Aims: To compare the vitreous levels of chemokines in diabetic patients with and without retinopathy. To find the relationship between stages of diabetic retinopathy (DR) and levels of vitreous chemokines.
Methods: The study involved 20 non-diabetic and 20 diabetic patients without clinical signs of DR (NDR) and 40 diabetic patients with proliferative diabetic retinopathy (PDR). The vitreous humor was collected and the levels of 40 chemokines were measured using magnetic color-bead-based multiplex assay.
Results: The control group, NDR group, PDR with vitreous hemorrhage (VH) group, and PDR with tractional retinal detachment group comprised 20, 20, 21, and 19 eyes, respectively. Only the concentration of CCL3 was significantly higher in the NDR group compared with the controls (p = 0.038). Twenty-five types of chemokines were statistically higher in the PDR with VH group in comparison to NDR group (all p < 0.05). All chemokines were statistically higher in the PDR with TRD group in comparison to NDR group (all p < 0.05) apart from 3 chemokines: GM-CSF, MIF, and CCL3(p = 0.086, p = 0.109, p = 0.094, respectively). The concentration of CCL21, CCL15 in PDR with TRD group was significantly higher compared with PDR with VH group, while other 36 chemokines were not significantly different between PDR with VH group and PDR with TRD group.
Conclusions: The inflammation gradually worsen with the progression of DR. CCL3 may be associated with the onset of early diabetic retinal damage, and CCL15 and CCL21 may be closely related to the formation of fibrovascular membrane and the progression of the end stage of DR.
Keywords: Chemokines; Diabetic retinopathy; Type 2 diabetes mellites; Vitreous.