Prognostic Factors of Renal Scarring on Follow-up DMSA Scan in Children with Acute Pyelonephritis

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.

Risk Factors for Vesicoureteral Reflux in Children with Upper and Lower Urinary Tract Infections.

Objective: Urinary tract infections (UTIs) are common in children and may signal vesicoureteral reflux (VUR). This study aimed to identify the risk factors associated with VUR and to emphasize value of diagnostic imaging studies in children. Methods: This study was assessed 173 medical records of children who had first-time UTI in Ege University Pediatric Nephrology Department between January 2008 and January 2010. Patients were divided into 2 groups according to localization of UTI infections. Patients with fever, elevated acute phase reactants, low urine osmolarity and positive urinary culture were defined as having an upper UTI (Group I). Patients without systemic symptoms were defined as having a lower UTI (Group II). Results: Ultrasonography (US) findings were abnormal in 43.4% patients. Abnormal dimercaptosuccinic acid (DMSA) was detected in 45% of patients and VUR was found in 41%. US had 52.4% sensitivity and 64.4% specificity for cortical defects in DMSA, and 52.4% sensitivity and 46.4% specificity for VUR. In Group I, DMSA had 70% sensitivity and 70% specificity for reflux in voiding cystourethrography. In Group II, US had 53% sensitivity and 48% specificity for cortical defects in DMSA, and 50% sensitivity and 41% specificity for VUR. DMSA had 62.5% sensitivity and 54.5% specificity for VUR. Conclusions: Patients with UTIs should not be evaluated according to age and localization, only but rather according to all risk factors.

Value of 99mTc-EC dynamic renography in diagnosis of renal scars in children / 临床儿科杂志

Objective To evaluate the diagnostic value of 99mTc-EC dynamic renography for renal scars in children with urinary tract infection. Methods The 99mTc-EC and 99mTc-DMSA renographic results of 67 children diagnosed with urinary tract infection were retrospectively studied. In comparison with 99mTc-DMSA cortical images, the value of 99mTc-EC dynamic renogra-phy for the diagnosis of urinary tract infection, hydronephrosis and renal scars was analyzed. Results The sensitivity and speci-ficity of the initial 2 minutes summed images in the 99mTc-EC images for the diagnosis of renal scars was 80.28%and 88.89%re-spectively, and the likelihood ratio was 7.23. Renal scars were more likely to be formed in patients with obstructed upper urinary tracts, as compared with patients with unobstructed upper urinary tracts and unsmooth upper urinary tracts (P0.05). Conclusions For children with urinary tract infection, the diagnostic sensitivity and specificity of the initial summed images of 99mTc-EC dynamic renography are high. Furthermore, the excretion of upper urinary tract showed by 99mTc-EC dynamic renogra-phy is valuable for the diagnosis of renal scars.

Daño renal cortical en niños con primera infección del tracto urinario alto / Cortical renal damage in children with a first infection of the high urinary tract

Introducción: entre el 5 y 22 % de los niños que padecen pielonefritis aguda desarrollarán cicatriz renal. Objetivo: describir los aspectos clínico-epidemiológicos del daño renal cortical en niños con la primera infección del tracto urinario alto. Métodos: estudio observacional prospectivo y longitudinal sobre el daño renal cicatricial en niños con la primera infección urinaria alta, ingresados en el servicio de nefrología del Hospital Pediátrico Universitario "William Soler", entre el 1º de enero de 2008 y diciembre 31 de 2009. Se diagnosticaron 50 pacientes, y 38 reunieron criterios para incluirlos en el estudio. Los pacientes tenían una edad media de 18 meses. A los 38 pacientes se les realizó ultrasonido renal durante la fase aguda de la enfermedad, y gammagrafía renal estática entre 6 y 12 meses después del cuadro agudo, para precisar la lesión renal cortical. En los casos con cicatriz renal, ausencia o disminución de captación del radiofármaco (99mTc-DMSA), se les realizó uretrocistografía miccional para precisar la existencia de reflujo vesicoureteral. Resultados: 28 pacientes (73,7 %) son del sexo femenino, 17 (44,7 %) menores de 6 meses, 17 (44,7 %) tienen entre 6 y 36 meses, y 4 (10,6 %) > 3 años. La infección urinaria fue atípica en 23 (60,5 %), y el germen aislado, la Escherichia coli en 33 (86,8 %). El ultrasonido de la fase aguda demostró dilatación pélvica renal en 3 (7,9 %) y asimetría renal en 1 (2,6 %). En 2 pacientes (5,2 %) se demostró cicatriz renal y en 11 (28,4 %) hipofunción de la corteza renal. La uretrocistografía miccional demostró reflujo vesicoureteral grado III en una niña, que además, tenía cicatriz renal. No existió relación entre el inicio de los síntomas, comienzo de la terapeútica y lesión cortical. Conclusiones: los factores de riesgo para desarrollar cicatriz renal pospielonefrítica fueron: sexo femenino, edad menor de 3 años y reflujo vesicoureteral grado III.

