• Childhood Kidney Diseases
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• 제21권2호
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• pp.128-135
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• 2017

Purpose: Extended-spectrum ${\beta}$-lactamase-producing bacteria-induced urinary tract infections are increasing and require more potent antibiotics such as carbapenems. We evaluated the clinical significance of extended-spectrum ${\beta}$-lactamase -urinary tract infection in children younger than 5 years to select proper antibiotics and determine prognostic factors. Differences were compared between age groups. Methods: We retrospectively studied 288 patients with their first febrile urinary tract infection when they were younger than 5 years. Patients were divided into extended-spectrum ${\beta}$-lactamase-positive and extended-spectrum ${\beta}$-lactamasenegative urinary tract infection groups. Clinical characteristics and outcomes were compared between the groups; an infant group was separately analyzed (onset age younger than 3 months). Results: Extended-spectrum ${\beta}$-lactamase urinary tract infection occurred in 11 % patients who had more frequent previous hospitalization (P=0.02) and higher recurrence rate (P=0.045). During the antimicrobial susceptibility test, the extended-spectrum ${\beta}$-lactamase-positive urinary tract infection group showed resistance to third-generation cephalosporins; however, 98% patients responded clinically. In the infant group, extended-spectrum ${\beta}$-lactamase-positive urinary tract infection occurred in 13% patients and was associated with a longer pre-onset hospitalization history (P=0.002), higher C-reactive protein level (P=0.04), and higher recurrence rate (P=0.02) than that in the older group. Conclusion: Extended-spectrum ${\beta}$-lactamase urinary tract infection requires more attention because of its higher recurrence rate. The antimicrobial susceptibility test demonstrated resistance to third-generation cephalosporins, but they can be used as first-line empirical antibiotics because of their high clinical response rate. Aminoglycosides can be second-line antibiotics before starting carbapenems when third-generation cephalosporins do not show bactericidal effects for extended-spectrum ${\beta}$-lactamase urinary tract infection.

• Childhood Kidney Diseases
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• 제21권2호
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• pp.114-120
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• 2017

Purpose: The aim of this study was to determine the clinical characteristics, frequency of renal abnormalities and benefits of a top-down approach in children with their first febrile urinary tract infection (UTI). Methods: We reviewed 308 patients retrospectively who were admitted to Yeungnam University Hospital and were treated for their first febrile UTI from February 2006 to December 2013. We performed a comparative analysis of laboratory findings and results of imaging techniques including a Tc-99m dimercaptosuccinic acid (DMSA) renal scan. Results: Among the patients, 69% (213/308) were males, and 90% (277/308) had their first UTI episode during infancy. A DMSA renal scan was performed on all patients, and showed positive findings in 60% (184/308) of cases. Laboratory indices of inflammation were significantly higher in the DMSA-positive group (P< 0.05). There was a statistically significant difference in the age distribution between the two groups. In the DMSA-positive group, 165 patients underwent voiding cystourethrography (VCUG), and 58 (35%) cases demonstrated vesicoureteral reflux. In total, 110 patients in the DMSA-positive group, underwent repeat scanning at 6 months; 33 children (30%) demonstrated static scarring, but 77 (70%) had improved completely. The concordance of the ultrasonography (US) and VCUG was low. Older patients had more renal scarring. Conclusion: DMSA is a sensitive method for assessing the severity of inflammation and kidney injury. However, the ability of US to predict renal parenchymal damage was limited. A top-down approach in children with their first febrile UTI showed significant value.

• 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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• 제22권2호
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• pp.42-46
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• 2018

Purpose: We investigated whether the white blood cell (WBC) count to hemoglobin (Hgb) level ratio is correlated with the presence of cortical defects on dimercaptosuccinic acid (DMSA) renal scan in children with febrile urinary tract infection (UTI). Methods: We examined 95 children who were consecutively admitted to our hospital with their first episode of febrile UTI. Blood tests (C-reactive protein [CRP], WBC, Hgb] were performed. All enrolled children underwent DMSA scanning during admission. Data were compared between children with positive and negative DMSA results. The correlations between WBC to Hgb ratio and the presence of cortical defects on DMSA scan, and between WBC to Hgb ratio and CRP level were analyzed using the Pearson chi-squared test. Multiple logistic regression analysis was used to evaluate whether WBC to Hgb ratio could predict the cortical defects on DMSA scan in children with febrile UTI. Results: The WBC to Hgb ratio was significantly higher in children with positive DMSA results than in those with negative DMSA results; positively correlated with the presence of cortical defects on DMSA scan and CRP; and was a significant factor for predicting the presence of cortical defects on DMSA scan. Conclusion: The WBC to Hgb ratio may predict the presence of cortical defects on acute DMSA scans in children with febrile UTI.

