Vesicoureteral Reflux and Urinary Tract Infection in Children with Congenital Hydronephrosis

PURPOSE: We checked voiding cystourethrography (VCUG) in patients with congenital hydronephrosis (CHN) and followed up the occurrence of urinary tract infection(UTI) in these patients. And we tried to figure out the relationship between CHN and VUR and UTI. METHODS: We performed a retrospective study in 122 CHN patients who received VCUG from 2002 to 2008 at Ajou University Hospital. We executed logistic regression, chi-square test and T-test using version 16.0 SPSS package for the statistical analysis. P<0.05 was regarded as significant. RESULTS: Most patients with CHN were male (73%) and there was a tendency of preferences for unilateral (77%) and left (84%) occurrence of hydronephrosis. The incidence of VUR was 18.9 % among 122 CHN patients and no laterality difference was found to the severity of VUR or hydronephrosis. The incidences of VUR and UTI was higher in group of higher grade (III-IV) CHN patients, when compared to the lower group, respectively. When VUR was present in CHN patients, the incidence of UTI during infancy was also higher. CONCLUSION: The incidence of VUR was higher in patients with higher grades of CHN. The incidence of UTI during infancy was higher when VUR was present in the CHN patients.

Urinary Protein and Enzyme Excretion of Spot Urine in Children with Vesicoureteral Reflux

PURPOSE: The aim of this study was to evaluate the clinical usefulness of measurement of beta2 microglobulin (beta2 MG), N-acetyl-beta-D-glucosaminidase (NAG) of spot urine samples as indices of renal tubular damage and microalbumin of spot urine samples as a parameter of glomerular damage in children with vesicoureteral reflux (VUR) or renal defects. METHODS: We studied 91 children with previous UTI. The children were classified as 62 children without VUR and renal defects (group I), 10 children with VUR, without renal defects (group II), and 19 children with VUR and renal defects (group III). Patients having VUR were separated according to the degree of VUR (mild VUR: VUR grade I-III, severe VUR: VUR grade IV-V). Urinary excretion of beta2 microglobulin (beta2 MG), microalbumin, N-acetyl-beta-D-glucosaminidase (NAG), creatinine were measured in samples of morning urine specimens. Children with VUR or renal defects detected by voiding cystourethrography (VCUG) and DMSA renal scan were investigated. RESULTS: Microalbumin/Cr ratio of spot urine was significantly increased in group III compared group I (42.3+/-27.2 mg/gCr vs 25.2+/-10.9 mg/gCr, P<0.05). NAG/Cr ratio of spot urine was significantly increased in group II compared group I (3.70+/-23.4 mg/gCr vs 18.7+/-12.7 mg/gCr, P<0.05). There was no statistically significant difference of beta2 MG/Cr ratio among three groups. CONCLUSION: Urinary microalbumin excretion of morning urine sample may be a simple and reliable clinical indicators for early identification of renal damage in children with VUR and renal defects. Urinary microalbumin excretion may be useful marker to predict the the severity of VUR.

Factors Associated with Renal Scar in Children with Vesicoureteral Reflux

PURPOSE : The urinary tract infection associated with vesicoureteral reflux(VUR) in children may result in serious complications such as renal scarring, hypertension, proteinuria and end stage renal disease. The purpose of this study was to evaluate the factors affecting renal scar such as age, gender, grade of VUR, and ACE gene polymorphism, and body growth in the patients with and those without renal scar associated with VUR METHODS : During the period from January 1994 to July 2000, We had 93 children with urinary tract infection associated with VUR who were admitted to the Department of pediatrics of Chonbuk National University Hospital. The patients were divided into two groups according to follow up 99mTc-DMSA renal scan; patients with renal scar group and those with non-scar group. We analyzed and compared the factors associated with renal scarring between the two groups. RESULTS : There were no significant difference in gender, causative organism, ACE gene polymorphism, height and weight at diagnosis between renal scar group and non-scar group. Fifty four patients were in renal scar group and forty seven of them had VUR. The age at diagnosis was significantly higher in renal scar group (2.48 +/-2.64yr) than in non renal scar group (1.26+/-1.83yr). Especially, the infants who were less than 1 year of age with VUR developed relatively more renal scar compared with infants older than 1 year of age. The incidence of renal scarring showed a direct correlation with the severity of VUR. CONCLUSION : The factors affecting renal scar formation were age at diagnosis, presence and grade of VUR, but the other factors such as gender, causative organism, ACE gene polymorphism were not associated with renal scarring. Therefore, further evaluation about uropathogenic E. coli and follow up study about body growth associated with severity of renal scar would be necessary.