Dyslipidemia in children with chronic kidney disease-findings from the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study.

BACKGROUND: Dyslipidemia is an important and modifiable risk factor for CVD in children with CKD. METHODS: In a cross-sectional study of baseline serum lipid levels in a large prospective cohort study of children with stage 3-5 (predialysis) CKD, frequencies of abnormal lipid levels and types of dyslipidemia were analyzed in the entire cohort and in subpopulations defined by fasting status or by the presence of nephrotic range proteinuria. Associated clinical and laboratory characteristics were determined by multivariable linear regression analysis. RESULTS: A total of 681 patients aged 12.2 ± 3.3 years with a mean eGFR of 26.9 ± 11.6 ml/min/1.73 m2 were included. Kidney diagnosis was classified as CAKUT in 69%, glomerulopathy in 8.4%, and other disorders in 22.6% of patients. Nephrotic range proteinuria (defined by a urinary albumin/creatinine ratio > 1.1 g/g) was present in 26.9%. Dyslipidemia was found in 71.8%, and high triglyceride (TG) levels were the most common abnormality (54.7%). Fasting status (38.9%) had no effect on dyslipidemia status. Except for a significant increase in TG in more advanced CKD, lipid levels and frequencies of dyslipidemia were not significantly different between CKD stages. Hypertriglyceridemia was associated with younger age, lower eGFR, shorter duration of CKD, higher body mass index (BMI-SDS), lower serum albumin, and higher diastolic blood pressure. CONCLUSIONS: Dyslipidemia involving all lipid fractions, but mainly TG, is present in the majority of patients with CKD irrespective of CKD stage or fasting status and is significantly associated with other cardiovascular risk factors.

Long-term Effects of Kidney Transplantation Compared With Dialysis on Intima-media Thickness in Children-Results From the 4C-T Study.

BACKGROUND: Children requiring kidney replacement therapy experience high burden of cardiovascular (CV) disease leading to increased mortality. Intima-media thickness (IMT) indicating atherosclerosis is a validated surrogate marker for future CV events. METHODS: We investigated the effect of different treatment modalities (dialysis, preemptive kidney transplantation (KTx), late KTx after dialysis) on IMT by multivariable linear mixed-effect modeling. Patients were enrolled in a prospective cohort study. RESULTS: A total of 261 analyzed children had a mean follow-up of 3 y. Children after preemptive and late KTx had lower levels of IMT when compared with dialysis. Using an interaction term, a significant progression of IMT over time was seen during dialysis (ß = 0.0053 mm/y, P   =  0.004). IMT before the start of therapy was the most influential determinant in all models. Low IMT was associated with maintenance steroid treatment after preemptive KTx. High IMT on dialysis was associated with higher systolic blood pressure, lower body mass index, lower serum albumin, and lower bicarbonate. CONCLUSIONS: IMT remained rather stable in children several years after KTx. In contrast, children on dialysis had higher IMT values, which increased over time. In these children, blood pressure control, calorie and protein intake, and acid-base homeostasis seem important. Taken together, children might profit from early transplantation to limit accumulation of CV risk.

Outcome of children with multicystic dysplastic kidney: Does involved side matter?

BACKGROUND: Multicystic dysplastic kidney (MCDK) is a common anomaly detected on antenatal ultrasound. We aimed to assess the profile of children with MCDK and to investigate whether the involved side has any effect on outcome. METHODS: Thirty-nine patients with MCDK and 20 controls were enrolled. Patients who estimated glomerular filtration rate (eGFR) values over 90 mL/min/1.73 m2 were compared with controls. Comparison was made between the involved sides. RESULTS: MKDB was right-sided in 20 (51.3%) and left-sided in 19 (48.7%) patients. 33.3% had additional urinary tract abnormality, 10.2% had systemic abnormality. 82% showed contralateral kidney enlargement. 48.7% involuted, 17.9% underwent nephrectomy. 35.8% suffered from urinary tract infection (UTI). 5.1% had renal scarring (RS). 30% developed microalbuminuria. 12.8% complicated with hypertension. 17.9% progressed to chronic kidney disease (CKD). Hypertension was independent risk factor for developing CKD. Blood pressure, cystatin C and urine microalbumin/creatinine levels were increased, and eGFR values were decreased in patients compared to controls. No significant difference was found between the two sides for rates of involution, UTI, RS, nephrectomy, and additional abnormality. Cystatin C levels were higher on the right than left sides (p = .033). CONCLUSION: Children with MCDK predispose to renal deterioration even at normal eGFR values. Although cystatin C levels tended to increase in right-sided patients, the involved side seemed to have no significant effect on renal outcome. Hypertension was main determinant for progression to CKD in MCDK.

PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins.

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.

The relevance of practical laboratory markers in predicting gastrointestinal and renal involvement in children with Henoch-Schönlein Purpura.

OBJECTIVES: Henoch-Schönlein Purpura (HSP) is the most common self-limiting vasculitis of childhood. Both serious gastrointestinal and renal complications may be observed during the disease course. The aim of this study was to evaluate the role of hematological markers in predicting the likely complications of the disease. METHODS: The demographic findings, clinical features, organ involvements and laboratory findings including white blood cell count (WBC), neutrophil, lymphocyte and platelet counts, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), mean platelet volumes (MPV), MPV/platelet count ratio (MPR) were evaluated retrospectively from the charts of the patients with HSP and all these parameters were compared with the same parameters of healthy children. RESULTS: A total of 376 patients with HSP and age- and sex-matched 233 healthy children were evaluated. Mean age at the diagnosis was 7.5 ± 3.5. All patients had palpable purpura, 46% had arthritis, 56.1% GIS involvement and 21.3% had renal involvement. While platelet counts, neutrophil counts, NLR, and PLR were higher, lymphocyte counts, MPV, and MPR were lower in patients with GIS involvement. NLR was the sole biomarker that was higher in patients with renal involvement. CONCLUSIONS: This study had shown that platelet counts, neutrophil counts, NLR, and PLR were increasing and lymphocyte counts, MPV, and MPR were decreasing when the patients had GIS involvement. However, these parameters were not relevant in distinguishing severe and mild GIS involvement. When patients had renal involvement NLR was the unique elevated parameter.

Primary coenzyme Q10 Deficiency-6 (COQ10D6): Two siblings with variable expressivity of the renal phenotype.

Primary coenzyme Q10 deficiency-6 (COQ10D6) is a rare autosomal recessive disorder caused by COQ6 mutations. The main clinical manifestations are infantile progressive nephrotic syndrome (NS) leading to end-stage renal disease and sensorineural deafness. A 7-year-old girl was diagnosed with steroid-resistant NS (SRNS) and an audiological work-up revealed bilateral sensorineural deafness. A renal biopsy demonstrated focal segmental glomerulosclerosis. Despite immunosuppressive therapy, her serum levels of creatinine increased and haemodialysis was indicated within 1 year after the diagnosis. Living-donor kidney transplantation was performed in the eighth month of haemodialysis. A diagnostic custom-designed panel-gene test including 30 genes for NS revealed homozygous c.1058C > A [rs397514479] in exon nine of COQ6. Her older brother, who had sensorineural hearing loss with no renal or neurological involvement, had the same mutation in homozygous form. COQ6 mutations should be considered not only in patients with SRNS with sensorineural hearing loss but also in patients with isolated sensorineural hearing loss with a family history of NS. The reported p.His174 variant of COQ8B was suggested to be a risk factor for secondary CoQ deficiency, while p.Arg174 appeared to improve the condition in a yeast model. Family segregation and the co-occurrence of biallelic p.Arg174 of COQ8B in a brother with hearing loss implied that the interaction of the altered COQ8B with the mutant COQ6 alleviated the symptoms in this family. CoQ10 replacement therapy should be initiated for these patients, as primary CoQ10 deficiency is considered the only known treatable mitochondrial disease.

