• Childhood Kidney Diseases
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• 제20권2호
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• pp.74-78
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• 2016

Purpose: Early diagnosis and treatment of urinary tract infection have been emphasized to prevent renal scarring. If untreated, acute pyelonephritis could cause renal injury, which leads to renal scarring, hypertension, proteinuria, and chronic renal failure. The purpose of this study was to assess risk factors of renal scarring after treatment of acute pyelonephritis (APN). Methods: The medical records of 59 patients admitted at Daegu Fatima Hospital because of APN between March 2008 and April 2015 whose renal cortical defects were confirmed by using initial technetium-99m dimercaptosuccinic acid (DMSA) scans were reviewed retrospectively. We divided 59 patients into 2 groups according to the presence of renal scar and assessed risk factors of renal scar, including sex, age at diagnosis, feeding method, hydronephrosis, bacterial species, vesicoureteral reflux, and vesicoureteral reflux grade. Results: Of 59 patients (41%), 24 showed renal scar on follow-up DMSA scan. No significant differences in sex, hydronephrosis, bacterial species, and fever duration were found between the renal-scarred and non-scarred groups. As for age at diagnosis, age of >12 months had 5.8 times higher incidence rate of renal scarring. Vesicoureteral reflux (VUR) affected renal scar formation. VUR grade III or IV had 14.7 times greater influence on renal scar formation than VUR grade I or II. Conclusion: Our data suggest that the presence of VUR and its grade and age at diagnosis are risk factors of renal scar on follow-up DMSA scan after APN.

• Clinical and Experimental Pediatrics
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• 제55권10호
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• pp.367-370
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• 2012

Urinary tract infection (UTI) is a common bacterial illness in children. Acute pyelonephritis in children may lead to renal scarring with the risk of later hypertension, preeclampsia during pregnancy, proteinuria, and renal insufficiency. Until now, vesicoureteral reflux (VUR) has been considered the most important risk factor for post-UTI renal scar formation in children. VUR predisposes children with UTI to pyelonephritis, and both are associated with renal scarring. However, reflux nephropathy is not always acquired; rather, it reflects reflux-associated congenital dysplastic kidneys. The viewpoint that chronic kidney disease results from renal maldevelopment-associated VUR has led to questioning the utility of any regimen directed at identifying or treating VUR. Despite the recognition that underlying renal anomalies may be the cause of renal scarring that was previously attributed to infection, the prevention of renal scarring remains the goal of all therapies for childhood UTI. Therefore, children at high risk of renal scar formation after UTI should be treated and investigated until a large clinical study and basic research give us more information.

• Childhood Kidney Diseases
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• 제15권2호
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• pp.179-183
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• 2011

영아때 방광요관역류 환아로 진단된 남아중 2세가 넘어 후천적으로 신반흔이 급격히 악화되는 경우는 드물다. 본 증례는 생후 4개월 때 첫 열성 요로감염으로 입원하여, 왼쪽 5등급 방광요관역류로 진단되었고, 부모가 수술을 원치 않아 2년간 예방적 항생제 요법만 시행받았다. 생후 29개월 때 열성 요로감염이 한 차례 재발하였고, 이후 3년간 추적관찰되지 않았다. 이 후, 5세 때 본원을 방문하여 신장초음파, DMSA 신스캔, 배뇨성 방광요도조영술을 재시행받았다. 추적 DMSA 신스캔에서 왼쪽 신상대섭취율이 생후 2세경 38%였으나, 8%까지 떨어졌으며, 왼쪽 방광요관역류는 4등급으로 남아있었다. 현재 방광요관역류의 수술적 요법이 신기능의 예후와 관련이 없다고 알려져 있으나, 이런 증례를 볼 때, 아직은 신반흔을 동반한 고등급의 방광요관역류 환자들에게 수술적 요법을 권유하는 것이 임상의들에겐 타당하다고 볼 수 있으며, 어떤 치료요법이 선택되어지든 상관없이 첫 요로감염 이후 환자를 장기적인 추적 관찰하는 것이 중요하다고 사려된다.

