Outcome and management of isolated severe renal pelvis dilatation detected at postnatal screening

The aim of this study was to evaluate the incidence and outcome of isolated severe renal pelvis dilatation (RPD; APD > 15 ≤ 20 mm) in an unselected population of 2-month-old infants prospectively followed up for 12–14 months of life. Isolated severe renal pelvis dilatation was detected in 46 of the 11,801 (0.39%) infants screened. Nephro-urological investigations were initiated if RPD persisted, or if urinary tract infection (UTI) occurred during follow-up, and antibiotic therapy was administered only when UTI occurred. At follow-up, RPD persisted in 24 infants. Of these, 8 infants presented with vesico-ureteral reflux (VUR) of grade ≥ 3 and 16 with ureteropelvic junction obstruction (UPJO). Incidence of UTI was significantly higher (p < 0.001) in infants of the study group than in infants of the control group (13.9 vs 2.5%). Our data suggest that isolated severe RPD may be a self-limiting condition and that antibiotic prophylaxis (AP) for the prevention of UTI should not be performed. Considering RDP resolution and the incidence of UTI during follow-up, investigations for uropathy in infants with isolated, severe RPD are justified in persistent cases, or when UTI occurs during follow-up. Careful clinical monitoring for signs of UTI and treatment of each episode of UTI may be sufficient and safe.     

Antenatal hydronephrosis: infants with minor postnatal dilatation do not need prophylaxis

The aim of this study was to determine the occurrence of urinary tract infection (UTI) in infants with antenatal renal pelvis dilatation (ARPD). Consecutive ultrasound (US) screening of 14,000 pregnant women detected ARPD ≥5 mm in 106 foetuses. After birth, two US examinations were performed: on the fifth to seventh day and during the third week of life. The findings were considered normal when renal pelvis dilatation (RPD) was ≤7 mm on both examinations and no other signs of abnormality were present. Voiding cystourethrography (VCUG) was done in all infants 6–8 weeks after birth. One hundred and three infants were followed for 2 years. Antibacterial prophylaxis (trimethoprim 1 mg/kg per day) was given to those with RPD ≥15 mm, vesicoureteric reflux (VUR) grades III–V and suspected obstruction. In 53/103 babies, both US examinations were normal, three had VUR grade I. Two girls had UTI at 18 and 24 months of age, respectively. Among the 50 infants with abnormal initial US, six had VUR, of which four were high grade (IV–V). All four developed UTI. We conclude that UTI is uncommon in infants with two normal postnatal US examinations. Routine use of antibacterial prophylaxis in these infants therefore cannot be recommended.     

Outcome of isolated antenatal hydronephrosis: a prospective cohort study

The purpose of this study was to report the outcome of infants with antenatal hydronephrosis. Between May 1999 and June 2006, all patients diagnosed with isolated fetal renal pelvic dilatation (RPD) were prospectively followed. The events of interest were: presence of uropathy, need for surgical intervention, RPD resolution, urinary tract infection (UTI), and hypertension. RPD was classified as mild (5-9.9 mm), moderate (10-14.9 mm) or severe (>or=15 mm). A total of 192 patients was included in the analysis; 114 were assigned to the group of non-significant findings (59.4%) and 78 to the group of significant uropathy (40.6%). Of 89 patients with mild dilatation, 16 (18%) presented uropathy. Median follow-up time was 24 months. Twenty-seven patients (15%) required surgical intervention. During follow-up, UTI occurred in 27 (14%) children. Of 89 patients with mild dilatation, seven (7.8%) presented UTI during follow-up. Renal function, blood pressure, and somatic growth were within normal range at last visit. The majority of patients with mild fetal RPD have no significant findings during infancy. Nevertheless, our prospective study has shown that 18% of these patients presented uropathy and 7.8% had UTI during a medium-term follow-up time. Our findings suggested that, in contrast to patients with moderate/severe RPD, infants with mild RPD do not require invasive diagnostic procedures but need strict clinical surveillance for UTI and progression of RPD.     