Introduction: between the 5 and the 22 % of children suffering acute pyelonephritis will develop a renal scar. Objective: to describe the clinical-epidemiological features of the cortical renal damage in children with a first infection of high urinary tract. Methods: a longitudinal, prospective and observational study was conducted on the cicatricial renal damage admitted in the Nephrology services of the "William Soler" University Children Hospital from January 1, 2008 to December 31, 2009. Fifty patients were diagnosed and 38 fulfilled the inclusion criteria to study. Patients had a mean age of 18 months and underwent renal ultrasound during the acute phase of disease and static renal scintigraphy between 6 and 12 months after the acute picture, to specify exactly the cortical renal injury. In cases of renal scar, lack or decrease of the radioactive drug capture (99mTc-DMSA) authors carried out miction uretrocystography to specify exactly the presence of vesicoureteral reflux. Results: twenty six patients (73.7 %) are females, 17 (44.7 %) aged under 6 months, 17 (44.7 %) have between 6 and 36 months and 4 (10.6 %) > 3 years old. The urinary infection was atypical in 23 (60.5 %) and as a isolated germ the Escherichia coli in 33 (86.8 %). Ultrasound of acute phase demonstrated a renal pelvis dilation in 3 (7.9 %) and renal asymmetry in 1 (2.6 %). In 2 patients (5.2 %) there was renal scar and in 11 (28.4 %) an decreased function of the renal cortex. The miction uretrocystography demonstrated the presence of grade III vesicoureteral reflux in a girl, who also had a renal scar. There was not relation between the onset of symptoms, the onset of therapeutics and the cortical injury. Conclusions: the risk factors to develop a post-pyelonephritis renal scar were: female sex, be aged under 3 and grade III vesicoureteral reflux.

Renal scar formation after urinary tract infection in children / 소아과

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.

Clinical Signif icance of Intrarenal Reflux in Children with Urinary Tract Infection

PURPOSE: Intrarenal reflux(IRR) is backflow of urine from the renal pelvis into the collecting ducts. IRR is the main cause of renal injury in children with vesicoureteral reflux (VUR) which leads to renal scars, hypertension, proteinuria, and chronic renal failure. The purpose of our study was to investigate the characteristics of intrarenal reflux. METHODS: We retrospectively reviewed the medical records of 80 patients who were diagnosed as having grades of III-V VUR from Jan. 2004 to Dec. 2006 in the department of pediatrics in Ajou University Hospital. The patients were divided into two groups according to the presence of IRR on voiding cystoureterogram and compared to each other for the possible factors associated with intrarenal reflux. RESULTS: Among 80 VUR patients, IRR(+) group comprised 17(21.3%) patients and 27 renal units(23.2%) and revealed younger age, higher grade of VUR, and more proteinuria compared to IRR(-) group. There were no significant difference in gender, laboratory findings and the rate of resolution in VUR or defects on renal scan between two groups. Also, intrarenal reflux mostly corresponded to the same site of photon defects on DMSA scan. CONCLUSION: We suggest that intrarenal reflux tends to be associated with younger age, higher grade of reflux, more proteinuria with no difference in resolution rate of VUR when compared to the VUR patients without IRR. From this study, we were able to understand the characteristics of intrarenal reflux in children with urinary tract infection.

