• Childhood Kidney Diseases
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• v.8 no.2
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• pp.223-228
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• 2004

Purpose and Methods: Urinary tract infection(UTI) is one of the most important diseases of childhood, especially for young infants. To characterize the patients diagnosed with febrile UTI in their first 6 months of life and to explore the risk factors of recurrent UTI, a retrospective study was performed. Results: Among the 90 patients studied, 77 were boys(86%). First episodes of UTI were diagnosed at the age of $2.5{\pm}1.4$ months. These patients underwent ultrasonographic evaluation of urinary tract(n=90) and voiding cystourethrography(n=81) where 53 and 35 studies showed abnormal findings respectively, and a total of 45 cases of urinary tract anomaly including vesicoureteral reflux(VUR, n=35) were diagnosed. Normal findings on ultrasonography indicated decreased risk of VUR in boys of 1-3 months of age(n=30). 53 patients were followed up more than 6 months and 45 episodes of subsequent UTI developed in 29 patients during the first 6-month period. Patients with relapse were older than patients without relapse at the diagnosis of first UTI, but other clinical parameters including abnormal findings on the imaging studies and prophylactic antibiotics prescription were not different between the two groups. Conclusion: UTI in early infancy occurred mainly in male infants and half of the patients had structural anomalies. USG was of clinical value in detecting anomalies requiring surgical intervention, and to rule out high grade VUR in 1-3 months old boys. Results of the imaging study or prophylactic antibiotics could not modify the risk of recurrent UTI. (J Korean Soc Pediatr Nephrol 2004;8:223-228)

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.56-62
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• 2009

Purpose : The aim of this study was to evaluate the clinical usefulness of measurement of ${\beta}_2$ microglobulin (${\beta}_2$ 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 ${\beta}_$ microglobulin (${\beta}_2$ 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 ($42.3{\pm}27.2\;mg/gCr$ vs $25.2{\pm}10.9\;mg/gCr$, P<0.05). NAG/Cr ratio of spot urine was significantly increased in group II compared group I ($3.70{\pm}23.4\;mg/gCr$ vs $18.7{\pm}12.7\;mg/gCr$, P<0.05). There was no statistically significant difference of ${\beta}_2$ 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.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.854-857
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• 2003

Purpose : It is known that single umbilical artery is frequently associated with gastrointestinal or urogenital anomaly, however, routine renal sonography has been debated in healthy neonate with isolated single umbilical artery. This study is designed to determine the usefulness of routine renal sonography in apparently healthy infants with an isolated single umbilical artery. Methods : Thirty healthy neonates with a single umbilical artery without a major anomaly from January 1995 to July 2002 were enrolled. The authors investigated the clinical background of babies and their mothers after renal sonography after 72 hours of age. When the abnormalities were found at the first renal sonography, the severity of hydronephrosis and degree of obstruction and renal function were analyzed by follow up renal sonography, voiding cystourethrography(VCUG) and technetium-99m-dimercaptosuccinic acid(DMSA) scan or technetium-99m-mercaptoacetyl-triglycerine (MAG3) scan. Results : Among the 30 healthy patients with isolated single umbilical artery, five patients(16.7%) showed abnormalities on first renal sonography with one major(3.3%) and four(13.4%) minor renal anomaly(minimal or mild hydroneohrosis). One major renal anomaly(severe hydronephrosis) showed severe decreased renal function on MAG3 scan without reflux, and the other four minor regressed spontaneously on follow up study. Conclusion : The value of routine early renal sonograpy for detecting renal anomaly in healthy infants with an isolated single umbilical artery remained unclear because most of the anomalies would regress spontaneously in the follow up study.

• Childhood Kidney Diseases
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• v.1 no.1
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• pp.46-52
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• 1997

Urinary tract infection (UTI) in children has been known to be a cause of renal damage, leading to scar formation, hypertension and renal failure. And vesico-ureteral reflex (VUR), frequently accompanying UTI in young children, has been incriminated as the main factor causing scar formation. This retrospective study has been undertaken to see the relationship among UTI, VUR and renal scar formation. Study population consisted of 291 children (boy 134, girl 42) with UTI, who have been admitted to the Pediatric Department of Kyungpook University Hospital during 6 1/2 year period from January 1990 to June 1996. VUR was diagnosed by VCUG and renal scar by ultrasonogram, DMSA scan (or DMSA SPECT) and IVP. The following result were obtained. Sexual difference showed male predominance (male to female, 134:42) below 1 year of age, and female predominance (male to female, 11:35) over 5 years of age were rioted. VUR has been found in 64 children (22%) and the degree of reflux, classfied by the method proposed by 'International Reflux Study in Children', were as follows ; Grade I : 4.0%, Grade II : 3.0%, Grade III : 2.7%, Grade IV : 5.8% and Grade V : 6.2%. There was no sexual difference E.coli was the most predominant infecting agent occurring in 167 children (57%), and end-stage renal failure was diagnosed at the time of first admission in 5 children with Grade V VUR. Renal scar has been noted in 49 out of 582 kidneys (8.4%), and the incidence of scar foramation according to the degree of VUR were as follow ; Grade 0 (No reflux) : 1.2%, Grade I : 6.7%, Grade II 27.3%, Grade III 29.4%, Grade IV : 57.1%, and Grade V : 100%. In summary, present study shows that renal scar formation in UTI has close correlation with the severity of VUR occurring more frequently in severe reflux, so that early diagnosis and proper treatment of UTI and VUR is of paramount importance in preventing renal damage in children with UTI.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.145-151
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• 1998

