Urinary and circulating levels of the anti-angiogenic isoform of vascular endothelial growth factor-A in patients with chronic kidney disease

Introduction The protective effects of vascular endothelial growth factor (VEGF)-A₁₆₅b on kidney tissue have been suggested in animal studies. However, the relevance of urinary and circulating VEGF-A₁₆₅b levels in chronic kidney disease patients remains unclear. Therefore, the present study aimed to investigate the urinary and circulating VEGF-A₁₆₅b levels in patients with chronic kidney disease. Methods This observational study enrolled a total of 92 Japanese patients with chronic kidney disease, who had undergone inulin renal clearance measurements for the accurate assessment of measured GFR. Urinary or circulating total VEGF-A and VEGF-A₁₆₅b levels were measured using enzyme-linked immunosorbent assay. Results Urinary VEGF-A₁₆₅b levels were significantly lower in G3a, G3b, and G4 + G5 category patients than in G1 + G2 category patients. Correlation analysis found that serum creatinine levels, serum cystatin C levels, eGFRcre, eGFRcys, and mGFR were weakly but significantly correlated with urinary VEGF-A₁₆₅b levels. Additionally, circulating VEGF-A₁₆₅b levels were significantly higher in G4 + G5 category patients than in G1 + G2 category patients. Conclusion A low urinary VEGF-A₁₆₅b level reflects renal dysfunction in the chronic kidney disease stage, while a high circulating VEGF-A₁₆₅b level cannot be attributed to decreased renal clearance.