BACKGROUND: Posterior urethral valve (PUV) is the most serious form of congenital anomalies of kidney and urinary tract (CAKUT) in boys with significant risk of progression to chronic kidney disease (CKD). We present our long-term results in children with PUV. METHODS: Retrospective chart review of 113 children with PUV followed within the years of 1996-2018 was performed. Clinical. laboratory and epidemiologic parameters were analyzed for their impact on renal outcome. RESULTS: The median age of diagnosis was 1.00 month (1.00-132.00) and the median follow-up period was 70 months (60.00-216.00). Antenatal diagnosis was present in 33 patients (51.5%) mainly with bilateral hydronephrosis and oligohydramnios. The most common postnatal presentation was recurrent urinary tract infection (UTI) in 14 cases (21.9%) and incontinence in three cases (4.7%). Vesicoureteral-reflux (VUR) was present in 31 cases (48.4%). All patients had surgery and urinary diversion was needed in 18 (28.2%). Varying stages of chronic kidney disease (CKD) developed in 23 cases (35.9%) and rise in serum creatinine was especially prominent after the 4th year of follow-up. Of 23 CKD patients, seven (10.9%) were in ESRD and on dialysis. Mortality occurred in one (1.5%) patient. Hypertension, proteinuria and high initial serum creatinine (>1.28 mg/dL) were statistically significant risk factors for CKD, as expected. Surprisingly VUR and UTI did not show such a significant impact on CKD development. Antenatal detection was with significantly less risk for CKD. CONCLUSIONS: Our results confirm that PUV has a considerable risk for CKD development. Antenatal diagnosis, management of proteinuria and hypertension may modify this progression. But already injured kidneys still have a potential risk. The need for further research to evaluate the impact of any intervention on long term renal outcome is obvious.

Background: Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are among the important causes of mortality and morbidity in childhood. Early diagnosis and treatment of the underlying primary disease may prevent most of CKD patients from progressing to ESRD. There is no study examining chronic kidney diseases and dialysis modalities in Syrian immigrant children. We aimed to retrospectively research the etiologic, sociodemographic, and clinical factors in CKD among Syrian refugee children, and at the same time, to compare the clinical characteristics of patients with ESRD on peritoneal dialysis and hemodialysis. Methods: Our study included a total of 79 pediatric Syrian patients aged from 2-16 years monitored at Hatay State Hospital pediatric nephrology clinic with diagnosis of various stages of CKD and with ESRD. Physical-demographic features and clinical-laboratory information were retrospectively screened. Results: The most common cause of CKD was congenital anomalies of the kidneys and urinary tracts (CAKUT) (37.9%). Other causes were urolitiasis (15.1%), nephrotic syndrome (10.1%), spina bifida (8.8%), hemolytic uremic syndrome (7.5%), and glomerulonephritis (7.5%). Twenty-five patients used hemodialysis due to bad living conditions. Only 2 of the patients with peritoneal dialysis were using automatic peritoneal dialysis (APD), with 5 using continuous ambulatory peritoneal dialysis (CAPD). Long-term complications like left ventricle hypertrophy and retinopathy were significantly higher among hemodialysis patients. There was no difference identified between the groups in terms of hypertension and sex. Conclusion: Progression to ESRD due to preventable reasons is very frequent among CKD patients. For more effective use of peritoneal dialysis in pediatric patients, the responsibility of states must be improved.

Haemolytic uraemic syndrome (HUS) is most commonly associated with Shiga toxin-producing Escherichia coli (STEC) while the recurrent hereditary atypical (aHUS) form secondary to complement system control protein mutations is relatively rare. A 6-year-old boy with complement factor H (CFH) and factor B (CFB) mutations and a history of bloody diarrhoea and PCR positivity for Shiga toxin was initially diagnosed as STEC+HUS. Acute kidney injury resolved with Eculizumab but he remains with chronic renal failure. Although the exact role of STEC in the pathogenesis of aHUS in this patient is not certain, there seems to be a relationship. However, several issues remain to be explained including the effect of genetic and environmental factors in modifying susceptibility to develop aHUS in some patients following STEC infection. Abbreviations: aHUS: atypical haemolytic uraemic syndrome; ANA: anti-nuclear antibody; ANCA: anti-neutrophil cytoplasmic antibody; ASO: anti-streptolysin O; BUN: blood urea nitrogen; CFB: complement factor B; CFH: complement factor H; EHEC: enterohaemorrhagic Escherichia coli; MCP: membrane co-factor protein; PD: peritoneal dialysis; STEC: Shiga toxin-producing Escherichia coli; STX 1–2: Shiga toxins 1–2

