Urinary Excretion of Epidermal Growth Factor in Children with Reflux Nephropathy

Abstract

Purpose We determined urinary levels of epidermal growth factor in children with reflux nephropathy to evaluate the clinical significance of urinary epidermal growth factor. Materials and Methods We studied 59 boys and 41 girls 3 to 15 years old with reflux nephropathy, and 64 boys and 36 girls 3 to 15 years old who were healthy. Levels of urinary epidermal growth factor were determined by sandwich enzyme immunoassay using spot urine samples. We also determined the levels of serum creatinine, urinary alpha 1-microglobulin and urinary microalbumin. Absolute values of function of the left and right kidneys were assessed by 99mtechnetium dimercapto-succinic acid (DMSA) uptake. Results Levels of urinary epidermal growth factor gradually decreased with age in healthy children. There were low levels of urinary epidermal growth factor in 20 of the 44 patients (45%) with unilateral low DMSA uptake and 18 of the 19 (95%) with low total DMSA uptake (right and left uptakes). Urinary epidermal growth factor significantly correlated with serum creatinine (R = -0.702, p <0.0001), urinary alpha 1-microglobulin (R = -0.606, p <0.0001), urinary microalbumin (R = -0.708, p <0.0001) and total DMSA uptake (R = 0.744, p <0.0001). Conclusions These results suggest that urinary epidermal growth factor may be a useful clinical tool to monitor functional nephron mass in children with reflux nephropathy.