Antenatal renal pelvis dilatation: 2-year follow-up with DMSA scintigraphy

The aim of this study was to determine whether a postnatal ultrasound (US) can detect infants with antenatal renal pelvis dilatation (ARPD) who run a minimal risk of renal damage 2 years after birth. The study cohort consisted of 14,000 pregnant women who consecutively underwent routine US examinations during the second trimester. Subsequent examinations were performed on the basis of obstetrical indications. In total, 106 foetuses were diagnosed with ARPD ≥5 mm. Two postnatal US were performed on the newborns: on postpartum days 5–7 and during the third week of life. The findings were considered to be normal when the renal pelvis diameter (RPD) was ≤ 7 mm and when there was no calyceal or ureteric dilatation or signs of renal dysplasia or other anomalies. Voiding cystourethrography (VCUG) was done at 6–8 weeks after birth. When the children reached 2 years of age, renal status was evaluated with DMSA scintigraphy or, if not possible, US. In 53 of the 103 children available for evaluation, the postnatal US findings were normal; 49 of the 53 children were also given a DMSA, and the results were normal in all cases. An US scan (all normal) only was performed in three children because the families refused a DMSA. One family refused any form of examination at the 2-year follow-up. Based on our results, we conclude that postnatal US can detect infants who do not require follow-up assessments of renal development.     

Management in children of mild postnatal renal dilatation but without vesicoureteral reflux

Infants with mild postnatal renal dilatation but without vesicoureteral reflux pose a challenge. For how long and in what way should they be followed? From May 1989 to December 2006, we prospectively followed 1,795 pregnancies in which the foetal renal pelvis measured 4 mm or greater. Voiding cystourethrography (VCUG) and renal ultrasound were performed on 1,315 infants at 6 weeks of age. Our study group comprised 208 (167 male) infants with normal VCUG findings who had a renal pelvis of 6–11 mm. We followed them for 1–17 years (mean 11 years). Medical and radiological records were reviewed to determine any urinary symptoms and final outcome. They underwent, on average, four further imaging tests. The renal dilatation had resolved by 24 months in approximately 70%. Urinary tract infection (UTI) developed in 16 (8%). Calyceal dilatation was more likely in those developing UTI (P?=?0.02). Twenty-two (10.6%) had a radiologically demonstrated urinary tract abnormality. Of the five who had renal scarring or severe obstruction, four became symptomatic. Most infants with mild postnatal renal dilatation can be investigated with only one further sonogram at 24 months of age. Mild postnatal renal dilatation is associated with subsequent UTI or renal tract abnormality in 18%. Severe renal abnormality occurred in 2.4%.     

Clinical features of community-acquired <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> urinary tract infections in children

This retrospective chart review sought to determine clinical, radiological, and gender-associated characteristics of community-acquired Pseudomonas aeruginosa (PA) urinary tract infections (UTIs) among children admitted to two medical centers. The records of 73 children with community-acquired PA UTIs were compared with records of 109 children with community-acquired UTIs caused by other pathogens. The mean age of both groups was similar. The PA UTI group included more boys. Features significantly more common in the PA UTI group were the number of patients who had undergone urinary tract surgery, patients with skeletal and/or neurological malformation, patients with >1 previous episode of UTI, patients on prophylactic antibiotic treatment on admission, and patients with pathological renal ultrasound and voiding cystourethrography (VCUG) findings. Multivariate logistic regression analysis revealed the following to be associated with PA UTI: >1 episode of UTI in the past [odds ratio (OR) = 35.5; 95% confidence interval (CI) 11.6–108.7], previous urinary tract surgery (OR = 34.1; 95% CI 7.00–166.2), and pathological VCUG results (OR = 2.62; 95% CI 0.96–7.15). In conclusion, PA UTI is associated with >1 previous UTI, urinary tract abnormalities, and past urinary tract surgery. We recommend that when UTI is suspected in children with these risk factors, a thorough radiologic investigation, including a VCUG, should be considered. Drs. Goldman and Rosenfeld-Yehoshua contributed equally to this work.     