• Childhood Kidney Diseases
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• 제19권2호
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• pp.125-130
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• 2015

Introduction: This study investigated whether renal and bladder ultrasonography (RBUS) findings performed in children with the first incidence of febrile urinary tract infection (UTI) can predict UTI recurrence, high-grade vesicoureteral reflux (high-grade VUR), or acquired renal scarring (aRS). Methods: In all, 917 children who were admitted to our hospital from January 2001 to October 2010, owing to the first incidence of febrile UTI were enrolled in this study. All children underwent RBUS during admission. The mean follow-up was 7.9 months (standard deviation $[SD]{\pm}13.3$). UTI recurrence rates were calculated according to various clinical parameters. By using bivariate and multiple logistic regression analyses, we determined whether age, sex, abnormal RBUS findings, abnormal dimercaptosuccinic acid renal scan findings, or RBUS findings parameters were predictive of UTI recurrence, high-grade VUR, or aRS. Results: On RBUS, hydronephrosis and congenital anomaly of the kidney and urinary tract significantly predicted UTI recurrence. A small kidney, hydroureter, hydronephrosis, cortical thinning, and increased parenchymal echogenicity significantly predicted high-grade VUR. However, their odds ratios (OR) are low compared to normal RBUS findings (recurrent UTI: OR 0.432 and 0.354 vs. 0.934, respectively, high-grade VUR: .019, 0.329, 0.126, 0.058, and 0.188 vs. 2.082, respectively). No RBUS findings significantly predicted aRS. Recurrent UTI, high-grade VUR, and abnormal RBUS findings significantly predicted aRS (OR of 4.80, 4.61, and 2.58, respectively). Conclusion: RBUS is necessary to exclude severe congenital renal scarring, obstructive uropathy, and renal abscess at the first incidence of febrile UTI and is helpful in determining the need for subsequent clinical imaging.

• Childhood Kidney Diseases
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• 제10권2호
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• pp.201-212
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• 2006

Purpose : Vesicoureteral reflux(VUR) is the major risk factor of urinary tract infection(UTI) in children and may result in serious complications such as renal scarring and chronic renal failure. The purpose of this study was to evaluate the relationship between VUR and renal scar formation, the usefulness and correlation of various imaging studies in reflux nephropathy, and the spontaneous resolution of VUR. Methods : We retrospectively reviewed 106 patients with VUR with no accompanying urogenital anomalies in the Department of Pediatrics, Bundang CHA Hospital during the period from Jan. 1996 to Mar. 2005. Ultrasonography and $^{99m}Tc$-dimercaptosuccinic acid(DMSA) scan were performed in the acute period of UTI. Voiding cystourethrography(VCUG) was performed 1 to 3 weeks after treatment with UTI. Follow-up DMSA scan was performed 4 to 6 months after treatment and a follow-up VCUG was performed every 12 months. Results : The mean age at detection of VUR was $13.8{\pm}22.2$ months and the male to female ratio was 2:1. The incidence of renal scarring showed a tendency of direct correlation between severity of VUR(P<0.001) and abnormal findings of renal ultrasonography(P<0.01). 63.2%(24 of 38 renal units) of renal parenchymal defects present in the first DMSA scan disappeared on follow-up DMSA scans. Follow-up DMSA scans detected renal scars in 7(14%) of 50 renal units with ultrasonographically normal kidneys. Meanwhile, ultrasonography did not show parenchymal defects in 7(36.8%) of 19 renal units where renal scarring was demonstrated on a follow-up DMSA scan. The spontaneous resolution rate of VUR was higher(75%) in cases with low grade(I to III) VUR(P<0.01). Conclusions : The presence and severity of VUR and abnormal findings of renal ultrasonography significantly correlated with renal scar formation. DMSA scan was useful in the diagnosis of renal defects. Meanwhile renal ultrasonography was an inadequate method for evaluating renal parenchymal damage. Therefore, follow-up DMSA scans should be performed to detect renal scars even in children with low-grade VUR and normal renal ultrasonography.

• Clinical and Experimental Pediatrics
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• 제52권9호
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• pp.976-983
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• 2009

Urinary tract infection (UTI), the most common bacterial disease in childhood, is frequently associated with urinary tract anomalies (15-50%) and can induce renal scarring, which is a cause of hypertension and chronic kidney disease. Despite the high risk of renal scarring in infancy, the diagnosis may be delayed due to its nonspecific presenting symptoms; moreover, over-diagnosis is frequent due to the contamination of urine samples. The delay in diagnosis and treatment may induce sepsis or renal scar, while over-diagnosis is responsible for unnecessary antibiotic treatment and costly urinary imaging studies. UTI guidelines have been ever-changing for the past three decades, but some controversial issues remain. This article is a revision of the previous KSPN (Korean Society of Pediatric Nephrology) guideline and addresses the recent controversies concerning childhood UTI.

