Characteristics and predictors of chronic kidney disease in children with myelomeningocele: a nationwide cohort study.

BACKGROUND: Myelomeningocele (MMC) is highly prevalent in developing countries, and MMC-related neurogenic bladder is an important cause of childhood chronic kidney disease (CKD). This nationwide study aimed to evaluate demographic and clinical features of pediatric patients with MMC in Turkey and risk factors associated with CKD stage 5. METHODS: Data from children aged 0-19 years old, living with MMC in 2022, were retrospectively collected from 27 pediatric nephrology centers. Patients > 1 year of age without pre-existing kidney abnormalities were divided into five groups according to eGFR; CKD stages 1-5. Patients on dialysis, kidney transplant recipients, and those with eGFR < 15 ml/min/1.73 m2 but not on kidney replacement therapy at time of study constituted the CKD stage 5 group. RESULTS: A total of 911 (57.8% female) patients were enrolled, most of whom were expectantly managed. Stages 1-4 CKD were found in 34.3%, 4.2%, 4.1%, and 2.4%, respectively. CKD stage 5 was observed in 5.3% of patients at median 13 years old (range 2-18 years). Current age, age at first abnormal DMSA scan, moderate-to-severe trabeculated bladder on US and/or VCUG, and VUR history were independent risk factors for development of CKD stage 5 (OR 0.752; 95%; CI 0.658-0.859; p < 0.001; OR 1.187; 95% CI 1.031-1.367; p = 0.017; OR 10.031; 95% CI 2.210-45.544; p = 0.003; OR 2.722; 95% CI 1.215-6.102; p = 0.015, respectively). Only eight CKD stage 5 patients underwent surgery related to a hostile bladder between 1 and 15 years old. CONCLUSION: MMC-related CKD is common in childhood in Turkey. A proactive approach to neurogenic bladder management and early protective surgery in selected cases where conservative treatment has failed should be implemented to prevent progressive kidney failure in the pediatric MMC population in our country.

Variable phenotype and genotype of pediatric patients with HNF1B nephropathy.

AIMS: Hepatocyte nuclear factor 1ß (HNF1B) mutations are the most common monogenic cause of congenital anomalies of the kidney and urinary tract (CAKUT). We aimed to investigate clinical and genetic characteristics of patients with HNF1B nephropathy to expand its phenotypic and genetic spectrum. MATERIALS AND METHODS: This retrospective cohort study included 16 unrelated pediatric patients (6 females, 10 males) from 13 families with genetically confirmed HNF1B-related nephropathy. RESULTS: Abnormal prenatal kidney abnormalities were present in 13 patients (81.3%). The most common antenatal kidney abnormality was kidney cysts, which were observed in 8 patients (61.5%). Urinary system abnormalities (vesicoureteral reflux (VUR) and ureteropelvic junction obstruction (UPJO)) were present in 4 patients (25%). HNF1B analysis uncovered missense variants in 4 families (30.8%) as the most common genetic abnormality. In addition, 4 novel pathological variations have been defined. During follow-up, hypomagnesemia and hyperuricemia were observed in 7 (43.8%) and 5 patients (31.3%), respectively. None of the patients with a missense variant had hypomagnesemia. However, 7 out of 12 patients (58.3%) with a non-missense variant had hypomagnesemia (p = 0.09). None of the patients had an HNF1B score below 8, and the mean score was 15.3 ± 4.4. The mean follow-up period was 7.4 ± 5.0 years. While 100% of patients (n = 4) with missense variants were in various stages of CKD (CKD2: 2 patients, CKD3: 2 patients), 25% of those with non-missense variants had CKD (CKD2, 3, and 5; 1 patient, respectively) (p = 0.026). CONCLUSION: Patients with HNF1B-associated disease have concomitant urinary system abnormalities such as VUR or UPJO. Missense variants seem to be the most common pathological variations in HNF1B gene and have higher risk of CKD.

Adolescence-onset atypical hemolytic uremic syndrome: is it different from infant-onset?