Procalcitonin as a predictor of renal scarring in infants and young children

The aim of this study was to evaluate the usefulness of procalcitonin (PCT) as a marker of renal scars in infants and young children with a first episode of acute pyelonephritis. Children aged 7 days to 36 months admitted for first febrile urinary tract infection (UTI) to a pediatric emergency department were prospectively enrolled. The PCT concentration was determined at admission. Acute ^99mTc-dimercaptosuccinic acid (DMSA) scintigraphy was performed within 7 days of admission and repeated 12 months later when abnormal findings were obtained on the first scan. Of the 72 children enrolled in the study, 52 showed signs of acute pyelonephritis (APN) on the first DMSA scan. A follow-up scintigraphy at the 12-month follow-up performed on 41 patients revealed that 14 (34%) patients had developed renal scars; these patients also presented significantly higher PCT values than those without permanent renal lesions [2.3 (interquartile range 1–11.6) vs. 0.5 (0.2–1.4) ng/mL; p = 0.007]. A comparison of the PCT concentration in patients with febrile UTI without renal involvement, with APN without scar development and with APN with subsequent renal scarring revealed a significant increasing trend (p = 0.006, Kruskal–Wallis test). The area under the ROC curve for scar prediction was 0.74 (95% confidence interval 0.61–0.85), with an optimum statistical cut-off value of 1 ng/mL (sensitivity 78.6%; specificity 63.8%). Based on these results, we suggest that serum PCT concentration at admission is a useful predictive tool of renal scarring in infants and young children with acute pyelonephritis.     

Urine IL-8 concentrations in infectious and non-infectious urinary tract conditions

Urine IL-8 concentrations are known to be elevated in urinary tract infection (UTI), as well as in vesicoureteral reflux (VUR) even in the absence of infection. In this study we further investigated urine IL-8 in infants with congenital anomalies of the kidneys and urinary tract and with antenatally diagnosed isolated pelvic dilatation. Urine IL-8 was measured in 159 infants aged 1 month to 1 year with acute UTI (group A, n = 26), resolved UTI (group B, n = 16), VUR without recent UTI (group C, n = 44), non-VUR congenital urinary anomalies without recent UTI (group D, n = 30), isolated antenatal pelvic dilatation (group E, n = 14) and in infants without known urinary tract condition (control group F, n = 29). Median values of urine IL-8/creatinine levels were 61.5, 4.64, 15.5, 14.3, 1.06 and 4.19 pg/μmol in groups A, B, C, D, E and F respectively. Compared with the control group, urine IL-8 was elevated in infants with acute UTI, VUR without acute UTI and congenital anomalies without acute UTI (p < 0.0001; p < 0.005; and p = 0.027 respectively), but not in infants with resolved UTI or with antenatal pelvic dilatation. Urine IL-8 levels are elevated in a variety of infectious and non-infectious urinary tract conditions, and hence may serve as a sensitive but not specific screening biomarker of urinary tract diseases.     

Urinary tract infection in preterm infants: the protective role of breastfeeding

Urinary tract infection (UTI) differs between preterm and older infants and children in terms of prevalence, clinical presentation, causative organism, and rate of underlying renal anomalies. Data on risk factors of UTI in preterm infants are limited. The aim of this study was to characterize UTI both clinically and microbiologically in premature infants and to define possible risk factors and the role of breastfeeding in its development. This case–control study was conducted in a tertiary-care neonatal intensive care unit (NICU) between 1995 and 2003. The study group included all premature infants (<37 weeks’ gestation) diagnosed with UTI. Pre-, peri-, and postnatal data on demographic, clinical, laboratory, and imaging variables were collected from the medical records and microbiology laboratory log and compared with a gestational age- and birth weight-matched infants without UTI (control group). The ratio of control infants to cases was 2:1. Of the 6198 premature infants admitted to the NICU during the study period, 56 (0.9%) were included in the study group. The main causative organism was Klebsiella spp. Logistic regression analysis identified gender [odds ratio (OR) 2.96, 95% confidence interval (CI) 1.28–6.85, P < 0.0001] and the presence of a peripheral intravenous catheter on the day of infection to be significantly associated with UTI, while breast milk was associated with a lower risk of infection (OR 0.314, 95% CI 0.140–0.707, P < 0.009).     

Imaging studies for first urinary tract infection in infants less than 6 months old: can they be more selective?