Purpose : DMSA renal scan is known as a valuable method for evaluating acute pyelonephritis and renal scar in patients with febrile urinary tract infection or vesicoureteral reflux. We made this study, to determine the most effective use of DMSA renal scan. Methods : 155 children were admitted to the Pediatric Department of Yonsei University, Severance hospital with the symptom of urinary tract infection from January, 1992 to June, 1995. DMSA scan, renal ultrasound and VCUG were performed. One consisted of 29 patients with the diagnosis of acute pyelonephritis without vesicoureteral reflux and the otherconsistedofllpatientswithvesicoureteralreflux. Results : The follow-up DMSA scans at mean $0.99{\pm}0.46$ months after the initial DMSA scans were performed in the 29 children with acute pyetonephritis. 21($72.4\%$) of 29 children showed normal DMSA scans. 8 children with abnormal DMSA scans had follow-up DMSA scans at 2.5 months after the initial scans and 6 of 8 children showed normal DMSA scans. Only 12($41.4\%$) of 29 children showed abnormal renal ultrasound. The data about DMSA scans in 32 children with vesicoureteral reflux showed that there were abnormal DMSA scans in Grade $I;25.0\%$, Grade $II;44.5\%$, Grade $III;64.3\%$, Grade $IV;92.9\%$ and Grade $V;100.0\%$. There was a significant difference in that 36 renal unit ($68.0\%$) on DMSA renal scan and 26 renal units ($49.1\%$) on renal ultrasound showed abnormal finding(P<0.05). Conclusion : DMSA renal scan is more useful than renal ultrasound for the diagnosis of acute pyelonephritis. It is considered that if the initial DMSA scan is abnormal, a follow-up DMSA scan must be performed after 10weeks (8-12weeks) and the change in DMSA scan evaluated.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.72-79
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• 1999

Renal scarring associated with vesico-ureteral reflux(VUR) is one of the major causes of end stage renal failure and renal hypertension in children. Urinary ${\beta}_2$-microglobulin(MG) has been suggested as a potential marker for presence of renal tubular damage. This study was designed to evaluate the significance of random urine ${\beta}_2$-MG as a predictor of presence of vesico-ureteral reflux in children with urinary tract infection(UTI). 57 children with urinary tract infection were studied. Patients were devided into two groups; 35($78.9\%$) children have UTI without VUR and 12($21.1\%$) children have UTI and VUR. Beta2-MG and creatinine in random urine sample was measured to decide the excretion ratio(${\beta}_2$-MG/creatinine). Among the 57 children with UTI, 44 children were confirmed by urine culture study and 13 children suspected by compatible clinical feature. Random urine ${\beta}_2$-MG of VUR group ($2.2{\pm}5.91$ mg/L) were significantly higher than that of simple UTI group($0.19{\pm}0.16mg/L$)(P=0.03). The ${\beta}_2$-MG/creatinine ratio of VUR group($32.41{\pm}25.7$) were significantly higher than that of simple UTI group($3.93{\pm}3.44$)(P=0.007). In conclusion, random urine ${\beta}_2$-MG and excretion ratio deserved early predictor of presence of VUR in children with UTI. And this method was more simple and inexpensive than the method of measuring ${\beta}_2$-MG with 24 hour urine collection, so might be a useful screening test for VUR in children with UTI.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.44-51
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• 2003

Purpose : Acute pyelonephritis in children may result in permanant renal damage which later in life may lead to hypertension and renal failure. The purpose of this study was to evaluate the factors that might be useful for predicting the development of renal scar in children with urinary tract infection(UTI). Methods : We retrospectively reviewed 442 patients with UTI who were admitted to the Department of Pediatrics of Chonbuk National University Hospital, during the period from April 1992 to March 2002. The patients were divided into two groups according to the presence of renal scar on the follow-up DMSA renal scan, and we compared the factors associated with renal scarring between the two groups. Results : There were no significant differences in sex, causative organism and acute phase reactants between the groups with and without renal scar. The age at diagnosis was significantly higher in the renal scar group compared to that without scar. Of the 60 patients with renal scar, 78% had vesicoureteral reflux(VUR), but 13% of patients without scar had VUR. Furthermore, the severity of VUR was significantly correlated with renal scar formation. 53% showed multiple cortical defects on the initial DMSA renal scan, compared to 32% in the non-scar group. In addition, 76% of patients showing multiple cortical defects on the initial DMSA renal scan with VUR had renal scar. Conclusion : The presence and grade of VUR, and findings on the initial DMSA renal scan would contribute to predict risk of renal scar formation in children with UTI.

