Colony Forming Unites - Endothelial Progenitor Cells (CFU-EPCs) – A Surrogate Marker for Diabetic Retinopathy and High Cardiovascular Mortality Rate

Purpose: Diabetic retinopathy is a risk factor for increased cardiovascular death. Our purpose was to find a significant difference in levels of endothelial progenitor cells (EPCs) in the peripheral blood of patients at different stages of diabetic retinopathy.

Design: A prospective study. Colony forming units of endothelial progenitor cells (CFU-EPCs) in peripheral blood were counted. 40 subjects were enrolled (10 healthy [41±8 y], 10 type 2 diabetes mellitus (T2DM) [64±12 y] without retinopathy, 10 T2DM patients [62±26 y] with non-proliferative retinopathy (NPDR), 10 T2DM patients [66±9 y] with proliferative retinopathy (PDR)). The study was approevd by the ethics committee of the hospital and every subject signed a soncent form before enrollment.

Methods: Growing CFU-EPCs was by the Hill`s EPCs protocol. Blood was drawn early in the morning and was processed within 1 hour. Mononuclear cells were separated and cultured on fibronectin-coated plates with EndoCult medium (StemCell technologies, Vancouver BC Canada) for 5 days. CFU-EPCs were counted on day 5 (an average of 8 wells).

Results: Healthy subjects had 36±8 CFU-EPCs, patients without retinopathy had 13±12 CFU-EPCs (p<0.01), patients with NPDR 22±26 CFU-EPCs (p=NS), and 2±2 CFU-EPCs in patients with PDR (p<0.01). A significant difference was found between patients with PDR and with NPDR (p<0.05).

Conclusions: CFU-EPCs are inhibited in T2DM patients with DPR. Levels of CFU-EPCs may be used as a surrogate biologic marker for severity of diabetic retinopathy and for cumulative vascular risk.