This retrospective study aimed to evaluate the applicability of the selective approach of imaging infants < 6 months old with urinary tract infection (UTI) according to the UTI guidelines of the National Institute for Health and Clinical Excellence (NICE) 2007. Infants < 6 months old with their first UTI from January 2001 to December 2006 having undergone an ultrasound examination of the urinary tract, a micturating cystourethrogram, and a late di-mercaptosuccinic acid (DMSA) scan, were included. Their condition was evaluated against a set of risk features according to the UTI guidelines. Those having any one of these were classified as atypical and those having none as typical. There were 134 infants reviewed, with a typical (98 infants) to atypical (36 infants) ratio of 2.7 to 1. Girls were found to be relatively more represented in the atypical group [male (M):female (F) = 1.3:1] than in the typical group (M:F = 4.4:1) (P < 0.004). There were significantly more infants with abnormal micturating voiding cystourethrograms (MCUGs) (P = 0.007), more refluxing ureters (P < 0.001) and more significant vesico-ureteral reflux (VUR) (≥ grade III) (P = 0.013) in the atypical group than in the typical group; while there was no significant difference in ultrasound (US) and DMSA scan findings between the two groups. In the atypical group there was no difference in imaging studies (and, thus, the results) between the conventional practice and the NICE UTI recommendation. In the typical group, if the recommendations of the guidelines had been followed (i.e. only those with abnormal US would have been further investigated), 25 refluxing ureters and 22 scarred kidneys would have been left undiagnosed. In conclusion, application of the suggested selective imaging approach would leave a significant number of VUR and renal scars undiagnosed, and it may not be an optimal practice for infants less than 6 months old with their first UTI. The best approach remains to be clarified.     

Neonates with extra-renal pelvis: the first 2 years

Extra-renal pelvis (ERpel) is a common ultrasonographic finding among neonates who have undergone recurrent ultrasound examinations for a better definition of prenatal renal pelvic dilatation. This study tries to determine whether or not ERpel has important prognostic implications. Seventy-nine neonates (17 female) were examined. All had a diagnosis of prenatal renal pelvis dilatation, which was shown by postnatal ultrasound to be ERpel. Sixty ERpel neonates were examined 1.5 months to 2.5 months after the ultrasound (US) diagnosis by both Tc-99m diethylene triamine penta-acetic acid (DPTA) dynamic renal scanning and ^99mTc-pertechnetate direct cystography. Clinical assessment, urine cultures and renal ultrasound follow-up were maintained for 2 years. The proportion of urinary tract infections (UTIs) in patients with ERpel was compared with that of the total neonatal and infantile population with normal US scans in the region of our hospital. Associated minor congenital malformations were found in 12 of 79 neonates (15.2%). Four had a family history of ERpel. Among 60 neonates who underwent renal scanning, 36 (60%) were found to have urinary retention in the collecting system. Another nine (15%) had vesico-ureteral (VU) reflux, of which seven had urinary retention. Fifteen (25%) showed normal isotope imaging. Urinary tract infection was diagnosed in 16 ERpel neonates in whom only one exhibited VU reflux (grade 2). The incidence of neonatal UTI in the ERpel group was more than that of either neonatal or infantile UTI in those with normal US scans in the local population (20.2% vs 1.2% and 4.3%, respectively). Fifty-three infants completed a 2-year follow-up. Repeat renal ultrasonography indicated that one infant (1.8%) had developed bilateral hydronephrosis, 12 (22.6%) had unchanged findings, 18 (40%) showed an improvement (decrease of ERpel width or resolution in one side) and, in 22 (41.5%) infants, the condition had resolved. No clinical or kidney function deterioration was observed. Seven patients (13.2%) each had one episode of UTI during the 2-year follow-up period; none of them had VU reflux. Neonatal ERpel is more frequent in male infants. It is associated with greater rates of minor congenital malformations, VU reflux and UTI than in the general population of the same ages. The increased UTI incidence is not attributed to VU reflux.     