The Decision of Voiding Cystourethrography in Children with Urinary Tract Infection

PURPOSE: We attempted to compare the independent factors such as age, sex, C-reactive protein(CRP), and white blood cell count(WBC) in children with radiologic studies and assess the necessity of performing voiding cystourethrography(VCUG). METHOD: 98 children who have been diagnosed their first time febrile urinary tract infection from Janurary 2002 to Januray 2005 were enrolled. In all patient, the duration of fever which occurred before and after treatment was recorded, and CRP, WBC, (99m)Tc-2,3-dimercaptosuccinic acid((99m)Tc-DMSA) renal scans, renal ultrasound and VCUG were analyzed. RESULTS: Of the 98 children diagnosed with urinary tract infection(UTI), 52 were male and 46 were female. 18 had abnormalities in VCUG, 17 had abnormalities in kidney ultrasound, and 20 had partial defects or diffuse uptake decrease in (99m)Tc-DMSA renal scans. There were no significant relationship between incidence of radiologic abnormalities and age. The risk of renal scar was significantly higher in children who had a longer febrile period before treatment than in those with shorter period. Both CRP and WBC were significantly elevated in children with the radiological abnormalities. A positive of (99m)Tc-DMSA renal scans and renal ultrasound were highly associated with vesicoureteral reflux(VUR). CONCLUSION: If there are abnormalities in the kidney ultrasound and (99m)Tc-DMSA renal scan of a child with initial UTI, a VCUG is recommended. Even in cases without abnormal findings in (99m)Tc-DMSA renal scan and renal ultrasound, clinical data such as CRP and WBC should be assessed, and VCUG should be performed for the undetected VUR.

Spontaneous Resolution Rate and Predictive Factors of Resolution in Children with Primary Vesicoureteral Reflux

PURPOSE: To analyze the clinical characteristics, spontaneous resolution rate and predictive factors of resolution in children with primary vesicoureteral reflux(VUR). METHODS: Between October 1991 and July 2003, 149 children diagnosed with primary VUR at Chonbuk National University Hospital were reviewed retrospectively. All of the patients were maintained on low-dose antibiotic prophylaxis and underwent radionuclide cystograms at 1- year intervals over 3 years after the initial diagnosis of VUR by voiding cystourethrogram was made. RESULTS: The median time to resolution of VUR was 24 months and the total 3 year-cumulative resolution rate of VUR was 61.7%. The following variables were associated with resolution of VUR according to univariate analysis-; age<1 year, male gender, mild grade of reflux, unilateral reflux, congenital hydronephrosis as clinical presentation at time of diagnosis of VUR, absence of focal defects in the renal scan at diagnosis, absence of recurrent UTI, renal scars and small kidney during follow-up. After adjustment by Cox regression model, five variables remained as independent predictors of VUR resolution; age<1 year, relative risk 1.77(P<0.05), VUR grade I+II 2.98(P<0.05), absence of renal scars 2.23(P<0.05), and absence of small kidney 5.20(P<0.01) during follow-up. CONCLUSION: In this study, spontaneous resolution rate of VUR, even high grade reflux, is high in infants during medical management, and it was related to age, reflux grade at diagnosis, absence of renal scars and small kidney during follow-up. Therefore early surgical intervention should be avoided and reserved for the selected groups.

Vesicoureteral Reflux and Renal Scar

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 99mTc-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+/-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.

