Urinary excretion of vascular endothelial growth factor is increased in children with reflux nephropathy.

BACKGROUND

We determined the urinary levels of vascular endothelial growth factor (VEGF) in patients with reflux nephropathy to elucidate its clinical significance as a predictor of the development of renal damage.

PATIENTS AND METHODS

Seventy-two patients (47 boys and 25 girls) aged 10-18 years with reflux nephropathy were studied. Vesicoureteral reflux was resolved surgically in all cases at least 2 years before enrollment. Urinary VEGF, alpha1-microglobulin and albumin levels were determined using morning spot urine samples. Plasma VEGF, serum creatinine and beta2-microglobulin levels were measured simultaneously. The severity of renal scarring and right and left kidney function were assessed by 99mTc dimercaptosuccinic acid renal scan.

RESULTS

No significant correlation was found between the plasma and urinary VEGF levels. Urinary VEGF increased significantly with the increase in severity of renal scarring (p < 0.0001). Urinary VEGF levels correlated significantly with serum beta2-microglobulin (p < 0.002) and urinary alpha1-microglobulin (p < 0.03). No significant correlation of urinary VEGF levels with serum creatinine and urinary albumin levels was found. Nearly 60% of the patients with elevated urinary VEGF had normal levels of serum beta2-microglobulin and/or urinary alpha1-miocroglobulin.

CONCLUSIONS

Urinary VEGF level appears to reflect its production in the kidney. Since urinary VEGF shows a propensity to elevate before the increase in serum beta2-microglobulin and/or urinary alpha1-microglobulin, urinary VEGF may serve as an early indicator of the development of reflux nephropathy.