Interleukin-8 and tumor necrosis factor-? levels in vitreous samples from patients with diabetic retinopathy

Abstract

AIM: To measure the interleukin-8 (IL-8) and tumor necrosis factor-? (TNF-?) levels in vitreous samples obtained the patients undergoing pars plana vitrectomy (PPV) due to diabetic retinopathy (DR), then to compare these results with those of the control group and to state their impact on DR pathogenesis. METHODS: From Istanbul Bilim University Ophthalmology Department, 57 eyes of 57 diabetes mellitus (DM) patients who had been diagnosed with proliferative diabetic retinopathy and 22 cases of macular hole, with no proliferative vitreoretinopathy were included in the study as the study and the control groups respectively. All of the 79 patients underwent a 3-port, 20 gauge PPV. Vitreous samples of 0.5mL were aspirated with vitrector at the beginning of the PPV operation before the intraocular infusion and being diluted. Samples were transferred to the freezer to be stored at -70°C. Results of IL-8 and TNF-? were calculated as pg/mL with ELISA method. RESULTS: IL-8 levels [82.7891±74.08700(0.08-307.09)pg/mL] in which vitreous samples obtained DR patients during vitrectomy were significantly elevated when compared to IL-8 levels [2.9805±3.77546(0.08-18.53)pg/mL] of control patients (P<0.001). Similarly, TNF-? level [18.0007±13.90015(2.32-51.11)pg/mL] was also significantly elevated in DR patients when compared to control patients' TNF-? level [1.7005±1.26949(0.1- 5.17)pg/mL] (P<0.001). CONCLUSION: The levels of TNF- ?, which plays a role in retinal neovascularization, and, IL-8, which acts as an inflammatory and angiogenic mediator were found to be high in DR patients.