The Occurrence of Renal Scarring in Children with Unilateral Vesicoureteral Reflux / 소아과

PURPOSE: We evaluated the occurrence of renal scarring in children with unilateral vesicoureteral reflux (VUR), and the relationships between renal scar formation and risk factors such as VUR, duration of fever, acute-phase reactant, age, and sex. METHODS: We retrospectively analyzed the data of 35 children newly diagnosed with unilateral vesicoureteral reflux after urinary tract infection (UTI) in Wallace Memorial Baptist Hospital between January 1996 and December 2004. Ultrasonography, Erythrocyte sedimentation rate (ESR), and C- reactive protein (CRP) were performed initially. Voiding cystourethrography (VCUG) was performed 1 to 3 weeks after treatment with UTI. (99m) Tc-dimercaptosuccinic acid (DMSA) scan was performed 4 to 6 months after treatment. RESULTS: Scintigraphic renal damage was present in 29 percent of the refluxing and in 3 percent of the nonrefluxing kidneys (P< 0.05). The severity of VUR was significantly correlated with renal scar formation (P< 0.05). The duration of fever before treatmen (5.0+/-1.3 vs 2.6+/-1.3) and prolonged fever of over 5 days were significantly different between renal scar group and non-renal scar group (P< 0.05). ESR (56.3+/-23.8 vs 27.9+/-18.1 mm/hr, P< 0.05) and CRP (12.8+/-7.3 vs 3.9+/-3.8 mg/dL, P< 0.05) at the diagnosis of UTI in the renal scar group were higher, compared to those of the non-renal scar group. There were no significant differences in age and sex between the two groups. CONCLUSION: The presence and grade of VUR, the duration of fever before treatment, prolonged fever over 5 days, ESR, and CRP were risk factors for renal scarring, irrespective of age and sex. Diagnosis and management of VUR, in children with UTI, is important to prevent renal scars.

Incidence and Risk Factors of Recurrent Urinary Tract Infections during Antibiotic Prophylaxis in Children with Primary Vesicoureteral Reflux

PURPOSE: Recurrent urinary tract infection(UTI) in primary vesicoureteral reflux(VUR) may lead to serious renal scarring, a major cause of childhood hypertension and end-stage renal disease. To prevent recurrent UTI, low-dose long-term antibiotic prophylaxis has been recommended. However, recurrent UTI still develops during antibiotic prophylaxis, the efficacy of which is now being disputed. The emergence of resistant bacteria has also raised concerns. To evaluate the effect of antibiotic prophylaxis, we investigated recurrent UTI during prophylactic antibiotic use in children with primary VUR. Materials:The incidence and risk factors of recurrent UTI were retrospectively evaluated in ninety-one children with primary VUR on trimethoprim-sulfamethoxazole(TMP/SMX) prophylaxis during the year following their index febrile UTI. RESULTS: Recurrent UTI occurred in 31.9%(29/91) children and comprised 0.32 episodes/ patient year. Febrile UTI was 0.26 episodes/patient year and afebrile UTI was 0.07 episodes/ patient year. The recurrent rate of UTI in male patients with phimosis was 37.2%(19/51), which was significantly higher than in males without phimosis 0%(0/5)(P=0.025). In the logistic regression analysis for recurrent UTI, renal scar was the significant risk factor for recurrent UTI [RR 3.8(95% CI 1.0-14.1) P=0.04]. For other well-known risk factors such as sex, age, degree of VUR, APN, and voiding dysfunction, the differences were not significant. CONCLUSION: TMP/SMX prophylaxis did not prevent recurrent UTI in children with primary VUR. Phimosis and renal scars were the risk factors for recurrent UTI but the grade of primary VUR was not. In VUR without phimosis and renal scar, a randomized controlled study without antibiotic prophylaxis is required.

Factors associated with Renal Scarring in Children with a First Episode of Febrile Urinary Tract Infection

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 April 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 were 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 24 hr prior to treatment. Renal scars developed in 34% of patients with remission of fever 48 hr after treatment. The risk for renal scars was significantly higher in children who had total duration of fever >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 24hr after onset of the fever, renal damage cannot be prevented completely and it is mainly associated with VUR.

