Introduction. The choice of empiric therapy of acute pyelonephritis (APN) in children should be based on the knowledge of Escherichia coli (E. coli) as the most common uropathogen and its antibiotic sensitivities considering that nowadays ESBL-producing [ESBL (+)] E. coli is on the rise worldwide. Objective. To examine in vivo susceptibility of ESBL (+) E. coli to ceftriaxone (CTX), and to evaluate the options for empiric therapy for APN in children. Methods. Retrospective study of CTX empiric therapy of APN in children treated at the University Children΄s Hospital in Belgrade from January 2005 to December 2009. ESBL phenotypic confirmatory test with ceftazidime, CTX and cefotaxime was performed for all urine isolates by disc diffusion method on Mueller-Hinton agar plates. In vivo sensitivity of CTX documented by clinical response to empiric CTX therapy was compared between two groups of children: group I with ESBL (+) E. coli and group II with ESBL (-) E. coli APN. Results. Group I with ESBL (+) APN consisted of 94 patients and group II of 120 patients with ESBL (-) APN, respectively. All patients received CTX as empiric therapy at a mean dose of 66.9 mg during 7.2±2.6 days of therapy. Clinical effect of CTX was similar in patients with ESBL (+) compared to those with ESBL (-) APN. Conclusions. In vitro resistance of ESBL E. coli to CTX determined by standard methods is not sufficiently predictive for its in vivo sensitivity. Therefore CTX may be used as empiric therapy for acute pyelonephritis in children.

Background: The pathophysiological mechanisms crucial in the development of nephrotic syndrome (NS) in the pediatric population are still not fully understood. This study aimed to investigate the relationship between hypertension, oxidative stress, and inflammation in pediatric patients during the acute phase of the disease. Methods: The study included 33 children, aged 2 to 9 years, with nephrotic syndrome. Blood samples were collected during the acute phase and remission. Parameters of oxidative status were determined, including total oxidative status (TOS), advanced oxidation protein products (AOPP), prooxidant-antioxidant balance (PAB), sulfhydryl groups (-SH), paraoxonase 1 (PON1), and total antioxidant status (TAS) in serum, measured spectrophotometrically. Inflam - matory parameters such as pentraxin 3 (PTX3), leptin, program med cell death ligand 1 (PD-L1), and E-cadherin were determined using enzyme-linked immunosorbent assay (ELISA). Results: Patients with nephrotic syndrome and hypertension had significantly higher levels of advanced oxidation protein products and total antioxidant status (p=0.029 and p=0.003, respectively). During the acute phase of the disease, lower activity of sulfhydryl groups and paraoxonase 1 was observed compared to remission (p<0.001, for both). Pentraxin 3 levels were higher, while leptin levels were lower during the acute phase (p<0.001, for both). Pentraxin 3 correlated with advanced oxidation protein products and total antioxidant status during the acute phase but not in remission (rs=0.42, p=0.027 and rs=0.43, p=0.025, respectively). A negative correlation between Advanced oxidation protein products and leptin was observed during the acute phase, which disappeared in remission (rs=-0.42, p=0.028). Conclusions: Results of this study show that hypertension influences oxidative stress markers, and decreased antioxidant capacity may contribute to nephrotic syndrome development. Pentraxin 3 appears as a potential disease activity marker, indicating a dynamic connection between inflammation and oxidative stress. Leptin may also play a role in oxidative stress in nephrotic syndrome.

Acute kidney injury (AKI) is a common complication in pediatric oncology patients, most often caused by nephrotoxic drugs. We aimed to assess whether levels of urinary kidney injury molecule-1 (uKIM-1), neutrophil gelatinase-associated lipocalin (uNGAL), liver fatty acid binding protein (uL-FABP) and Vanin-1 (uVNN-1), individually and in combination-integrated could be early markers for cytotoxic treatment induced AKI. Children with different malignant diseases treated with cisplatin (CIS) or ifosfamide (IFO) were included. AKI was defined using pediatric KDIGO (Kidney Disease Improving Global Outcomes) criteria by comparing pretreatment serum creatinine (sCr) values with those acquired at 48 h after the first or second chemotherapy cycle. Five serum (at baseline, 2, 6, 24 and 48 h after treatment) and four urine samples (at baseline, 2, 6 and 24 h after treatment) were obtained. Urinary biomarkers (uBm) were normalized to urine creatinine. Thirty-eight patients were assessed. Within 48 h following chemotherapy 6 (15.79%) patients experienced AKI. Patients with AKI were younger and tend to have lower baseline sCr values than patients without AKI, but these differences were not statistically significant. Compared to baselines, all uBm were significantly increased during the first 6 h while sCr concentrations did not change significantly during the study period. The median increases in uBm during the first 6 h after treatment were 529.8% (interquartile range – IQR, 63.9-1835.2%) – 2194.0% (IQR, 255.3-4695.5%) in AKI vs. 302.2% (IQR 114.6-561.2%) -429.8% (156.5–1467.0%) in non-AKI group depending of tested uBm. The magnitude of these changes over time didn’t differ significantly between groups. The area under receiver operator curve (AUC) for uL-FABP and uNGAL at 24 h after chemotherapy were 0.81 and 0.72, respectively. The ROC analysis revealed that the other individual biomarkers’ performance at any time-point wasn’t statistically significant (AUC < 0.7). A model of integrated-combined uBm, 2 h (AUC 0.78), 6 h (AUC 0.85) and 24 h after (AUC 0.92) treatment with CIS and/or IFO showed good utility for early AKI prediction. The results of this study support that the use of the uBm to improves early AKI prediction in patients receiving CIS and/or IFO containing chemotherapy. Further studies on larger comparable groups of patients are needed.