Background/aim: This study aimed to evaluate the efficacy of rituximab in children with difficult-to-treat nephrotic syndrome, considering the type of disease (steroid-sensitive or -resistant) and the dosing regimen. Materials and methods: This multicenter retrospective study enrolled children with difficult-to-treat nephrotic syndrome on rituximab treatment from 13 centers. The patients were classified based on low (single dose of 375 mg/m(2)) or high (2-4 doses of 375 mg/m(2)) initial dose of rituximab and the steroid response. Clinical outcomes were compared. Results: Data from 42 children [20 steroid-sensitive (frequent relapsing / steroid-dependent) and 22 steroid-resistant nephrotic syndrome, aged 1.9-17.3 years] were analyzed. Eleven patients with steroid-sensitive nephrotic syndrome (55%) had a relapse following initial rituximab therapy, with the mean time to first relapse of 8.4 +/- 5.2 months. Complete remission was achieved in 41% and 36% of steroid-resistant patients, with the median remission time of 3.65 months. At Year 2, eight patients in steroid-sensitive group (40%) and four in steroid-resistant group (18%) were drug-free. Total cumulative doses of rituximab were higher in steroid-resistant group (p = 001). Relapse rates and time to first relapse in steroid-sensitive group or remission rates in steroid-resistant group did not differ between the low and high initial dose groups. Conclusion: The current study reveals that rituximab therapy may provide a lower relapse rate and prolonged relapse-free survival in the steroid-sensitive group, increased remission rates in the steroid-resistant group, and a significant number of drug-free patients in both groups. The optimal regimen for initial treatment and maintenance needs to be determined.

Pauci-immune glomerulonephritis (GN) is more common in elderly people compared to children and the etiology is not completely understood yet. Antineutrophil cytoplasmic antibody (ANCA) positivity occurs in 80% of the patients. We report a case of a 7-year-old girl who presented with malaise and mildly elevated creatinine diagnosed as ANCA-associated pauci-immune crescentic glomerulonephritis with crescents in 20 of 25 glomeruli (80%). Of these 20 crescents, 12 were cellular, 4 fibrocellular, and 4 globally sclerotic. She did not have purpura, arthritis, or systemic symptoms and she responded well to initial immunosuppressive treatment despite relatively severe histopathology. The patient was given three pulses of intravenous methylprednisolone (30 mg/kg on alternate days) initially and continued with cyclophosphamide (CYC; 2 mg/kg per day) orally for 3 months with prednisone (1 mg/kg per day). In one month, remission was achieved with normal serum creatinine and prednisone was gradually tapered. The case of this child with a relatively rare pediatric disease emphasizes the importance of early and aggressive immunosuppressive treatment in patients with renal-limited ANCA-associated pauci-immune crescentic GN even if with a mild clinical presentation. As in our patient, clinical and laboratory findings might not always exactly reflect the severity of renal histopathology and thus kidney biopsy is mandatory in such children to guide the clinical management and predict prognosis.

Objective: Acute tubulointerstitial nephritis (aTIN) is a rare cause of acute renal injury in children. The incidence of cases linked to insensible use of energy drinks has increased in recent years. In thıs study, we aimed to examine patients with aTIN connected to energy drink in detail in our own patients.Methods: In this study, the files of patients with acute tubulointerstitial nephritis (aTIN in the pediatric nephrology clinic were retrospectively screened.Results: 32 patients were included in the study (F/M: 22/10). Mean age was 12±4.3 years (9-17). The most common causes in etiology were drugs (18; 56.2%) and energy drinks (9; 28.1%). The most common attendance symptoms were vomiting (84.3%), fatigue (68.7%), hypertension (56.2%), abdominal pain (40.6%), joint pain (34.3%), fever (31.2%). The mean duration from onset of symptoms to first attendance at hospital was 3.8±2.1 days, with the mean duration between first intake of causative agent to onset of symptoms 9±4.1 days.Conclusion: The inclusion of energy drink use among candidates for causes of aTIN in recent years is an important health problem. Due to serious side effect profile beginning with acute kidney injury and resulting in CKD, it is a cause that should definitely be questioned in the anamnesis of young patients especially.