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare, mostly complement-mediated thrombotic microangiopathy. The majority of patients are infants. In contrast to infantile-onset aHUS, the clinical and genetic characteristics of adolescence-onset aHUS have not been sufficiently addressed to date. METHODS: A total of 28 patients (21 girls, 7 boys) who were diagnosed as aHUS between the ages of ≥10 years and <18 years were included in this study. All available data in the Turkish Pediatric aHUS registry were collected and analyzed. RESULTS: The mean age at diagnosis was 12.8±2.3 years. Extra-renal involvement was noted in 13 patients (46.4%); neurological involvement was the most common (32%). A total of 21 patients (75%) required kidney replacement therapy. Five patients (17.8%) received only plasma therapy and 23 (82%) of the patients received eculizumab. Hematologic remission and renal remission were achieved in 25 (89.3%) and 17 (60.7%) of the patients, respectively. Compared with the infantile-onset aHUS patients, adolescent patients had a lower complete remission rate during the first episode (p = 0.002). Genetic analyses were performed in all and a genetic variant was detected in 39.3% of the patients. The mean follow-up duration was 4.9±2.6 years. At the last visit, adolescent patients had lower eGFR levels (p = 0.03) and higher rates of chronic kidney disease stage 5 when compared to infantile-onset aHUS patients (p = 0.04). CONCLUSIONS: Adolescence-onset aHUS is a rare disease but tends to cause more permanent renal dysfunction than infantile-onset aHUS. These results may modify the management approaches in these patients.

Laparoscopic peritoneal dialysis catheter insertion with omentopexy-sparing the omentum in children.

INTRODUCTION: Continuous ambulatory peritoneal dialysis is an important modality of renal replacement therapy in children. Catheter dysfunction (commonly obstruction) is a major cause of morbidity and is a significant concern that hampers renal replacement therapy. As omentum is a significant cause of obstruction, some recommend routine omentectomy during insertion of the peritoneal dialysis catheter. Omentopexy rather than omentectomy has been described in adults to spare the omentum as it may be needed as a spare part in many conditions. Laparoscopic approach is commonly preferred as it provides global evaluation of the peritoneal space, proper location of the catheteral end in the pelvis and lesser morbidity due to inherent minimally invasive nature. AIM: The aim of this study is to present the technique of laparoscopic peritoneal dialysis catheter placement in children with concurrent omentopexy. METHODS: We retrospectively evaluated our patients who underwent laparoscopic placement of peritoneal dialysis catheter with concomitant omentopexy or omentectomy. RESULTS: A total of 30 patients were enrolled who received either omentectomy (n = 18) or omentopexy (n = 12). Four catheters were lost in the omentopexy group (33%) and 3 in the omentectomy group (17%), but none were related to omental obstruction. Three out of 4 patients in the omentopexy group and 2 out of 3 patients in the omentectomy group had a previous abdominal operation as a potential cause of catheter loss. Previous history of abdominal surgery was present in 6 patients (50%) in the omentopexy group and 3 patients (17%) in the omentectomy group. CONCLUSIONS: As omentum was associated with catheter failure, omentectomy is commonly recommended. Alternatively, omentopexy can be preferred in children to spare an organ that may potentially be necessary for many surgical reconstructive procedures in the future. Laparoscopic peritoneal dialysis catheter placement with concomitant omentopexy appears as a feasable and reproducible technique. Although the catheter loss seems to be higher in the omentopexy group, none was related with the omentopexy procedure and may be related to the higher rate of history of previous abdominal operations in this group.

A broad clinical spectrum of PLCε1-related kidney disease and intrafamilial variability.

BACKGROUND: The phenotypic and genotypic spectrum and kidney outcome of PLCε1-related kidney disease are not well known. We attempted to study 25 genetically confirmed cases of PLCε1-related kidney disease from 11 centers to expand the clinical spectrum and to determine the relationship between phenotypic and genotypic features, kidney outcome, and the impact of treatment on outcome. METHODS: Data regarding demographics, clinical and laboratory characteristics, histopathological and genetic test results, and treatments were evaluated retrospectively. RESULTS: Of 25 patients, 36% presented with isolated proteinuria, 28% with nephrotic syndrome, and 36% with chronic kidney disease stage 5. Twenty patients underwent kidney biopsy, 13 (65%) showed focal segmental glomerulosclerosis (FSGS), and 7 (35%) showed diffuse mesangial sclerosis (DMS). Of the mutations identified, 80% had non-missense, and 20% had missense; ten were novel. No clear genotype-phenotype correlation was observed; however, significant intrafamilial variations were observed in three families. Patients with isolated proteinuria had significantly better kidney survival than patients with nephrotic syndrome at onset (p = 0.0004). Patients with FSGS had significantly better kidney survival than patients with DMS (p = 0.007). Patients who presented with nephrotic syndrome did not respond to any immunosuppressive therapy; however, 4/9 children who presented with isolated proteinuria showed a decrease in proteinuria with steroids and/or calcineurin inhibitors. CONCLUSION: PLCε1-related kidney disease may occur in a wide clinical spectrum, and genetic variations are not associated with clinical presentation or disease course. However, clinical presentation and histopathology appear to be important determinants for prognosis. Immunosuppressive medications in addition to angiotensin-converting enzyme inhibitors may be beneficial for selected patients. "A higher resolution version of the Graphical abstract is available as Supplementary information".

