Is there any relation between connective tissue growth factor and scar tissue in vesicoureteral reflux?

Abstract

Vesicoureteral reflux (VUR) is the most common uropathy in childhood which leads to increased frequency of urinary tract infection (UTI) and renal scarring. Connective tissue growth factor (CTGF) plays an important role in the development of glomerular and tubulointerstitial fibrosis in progressive kidney diseases. The aim of this study was to investigate the relation between urinary CTGF and renal damage resulted from VUR. This cross sectional study included 70 patients with VUR and 62 healthy sex and age matched children. Urinary creatinine and CTGF (uCTGF) concentrations were analysed in all cases and CTGF to creatinine ratio were calculated. The records of radiologic evaluations of the patients including ultrasound, voiding cystouretrography and 99m-technetium dimercaptosuccinic acid (DMSA) scintigraphy were obtained retrospectively. The patient group was further divided into two groups according to the existence of renal cortical scarring in the DMSA scan. The study consisted of three groups; Group 1 (control group) 62 children, Group 2 (VUR positive, scar negative) 24 patient, Group 3 (VUR positive, scar positive) 46 patient (VUR+scar). The medians of uCTGF and uCTGF to creatinine ratio of the three groups were significantly different (p <0.001). Pairwise group comparisons revealed that Group 1 had significantly lower uCTGF level and uCTGF/creatinine ratio, as compared to Groups 2 and 3 (p <0.001 and p=0.002, respectively). There was no statistically significant difference between Groups 2 and 3 (p=0.052). uCTGF is significantly increased in children with VUR, independent on the presence of renal scarring. Increased uCTGF, even in the absence of the renal scarring, could be interpreted as development and a progression of glomerular and tubulointerstitial fibrosis in vesicoureteral reflux. Further experimental and clinical investigations are required to fully elucidate the mechanism of CTGF in vesicoureteral reflux.