• Childhood Kidney Diseases
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• 제24권2호
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• pp.98-106
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• 2020

Purpose: The aim of this study is to evaluate the clinical utility of late 6-month dimercapto-succinic acid (DMSA) renal scan in predicting vesicoureteral reflux (VUR) and long-lasting renal scars in children with first acute pyelonephritis (APN). Methods: A retrospective case study of children admitted with APN from January 2010 to July 2017 was performed. The study included patients with voiding cystourethrography (VCUG) and acute and late 6-month DMSA scan. We analyzed the clinical, laboratory and imaging findings of patients with and without late cortical defects at 6 months and those with or without VUR. Results: Among 145 children with APN, 50 (34.5%) had cortical defects on the late DMSA renal scan and 60 (41.4%) showed VUR. Thirteen of 38 (34.2%) children undergoing 18-month DMSA renal scan showed a long-lasting renal scars. Compared with children without late cortical defects, patients with late 6-month cortical defects had a higher incidence of VUR and long-lasting renal scars, and relapse of UTI (all P<0.05). In a multivariable analysis, both high-grade VUR and relapse of UTI were independently correlated with the presence of late 6-month cortical defects (P<0.05). Late cortical defects and relapse of UTI were also associated with the presence of VUR (P<0.05). Only the late 6-mo cortical defects was an independent predictor of long-lasting renal scars in children with APN (P<0.05). Conclusion: An abnormal late 6-month DMSA renal scan may be useful in identifying VUR and long-lasting renal scars in children diagnosed with APN.

• Childhood Kidney Diseases
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• 제5권1호
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• pp.43-50
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• 2001

목 적 : 소아기 요로 감염은 신손상을 유발하여 신반흔, 고혈압, 단백뇨, 말기신부전증등을 일으키며 특히 방광 요관 역류는 신반흔과 밀접한 관련이 있는 것으로 알려져 있다. 본 연구의 목적은 방광 요관 역류가 있으면서 신반흔을 형성한 환아군과 형성하지 않은 환아군의 연령, 성별, 역류 등급, ACE 유전자 다형성, 그리고 신체적 성장의 소견을 비교 분석하여 신반흔에 관련된 인자들을 평가하기 위한 것이다. 대상 및 방법 : 1992년 7월부터 2000년 6월까지 요로 감염으로 전북대병원 소아과에 내원한 환아 545명중에 방광 요관 역류로 진단된 15세 미만의 환아 93명을 대상으로 후향적으로 조사하였다. 환아들은 신반흔의 유무에 따라 두 군으로 분류하여 진단시 연령과 성별, 키, 체중등을 조사하였고 방광 요관 역류와 그 정도는 배뇨중 방광 요도 조영술을 시행하였으며 신반흔은 99mTc-DMSA 신스캔으로 추적 검사를 시행하여 확진하였다. ACE 유전형은 말초 혈액의 genomic DNA에서 PCR법으로 결정하였고, 신장과 체중은 HSDS와 WHI로 나타내어 비교 분석하였다. 결 과 : 신반흔이 있는 환아 54명 중에 방광 요관 역류 환아는 47명(87$\%$)으로 방광 요관 역류가 신반흔의 중요한 인자이었다. 신반흔 형성군과 무형성군 사이의 남녀별 차이는 없었으며 신반흔 형성군의 진단시 평균 연령은 2.48${\pm}$2.65세로 무형성군의 1.26${\pm}$1.83세에 비해 유의하게 높았다(P<0.05). 방광 요관 역류의 정도는 역류 등급이 높을수록 신반흔이 생기는 비율이 높았다(P<0.05). 1세 미만의 역류가 있는 환아들은 비교적 신반흔을 잘 형성하였고 모든 연령분포에서 역류의 정도가 심할수록 신반흔이 잘 발생하였다(P<0.05) 전체 요로감염이 있었던 환아의 17.5$\%$에서 방광 요관 역류가 있었고, 이 때 동반된 요로 감염의 대부분의 원인균은 E. coli였으며(75.3$\%$, E. coli가 차지하는 비율은 양 군($76.6\%/73.9\%$)사이에 유의한 차이는 없었다(P>0.05). ACE 유전자 다형성에 따른 신반흔 형성과의 관계를 보기 위해 양 군사이를 비교하였으나 유의한 차이는 없었다(P>0.05). 신반흔의 정도와 신체적 성장과의 관계를 보기 위해 진단시의 키와 체중을 매개변수인 HSDS와 WHI로 환산하여 양 군사이를 비교하였을 때 유의한 차이는 없었다(P>0.05). 결 론 : 본 연구에서 신반흔에 관련된 인자로서는 진단시의 연령, 방광 요관 역류의 유무, 또한 역류의 정도와 관계가 있고 성별, 원인균, ACE유전자형과는 무관하였으며, 앞으로 세균의 독성요소로 작용하는 E. coli의 특성에 대한 자세한 연구와 신반흔의 정도에 따른 신체적 성장의 추적 관찰에 대한 연구가 필요할 것으로 생각된다.

