Vezikoüreteral Reflüde Renal Parankimal Hasarın Belirlenmesinde ve Oluşmasında Konnektif Doku Büyüme Faktörünün ve Nötrofil Jelatinaz İlişkili Lipokalinin Önemi

Abstract

The purpose of our study was to investigate the diagnostic and prognostic significance of urinary connective tissue growth factor (CTGF) level, together with urinary beta 2 microglobulin (ß2M) and neutrophil gelatinase associated lipocalin (NGAL) levels in renal injury in patients who had primary vesicoureteral reflux with or without renal parenchymal scarring. Ninety four children aged between 1-16 years with primary VUR who were free of UTI within the previous 3 months, who had an estimated glomerular filtration rate calculated by using Schwartz formula of ?90 ml/dk/1.73 m2 and no proteinuria and 42 healthy children aged between 1-16 years were enrolled in this study. The study group consisted 32 patients with Ist-IInd grades of VUR, 41 patients with IIIrd grade of VUR and 21 patients with IVth-Vth grades of VUR. The patients in VUR groups were also divided into subgroups according to the presence or absence of renal scars on technetium (Tc)-99m dimercaptosuccinic acid (DMSA) scans (0: patients without renal parechymal scarring, 1: patients with parenchymal scarring). Renal parenchymal scarring was present in 27.6% of patients with primary VUR. The ages of the patients with renal parenchymal scarring at diagnosis and at enrollment in the study were higher than of the patients without renal parenchymal scarring. Higher rates of renal parenchymal scarring were observed in patient groups with higher grades of VUR. The urinary protein, ß2M, NGAL and CTGF levels of the patients were measured and compared with those of the control group. A statistically significant difference was found for the ratios of urinary protein/creatinine, NGAL/creatinine and CTGF/creatinine between patients with VUR and healthy controls, respectively. Although there was no statistically significant difference in these parameters among VUR groups, the patients with high reflux grade had higher ratio of urinary ß2M/creatinine and lower ratios of NGAL/creatinine and CTGF/creatinine than the patients with Ist-IInd grades and the patients with IIIrd grade vii of VUR. The ratio of urinary protein/creatinine positively correlated with the ratios of urinary ? 2M/creatinine, NGAL/creatinine and CTGF/creatinine in patients with VUR. Although a statistically significant difference was found only for the ratio of ß2M/creatinine between patients with and without renal parenchymal scarring, the patients with renal parenchymal scarring had higher ratios of the urinary NGAL/creatinine and CTGF/creatinine than the patients without renal parenchymal scarring. At the best cut-off value, the ratio of urinary ß2M/creatinine showed a moderately good diagnostic profile in identifying renal parenchymal scarring in patients with VUR and it was better than the diagnostic profiles of the ratios of urinary NGAL/creatinine and CTGF/creatinine. We suggest that tubular injury may be present in patients with VUR and the urinary ß2M level may detect renal injury before overt proteinuria evolves in the patients with VUR. We suggest that the ratios of urinary NGAL/creatinine and CTGF/creatinine do not show predominancy over the ratio of urinary ß2M/creatinine in detecting renal parenchymal scarring in patients with VUR. We also suggest that the detection of alterations of urinary CTGF/creatinine ratio regularly evaluated during follow-up of the patients with VUR and renal parenchymal scarring and the demonstration of the relationship between CTGF expression in renal tissue and renal scarring may clarify this subject.