Elevated plasma vascular endothelial growth factor levels in non-diabetic predialysis uraemia

Chronic renal impairment is associated with increased vascular morbidity and mortality. The pathogenesis of this aggressive vascular pathology is unknown but believed to be multi-factorial in origin. There is accumulating in vivo and in vitro evidence to suggest that the vascular endothelium is dysfunctional in uraemia, including the propensity of endothelial cells to produce VEGF in response to acidosis. There is also preliminary data to suggest abnormally increased endothelial permeability in uraemia. To investigate the potential abnormal circulating levels of VEGF in uraemia, EDTA plasma samples were collected from 20 non-diabetic predialysis patients and matched controls. Free plasma VEGF levels were detected using a commercially available ELISA kit. There were significantly higher plasma levels of VEGF predialysis group (median 351 pg/ml, range 70-636 pg/ml) compared to matched controls (median 125.5 pg/ml, range 22-450 pg/ml), p < 0.002. In conclusion, free plasma VEGF levels are high in chronic renal impairment. We hypothesise that this potent growth and permeability factor may contribute to the endothelial dysfunction of uraemia.