• Childhood Kidney Diseases
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• 제21권1호
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• pp.15-20
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• 2017

Purpose: Febrile urinary tract infection (UTI) is one of the commonest bacterial infections in children. The purpose of this study is to investigate the clinical characteristics of the first episode of febrile UTI occurring in children over 5 years compared to those in infants younger than a year. Methods: We retrospectively reviewed the medical records of 10 patients over 5 years, having febrile UTI, and 25 controls under 1 year. Clinical characteristics including symptoms at admission, the time interval between symptom onset and hospital visit and/or diagnosis, duration of fever, urinalysis, and other laboratory and imaging test results were compared between the two groups. Results: Most patients in the control group showed only high fever at the time of presentation to the hospital. However, 60% of the case group had fever along with gastrointestinal (GI) symptoms such as abdominal and flank pain, vomiting, as well as relatively mild pyuria. The case group showed a longer duration between symptom onset and hospital visit and/or diagnosis. Conclusions: Delay in diagnosis and initiation of treatment of UTI increases the risk of permanent renal scarring and associated complications. Therefore, early diagnosis and treatment of febrile UTI is vital for very young infants, as well as children considering that febrile UTI could be an important cause of febrile illness in children over 5 years.

• Childhood Kidney Diseases
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• 제21권2호
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• pp.94-100
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• 2017

Purpose: The American Academy of Pediatrics provides guidelines for managing febrile urinary tract infection (UTI) in infants and children 2-24 months old, but little guidance is offered regarding UTIs in those younger than 8 weeks of age. The definition of UTI is unclear and whether to proceed with micturating cystourethrography (MCUG) or $^{99m}$technetium-dimercaptosuccinic acid (DMSA) scintigraphy scan in this age group is controversial. Methods: We retrospectively analyzed 29 neonates and infants younger than 2 months of age who underwent late DMSA scans 9 months following the first episode of febrile or symptomatic UTI between July 2009 and June 2016. Results: In total, 192 children aged 0-24 months underwent ultrasound and DMSA scans (MCUG in 174/192). Neonates and infants younger than 2 months of age were significantly less likely to develop fever, and had a lower fever peak, shorter duration of fever before admission and after starting antibiotics, longer hospitalization period, lower C-reactive protein, and greater incidence of nonEscherichia coli infection. There was no difference in pyuria response at diagnosis. The prevalence rates of an ultrasound abnormality (28%), vesicoureteral reflux (28%), UTI recurrence (38%), and renal scarring (10%) in infants younger than 8 weeks of age were similar to those in children 2-24 months old. Conclusion: Neonates and infants younger than 2 months of age with UTI warrant special consideration because the fever response used for diagnosis in older children may be absent or blunted. Clinical guideline is needed for the diagnosis and management of UTI in this age group.

• Pediatric Infection and Vaccine
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• 제11권1호
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• pp.90-100
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• 2004

목 적 : 최근 요배양이 음성이거나 기준이하의 세균 집락이 있었던 경우에서도 신피질 손상이나 요역류가 있음이 보고되고 있으며, 실제 소변 배양검사에서 낮은 세균 집락을 보인 경우에도 요로 감염이 확인된 연구 보고들이 있다. 이에 저자들은 발열과 농뇨가 있는 영아에서 전형적인 요로 감염의 특성을 분석하고, 요로 감염이 의심되나 소변 배양 검사가 음성인 경우에도 영상 및 기능 검사상 이상 여부를 파악하여 관련 인자를 확인하고자 하였다. 방 법 : 2001년 1월부터 2003년 2월까지 가톨릭대학교 의과대학 성모자애병원 소아과에 발열을 주소로 내원하여 일반 요 검사상 농뇨 소견을 보여 입원한 12개월 이하의 환아 136명을 대상으로 소변 배양 검사를 실시하고, 배양 검사 결과와 상관없이 요로 감염 의심 시 신장의 급성 감염 상태를 방영하는 DMSA scan과 요 역류 검사를 시행하여 이상 여부와 관련 인자를 분석하였고, 동시에 임상특성과 원인균도 분석하였다. 결 과 : 136명 중 53명의 환아에서 소변 배양 검사에서 세균이 배양되었으며 57균주가 동정되었다. 단일 균주에 의한 감염 빈도가 92.5%(49/53)이었고, E. coli가 49주(86%)로 가장 많았으며 E. faecalis, M. morganii, Proteus, P. aeruginosa, S. aureus, E. fergusonii 순으로 분리되었다. 이들 균주는 대체적으로 cephalosporins 및 aminoglycosides에 감수성이 높았으나, aminopenicillins에는 감수성이 낮았다. DMSA scan과 요 역류 검사는 배양검사 양성인 경우와 음성인 경우에서 유사한 비율로 이상 소견을 보였다. 소변 배양 검사 양성 유무와 상관없이 농뇨를 보인 영아에서 발열 기간이 48시간 이상인 경우, 연령이 증가할수록, CRP가 높을수록 급성기에 시행한 DMSA scan 검사 이상 유무에 유의성이 있음을 확인하였다. 결 론 : 요로 감염 균주에 대해 1세대, 3세대 cephalosporins와 amikacin에 감수성이 높아 요로 감염 영아에서 이들 항생제의 병합요법이 고려될 수 있다. 또한 발열과 농뇨가 있는 영아에서, 소변 배양 검사가 음성이더라도 나이가 3개월 이상이고 48시간 이상의 발열을 보인 경우, C-반응 단백 수치가 높은 경우에는 급성기의 DMSA scan 검사와 요역류 검사를 시행하여 신장 이상 유무를 확인하고 조기 치료 방침을 결정하는 것이 이후에 신장실질 질환으로의 이환을 막는데 도움을 줄 수 있을 것이다.