Probiotics prophylaxis in children with persistent primary vesicoureteral reflux

Probiotics, beneficial living microorganisms, have been proven to be effective in preventing gastrointestinal infections, but their effect in preventing urinary tract infection (UTI) is inconclusive. A prospective randomized controlled study was done to compare the preventive effect of probiotics with conventional antibiotics in children with persistent primary vesicoureteral reflux (VUR). One hundred twenty children who had had persistent primary VUR after antibiotic prophylaxis for 1 year were randomly allocated into a probiotics (Lactobacillus acidophilus 10⁸ CFU/g 1 g b.i.d., n = 60) or an antibiotics (trimethoprim/sulfamethoxazole 2/10 mg/kg h.s., n = 60) prophylaxis group during the second year of follow-up. The incidence of recurrent UTI was 18.3% (11/60) in the probiotics group, which was not different from 21.6%(13/60) in the antibiotic group (P = 0.926). The causative organisms of recurrent UTI were not significantly different between the two groups (P = 0.938). Even after stratification by VUR grade, age, gender, phimosis, voiding dysfunction and renal scar, the incidence of recurrent UTI did not differ significantly between the two groups (P > 0.05). The development of new renal scar was not significantly different between the two groups (P > 0.05). In conclusion, probiotics prophylaxis was as effective as antibiotic prophylaxis in children with persistent primary VUR.     

Antenatal and postnatal ultrasound in the evaluation of the risk of vesicoureteral reflux

Antenatal hydronephrosis (ANH) is a frequent anomaly detected on fetal ultrasound scans. There is no consensus recommendation for the postnatal follow-up and/or the necessity to perform a voiding cystourethrography (VCUG) to diagnose vesicoureteral reflux (VUR). We conducted a cohort/non-randomized trial of 121 patients with ANH, defined as an anterior posterior diameter (APD) ≥5 mm after the 20th week of gestation, to evaluate the ability of the antenatal and postnatal ultrasonography results to predict VUR. All infants had two successive ultrasounds at 5 days and 1 month, respectively, after birth. A VCUG was performed at 6 weeks in children with a persistent APD ≥5 mm and/or an ureteral dilatation observed on at least one of two postnatal ultrasounds. In total, 88 patients had VCUG and nine had VUR, with five having high-grade reflux (>grade II). The risk of VUR increased significantly with the degree of APD detected on the postnatal ultrasound scan (p = 0.03). The odds ratios were 5.0 [95% confidence interval (CI) 0.5–51.2] for APD = 7–9 mm and 9.1 (95% CI 1.0–80.9) for APD ≥10 mm. The results of this study show that among our patient cohort antenatal ultrasound was not predictive of reflux. There was, however, a relation between the importance of the postnatal renal pelvis diameter and the risk of VUR. A cut-off of 7 mm showed a fair ability of ultrasonography to predict VUR and a cut-off of 10 mm enabled all severe refluxes in the 88 patients who had a VCUG to be diagnosed.     

Complications and long-term outcome of primary obstructive megaureter in childhood

We assessed the clinical outcome of 49 children with 56 primary obstructive megaureters (POM) treated with the primarily conservative approach recommended by the 2001 German consensus guidelines. POM occurred more often in boys (71%) and on the left side (67%). Forty-three POM (77%) were treated conservatively. Four kidneys underwent immediate surgery and nine of 52 kidneys managed primarily conservatively worsened subsequently, requiring surgery. Urinary tract infections (UTI) were the most common complication (mean 1.3 per patient), with frequent hospital admission (45%). During the first year of life, the incidence of UTIs was 55% less during prophylactic antibiotic treatment (0.94 vs.0.42 UTIs per year, p < 0.05). Spontaneous regression occurred in 80% of POMs with dilated non-obstructive renogram, but in <20% with intermediate or relevant obstruction. All megaureters with <8.5 mm sonographic diameter regressed, but none over 15 mm. Eight patients had a poor outcome (partial kidney function <40% (n = 6), renal atrophy (n = 3)), but in seven of the patients, these findings were already present postnatally. In summary, the long-term outcome of POM appears favorable with mainly conservative treatment. UTI as the most common complication was 55% lower with antibiotic prophylaxis in infants. Adverse outcome was more closely related to congenital kidney hypoplasia than to degree of obstruction.     

