• Clinical and Experimental Pediatrics
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• v.62 no.12
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• pp.442-443
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• 2019

• Childhood Kidney Diseases
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• v.20 no.2
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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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• v.24 no.2
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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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• v.7 no.1
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• pp.38-43
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• 2003

Purpose : Accurate diagnosis of acute pyelonephritis(APN) using clinical and laboratory parameters is often difficult in children. Clinical and experimental studies have demonstrated that renal scarring can be prevented or diminished by early diagnosis and aggressive treatment of acute pyelonephritis. dimercaptosuccinic acid(DMSA) renal scan has been reported to be useful in children for confirmation of the diagnosis of acute pyelonephritis. An analysis was undertaken to correlate the clinical and laboratory manifestations of APN With the results of the DMSA renal scan in different age groups. Methods : We determined the sensitivity of DMSA renal scan in febrile urinary tract infections(UTI) in two groups according to age : group I in less than 2 years; group II in older than 2 years. During the period March 2001 through September 2002, 67 children presented with febrile UTIs. All patients had DMSA renal scan done in the acute period, 55 had voiding cystourethrography(VCUG) and 66 had renal ultrasonogram(RUS) done. Results : There were no significant difference between the two groups in DMSA renal scan (P>0.05). But, in group I sensitivity of DMSA renal scan was 47%; in group II sensitivity of DMSA renal scan was 70%. The grade of reflux correlated with a positive DMSA renal scan. Vesicoureteral reflux did not correlate with age. RUS did not correlate with a positive DMSA renal scan in any age group. Abnormality of RUS did not correlate with age. Conclusion : At present, we believe that DMSA renal scan is the prevailing method in differention of the APN. In addition, it is not invasive and less costly. Even though there is no statistical difference in the sensitivity of DMSA renal scan between young and older children, we can observe that in the younger group, the sensitivity of DMSA renal scan seemed to be lower(47%).

• Childhood Kidney Diseases
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• v.18 no.2
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• pp.111-115
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• 2014

Hyperkalemia is often detected in young infants, particularly in association with acute pyelonephritis or a urinary tract anomaly. Cases of hyperkalemia in this population may also be due to transient pseudohypoaldosteronism, or immaturity of renal tubules in handling potassium excretion. Symptoms of hyperkalemia are non-specific, but are predominantly related to skeletal or cardiac muscle dysfunction, and can be fatal. Therefore, treatment has to be initiated immediately. Administration of fludrocortisone for hyperkalemia is appropriate in cases with hypoaldosteronism, but is challenging in young infants with hyperkalemia due to renal tubular immaturity, without pseudohypoaldosteronism. We report the case of a 25-day-old male presenting with persistent hyperkalemia with normal serum aldosterone, who was admitted with a first episode of pyelonephritis and unilateral high-grade vesicoureteral reflux. The patient was treated successfully with fludrocortisone.

• Childhood Kidney Diseases
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• v.18 no.1
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• pp.42-46
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• 2014

Kawasaki disease (KD) is a systemic vasculitis that can affect many organ systems. Renal manifestations include pyuria, hematuria, proteinuria, tubulointerstitial nephritis, acute renal failure, hemolytic uremic syndrome, or renal scarring. Although its precise pathogenesis remains unknown, it is considered an autoimmune disease. In the literature, it has been reported that KD may develop in conjunction with urinary tract infections. However, many of these previous studies did not use imaging methods such as renal sonograms, dimercaptosuccinic acid renal scans, and voiding urethrocystograms. We report a case of an 8-month old male infant with high grade vesicoureteral reflux, who developed incomplete KD after recurrent pyelonephritis. Acute pyelonephritis can be an early manifestation of KD. Such cases require the evaluation of urinary tract anomalies according to the guidelines for the management of urinary tract infections.

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.35.1-35.1
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• 2004

• Journal of Korean Medical Science
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• v.33 no.49
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• pp.317.1-317.2
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• 2018

• Childhood Kidney Diseases
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• v.5 no.1
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• pp.69-72
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• 2001

Infrequent voiding is defiled as two or less micturitions in a day without organic causes. It can 1ead to bladder capacity enlargement and increase in the volume of residual urine and as a consequence it may produce recurrent urinary tract infections(UTI) and or renal damages. We report a case of acute pyelonephritis due to infrequent voiding in a 13 year old girl. The imaging studies revealed floating debris in the bladder on VCUG and dilated ureter on ultrasonography, and parenchymal defects on 99mTc DMSA scan. (J. Korean Soc Pediatr Nephrol 5 : 69- 72, 2001)

• BMB Reports
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• v.30 no.2
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• pp.101-105
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• 1997

Extracellular phospholipase $A_2$ activity has been detected in urine of patients with acute pyelonephritis (APN). This enzyme required micromolar $Ca^{2+}$ ion for its maximum activity and showed a broad range of pH (4.5~10) optimum. Urine enzyme hydrolyzed phosphatidylethanolamine (PE) and phosphatidylserine (PS) more effectively than phosphatidylcholine (PC). $PLA_2$ activity in the urine of patients with APN was about 5-fold higher than that of healthy individuals. When urine was subjected to heparinSepharose column chromatography, phospholipase $A_2$ activity was detected in both heparin-non-binding and binding fractions. Both phospholipase $A_2$ activities were sensitive less than a micromolar calcium concentration and did not react with anti-human 14-kDa group II phospholipase $A_2$ monoclonal antibody, HP-l. These findings suggest that two kinds of novel extracellular phospholipase $A_2$. which may not belong to the 14-kDa group II phospholipase $A_2$ family, exist in the urine of patients with APN.