The nutcracker syndrome: The usefulness of different MRI sequences for diagnosis and follow-up.

OBJECTIVE: Nutcracker Syndrome (NCS) is the extrinsic compression of the left renal vein by neighboring arterial, ligamentous, muscular, or osseous structures. Diagnosis is made by Doppler ultrasonography (US), multidetector computerized tomography (MDCT), magnetic resonance imaging (MRI), phlebography. The aim of the current study is to assess the value of MRI and compare the efficiency of different sequences in diagnosis and follow up of children with NCS. MATERIAL AND METHODS: A total of 40 children (female/male ratio 3:1) with NCS were included in this prospective study. A standardized abdominal MRI protocol was used and T2-TRUFI (True Fast Imaging with Steady-State Free Precession), T2-HASTE (Half Fourier Acquisition with Single Shot Turbo Spin Echo), T1-VIBE (Volumetric Interpolated Breath Hold Examination), and out-of-phase (opposed-phase) T1 sequences were obtained. The sequences were compared according to anatomical depiction, measurability, and pulsation artifact. RESULTS: A four point-scale was used to assess subjective image quality and the results were listed as: 1 = poor, 2 = fair, 3 = good, and 4 = excellent. Both in total and for each individual criterion, the highest scores were obtained with T2-TRUFI (total mean 3.74 ±â€¯0.45, anatomical depiction 3.9 ±â€¯0.3, measurability 3.8 ±â€¯0.4, aortic pulsation artifact 3.52 ±â€¯0.55). CONCLUSION: Although Doppler US is the gold standard technique in the diagnosis of NCS, MR imaging may be used as an additional modality, as it is superior to Doppler US in terms of anatomic depiction and a lower rate of imaging artifacts. Non-contrast MR imaging, particularly TRUFI sequence, may have an incremental value in the accurate diagnosis and follow-up of these patients.

The clinical spectrum of Henoch-Schönlein purpura in children: a single-center study.

OBJECTIVES: Henoch-Schönlein purpura (HSP) is the most common vasculitis of children. The aim of this study is to evaluate the demographic and clinic findings of patients with HSP and also to determine predictive factors for assessing the development of gastrointestinal system (GIS) and renal involvement. METHODS: This study was performed prospectively among children with HSP who are under 18 years of age and being followed-up in the Pediatric Rheumatology Unit of Health Sciences University Kanuni Sultan Süleyman Training and Research Hospital between January 2016 and January 2018. RESULTS: A total of 265 patients, 137 boys (51.7%) and 128 girls (48.3%), were involved to the study. The mean ± standard deviation of age at the diagnosis was 7.5 ± 3.2. The most common disease onset season was spring (31.7%). The rate of arthritis, GIS involvement, and renal involvement were 54%, 51.3%, and 29.1%, respectively. GIS bleeding was more frequent in males than females (p = 0.007). Boys over 7 years of age had significantly more common GIS bleeding (p = 0.04). Intussusception, relapse, and serious GIS involvement requiring hospitalization and steroid treatment were highly associated with severe renal involvement. CONCLUSIONS: We demonstrated that patients suffering intussusception, relapse, and serious GIS involvement or requiring hospitalization and steroid treatment had tendency to present with severe renal involvement. Therefore, these patients should be followed up carefully for not overlooking renal involvement of HSP.

Effects of nutritional vitamin D supplementation on markers of bone and mineral metabolism in children with chronic kidney disease.

