A study of the impact of cytokine gene polymorphism in acute rejection of renal transplant recipients

Acute rejection is a common phenomenon in transplantation. Inflammatory and anti-inflammatory mediators affect the graft microenvironment. Th1 responses cause acute rejection while Th2 immune responses help the survival of the graft. In this study, we evaluated gene polymorphisms of IL - 6 G - 174C , TGF - β T + 869C , IL - 4 C - 590T , and IFN - γ T + 874A cytokines in renal transplant patients. ARMS-PCR method was used to characterize IL - 6 G - 174C (rs76144090), TGF - β T + 869C (rs1800471), and IFN - γ T + 874A (rs2430561) polymorphisms and PCR-RFLP, for characterization of IL - 4 C - 590T (rs2243250) in 100 renal transplant patients. Acute rejection episodes were diagnosed according to the standard criteria. Analysis of the results showed that IL - 6 - 174 GG genotype ( P = 0.018, OR = 3.023, 95% CI = 1.183–7.726) and IL-6 - 174G allele ( P = 0.046, OR = 2.114, 95% CI = 1.005–4.447) were more frequent, but IL - 6 - 174GC genotype was less frequent in acute rejection of kidney transplantation in comparison with control group ( P = 0.024, OR = 0.302, 95% CI = 0.103–0.883). IFN - γ + 874 T allele was associated with a higher risk of acute rejection ( P = 0.019, OR = 2.088, 95% CI = 1.124–3.880) while IFN - γ+874 AA genotype was associated with a lower risk of rejection ( P = 0.023, OR = 0.318, 95% CI = 0.115–0.875). Frequencies of TGF - β T + 869C and IL - 4 C - 590T were not significantly different ( P > 0.05). Consequently, our results show that IL - 6 G - 174C and IFN - γ T + 874A gene polymorphisms have predictive values for acute rejection after renal transplantation in Iranian patients.