• Childhood Kidney Diseases
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• 제9권1호
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• pp.56-63
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• 2005

목 적 : 요로 감염은 조기 진단 및 치료를 적절히 하지 않으면 비 가역적인 신 손상을 초래하기 쉽다. 신 반흔을 막기 위한 요로 감염의 적절한 치료 시작 시기와 소아의 첫 발열성 요로 감염에서 신 반흔 발생과 관련한 인자를 알아보았다. 방 법 : 2000년 4월부터 2004년 4월까지 첫번째 발열성 요로 감염으로 진단된 2세이하 환아163명을 대상으로 후향적으로 조사하였다. 요로감염 급성기에는 DMSA 신 스캔, 치료 후 VCUG을 시행하고 치료 6개월 후 추적 DMSA 신 스캔을 시행, 신 반흔 유무를 평가하였다. 치료 전 발열 기간, 치료 후의 발열 기간, 총 발열기간에 따라 각각 두 군으로 분류, 진단시와 6개월 후 추적 DMSA 신 스캔 소견을 비교 분석하였다. 또한 신 반흔 유무에 따라 신 반흔 형성군과 무형성군으로 분류하여 관련된 예측 인자와의 관계를 분석하였다. 결 과 : 치료 전 발열 기간이 24시간 이하 군에서 초기 DMSA 신 스캔의 이상 소견 빈도는 23%였고 이중 33%에서 신 반흔이 발생하였다. 24시간초과 그룹에서는 각각 43%, 38%였으나 군간 유의한 차이는 없었다. 치료시작 후 발열기간이 48시간 이하이며서 초기 DMSA 검사에서 이상을 보인 환아 중 34%에서 신 반흔이 생겼고, 치료 후 열이 48시간 이상 지속된 경우는 50%에서 신 반흔이 형성되어 두 군간 차이는 없었다. 총 발열 기간 72시간 이하인 환아군의 45%에서 신 피질 결손, 19%에서 신 반흔이 나타났고, 72시간 초과인 환아군에서는 각각 31%, 57%로 신 반흔 형성률이 의미있게 높았다. 총 발열기간, 높은 CRP, 방광요관 역류가 신 반흔 형성과 관련 있었으며 이중 방광요관 역류가 가장 높은 연관을 보였다. 결 론 : 소아의 발열성 첫 요로 감염에서 치료 전 발열 기간이 24시간 이내라도 신 반흔을 완전히 예방할 수 없었고 이에 관여하는 주된 인자는 방광요관 역류였다.

• Clinical and Experimental Pediatrics
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• 제62권12호
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• pp.433-437
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• 2019

Acute pyelonephritis (APN) should be detected and treated as soon as possible to reduce the risk of the development of acquired renal scarring. However, in the medical field, urine culture results are not available or considered when the prompt discrimination of APN is necessary and empirical treatment is started. Furthermore, urine culture cannot discriminate APN among children with febrile urinary tract infection (UTI) (pyelitis, lower UTI with other fever focus). Therefore, the usefulness of urine culture for diagnostic purposes is small and the sampling procedure is invasive. Congenital hypoplastic kidney is the most common cause of chronic kidney injury in children. Thus, it is desirable that a main target be detected as early as possible when imaging studies are performed in children with APN. However, if APN does not recur, no medical or surgical treatment or imaging studies would be needed because the acquired renal scar would not progress further. Therefore, the long-term prognosis of APN in young children, particularly infants, depends on the number of recurrent APN, not other febrile UTI. New methods that enable prompt, practical, and comfortable APN diagnosis in children are needed as alternatives to urinary catheterization for urine culture sampling.