Background: We investigated the effects of nutritional vitamin D supplementation on markers of bone and mineral metabolism, i.e. serum levels of fibroblast growth factor 23 (FGF23), Klotho, bone alkaline phosphatase (BAP) and sclerostin, in two cohorts with chronic kidney disease (CKD). Methods: In all, 80 vitamin D-deficient children were selected: 40 with mild to moderate CKD from the ERGO study, a randomized trial of ergocalciferol supplementation [estimated glomerular filtration rate (eGFR) 55 mL/min/1.73 m2], and 40 with advanced CKD from the observational Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study (eGFR 24 mL/min/1.73 m2). In each study, vitamin D supplementation was started in 20 children and 20 matched children not receiving vitamin D served as controls. Measures were taken at baseline and after a median period of 8 months. Age- and gender-related standard deviation scores (SDSs) were calculated. Results: Before vitamin D supplementation, children in the ERGO study had normal FGF23 (median 0.31 SDS) and BAP (-0.10 SDS) but decreased Klotho and sclerostin (-0.77 and -1.04 SDS, respectively), whereas 4C patients had increased FGF23 (3.87 SDS), BAP (0.78 SDS) and sclerostin (0.76 SDS) but normal Klotho (-0.27 SDS) levels. Vitamin D supplementation further increased FGF23 in 4C but not in ERGO patients. Serum Klotho and sclerostin normalized with vitamin D supplementation in ERGO but remained unchanged in 4C patients. BAP levels were unchanged in all patients. In the total cohort, significant effects of vitamin D supplementation were noted for Klotho at eGFR 40-70 mL/min/1.73 m2. Conclusions: Vitamin D supplementation normalized Klotho and sclerostin in children with mild to moderate CKD but further increased FGF23 in advanced CKD.

Metabolic acidosis is common and associates with disease progression in children with chronic kidney disease.

Recent studies in adult chronic kidney disease (CKD) suggest that metabolic acidosis is associated with faster decline in estimated glomerular filtration rate (eGFR). Alkali therapies improve the course of kidney disease. Here we investigated the prevalence and determinants of abnormal serum bicarbonate values and whether metabolic acidosis may be deleterious to children with CKD. Associations between follow-up serum bicarbonate levels categorized as under 18, 18 to under 22, and 22 or more mmol/l and CKD outcomes in 704 children in the Cardiovascular Comorbidity in Children with CKD Study, a prospective cohort of pediatric patients with CKD stages 3-5, were studied. The eGFR and serum bicarbonate were measured every six months. At baseline, the median eGFR was 27 ml/min/1.73m2 and median serum bicarbonate level 21 mmol/l. During a median follow-up of 3.3 years, the prevalence of metabolic acidosis (serum bicarbonate under 22 mmol/l) was 43%, 60%, and 45% in CKD stages 3, 4, and 5, respectively. In multivariable analysis, the presence of metabolic acidosis as a time-varying covariate was significantly associated with log serum parathyroid hormone through the entire follow-up, but no association with longitudinal growth was found. A total of 211 patients reached the composite endpoint (ESRD or 50% decline in eGFR). In a multivariable Cox model, children with time-varying serum bicarbonate under 18 mmol/l had a significantly higher risk of CKD progression compared to those with a serum bicarbonate of 22 or more mmol/l (adjusted hazard ratio 2.44; 95% confidence interval 1.43-4.15). Thus, metabolic acidosis is a common complication in pediatric patients with CKD and may be a risk factor for secondary hyperparathyroidism and kidney disease progression.

Therapeutic approaches and long-term follow-up for prenatal hydronephrosis.

OBJECTIVE: This study summarises the outcomes of 149 patients who underwent surgery for antenatally diagnosed unilateral hydronephrosis. METHODS: The medical records of such patients over a 23-year period were reviewed retrospectively. Age at the time of operation, preoperative and postoperative mean pelvic diameter on ultrasound, split renal function, washout patterns on scintigraphy, and early and late complications were recorded. RESULTS: The mean preoperative follow-up period was five months (range: 1-66 months). One patient was operated on after 12 months and two patients after five years of follow-up. Mean preoperative pelvic diameter and renal function were 30.8 mm and 38.6%, respectively; all patients had an obstructive wash-out pattern. In the postoperative period, the corresponding measurements were 11.7 mm and 39.2%, with 111 non-obstructive, 24 partially obstructive, and 14 obstructive wash-out patterns. Three patients with severe caliectasis and low renal function underwent surgery despite mild hydronephrosis. The mean postoperative follow-up period was six (range 4-11) years. Complications developed in 14 (9.3%) patients. CONCLUSION: Patients with antenatal hydronephrosis may need surgery even after a follow-up period of six years. Because of the potential late development of complications, postoperative follow-up should be continued for 10 years.

