Effect of chemokine and chemokine-receptor gene polymorphisms on the development of diabetic retinopathy in the Turkish cohort

It is known that in many acute and chronic inflammatory diseases, chemokines are secreted into the environment and increase during the inflammation process. Inflammation is thought to be important in the pathogenesis of diabetic retinopathy (DR) and various cytokines and chemokines play a role. Accordingly, the aim of the present study is to determine the relationship between DR and chemokines and their receptor gene polymorphisms (CXCL12, CXCR4, CCL2, CCR2) in Turkish population. This study included 353 patients with type 2 diabetes mellitus (with and without retinopathy) and 204 controls. Genomic DNA was isolated from whole blood and genotype distribution of polymorphisms was determined by PCR-RFLP method. It was determined that the G allele of the CCL2 rs1024611 SNP could prevent the development of DR (1.42 fold) and PDR (proliferative diabetic retinopathy) (1.92 fold). Binary logistic regression analysis also showed that the TT genotype of CXCL12 rs1801157 SNP may have a protective effect (OR = 0.258) on the development of DR. In contrast, CXCR4/rs2228014 and CCR2/rs1799864 SNPs did not show a significant effect on DR in the Turkish population. Findings of the present study suggest that the CCL2 rs1024611 SNP may play a role in the etiology of DR and PDR, and the G allele has a protective effect in Turkish population. Furthermore, TT genotype of CXCL12 rs1801157 SNP may also provide protection against the development of DR. Large-scale studies including a large number of patients are recommended to confirm these results.