Association of IL-4 (− 590 C/T) and IL-6 (− 174 G/C) gene polymorphism in South Indian CKD patients

Aim The present study was undertaken to examine the role of IL-4 (− 590 C/T) (rs2243250) and IL-6 (− 174G/C) (rs1800795) polymorphism and the serum levels of IL-4 and IL-6 in chronic kidney disease (CKD). Methods The IL-4 (− 590C/T) and IL-6 (− 174 G/C) polymorphisms were genotyped in 132 CKD patients and 161 controls using PCR–RFLP. Serum IL-4 and IL-6 quantifications were performed by ELISA. Results Significant susceptible associations of CT genotype (OR = 4.56; p < 1.84 × 10 –9 ) and T allele (OR = 1.56; p < 0.010) of IL-4 (− 590C/T) and CC genotype (OR = 2.63; p < 0.032) of IL-6 (− 174G/C) were observed for CKD. The CC genotype (OR = 0.27; p < 9.314 × 10 –7 ) and C allele (OR = 0.63; p < 0.010) of IL-4 (− 590 C/T) revealed strong protective associations. Five-fold increased levels were observed for both IL-6 ( p < 0.0001) and IL-4 ( p < 0.0043) cytokines in CKD patients than the controls. The IL-4 serum levels (pg/ml) increased significantly in patients with CT and TT genotypes of IL-4 (− 590 C/T) than the controls (6.18 ± 1.80 vs. 3.33 ± 0.48 and 6.14 ± 1.96 vs. 3.21 ± 0.56 respectively). For IL-6 (− 174 G/C) polymorphism, the patients with CC genotype (6.50 ± 1.30 vs. 3.49 ± 1.39) revealed with higher IL-6 serum levels followed by GC genotype (5.00 ± 1.91 vs. 4.01 ± 1.74). Conclusion The genotypes of IL-4 (590 C/T) and IL-6 (174 G/C) polymorphisms contribute differential susceptibility in south Indian CKD patients. A fivefold increased serum levels of IL-4 (anti-inflammatory) and IL-6 (pro- and anti-inflammatory) cytokines were documented in CKD patients. There observed an opposite trend in disease association for these two cytokines and associated SNPs with CKD in south India.