Evaluation of erythropoietin level in vitreous and serum with detection of erythropoietin gene polymorphism in Egyptian patients with proliferative diabetic retinopathy

Purpose: To measure erythropoietin (EPO) level in vitreous and serum of patients with proliferative diabetic retinopathy (PDR) and to detect EPO single nucleotide polymorphism (SNP) genotyping expression in them. Materials and Methods: Concentrations of EPO in vitreous and serum of twenty diabetic patients with PDR undergoing vitrectomy (PDR group) were measured by chemiluminescent immunoassay and compared with those in nondiabetic (ND) patients undergoing vitrectomy for recent retinal detachment (ND group). Genotyping of EPO gene SNP (rs551238) was performed using real-time polymerase chain reaction technique. Results: There were a significant increase in serum EPO level in PDR group than in ND group and a highly significant increase in vitreous EPO level in PDR group than in ND group. Within the PDR group, vitreous EPO level was significantly higher than its serum level; there was up to 6-fold increase in the EPO vitreous level than its serum level. EPO gene SNP rs551238 was significantly associated with PDR in Egyptian patients. Conclusion: The results of the current study suggest the involvement of EPO in the pathogenesis of PDR. Hence, augmenting vascular endothelial growth factor inhibition with the use of EPO inhibitors may provide a better outcome in PDR treatment. The detection of EPO gene SNP rs551238 in Egyptian patients with PDR may help in the identification of the genetic predisposition to diabetic retinopathy in Egyptians and so may help in prevention and early detection of susceptible candidates to PDR.