COVID-19 in pediatric nephrology centers in Turkey.

BACKGROUND: There is limited data on COVID-19 disease in children with kidney disease. We aimed to investigate the characteristics and prognosis of COVID-19 in pediatric nephrology patients in Turkey. METHODS: This was a national, multicenter, retrospective cohort study based on an online survey evaluating the data between 11th March 2020 and 11th March 2021 as an initial step of a detailed pediatric nephrology COVID-19 registry. RESULTS: Two hundred and three patients (89 girls and 114 boys) were diagnosed with COVID-19. One-third of these patients (36.9%) were between 10-15 years old. Half of the patients were on kidney replacement therapy: kidney transplant (KTx) recipients (n = 56, 27.5%), patients receiving chronic hemodialysis (n = 33, 16.3%) and those on peritoneal dialysis (PD) (n = 18, 8.9%). Fifty-four (26.6%) children were asymptomatic. Eighty-two (40.3%) patients were hospitalized and 23 (28%) needed intensive care unit admission. Fifty-five percent of the patients were not treated, while the remaining was given favipiravir (20.7%), steroid (16.3%), and hydroxychloroquine (11.3%). Acute kidney injury developed in 19.5% of hospitalized patients. Five (2.4%) had MIS-C. Eighty-three percent of the patients were discharged without any apparent sequelae, while 7 (3.4%) died. One hundred and eight health care staff were infected during the study period. DISCUSSION: COVID-19 was most commonly seen in patients who underwent KTx and received HD. The combined immunosuppressive therapy and frequent exposure to the hospital setting may increase these patients' susceptibility. Staff infections before vaccination era were alarming, various precautions should be taken for infection control, particularly optimal vaccination coverage.

A nationwide retrospective study in Turkish children with nephrocalcinosis.

BACKGROUND: Nephrocalcinosis (NC) is defined as calcium deposition in the kidney parenchyma and tubules. This study aims to determine the etiology, risk factors, and follow-up results of patients with NC in Turkey. METHODS: Patients diagnosed with NC in the pediatric nephrology Department Units of 19 centers from all geographical regions of Turkey over a 10-year period (2010-2019) were included in the study. The medical records from the centers were reviewed and demographic data, admission complaints, medical history, systemic and genetic disorders, risk factors for NC, treatment details, and presence of NC after one-year follow-up, were recorded retrospectively. RESULTS: The study sample included 195 patients (88 females, 107 males). The mean age at diagnosis was 39.44 ± 47.25 (0.5-208) months; 82/190 patients (43.2%) were diagnosed incidentally; 46/195 patients (23.6%) had an underlying disease; idiopathic hypercalciuria was detected in 75/195 (38.4%) patients. The most common systemic diseases were distal renal tubular acidosis in 11/46 patients (23.9%), primary hyperoxaluria in 9/46 patients (19.6%) and Bartter syndrome in 7/46 patients (15.3%). After one year of follow-up, NC resolved in 56/159 patients (35.2%) and they all did not have an underlying systemic disease. DISCUSSION: The most common presentation of NC was incidental. Distal renal tubular acidosis and primary hyperoxaluria were the main systemic diseases leading to NC, while hypercalciuria was the most common metabolic risk factor. Nephrocalcinosis was found to remain in most of the patients at a one-year follow-up. It may resolve particularly in patients with no underlying systemic disease.

Cardiac functions in children with steroid-sensitive nephrotic syndrome.

