Association Between <b><i>IFN-γ</i></b> Gene Polymorphisms and IgA Nephropathy in a Chinese Han Population

Abstract

<b><i>Background/Aims:</i></b> <i>IFN-γ</i> was reported to be involved in the development and progression of Immunoglobulin A nephropathy (IgAN), however, few studies have investigated the association between <i>IFN-γ</i> polymorphisms and IgAN. Therefore, we performed a case-control study to assess the association between <i>IFN-γ</i> polymorphisms and the risk of IgAN. <b><i>Methods:</i></b> Sequenom MassARRAY was used to genotype two SNPs (rs1861494 and rs2430561) in 351 patients with IgAN and 310 healthy controls. Associations were evaluated as odd ratios (OR) with 95% confidence intervals (CI). <b><i>Results:</i></b> No association was found between <i>IFN-γ</i> rs1861494 and IgAN risk or clinical parameters. For rs2430561, the AA genotype was more common in patients with IgAN, compared with controls (AT vs. AA: OR = 0.57, P = 0.035). <i>IFN-γ</i>-rs2430561 T allele may be a protective factor for IgAN susceptibility (T vs. A: OR = 0.59, P = 0.04). Subgroup analysis based on clinical features revealed no significant association between rs2430561 polymorphism and clinical data such as gender, 24-h urine protein, blood pressure, Oxford classifcation and estimated glomerular fltration rate. IgAN patients had a higher <i>IFN-γ</i> serum level than healthy controls and patients with rs1861494 AA genotype had a higher <i>IFN-γ</i> serum level compared with those with AG/GG genotypes. <b><i>Conclusions:</i></b> <i>IFN-γ</i> polymorphisms may be involved in the development and progression of IgAN.