Pro-inflammatory and Anti-inflammatory Cytokines in Vitreous Fluid of Patients with Proliferative Diabetic Retinopathy

Abstract

To determine the intra-vitreous levels of two pro-inflammatory cytokines [interleukin-8 (IL-8), monocyte
chemoattractant protein-1 (MCP-1)] and the anti-inflammatory cytokine interleukin-10 (IL-10) in patients with
proliferative diabetic retinopathy (PDR). In addition, the relationship between the level of cytokines and PDR activity had also been evaluated. The study included 23 diabetic patients with PDR (13 diabetic patients with inactive PDR and 10 diabetic patients with active PDR). Sixteen age-matched non-diabetic patients with macular hole served as a control
group. IL-8, MCP-1 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). The vitreal levels of
both IL-8 and MCP-1 were significantly higher in diabetic patients with PDR in comparison with the control group. In
addition, the vitreous concentrations of IL-8 and MCP-1 were higher in patients with active PDR than in those patients
with inactive PDR However, no significant difference was detected in the vitreal levels of IL-10 between diabetic patients and the control group. The pro-inflammatory cytokines IL-8 and MCP-1 are increased in the vitreous fluid of PDR patients without an increase in the anti-inflammatory cytokine IL-10. In addition, both intra-vitreous IL-8 and MCP-1
levels are asssociated with PDR activity, thus suggesting that these cytokines may be pathogenically related to PDR.