• 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.9 no.1
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• pp.64-68
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• 2005

Purpose : Renal abscess is very rare in children and its diagnosis is difficult because symptoms are often nonspecific. In previous studies, on]y 15% to 25% of patients were reported to be diagnosed at the time of admission. Early diagnosis and treatment are important be cause mortality rate correlates positively with the time of diagnosis. The purpose of this study is to clarify the clinical features of children with renal abscess and to investigate the possible indicators of this disease for early diagnosis and Proper treatment. Methods : Twelve children diagnosed with renal abscess from Jan. 1996 to Jul. 2004 were included. The age of patients ranged from S months to 15 years. We retrospectively analyzed the demographics of patients, their symptoms, predisposing factors, diagnostic methods and causative organisms and the treatment modalities. Results : Fever was the most common manifestation, Five children(42%) had vesicoureteral reflux. Renal ultrasonography and computerized tornography were the most frequently used imaging tools to detect renal abscess. Gram negative bacteria were isolated in 7 patients and Staphylococcus aureus grew in 2 patients. All patients received intravenous antibiotics and 4 patients underwent aspiration or drainage of renal abscess. The average admission duration was 30 days. Conclusion : Renal abscess should be included in the differential diagnosis of prolonged fever in children, especially when flank pain is combined. For early diagnosis and a better prognosis, patients should be promptly investigated with ultrasonography or computerized tomography.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.8-14
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• 2005

Purpose : This study was peformed to study normative blood pressure data in full-term neonates that may be used to facilitate Identification of neonatal hypertension.Methods : 383 newborns born in our hospital from May 2003 to January 2004 were enrolled in this study Using an oscillometric device(BP-88 NEXT, COLIN Corp.), their blood pressures were measured more than one time within a week after birth. According to each clinical variable such as sex, delivery mode, birth weight, gestational age and presence of maternal disease or perinatal problems, we divided the population into groups and calculated the mean blood pressures of each group. We compared mean blood pressures between the divided groups according to each clinical variable statistically.Results : Mean systolic and diastolic blood pressure of the Population was 70.8$\pm$ 10.9 mmHg and 43.4 $\pm$ 8.0 mmHg, respectively. There was no satistically significant difference in blood pressure according to clinical variables. Mean systolic pressure showed positive correlation with birth weight and gestational age(r=0.1420, 0.03130).Conclusion : Our results are almost in agreement with Zubrow's data from 695 newborns in U.S.A, 1995. Our data may be helpful for early detection and management of neonatal hypertension, thereby maintaining renal function ,and preventing possible complications of renal disease.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.15-20
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• 2005

Purpose : Nutcracker syndrome must be considered when hematuria or proteinuria occurs in a healthy child. The purpose of this study is to investigate the prevalence of nutcracker syndrome among children with asymptomatic hematuria or proteinuria, and to obtain the ratios of the peak velocity of the left renal vein between the aortomesenteric portion and the hilar portion in children with asymptomatic hematuna or protelnuria in which nutcracker syndrome was excluded and to observe whether the ratios are affected by sex, age or urinalysis findings. Methods : Using Doppler ultrasonography, we measured the flow velocity and obtained the peak velocity ratios of the left renal vein at the aortornesenteric portion and at the hilar Portion of the left kidney in children with asymptomatic hematuria or proteinuria who visited the Division of Pediatric Nephrology, Severance Hospital from May 2001 to March 2004. Results : Of 304 children with asymptomatic hematuna or proteinuria, 107 children(35.2%) were diagnosed with nutcracker syndrome. For 197 children with asymptomatic hematuria or proteinuria excluding nutcracker syndrome, the mean ratio of the peak velocity was 2.54 $\pm$0.73, which was not affected by sex, age or urinalysis findings. Conclusion : Nutcracker syndrome was the major cause of asymptomatic hematuria or proteinurla In children, comprising 35% of all cases. Doppler ultrasonography was helpful in the screening of nutcracker syndrome and prevention of its complications. For children with asymptomatic hematuria or proteinuria excluding nutcracker syndrome, the peak velocity ratio of the left renal vein did not differ from that of normal children and was not affected by sex, age or urinalysis findings. (J Korean Soc Pediatr Nephrol 2005;9:15-20)

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.31-37
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• 2005