Effect of renal pelvic distension on the ureteropelvic and ureterovesical junctions and the urinary bladder: the renal pelvivesical reflex

For investigation of the effect of distension of the renal pelvis on the ureteropelvic (UPJ) and uretero vesical junctions (UVJ) and on the urinary bladder, nephrostomy was performed on 14 anesthetized mongrel dogs. The pressure was measured in the UPJ by a catheter with a side port introduced through the nephrostomy and in the UVJ and urinary bladder by two catheters inserted cystoscopically. Likewise, a balloon mounted on the tip of a catheter was introduced into the renal pelvis. It was filled with saline in increments of 1 ml, and the pressure response of the UPJ, the UVJ, and the urinary bladder was determined. The test was repeated on the anesthetized renal pelvis, UVJ, and bladder. Whereas renal pelvic distension with 1 ml of saline effected no pressure response in the UPJ, UVJ or bladder, distension with 2–4 ml produced a significant pressure drop (P < 0.01, P < 0.01, and P < 0.05, respectively). There was no difference in the pressure drops recorded at distensions with 2, 3, or 4 ml of saline (P > 0.05). Distension of the anesthetized renal pelvis produced no pressure response in the UPJ, UVJ, or bladder. Furthermore, renal pelvic distension did not elicit a pressure response in the anesthetized UPJ or the bladder. In conclusion, the opening of the UVJ synchronously with the UPJ upon renal pelvic distension appears to assist the delivery of urine from the renal pelvis to the urinary bladder and to protect both the renal pelvis and the ureter against dilatation. This process is supported by a vesical pressure drop. The opening of the UPJ together with the UVJ and the vesical relaxation observed on renal pelvic distension seem to be reflex in nature. A “renal pelvivesical reflex” is postulated to regulate the flow of urine from the renal pelvis to the urinary bladder, preventing the occurrence of urine collection in, or backflow into, the renal pelvis or the ureter.     

Surgical management of vesicoureteral reflux in children

Vesicoureteral reflux (VUR) is the most common uropathy affecting children. Compared to children without VUR, those with VUR have a higher rate of pyelonephritis and renal scarring following urinary tract infection (UTI). Options for treatment include observation with or without antibiotic prophylaxis and surgical repair. Surgical intervention may be necessary in patients with persistent reflux, renal scarring, and recurrent or breakthrough febrile UTI. Both open and endoscopic approaches to reflux correction are successful and reduce the occurrence of febrile UTI. Estimated success rates of open and endoscopic reflux correction are 98.1% (95% CI 95.1, 99.1) and 83.0% (95% CI 69.1, 91.4), respectively. Factors that affect the success of endoscopic injection include pre-operative reflux grade and presence of functional or anatomic bladder abnormalities including voiding dysfunction and duplicated collecting systems. Few studies have evaluated the long-term outcomes of endoscopic injection, and with variable results. In patients treated endoscopically, recurrent febrile UTI occurred in 0–21%, new renal damage in 9–12%, and recurrent reflux in 17–47.6% of treated ureters with at least 1 year follow-up. These studies highlight the need for standardized outcome reporting and longer follow-up after endoscopic treatment.     

Vesicoureteral reflux in children with suspected and proven urinary tract infection

The aim of this study was to estimate the prevalence of vesicoureteral reflux (VUR) and clinically significant ultrasonography (US) abnormalities in a large group of children with proven and suspected urinary tract infection (UTI). The medical reports on renal US and voiding cystouretrographies (VCUG) of 2,036 children were reviewed. Renal US was performed on all children and VCUG on 1,185 children (58%). Based on the urine culture data, the UTI diagnoses were classified into five reliability classes (proven, likely, unlikely, false and no microbial data). The UTI diagnose was considered proven in 583/2036 (28.6%) and false in 145 (7.1%) cases. The prevalence of VUR was similar among those with proven and false UTI [37.4 vs. 34.8%; relative risk (RR) 1.08, 95% confidence intervals (95% CI) 0.7–1.7, P = 0.75] and decreased with increasing age (P = 0.001). Clinically significant US abnormalities occurred in 87/583 (14.9%) cases with proven UTI and significantly less often (11/145, 7.6%) in the false UTI class (RR 1.96, 95% CI 1.1–3.6, P = 0.02). Our finding supports the claim that VUR is not significantly associated to UTI and that its occurrence among children even without UTI is significantly higher than traditional estimates. This challenges the recommendations of routine VCUG after UTI.     