Coexistence of early onset sarcoidosis and partial interferon-γ receptor 1 deficiency.

Pediatric sarcoidosis comprises a spectrum of childhood granulomatous inflammatory conditions. Pathological hallmark of the disease is granuloma formation that is seen in the affected tissues and almost any organ or system can be involved. There are two forms of pediatric sarcoidosis. One is seen in older children and the clinical picture is very similar to that of adult sarcoidosis and the other one is seen in early childhood. Sarcoidosis in early childhood can be divided as Blau syndrome (familial form) and early onset sarcoidosis (sporadic form). In both of the diseases there is a defect in the NOD2/CARD15 gene. The typical triad of early onset sarcoidosis is polyarthritis, dermatitis and uveitis. Interferon-γ receptor 1 deficiency is caused by defects in the IFNγR1 gene and non-tuberculosis mycobacterial pathogens are the leading causes of infections that start in early childhood. Herein we report a patient who presented with the symptoms of early onset sarcoidosis and also had partial interferon-γ receptor 1 deficiency that presented with BCG-osis. In addition to anti-mycobacterial treatment, methotrexate and prednisolone were used in therapy.

The utility of bioimpedance analysis for monitoring the children with nutcracker syndrome.

UNLABELLED: We aimed to evaluate anthropometric and bioimpedance analysis (BIA) indices of children with nutcracker syndrome (NCS). Eighteen patients and 20 age-gender matched controls were enrolled. Weight, height, body mass index (BMI), mid-arm circumference (MAC), waist circumference (WC), waist/hip ratio measurements, and BIA results were assessed. Laboratory parameters and Doppler sonographic findings were recorded. The weight, BMI, MAC, WC, body fat z scores, and waist/hip ratio were significantly lower in patients than in controls (p < 0.05). Serum creatinine (Scr), albumin, HDL cholesterol, and urine protein (Up) were significantly increased in NCS patients compared to controls (p < 0.05). On multivariate analysis, body fat z score was independently related to Up and the degree of superior mesenteric artery (SMA) angle (beta = -0.965, p = 0.018 and beta = 0.841, p = 0.04, respectively). CONCLUSION: NCS might be considered in slim proteinuric patients with unproven etiology. Serial anthropometric measurements and BIA analysis would estimate the severity of entrapment in LRV. Long-term follow-up of Scr might be required in NCS. WHAT IS KNOWN: • Nutcracker syndrome (NCS) is very rare and characterized by the compression of LRV between aorta and SMA. What is new: • Patients with NCS have a slimmer body feature with lower anthropometric and BIA indices. • Fat percentage indicates the degree of LRV entrapment and amount of proteinuria in NCS.

Metabolic disorders in Turkish children with urolithiasis.