Risk Factors for Atrophic Renal Scar

PURPOSE: An atrophic renal scar(RS) is one of the underlying causes for childhood hypertension and chronic renal failure. The risk factors for atrophic renal scar were evaluated. METHODS: 41 children, who presented with first febrile urinary tract infection at the Ewha Womans University Hospital between 1995 and 2003 and had generalized atrophic RS on 99mTc-DMSA renal scan, were retrospectively studied. Atrophic RS was divided into severe atrophic RS(n=14) if relative uptake on renal scan was below 10%, or mild atrophic RS(n= 27) if relative uptake on renal scan was between 10-35%. RS was defined as congenital if the scar was detected on the first renal scan, and as acquired if the scar developed on the follow-up renal scan from acute pyelonephritis of the first renal scan. The control group was consisted of randomly selected 41 children with segmental RS. The risk factors for atrophic RS such as the generation time, VUR, gender and ACE gene polymorphism were evaluated. RESULTS: The age distribution of atrophic RS and segmental RS did not differ significantly (P>0.05). The rate of congenital RS in atrophic RS was 61.0%(25/41), which was significantly higher than 9.8%(4/41) of segmental RS(P0.05). But in children with VUR, there was a higher proportion of males with severe atrophic RS than segmental RS(85.7%:45.5%). ACE gene polymorphism did not differ between the atrophic and segmental RS groups, irrespective of the presence of VUR(P>0.05). CONCLUSION: Most atrophic RSs were congenital which could not be preventable postnatally and the major risk factors were VUR and the male gender. ACE gene polymorphism was not the significant risk factor for an atrophic RS.

Urinary Transforming Growth Factor-beta1 (TGF-beta1)/Creatinine Ratio and Its Clinical Implications in Childhood Acute Pyelonephritis / 대한신장학회잡지

BACKGROUND: Pyelonephritis is one of the major causes of chronic renal failure in children, and the transforming growth factor-beta1 (TGF-beta1) is a molecule with pivotal roles in fibrogenesis. This study was performed to investigate the alteration and clinical implications of urinary TGF-beta1/creatinine ratio in children with acute pyelonephritis. METHODS: Urine was collected from 67 normal children and 25 children with acute pyelonephritis. After routine urinalysis, urine TGF-beta1 was quantitated by ELISA method and creatinine was measured by alkaline picrate method. Urinary TGF-beta1/ creatinine ratios in children with pyelonephritis were compared with those of age-matched controls, and sequential changes of the ratios in pyelonephritic children were traced after antibiotic treatment. Correlation of urinary TGF-beta1/creatinine ratio with the degree of pyuria and renal scar was analyzed each. RESULTS: Neonates showed higher urinary TGF-beta1/creatinine ratios than older children. The ratio increased in acute pyelonephritis and gradually returned to the control level two days after antibiotic treatment. Urinary TGF-beta1/creatinine ratio in acute pyelonephritis was not correlated with the degree of pyuria and renal scar. CONCLUSION: The age should be considered in evaluation of urinary TGF-beta1/creatinine ratio in children. The ratio increases in acute pyelonephritis, and is independent of the degree of pyuria or renal scarring.

Initial 99mTechnetium-dimercaptosuccinic Acid(DMSA) Renal Scan Finding and Vesicoureteral Reflux as Predicting Factor of Renal Scarring

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.

Effects of Methylprednisolone on TGF-beta, Apoptosis and Renal Scarring in Experimental Acute Pyelonephritic Weaning Rats