• Childhood Kidney Diseases
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• 제20권2호
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• pp.37-44
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• 2016

Although asymptomatic bacteriuria, cystitis, and acute pyelonephritis (APN) have been categorized as urinary tract infections (UTIs), the immunopathogenesis of each disease is different. APN shows an age predilection; the majority of children (over 70-80%) with APN are under 1-2 years of age, with a male predominance. After 1-2 years of age, female predominance has been reported. This finding suggests that the immature immune state of infancy may be associated with the pathogenesis of APN. Escherichia coli is the most common etiologic agent; other uropathogens associated with UTIs originate from the host and comprise normal flora that are continuously altered by environmental factors. Therefore, uropathogens may have characteristics different from those of extraneous bacterial pathogens. Although antibiotic-resistant uropathogens, including extended-spectrum beta-lactamase-producing strains, are increasing in Korea and worldwide, treatment failure is rare in immune-competent children. The immunopathogenesis of APN remains unknown. Intact bacteria may not be the causative substances in renal cell injury; rather, smaller substances produced during bacterial replication may be responsible for renal cell injury and scarring. Moreover, substances from host cells such as proinflammatory cytokines may be involved in renal cell injury. A dimercaptosuccinic acid scan is used to detect the site of bacterial replication in the renal parenchyma, and may be influenced by the size of the focus and the stage of APN. Traditional aggressive studies used to identify vesicoureteral reflux after the first episode of APN have been modified because of rare cases of chronic kidney disease in patients with recurrent UTI.

• Childhood Kidney Diseases
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• 제14권2호
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• pp.184-194
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• 2010

목 적 : 선천성 및 첫 발열성 요로감염으로 진단시 발견된 수신증 환자들에서 임상적 특성에 따른 발열성 요로감염의 발생률을 확인하고자 하였다. 방 법 : 본 연구는 2000년부터 2009년까지 10년간 선천성 수신증으로 진단 받은 200명(군 1)과 첫 발열성 요로감염으로 진단 시 발견된 신장 초음파상 수신증으로 진단받은 252명(군 2)을 대상으로 하였다. 두 군에서 각각 임상적 특징, VUR의 유무, 수유방법, 그리고 선천성 수신증의 임상 경과에 따른 요로감염의 발생 빈도에 대해 알아보았다. 그리고, 그 결과들을 분석하였고, 두 군을 서로 비교하였다. 결 과 : 군 1과 군 2에서 요로감염의 발생률 및 재발률은 각각 10%, 16.7%이며, 요로감염의 연간 발생 빈도(episodes per person-years) 및 재발 빈도는 각각 0.028, 0.051였다. 군 2에서 군 1에 비해 VUR이 많았고(3% vs. 27%, P<0.05), 요로감염의 발생률이 높았다. 군 2에서만 VUR등급이 높을수록 요로감염의 발생률이 높았다(P=0.032). 군 1에서 SFU grade 4와 VUR grade 4-5에서 요로감염의 발생률은 각각 80%, 44.4%였다. 두 군 모두에서 모유 수유 환아들과 분유 수유 환아들 사이에 요로감염의 발생률은 차이가 없었다(P 1=0.274, P 2=0.4). 선천성 수신증의 호전 시기(<1 vs. 1-2 vs. >2 year-old vs. no resolution over 2 year-old)에 따른 요로감염의 발생률과 VUR의 유무는 유의한 차이가 없었다. 결 론 : 선천성 수신증 및 첫 발열성 요로감염으로 진단 시 발견된 수신증 환아에서 SFU grade 4 또는 VUR 4-5를 제외하고는 전반적인 요로감염의 발생률은 낮았다. 모유 수유는 급성 요로감염의 발생 예방에 효과가 없다.

• 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.