Urinary epidermal growth factor excretion in children with chronic renal failure

To investigate the excretion of urinary epidermal growth factor (EGF) in children with chronic renal failure (CRF), we have measured the urinary EGF/creatinine ratio (EGF/Cr) and the 24-hour urine EGF concentration in 19 children with CRF, 11 children with kidney disease and normal creatinine clearance, and 12 healthy children. Children with CRF had a significantly lower daily urine EGF concentration as well as urinary EGF/Cr. In contrast, children with kidney disease and normal renal function had normal daily urine EGF levels and urinary EGF/Cr. Accompanied by no difference in serum EGF between these two groups of patients, these data provide indirect evidence of the kidney as a source of human urinary EGF. There was a positive correlation of urinary EGF/Cr with creatinine clearance in all renal patients (r = 0.608, n = 30, p < 0.001). A much better correlation was found between daily urine EGF and creatinine clearance (r = 0.855, n = 30, p < 0.001). Our results implicate that there is a functional relationship between glomerular filtration and urinary EGF excretion, and that the urinary EGF/Cr may be a reliable indicator of urinary EGF excretion in children with CRF.