Puruose : Thin glomerular basement membrane disease(TGBMD) is found in patients with family history of hematuria. TGBMD is autosomal dominant and is known to be one of the commonest causes of asymptomatic hematuria. This study was conducted to evaluate the histological and clinical features of patients with TGBMD. Methods : 150 cases diagnosed with TGBMD by renal biopsy while admitted in the department of pediatrics, Kyungpook National University Hospital between January 1999 and December 2003 comprised the study group. The following parameters were retrospectively anaIyzed age of onset, hematuria pattern, existence of proteinuria, process of diagnosis, laboratory findings, thickness and character of basement membrane and family history. Results : The mean age at the time of diagnosis was 7.9 years. The male to female ratio was 65:77. 94 patients or 66% visited the hospital with a chief complaint of persistent microscopic hematuria. Gross hematuria accounted for 13 cases or 9%. 78 cases(55%) were found to have hematuria for the first time from a routine school urinalysis screening. The renal biopsy showed the thickness of basement membrane to be 186$\pm$36 nm. Focal lamellation of the basement membrane was found in eight cases. In the family history, hematuria was shown in 10 cases on the Paternal side, 13 on The maternal side and none on both sides. In seven cases, hematuria was shown among siblings. No significant differences were found among the laboratory test results which were conducted at an average interval of fifteen months. Conclusion : TGBMD is one of the major causes of asymptomatic hematuria in children, which was diagnosed in increasing numbers since school urinary mass screening test started in 1998. In cases with familial progressive renal disease or focal duplication in the basement membrane Alport syndrome should be considered.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.18-26
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• 2006

Purpose : Empirical antimicrobial treatment is indicated before bacteriological results are available for young children with febrile UTI to minimize renal scarring. To ensure appropriate therapy, knowledge of the prevalence of causative organisms and their susceptibility patterns to antimicrobials is mandatory. We performed a retrospective analysis investigating the local prevalence and resistance patterns of uropathogens, primarily E. coli, isolated from community-acquired UTIs. Methods : A total of 103 positive urine cultures from children with febrile UTI collected at Bundang CHA General Hospital from February 2004 to February 2005 were analyzed. Inclusion criteria were fever higher than $37.5^{\circ}C$, significant bacteriuria with single strain growth of at least 10s colony forming units/mL urine, and leukocyturia >5/HPF. Results : E. coli(89.3%) was the leading uropathogen followed by Enterococcus spp.(3.9%) Klebsiella spp.(2.9%), Citrobctcter spp.(1.9%) and Enterobacter spp.(1.9%). E. coli strains revealed a low proportion of antimicrobial susceptibility to ampicillin(AMP; 27.2%) ampicillinsulbactam(AMS; 34.8%) and trimethoprim-sulfamethoxazole(SXT; 65.2%). Susceptibility patterns to cephalosporins were as follows; cefazolin(1st generation; 91.3%), cefoxitin(2nd; 100%), ceftriaxone(3rd; 97.8%) and cefepime(4th; 97.8%). Three E. coli isolates produced ex tended - spectrum beta-lactamase(ESBL). Conclusion : Empirical treatment with AMP, AMS and SXT, which are commonly used in pediatric clinics, is not recommended for childhood UTI due to high incidence of resistance. The high level of susceptibility to cephalosporins makes these drugs reasonable alternatives. However the emergence of ESBL-producers, even though they are quite few, may have an impact on cephalosporin treatment in the future. (J Korean Soc Pediatr Nephrol 2006;10:18-26)

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.27-32
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• 2006

Purpose : Conservative management of multicystic dysplastic kidney(MCDK) without nephrectomy has recently been advocated. The purpose of this study was to determine the clinical course of conservatively managed MCDK and to find out possible predictive factors for involution of MCDK by ultrasonography(US). Methods : A retrospective analysis was made on 45 patients(26 boys and 20 girls) in whom MCDK was detected and had been traced by US between Dec. 1993 and Aug. 2005 at Severance Hospital. Results : Median follow-up time was 30 months(range 2-102 months). All patients under-went radionuclide scans and voiding eystourethrograms. The serial follow-up US showed complete involution in 11(24%), partial involution in 19(41%), and no interval change or increased in cyst size in 13(28%) patients. Nephrectomy was done in 3 patients(7%) due to relapsing urinary tract infection(UTI) and severe abdominal distension. The mean age of complete involution of MCDK was 37 months(range 12-84 months). Episodes of UTI were present in 17 patients(37%) and additional genitourinary(GU) abnormalities were found in 22 patients(44%). Hypertension and renal insufficiency was complicated in one patient. No child developed malignant tumor. Univariate analysis showed that five variables were associated with complete involution of the MCDK; gender, site, UTI episode, additional GU abnormalities, and renal length on initial US. After adjusting using the Pearson model, the presence of additional GU abnormalities was exclusively associated with complete involution among the 5 variables(P=0.034). Conclusion : In our review of 46 cases of MCDK, non-surgical approach for patients with MCDK was advisable and we could predict poor prognosis when MCDK is associated with other GU anomalies.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.33-39
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• 2006

