Collagen studies for pediatric ureteropelvic junction obstruction

Abstract

Objectives. Ureteropelvic junction (UPJ) obstruction is the most common form of urinary tract obstruction in pediatrics. There is controversy regarding the need for early surgical intervention in many patients with apparent neonatal UPJ obstruction. To demonstrate the differences in type and amount of collagen in adult and pediatric UPJ obstruction, collagen studies were performed. Methods. The experimental groups are 9 pediatric patients with UPJ obstruction and 13 adult patients with UPJ obstruction. Six patients with normal UPJ were assigned as controls for each experimental group. The collagen content of UPJ was quantitated by hydroxyproline analysis. Immunohistochemical staining and Western blotting for collagen types I and III were performed. Results. The collagen content of pediatric UPJ was significantly lower in value than that of adult UPJ ( P <0.05). Immunohistochemical staining revealed that collagen type I was located in interfascicular space and collagen type III was located in intrafascicular space in both age groups. In Western blotting the relative intensity of collagen type III for pediatric UPJ was weaker than that of adult groups. Conclusions. These results suggest that a larger series of patients should be examined to determine whether quantitative analysis for collagen types I and III would provide some kind of prognostic test for UPJ outcome in pediatric patients.