Purchase this article with an account.
Nikolaos Trichopoulos, Dip S. Jadav, Neeru Kumar, Randolph D. Glickman; Erythropoietin and Interleukin 8 Levels in the Vitreous Fluid of Non-diabetic Patients and Diabetic Patients with Progressive Stages of Diabetic Retinopathy. Invest. Ophthalmol. Vis. Sci. 2012;53(14):2413.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Erythropoietin (EPO) is reported to have angiogenic activity but its role in retinal neovascularization is not completely understood. Chronic inflammation also contributes to the complications of diabetes. The purpose of this study was to evaluate whether the levels of EPO and pro-inflammatory cytokine interleukin 8 (IL-8) are elevated in the vitreous fluid of patients with diabetic retinopathy (DR).
Prospective analysis of undiluted vitreous samples was performed in discarded vitreous fluid of 64 patients undergoing scheduled vitrectomies. Patients with retinal vascular abnormalities other than DR (e.g. central retinal vein occlusion) were excluded. Twenty patients were non-diabetics and 44 had diabetes mellitus (DM). Ten of these 44 DM patients did not have DR, 7 had non-proliferative diabetic retinopathy (NPDR) and 27 had proliferative diabetic retinopathy (PDR) with or without vitreous hemorrhage. All vitreous samples were analyzed for EPO and IL-8 content using enzyme-linked immunosorbent assay kits.
Average EPO levels were as follows: non-diabetics (n=20): 16.32 ± 16.25 mIU/ml; diabetics with NPDR or no DR (n=17): 32.91 ± 33.25mIU/ml; and diabetics with PDR (n=27): 190.48 ± 138.21 mIU/ml. Average IL-8 levels were: non-diabetics: 22.49 ± 23.77 pg/ml; diabetics with NPDR or no DR): 39.67 ± 69.95 pg/ml; and diabetics with PDR: 47.81 ± 54.01 pg/ml. A Mann-Whitney "U" test was used to compare these differences. The EPO and IL-8 levels of the non-diabetics and the diabetics with NPDR or no DR did not differ significantly from each other (p > 0.05). In contrast, there were significant differences between the EPO and IL-8 levels of the diabetics with PDR and the diabetics with NPDR or no DR (p ≤.001 for EPO and p ≤.04 for IL-8) and the non-diabetics (p ≤.001 for EPO and p ≤.03 for IL-8).
Our findings suggest that EPO and IL-8 are increasingly elevated as a consequence of the ischemia and inflammation induced by worsening stages of DR. Further studies may elucidate the interaction between these two molecules to show whether inhibition of EPO and IL-8 could provide a new therapeutic strategy in precluding or arresting pathologic angiogenesis and disease progress in DR.
This PDF is available to Subscribers Only