• Clinical and Experimental Pediatrics
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• v.45 no.10
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• pp.1213-1218
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• 2002

Purpose : Hydronephrosis constitutes a great portion of fetal anomalies screened by prenatal sonogram. The present authors made an attempt to access its natural courses through follow up neonatal hydronephrosis diagnosed by prenatal sonogram. Methods : The study was composed of 23 neonates(36 renal units) who were diagnosed with hydronephrosis through prenatal sonogram screening and confirmed 3-7 days after birth with sonographic evaluation at Kyung Hee University Hospital. The neonates were closely monitored for 12-24 months with renal sonogram, diuretic renogram, intravenous pyelography(IVP) and voiding cystoureterography(VCUG). Results : The underlying diseases were composed of 16 cases(44%) of functional abnormalities, 14 cases(39%) of ureteropelvic junction(UPJ) obstruction, three cases(8%) of vesicoureteral reflux (VUR) and on case each of multicystic dysplastic kidney, UPJ obstruction with ureteral stenosis and ureterovesical junction(UVJ) obstruction with VUR. The degree of hydronephrosis was divided into three classes according to its severity. In 30 renal units with UPJ obstruction and functional abnormalities, 26(87%) showed mild hydronephrosis, while four(13%) were moderate. During the follow up period, six cases(20%) showed natural resolution of hydronephrosis, 15 cases(50%) showed improvement while two cases(7%) were aggravated with improvement only after surgery of the underlying disease. The cases which showed natural resolution were all mild hydronephrosis at diagnosis and the cases which underwent surgery due to continuous aggravation were mild one case and moderate one case. Conclusion : Those with cases of mild hydronephrosis show rapid natural improvement. On the other hand, in some cases, follow up monitoring reveal aggravation of the situation, emphasizing the necessity for thorough follow up for a long period of time.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.56-63
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• 2005

Purpose : Development of renal scarring is associated with delayed diagnosis and treatment of urinary tract infection(UTI). This study was performed to clarify how soon treatment should be started to Inhibit renal scarring after onset of UTI and the factors associated with renal scarring in children with a first episode of febrile UTI. Methods : We retrospectively reviewed 163 patients with a first episode of febrile UTI under the age of 2 years from April 2000 to Ap,il 2004. All patients had a DMSA renal scan and voiding cystourethrogram done in the diagnostic period, 6 months after which a follow-up renal scan was done. After patients wet-e divided into 2 groups according to the duration of fever prior to start of treatment, the duration of fever after start of treatment, and total duration of fever, initial and follow-up DMSA scan findings were analyzed among the different groups. We compared the factors associated with renal scars between the groups with and without renal scars. Results : The initial DMSA renal scan identified abnormal finding in 23% of the patients who were treated $\leq$24 hr from the onset of disease and in 43% of those with fever more than 24 hr. Renal scars developed in 33% of patients who were treated $\leq$24 hr and 38% of those with fever >24 hr prior to treatment. Renal scars developed in 34% of patients with remission of fever $\leq$48 hr after treatment and ill 50% of those with fever >48 hr after treatment. The risk for renal scars was significantly higher in children who had total duration of feyer >72 hr(67%) than in those with shorter duration(19%). In children with renal scars, VUR was most highly associated with an increased risk of renal scar formation. Conclusion : Although children with a first episode of febrile UTI are treated within 24 hr after onset of the fever, renal damage cannot be prevented completely and it is mainly associated with VUR. (J Korean Soc Pediatr Nephrol 2005;9:56-63)

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.181-188
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• 2003

Purpose : Vesicoureteral reflux(VUR) is known to be the main cause of childhood hypertension and renal failure. Knowing its familial occurrence, we determined the incidence of VUR and renal scar in asymptomatic siblings of Korean patients with primary VUR Methods : A total of 50 siblings from 37 index patients were included. Voiding cystourethro-graphy(VCUG) and renal scintigraphy using $^{99m}Tc-DMSA$ were peformed in these siblings from June, 1994 to May, 2001, Index patients were classified into two groups according to the presence of VUR in their siblings, and the clinical factors of the index patients such as age, sex, grade of reflux and renal cortical defect were compared between the groups. Results : Among the 50 siblings, VUR were found in 8(16%) and renal cortical defects were detected in 8(16%) siblings respectively. The incidence of renal cortical defects was 87.5%(7 out of 8) in the VUR(+) siblings. There was a case of VUR(-) cortical defect in one sibling, presumed as a scar from an old VUR. There was no relationship among age, sex, grade of reflux and renal cortical defect of the index patient to the presence of VUR in siblings. Conclusion : This study confirmed a significant incidence of VUR(16%) and renal cortical defects(16%) in the asymptomatic siblings of patients with primary VUR in Korea. It Is resonable to recommend screening studies to the siblings of patients with VUR for the early detection and prevention of probable reflux nephropathy. (J K orean Soc Pediatr Nephrol 2003;7:181-188)