Interferon-gamma gene polymorphism +874 (a/t) in Chinese children with Henoch-Schonlein purpura

The aim of this study was to investigate the possible influence of Interferon-gamma (IFN-γ) gene polymorphism +874 (A/T) (rs2430561) in the susceptibility and renal complications of patients with Henoch-Schonlein purpura (HSP). We also studied the effects of IFN-γ allelic variation on serum levels of pro-and anti-inflammatory cytokines in HSP patients. The study population comprised 97 patients suffering from HSP and 97 control participants. Patients and controls were genotyped for a single nucleotide polymorphism +874 (A/T) in the first intron of the IFN-γ gene by the TaqMan PCR method. Frequencies of individuals with IFN-γ +874 AA, AT and TT genotypes were 77.3%, 21.6% and 1% in HSP patients and 79.4%, 17.5% and 3.1% in controls, respectively. The frequency of the AA genotype in HSP patients with nephritis was slightly higher (83.3%) than in HSP patients without nephritis (73.8%). The allele A occurred more commonly in HSP patients with nephritis (92%) than in HSP patients without nephritis (86%), but these differences were not statistically significant (p= 0.469 and p= 0.244, respectively). In addition, significant difference in serum IL-10 levels between IFN-γ +874 different genotype groups was found. Our results do not support a role for IFN-γ gene polymorphism +874 (A/T) in the susceptibility to HSP and allelic variation at IFN-γ +874 locus had no effect on serum levels of cytokines in patients with HSP except for IL-10.