PURPOSE: Acute pyelonephritis of growing kidneys may result in renal scarring. TGF-beta, inflammatory cytokine, has been suggested to play an important role in promoting renal scarring through apoptosis, suppression of cellular proliferation and fibrosis. We observed the effects of a potent anti-inflammatory agent, methylprednisolone on apoptosis and renal scarring in experimentally induced acute pyelonephritic weaning rats. MATERIALS AND METHODS: To induce ascending pyelonephritis a saline solution containing Escherichia coli type ATCC No. 25922, pili-form (107 bacteria/mL) was infused into the bladder through the 16-guage silicone cannula for 48 hours to 102 three-week-old Sprague-Dawley rats (50-60g). Experimental groups were divided into three groups according to the treatment protocols, group I (ceftriaxone only, n=31), group II (methylprednisolone+ceftriaxone n=28), control group (n=43) was not treated. Histopathologic scores of inflammatory changes, fibrosis and tubular atrophy, the apoptosis index and TGF-beta1 expression score were observed at post-infection 1 and 3 week. Datas were analysed using ANOVA test and P value below 0.05 was interpreted as significant. RESULTS: The mortality rate (21.4%) of group II was not different to the control group (41.9%) and group I (32.3%). The inflammatory score of group II (0.8+/-0.87) at week 1 was significantly lower than those of the control group (2.3+/-0.87) and Group I (1.7+/-0.79) (P<0.05). Apoptosis index of group II (2.9+/-2.15) at week 1 was significantly lower than (10.0+/-0.95) and group 1 (8.3+/-2.53) (P<0.05). TGF-beta1 expression score of group II (0.8+/-0.72) at week 1 was significantly lower than those of the control group (1.9+/-0.68) and group I (1.8+/-0.60) (P<0.05). The fibrosis score of group II (1.1+/-0.10) at week 3 was significantly lower than that of the group I (1.8+/-0.83) (P<0.05). CONCLUSION: Combined treatment with methylprednisolone and ceftriaxone reduced inflammation, fibrosis, apoptosis and TGF-beta expression in acute pyelonephritic weaning rats, compared to ceftriaxone alone. Anti-inflammatory agent supplemented to antibiotics could prevent renal scarring more effectively.

Childhood Urinary Tract Infection

Childhood UTI is a common bacterial infection in children and frequently associated with urinary tract anomaly and high recurrent rate. Recurrent UTI and even the first UTI, if not diagnosed and untreated, may lead to serious renal scarring, a cause of childhood hypertention and end stage renal failure. It is very important to prevent the sequence of recurrent UTI and the development of renal scarring from the first UTI. However, early diagnosis is very difficult because the symptoms and signs are non-specific in young children and commonly presented with high fever only. In young infants with unexplained high fever, urinalysis and urine culture should be considered for early diagnosis. Emperic antibiotic treatment should be initiated in suspicious UTI and imaging studies of the urinary tract should be performed for the evaluation of urinary tract anomaly and renal scar in confirmed cases of UTI. Antimicrobial prophylaxis has been the common clinical practice in children with high risk factors for recurrent UTI and renal scar. In summary, early diagnosis and proper management of childhood UTI are very important to prevent hypertention and end stage renal disease by renal scar.

The Diagnostic Value of 99mTc DMSA Renal Scan SPECT Images in Addition to Planar Image in Children with Urinary Tract Infection

PURPOSE : 99mTc DMSA renal scan have been widely used not only for the evaluation of renal scars but also for the diagnosis of acute pyelonephritis. Recent studies have shown SPECT images have higher accuracy than the planar images with some controversy. We evaluated the availability of the SPECT images adding to planar images for the diagnosis of acute pyelonephritis(APN) and renal scar in children with urinary tract infection (UTI). METHODS : 130 children with UTI (260 kidney units) and 22 follow-up children (44 kidney units) were included between January 1, 1997 and July 31, 1999 at Ewha University Mokdong Hospital. Planar Anterior and posterior images and SPECT axial and coronal images of 99mTc DMSA renal scan were obtained with Starcam 4000-i U.S.A. GE at 3 hours after 99mTc DMSA I.V. injection. The data were analyzed by Chi square test after Yates's correction. RESULTS : The detection rate of the acute pyelonephritis by SPECT images was 12.3% higher than that of planar images (47.7% vs 35.4%) by the patient and 6.9% higher also (31.9% vs 25.4%) by the kidney unit. 18 kidney units with negative planar images had focal defect in 10 kidney units (3.8%) and multifocal defect in 8 kidney units (3.1%) on SPECT images, but 1 kidney unit with positive planar image had negative SPECT image. SPECT images were superior to the planar images in 17.3%, identical in 82.3% and inferior in 0.4% to planar image. The detection rate of the renal scars by SPECT images was 13.7% higher than planar images by the patient (68.2% vs 54.5%) and 6.8% higher also (43.2% vs 36.4%) by the kidney unit. SPECT images were superior to the planar images in 17.3% and identical in 82.3% to planar image. CONCLUSION : SPECT images had shown higher detection rate and better image than planar images for the diagnosis of the acute pyelonephritis and the evaluation of the renal scars.