OBJECTIVE: To review metabolic disorders in Turkish children with urinary tract stone disease. MATERIALS AND METHODS: The medical records of 308 pediatric patients with the diagnosis of urolithiasis between 1996 and 2008, whose disease progression was followed in a single tertiary-care center, were reviewed retrospectively. Two hundred forty-eight patients whose metabolic analyses were performed were included in the study. RESULTS: Of the 248 patients participating in the study, 142 (57%) were men and 106 (43%) were women. The median age of the patients was 48 months (minimum-maximum, 2-180 months). Seventy-six percent of the patients had metabolic disorders. Of all patients, 44% had 1, 23% had 2, and 7% had 3 metabolic disorders. Hypercalciuria, hypocitraturia, hyperoxaluria, hyperuricosuria, and cystinuria were detected in 41%, 39%, 22%, 9%, and 4% of the patients, respectively. The rate of multiple stone formation, infection, and recurrence was significantly higher in the 0-2 years age group (P = .030, P = .001, P = .019, respectively). The median age of patients was greater (P = .001) in patients with hyperoxaluria in comparison with other metabolic disorders. Compared with other metabolic disorders, multiple stones and recurrence were more frequent in patients with cystinuria (P = .022 and P = .008, respectively). The size of the stones was greater in patients with hyperuricosuria in comparison with other metabolic disorders (P = .009). CONCLUSION: The majority of children with urinary tract stone disease exhibited ≥1 metabolic risk factors. Metabolic risk factors should be evaluated in all children with urinary stone disease to provide appropriate treatment.

Misdiagnoses caused by use of indwelling urethral catheters in children with ureterovesical junction anomalies.

PURPOSE: Children commonly undergo vesicograms for diagnosing vesicoureteral reflux (VUR). This requires urethral catheterization with transurethral replacement. We report misdiagnosed or related complications due to indwelling urethral catheters unintentionally placed in the ureter. METHODS: From our computerized urology records over an 18-year period from January 1995 to May 2013, we retrospectively identified nine cases of 1850 vesicograms that had misdirection of a urethral catheter placed in a ureter. Foley catheters with inflating balloons were used to obtain the vesicograms. RESULTS: In all, 1850 vesicograms were performed (746 males, 1104 females; age 1 week to 14 years, mean age 3.8 years) using standard radiological techniques. Size 6-10 Fr indwelling urethral catheters were used, depending on the patient's age and gender. In nine cases (five females, four males), a misdirected urethral catheter was discovered in one of the ureters. The urethral catheter was in the left ureter in four patients and in the right ureter in five patients. Cystoscopic examination found ectopic ureteral openings in six patients: at the bladder neck in four and just below the bladder trigone in two. Three patients in this group with ectopic ureters were followed due a misdiagnosis of VUR. The remaining three patients had grade 3 or 4 VUR. In this group, the catheter passed into the ureter because of the enlarged ureterovesical junction. In one patient with VUR, intraparenchymal fluid leakage and transient hematuria occurred due to the rapid tension increase following the fast injection of contrast with liquid to one ureter. CONCLUSION: Although placing an indwelling urethral catheter is a relatively safe procedure, complications can occur, particularly in patients with ureterovesical anomalies, such as high-grade VUR or an ectopic ureter. Using catheters with inflating balloons can cause rapid increases in tension in the ureter, and related complications.

Renal outcome of children with horseshoe kidney: a single-center experience.

OBJECTIVE: To assess the clinical features, additional abnormalities, and renal consequences of children with horseshoe kidney (HSK). METHODS: The medical records of 41 children with HSK followed in our pediatric nephrology clinic between the years of 2004 and 2014 were retrospectively reviewed. RESULTS: There were 22 girls (53.6%) and 19 boys (46.4%) aged 60 (2-192) months. The median follow-up time was 48 (12-120) months. HSK was incidentally found in 12 patients (29.3%), and 5 patients (12.2%) were prenatally diagnosed. Urinary tract abnormalities including vesicoureteral reflux (n = 8), ureteropelvic junction obstruction (n = 7), and duplex system (n = 3) were identified in 18 patients (43.9%). Eight children (19.5%) had bladder dysfunction, and 9 patients (21.9%) had additional systemic abnormalities. Urinary tract infection had been detected in 17 patients (41.4%). Seven patients (17%) required surgical intervention including pyeloplasty (n = 3), ureteroneocystostomy (n = 3), and upper pole heminephrectomy (n = 1). Renal scarring (RS) occurred in 10 patients (24.4%). Six patients (14.6%) developed proteinuria and 4 (9.8%) complicated with hypertension. Three patients (7.3%) progressed to chronic kidney disease (CKD). Multivariate logistic regression analysis showed that proteinuria, hypertension, and RS are independently associated with CKD. CONCLUSION: Children with HSK might be examined for additional urologic and nonurologic abnormalities. Patients might be closely followed up for the increased risk of urinary tract infection and RS. Proteinuria, hypertension, and presence of RS seem to be the major determinants for progression to CKD in children with HSK.