Urinary tract infection following kidney transplantation: frequency,risk factors and graft function

The aim of this study was to determine the proportion of children who develop urinary tract infection (UTI) after kidney transplantation (KTx) and to identify the factors associated with UTI and its impact on graft function. To this end, we undertook a chart review of children who underwent KTx at Red Cross Children’s Hospital between January 2003 and December 2009 and were followed-up for at least 6 months after transplantation. Sixty-two children (53.2% males) were followed-up for a mean (standard deviation) period of 36.9 (19.7) months. Mean age at transplantation was 10.0 (4.6) years. Twenty-five (40.3%) children had 89 UTI episodes during the study period, equivalent to 0.94 UTI episodes per one patient-year of follow-up. Acute pyelonephritis occurred in 17 (27.4%) children; another 17 (27.4%) had multiple post-KTx UTI. Klebsiella (40.0%) and Escherichia (28.0%) were the commonest organisms. Those with post-KTx UTI were, at transplantation, younger (8.3 vs. 11.2 years; p = 0.017), had lower urinary tract abnormality (LUTA) (13 vs. 1; p = 0.000) and had pre-KTx UTI (13 vs. 5; p = 0.001). Multivariate analysis revealed that only age <5 years at transplantation and LUTA remained significant and that UTI KTx was not associated with worsening graft function. UTI is common after post-KTx. Among our patient cohort, younger age and LUTA were risk factors, but UTI did not affect graft function.     

Lactobacillus colonization status in infants with urinary tract infection

To explore the potential protective role of urogenital lactobacilli against urinary tract infection (UTI), lactobacillus cultures were performed on stool and urine specimens and periurethral/vaginal swabs of febrile infants who were suspected of having UTI. Those infants diagnosed with UTI based on the results of the suprapubic urine cultures were allocated to the UTI group (n = 60), and those who had a simple viral illness with negative urine cultures were allocated to the control group (n = 31). Lactobacilli were anaerobically cultured in lactobacillus-specific DifcoTM Rogosa SL agar for 48 h at 37°C and then counted. The lactobacillus colony counts for the stool and urine specimens and periurethral swabs from the UTI group were significantly lower than those for the control group (P < 0.05). The geometric means of stool, periurethra, and urine lactobacilli in the UTI group were significantly lower than those in the control group (P < 0.05). The colony count of the vaginal lactobacillus demonstrated an equivocal difference between the UTI and control group. In conclusion, this is the first prospective case–control study to demonstrate reduced lactobacillus urogenital colonization in infants with UTI. Our results support the view that less urogenital lactobacillus colonization may be a risk factor for UTI in infants even though there is an unclear possibility that the UTI itself could be the cause of the lower lactobacillus colonies.     

Long-term follow-up of renal function in patients after surgery for obstructive uropathy

In this prospective study, selected biochemical markers of glomerular and tubular function, proteinuria, and ultrasound findings in 62 pediatric patients who underwent surgery for obstructive uropathy were examined. Patients were younger than 12 months, normocreatininemic at the time of surgery, and examined at a mean age of 6.3 ± 0.9 years. Out of the markers tested, serum concentration of cystatin C was significantly higher in patients when compared with the control group (p < 0.001), and serum creatinine concentration was within reference interval in all patients. With respect to tubular function, 26% of patients had decreased concentration ability. Proteinuria was detected in 4.8% of patients. On ultrasound, 66.7% of kidneys after surgery had residual dilatation of the renal pelvis. The patients thrive well, and their somatic parameters do not differ from their peers. Half of the patients had one or more urinary tract infections from the date of surgery to the date of examination. Study results support the need for long-term nephrologic follow-up in patients after surgery for obstructive uropathy. The hypothesis that renal function in patients undergoing surgery aged younger than 3 or 6 months is better when compared with those aged 6 to 12 months has not been confirmed.