Pro- and antiangiogenic VEGF and its receptor status for the severity of diabetic retinopathy.

PURPOSE

Alteration of pro- and antiangiogenic homeostasis of vascular endothelial growth factor (VEGF) isoforms in patients with hyperglycemia seems crucial but substantially unexplored at least quantitatively for diabetic retinopathy (DR). Therefore, in the present study we aimed to estimate the difference between the pro- (VEGFa) and antiangiogenic (VEGFb) VEGF isoforms and its soluble receptors for severity of DR.

METHODS

The study included 123 participants (diabetic retinopathy: 81, diabetic control: 20, non-diabetic control: 22) from the Regional Institute of Ophthalmology, Kolkata. The protein levels of VEGFa (proangiogenic), VEGFb (antiangiogenic), VEGF receptor 1 (VEGFR1), VEGFR2, and VEGFR3 in plasma were determined with enzyme-linked immunosorbent assay (ELISA).

RESULTS

An imbalance in VEGF homeostasis, a statistically significant concomitant increase (p<0.0001) in the level of VEGFa and a decrease in the level of VEGFb, was observed with the severity of the disease. Increased differences between VEGFa and VEGFb i.e. VEGFa-b concomitantly increased statistically significantly with the severity of the disease (p<0.0001), patients with diffuse diabetic macular edema (DME) with proliferative DR (PDR) had the highest imbalance. The plasma soluble form of VEGFR2 concentration consistently increased statistically significantly with the severity of the disease (p<0.0001).

CONCLUSIONS

The increased difference or imbalance between the pro- (VEGFa) and antiangiogenic (VEGFb) homeostasis of the VEGF isoforms, seems crucial for an adverse prognosis of DR and may be a better explanatory marker compared with either VEGF isoform.