Risk factors for community-acquired urinary tract infection caused by ESBL-producing bacteria in children.

BACKGROUND: The aim of the present study was to investigate the risk factors of antimicrobial resistance in children with urinary tract infection caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria. METHODS: A total of 344 patients diagnosed with urinary tract infection (UTI) between January 2008 and December 2009 were enrolled in this retrospective study. Causative microorganisms were ESBL-producing bacteria in 148 patients and non-ESBL-producing bacteria in 196 patients. There was no difference between the two groups regarding distribution of age, sex and length of follow up. RESULTS: The most frequent causative agent was Escherichia coli, of which 41.4% were ESBL producing. Among Klebsiella species, 53.2% were ESBL producing. The proportion of ESBL-producing bacteria that were resistant to antibiotics was 83.1% for trimethoprim/sulfamethoxazole, 18.2% for nitrofurantoin, 47.3% for quinolones, and 39.9% for aminoglycosides. For non-ESBL-producing bacteria, the resistance rate was 62.2% for trimethoprim/sulfamethoxazole, 4.6% for nitrofurantoin, 9.7% for quinolones, and 9.7% for aminoglycosides. Age <1 year, high UTI recurrence rate, long duration of prophylaxis, use of cephalosporins for prophylaxis, hospitalization within the previous 3 months and clean intermittent catheterization were found to be significant risk factors for ESBL-producing bacteria (P < 0.05). Logistic regression analysis identified age <1 year and high recurrence UTI rate to be independent risk factors, increasing the risk 1.74-fold and 2.25-fold, respectively. CONCLUSIONS: Recognition of the risk factors for ESBL-producing bacteria may be helpful to determine new policies in the management of UTI. Recurrence of UTI should be prevented especially in the first year of life, and prophylactic cephalosporins should be avoided.

Matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 in vesicoureteral reflux.

The aim of this study was to investigate whether urine levels of matrix metalloproteinase 9 (uMMP9) and tissue inhibitor of metalloproteinase 1 (uTIMP1) are novel biomarkers of vesicoureteral reflux (VUR) and to determine the optimal cut-off levels of these enzymes to predict VUR in children. The study group consisted of 67 children with VUR and 20 healthy children. Urine MMP9 and TIMP1 levels were measured by an enzyme-linked immunosorbent assay. Children with VUR had significantly higher uMMP9 (1,539.8 vs. 256.4 pg/mL; p = 0.0001) and uTIMP1 (182 vs. 32.6 pg/mL; p = 0.0001) levels than healthy children. For the prediction of VUR, the sensitivity of uMMP9 was 67%, with a specificity of 85% [cut-off value 1,054 pg/mL; area under the curve (AUC) 0.77], and the sensitivity of uTIMP1 was 74%, with a specificity of 65% (cut-off value 18.7 pg/mL; AUC 0.73). Both uMMP9 and uTIMP1 levels were significantly higher in patients with renal scar (uMMP9: 3,117.3 vs. 1,234.15 pg/mL; p = 0.0001; uTIMP1: 551.05 vs. 128.64 pg/mL; p = 0.0001). Urine MMP9 levels had a sensitivity of 81.2%, with a specificity of 85% to predict renal scar in the VUR group (cut-off 1,054 pg/mL; AUC 0.88). The sensitivity of uTIMP1 was 75%, with a specificity of 90% to predict renal scar (cut-off 243.7 pg/mL; AUC 0.82). Based on these results, we suggest that uTIMP1 may be a useful marker to predict renal scarring with a different cut-off value from VUR and a high specificity at this cut-off point. Although uMMP9 seemingly cannot distinguish renal scar from VUR, the simultaneous increase in the level of both markers may indicate ongoing renal injury due to VUR.