Purpose : Neonatal hydronephrosis is diagnosed with an incidence of 4.5-7% of pregnancies. Recently, early detection of neonatal hydroneprosis with antenatal ultrasonography has be-come possible. But consensus about its management has not been reached, especially concerning surgical intervention. The purpose of this study is to analyze the natural course of neonatal hydronephrosis and to determine the guideline of surgical intervention and follow up study. Methods : Sixty nine hydronephrotic kidneys were confirmed from April 2001 to April 2005. All cases were rechecked by ultrasonography once at least and had a minimum follow-up of 6 months. We classified the patients into 4 groups according to the anterior posterior pelvic diameter(APPD) on perinatal ultrasonography. Ultrasonography to measure the APPD diameter and Society for Fetal Urology(SFU) grade, $^{99m}Tc-MAG3$ scan were done to a set protocol. Pyeloplasty was peformed according to the protocol. Results : Pyeloplasty was not needed in most cases where the APPD was below 10 mm and where the SFU grade were less than grade 3. Many cases with APPD 10 mm above or SFU grade III above had undergone pyeloplasty. We found a correlation between obstruction grade on MAG3 scan and whether surgery was performed or not. Conclusion : If APPD is above 10 mm, SFU grade is above grade 3 or urinary tract obstruction is suspected by MAG3 scan, pyeloplasty must be considered. In cases where APPD is below 10mm and SFU grade is less than grade 3, we can observe the natural course of neonatal hydronephrosis with consecutive follow-up. (J Korean Soc Pediatr Nephrol 2006;10:33-39)

• 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)

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.157-165
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• 2003

Purpose : $Henoch-Sch\"{o}nlein$ purpura(HSP) is a systemic vasculitis that involves multiple organs, especially the kidney, which is the most important organ in determining the prognosis of the disease. The morbidity of HSP nephritis in adults is low and there have been little research done on its clinical course so far. Therefore, we have compared the clinical course of HSP nephritis in children and adults in Korea. Methods : We retrospectively analyzed 81 cases of HSP nephritis in children younger than 15 years of age, and 25 cases of adults older than 15 years of age who were admitted to Yonsei University Medical College Severance Hospital from Jan. 1986 to May 2003. Results : The male to female ratio was 1.5 : 1 in children and 1.3 : 1 in adults. The incidence of HSP nephritis for both age groups was found to be increased during the autumn and winter. Infection was the predisposing factor in 39 cases(48.1%) of children, 16 cases(64.0%) of adults, and drugs were the predisposing factor in 8 cases(9.9%) of children and 4 cases (16.0%) of adults. All patients initially presented with microscopic hematuria. Thirteen cases (16.0%) of children and 7 cases(28.0%) of adults initially showed proteinuria of nephrotic range. Thirty four cases(42.0%) of children and 4 cases(16.0%) of adults showed normal urinalysis after treatment. Asymptomatic urinary abnormalities were found in 41 cases(50.6%) of children and 18 cases(72.0%) of adults. Complications such as nephrotic syndrome and hypertension were found in 3 cases(3.7%) of children and 2 cases(8.0%) of adults. Three children(3.7%) and 1(4.0%) adult required dialysis or renal transplantation. Follow-up renal biopsies were performed on 21 children, of whom 10 cases(47.6%) did not show any histologic change, 9 cases(42.9%) showed low grade changes, and 2 cases(9.5%) showed high grade changes. Prognosis was gloomy when proteinuria of nephrotic range and high grade of abnormal histology were present at diagnosis, and there was no significant difference between the two groups(P<0.05) Conclusion : This study showed that there was no difference in terms of the clinical features and courses between the children and adults with HSP nephritis. Proteinuria of nephrotic range and the severity of abnormal histologic changes at diagnosis were found to be associated with a bad prognosis, therefore we recommend that patients with these features require long term follow-up and management.