Polymorphisms of interleukin-8 and -18 genes and diabetic retinopathy
We evaluated possible roles of interleukin-8 gene polymorphisms (1633T/C-rs2227543, 251A/T-rs4073) and interleukin-18 gene polymorphisms (-607C/A-rs1946518, -137G/C-rs187238) in the development of diabetic retinopathy (DR) in Caucasians with type 2 diabetes. 271 patients with DR and 113 without diabetic retinopathy were enrolled in this cross-sectional study. We did not observe an association between either interleukin-8 gene polymorphisms (1633T/C, 251A/T) or interleukin-18 gene polymorphisms (-607C/A, -137G/C) and diabetic retinopathy in Caucasians with type 2 diabetes. We did not find statistically significant differences in interleukin-8 serum levels between diabetics with the TT and AA genotype and those with other genotypes. The interleukin-18 serum levels between diabetics with the CC genotype of the -607C/A polymorphism and those with other genotypes (AA, AC) were not significantly different. Moreover, we did not observe a statistically significant effect of the tested polymorphisms of either interleukin-8 or interleukin-18 genes on serum levels in diabetics. In conclusion, our study indicates that the examined polymorphisms of interleukin-8 (1633T/C, 251A/T) and interleukin-18 (-607C/A or the -137G/C) genes are not genetic risk factors for diabetic retinopathy. Therefore, they may not be used as genetic markers for diabetic retinopathy in Caucasians with type 2 diabetes.