Urinary MMP-9/NGAL complex in children with acute cystitis.

The matrix metalloproteinase-9 (MMP-9) and neutrophil gelatinase associated lipocalin (NGAL) are shown to increase in an inflammatory situation. Based on our previous reports that NGAL can be detected in the urine of children with urinary tract infection (UTI), we also asked whether MMP-9/NGAL complex could be detected in the urine of children with UTI. This multicenter, prospective study was conducted between October 2009 and October 2010. Seventy-one patients with symptomatic culture proven UTI, 37 asymptomatic children with contaminated urine and 37 healthy children were recruited. Mean uMMP-9/NGAL/Cr levels were significantly higher in the UTI group than in the control group (p < 0.0001). According to ROC analysis, the optimal cut-off level was 0.08 ng/mg to predict UTI. Using a cut-off value, sensitivity and specificity were 98.6 and 97.3%, respectively. The mean levels of uMMP-9/NGAL/cr in the UTI group were also significantly higher than those in the contamination group (p < 0.0001). There was no statistically significant difference between contamination group and the control group (p = 0.21). The mean uMMP-9/NGAL/Cr in the UTI group were significantly higher before treatment than after treatment (p < 0.0001). The area under the curve was 0.997 (SE: 0.002, 95% CI: 0.993 to 1.001) for uMMP-9/NGAL/Cr. Urinary MMP-9/NGAL/Cr level was also correlated with positive urine nitrite test, positive urine leukocyte esterase reaction and renal scarring (p = 0.0001, p = 0.0001, p = 0.04, respectively) whereas was not correlated to leukocytosis and positive CRP level in serum. Urine MMP-9/NGAL/cr can be used as a diagnostic biomarker for UTI in children. Identification of NGAL-MMP-9/cr levels in the urine of suspected UTI patients may also be useful to differentiate between contamination and infection and for monitoring of treatment response in children.

Urinary macrophage migration inhibitory factor in children with urinary tract infection.

Macrophage migration inhibitory factor (MIF) plays an essential pathophysiological role in inflammatory reactions. The aim of this study was to investigate the clinical utility of urine MIF (uMIF) level in predicting urinary tract infections (UTI). This multicenter, prospective study was conducted over a 1-year period between March 2008 and March 2009. Sixty patients with symptomatic culture-proven UTI and 29 healthy children were recruited. Urine MIF was measured by enzyme-linked immunosorbent assay. The mean MIF level was found to be significantly higher in the UTI group than in the control group (1082.82 vs. 211.45 pg/ml, p = 0.0001). Receiver operating characteristic (ROC) analysis revealed that the optimal cut-off uMIF level was 295 pg/ml for uMIF to predict UTI. The sensitivity and specificity of this cut-off level were 91.7% and 69%, respectively. Mean uMIF/creatinine (Cr) was also significantly higher in the UTI group than in the control group (2400.69 vs. 267.56 pg/mgCr, p = 0.0001). At a cut-off of 815 pg/mgCr for uMIF/Cr, the sensitivity and specificity were 95 and 79%, respectively. The area under curve (AUC) was 0.848 (standard error 0.040, 95% confidence interval 0.756-0.915) for uMIF and 0.889 (0.034, 0.805-0.946) for uMIF/Cr. Urine MIF/Cr was significantly higher in the patients with a positive leukocyte esterase reaction in the urine (p = 0.047), leukocytosis (p = 0.0001) and positive C-reactive protein level in serum (p = 0.003). The uMIF level was not related to leukocytosis, positive CRP level in serum and leukocyte esterase reaction in the urine. Neither uMIF nor uMIF/Cr were correlated to the positive urine nitrite test, pyuria, urine pH and specific gravity (p > 0.05). These results suggest that urine MIF and uMIF/Cr can be used for the early prediction of UTI in children.