2056626, and IRF5 rs10488631 polymorphisms are not.
The aim of this study was to investigate the association of signal transducer and activator of transcription 4 (STAT4) rs7574865 and interferon regulatory factor 5 (IRF5) rs2004640 polymorphisms with risk of SSc.
The results demonstrated that STAT4 rs7574865 and IRF5 rs2004640G/T substitution are associated with a susceptibility to SSc, and they may serve as the SSc genetic susceptibility factor.
The SNP rs2004640 was significantly associated with SLE, MS, and SSc, but not with JIA [odds ratio (OR)=1.06, 95% confidence interval (CI)=0.90-1.24, P=0.48] or RA (OR=1.03, 95%CI=0.95-1.11, P=0.44).
Conditional analysis revealed that rs2280714 could account for most of the association of these SNPs, while an additional contribution of rs2004640 was also suggested for dcSSc.
An additive effect of the STAT4 rs7574865 T allele and the IRF5 rs2004640 T allele was observed, resulting in a multiple increased 1.28-fold risk of SSc.