A Family Screening of Patients with Vesicoureteral Reflux

PURPOSE : Vesicoureteral reflux is the most commonly inherited disease detected in children with urinary tract infection. The incidence of vesicoureteral reflux among siblings of children with known vesicoureteral reflux is 8% to 45% according to different authors. Family screening of a patient with vesicoureteral reflux is important in order to prevent reflux nephropathy. The purpose of this study is to determine the incidence of vesicoureteral reflux in asymptomatic family of children with vesicoureteral reflux and the factors which influence the family history. METHODS : The study group consisted of 27 families of patients with vesicoureteral reflux. The total number in the group were 79 persons. BUN, Cr, urineanalysis, voidingcystourethrography(VCUG) and 99mTc -dimercaptosuccinic acid(DMSA) renal scan were performed on the siblings. As for the parents the same tests were performed except the VCUG. RESULTS : The abnormality was detected in 7 of 27 families(25.9%). Vesicoureteral reflux was detected in 5 of 20 siblings and renal scar was detected in 3 of 32 parents. In children with vesicoureteral reflux, renal scar was detected in 24 of 32 children. Between the group with the abnormality in its family(Group A) and the group without the abnormality in its family(Group B), There was no difference of creatinine clearance between two groups. More renal scars were detected in group A according to the DMSA(A:100%, B:75%, t-test p<0.05). There was no difference of grade of VCUG between two groups. There was no difference between one site and both sites in two groups. In the case of the siblings with vesicoureteral reflux, there was high incidence of renal scar in a patient with vesicoureteral reflux according to the DMSA. CONCLUSION : It is important to screen vesicoureteral reflux and renal scar in case of urinary tract infection to prevent reflux nephropathy. This study implies that it is necessary to screen the family of a patient with vesicoureteral reflux especially with renal scar.

Factors Associated with Renal Scar in Children with Vesicoureteral Reflux

PURPOSE : The urinary tract infection associated with vesicoureteral reflux(VUR) in children may result in serious complications such as renal scarring, hypertension, proteinuria and end stage renal disease. The purpose of this study was to evaluate the factors affecting renal scar such as age, gender, grade of VUR, and ACE gene polymorphism, and body growth in the patients with and those without renal scar associated with VUR METHODS : During the period from January 1994 to July 2000, We had 93 children with urinary tract infection associated with VUR who were admitted to the Department of pediatrics of Chonbuk National University Hospital. The patients were divided into two groups according to follow up 99mTc-DMSA renal scan; patients with renal scar group and those with non-scar group. We analyzed and compared the factors associated with renal scarring between the two groups. RESULTS : There were no significant difference in gender, causative organism, ACE gene polymorphism, height and weight at diagnosis between renal scar group and non-scar group. Fifty four patients were in renal scar group and forty seven of them had VUR. The age at diagnosis was significantly higher in renal scar group (2.48 +/-2.64yr) than in non renal scar group (1.26+/-1.83yr). Especially, the infants who were less than 1 year of age with VUR developed relatively more renal scar compared with infants older than 1 year of age. The incidence of renal scarring showed a direct correlation with the severity of VUR. CONCLUSION : The factors affecting renal scar formation were age at diagnosis, presence and grade of VUR, but the other factors such as gender, causative organism, ACE gene polymorphism were not associated with renal scarring. Therefore, further evaluation about uropathogenic E. coli and follow up study about body growth associated with severity of renal scar would be necessary.