IgA nephropathy is the most common primary glomerulonephritis, with pathohistological changes described by the Oxford classification, while the Banff classification is used in transplant pathology. This study included 253 patients with IgA nephropathy in native kidneys, divided into the pediatric (n = 105) and adult (n = 148) groups. It aimed to examine clinical, and Oxford and Banff morphological parameters in relation to age, correlations of clinical data with pathohistological parameters, and predictors of the disease outcome. Pediatric patients more frequently presented with macroscopic hematuria, while adults showed higher urea and creatinine levels, and lower eGFR. Examining Oxford classification parameters, chronic glomerular and tubulointerstitial lesions were more common in adults. Banff parameters revealed more frequent chronically active glomerular, inflammatory, chronic tubulointerstitial, and vascular lesions in adults. All inflammatory, chronic tubulointerstitial, and vascular parameters correlated with serum urea levels, eGFR and CKD stage in adults, while less frequent in pediatric patients. Tubulointerstitial Oxford and Banff parameters were strong predictors of CKD and proteinuria progression in children, while such predictors were fewer in adults; segmental glomerulosclerosis predicted hematuria progression in adults. Banff parameters (cg, t, ti, i, i-IFTA, ptc, cv), not in Oxford classification, significantly predict outcomes and are recommended for incorporation into IgA nephropathy reports.

Background/Objectives: Continuous renal replacement therapy (CRRT) is an important treatment method that is becoming a commonly-used procedure in neonatal intensive care units (NICUs), especially in critically-ill neonates. Methods: We conducted a retrospective study aimed to evaluate factors influencing the outcomes of CRRT in neonates and preterm infants. The study analyzed data from 41 newborns treated with CRRT at our NICU over a ten-year period. Demographic, clinical, and laboratory parameters were assessed, including gestational age, birth weight, PRISM III score, and laboratory markers like urea, creatinine, and potassium levels, as well as characteristics of CRRT. Results: Our research found that the duration of CRRT, the presence of anuria, and higher potassium levels after initiation of CRRT were significant predictors of a poor outcome. Despite the lack of significant correlation between demographic characteristics, PRISM III score and the outcome, our findings highlight the importance of timely CRRT initiation and efficient management to improve survival. Conclusions: Our study identified several significant prognostic indicators in neonates undergoing renal replacement therapy. While these findings provide valuable insights, further research is needed to establish clear theoretical guidelines and improve clinical decision-making.

Introduction: Renal blood vessel (RBV) stenosis is the cause of secondary arterial hypertension (AH) in 10% of children. Digital subtraction angiography (DSA) is the gold standard in diagnosing RBV stenosis. Many authors suggest Mr angiography (MRA), a non-invasive method without radiation, as an adequate diagnostic method. Our aim was to analyze the experience of our center in using MRA in children with AH. Method: This retrospective study included 148 patients hospitalized at the University Children's Hospital in Belgrade, due to AH. After initial examination, patients underwent DSA and/or MRA. Results: According to the current guidelines, DSA was performed in patients with highly suspected RBV stenosis, and the diagnosis was confirmed in 13/29 (45%). Diagnostic MRA was done in 116/119 (97.5%) patients, and control MRA was done after therapeutic revascularization in 3/119 (2.5%). In 4/116 (3.5%) patients, the findings indicated RBV stenosis, and in 44/116 (38%) it indicated some other abnormality of the kidney parenchyma and the urinary tract or RBV varieties. After MRA, DSA was performed in 7/116 (6%) patients (4 with RBV stenosis on MRA and 3 with clinical suspicion of RBV stenosis), but all findings were normal. Conclusion: According to the results, it is justified to perform a diagnostic MRA before DSA in children with highly suspected RBV stenosis, in order to avoid DSA which is an invasive procedure with radiation, in some patients with normal findings. Also, over time, we would have a clearer view of the sensitivity and specificity of MRA as a diagnostic method in RBV stenosis in children.