Monokine Induced by Interferon (Mig) (CXCL9) in the Vitreous of Patients With Proliferative Diabetic Retinopathy

Abstract

Purpose:: To determine the intra-vitreous levels of human monokine induced by interferonγ(Mig)(CXCL9) in patients with proliferative diabetic retinopathy (PDR). In addition, the relationship between the concentration of Mig and PDR activity has also been evaluated.

Methods:: Vitreous samples were collected at the time of vitreoretinal surgery from 17 eyes of PDR patients and from 11 eyes of nondiabetic patients (control subjects) who had macular hole and epiretinal membrane (6 and 5 eyes, respectively). Stages of PDR were classified as active or quiescent. Concentrations of Mig and vascular endothelial growth factor (VEGF) in vitreous fluid were simultaneously measured by cytometric bead array using flow cytometer.

Results:: Intravitreous concentrations of Mig were significantly higher in PDR (4897.5 pg/ml) than in control patients (17.2 pg/ml) (p<0.001). Intravitreous concentrations of VEGF were also higher in PDR (945.2pg/ml)than in control patients(8.8pg/ml)(p<0.001). The vitreous fluid level of Mig weas significantly correlated with that of VEGF (p<0.001).

Conclusions:: We found that level of Mig in vitreous fluid of PDR patients are significantly higher than in nondiabetic patients and that the levels of Mig are elevated in the active PDR stage. These findings suggest that Mig contributes to the development and progression of PDR in combination with VEGF.

Keywords: diabetic retinopathy • cytokines/chemokines • retina