BACKGROUND: The aim of the present study was to evaluate the presence of cardiac systolic and diastolic dysfunction in pediatric patients with steroid-sensitive nephrotic syndrome (NS). METHODS: The study population consisted of 19 patients with debut-relapse of NS aged 1-18 years and 30 sex and age-matched healthy controls. Blood and urine samples, two M-mode conventional echocardiograms and tissue Doppler velocity imaging were evaluated in both attack and remission periods. RESULTS: With regard to conventional pulse wave Doppler (cPWD), steroid-sensitive NS patients (both in debut / relapse and in remission periods) had a higher peak of late diastolic flow velocities (A peak), and patients in debut / relapse had a lower E/A ratio than the control group, indicating diastolic dysfunction (overall P = 0.003 and P = 0.006, respectively). Based on tissue Doppler velocity imaging echocardiography results, patients in debut/relapse had a higher A' and a lower E'/A' ratio (overall P < 0.001 and P = 0.001, respectively). There was also a significant difference in the cPWD E/TDI E' ratio between the patients showing an increased cPWD E/TDI E' ratio in remission periods compared to in debut/relapse periods (P = 0.09). The albumin levels were positively correlated with E'/A' and E/ E' ratio (r = 0.609; P = 0.007, r = 0.472; P = 0.041 respectively). CONCLUSIONS: Systolic cardiac functions are preserved but diastolic functions are affected in steroid-sensitive NS patients both in debut/relapse and in remission periods in a relatively short time. The persistence of left ventricular (LV) dysfunction during the remission period requires special attention during the follow up for early detection of cardiac abnormalities.

Disseminated fungal infection by Aureobasidium pullulans in a renal transplant recipient.

Renal transplant recipients are on long-term potent immunosuppressive therapy, which makes them highly vulnerable to opportunistic fungal infections. Dematiaceous, or dark-pigmented saprophytic fungi, are being increasingly seen as opportunistic pathogens of mycoses in immunosuppressed patients. One of these is Aureobasidium pullulans, which is a black yeast-like dematiaceous fungus found ubiquitously in the environment that can cause various opportunistic human infections. Most infections occur by traumatic inoculation, such as keratitis and cutaneous lesions; disseminated mycoses are very rare and occur only in severely immunocompromised patients. We report a case of disseminated fungal infection due to A. pullulans in a pediatric patient who underwent renal transplant. The use of voriconazole and vacuum-assisted closure along with surgical drainage most likely contributed to the patient's positive outcome.

Abdominal pain in a 5-year-old girl with bilateral nephromegaly: Answers.

Renal involvement in non-Hodgkin lymphoma is a recognized development, but it mostly follows a diagnosis of lymphoma. We describe a rare case of a T-cell-type non-Hodgkin lymphoma that first presents as nephromegaly in a 5-year-old girl admitted to the emergency department with abdominal pain. Further investigation revealed bilateral nephromegaly, but the results of blood tests, imaging studies, and bone marrow aspiration were inconclusive. During the second week of hospitalization, significant physical examination revealed an enlarged lymph node in the anterior cervical chains, confirming a diagnosis of Non-Hodgkin's lymphoma. This case illustrates that it is important to have a high degree of suspicion in any patient presenting with unexplained enlarged kidneys without any identifiable cause because it could be the first presentation of a hematologic malignancy.

Eculizumab therapy in a patient with dense-deposit disease associated with partial lipodystropy.

BACKGROUND: Dense deposit disease (DDD) (also known as membranoproliferative glomerulonephritis type II) in childhood is a rare glomerulonephritis with frequent progression to end-stage renal disease (ESRD) and a high recurrence after kidney transplantation. The pathophysiologic basis of DDD is associated with the uncontrolled systemic activation of the alternative pathway (AP) of the complement cascade. CASE-DIAGNOSIS/TREATMENT: A 14-year-old girl presented with edema and nephrotic range proteinuria. Blood tests showed hypoalbuminemia, nephrotic range proteinuria, normal renal function, and a low C3 level. Renal biopsy confirmed the diagnosis of crescentic DDD. Complement analysis revealed strong AP activation (low C3), positive C3 nephritic factor (C3NeF), and a decreased complement factor H (CFH) levels with CFH polymorphisms. Therapy with eculizumab was considered after the failure of corticosteroid and plasmapheresis to modulate the ongoing massive proteinuria and persistence of low serum C3 levels. There was a marked clinical and biochemical response following the administration of eculizumab. CONCLUSIONS: Our case emphasizes the efficacy of eculizumab in the management of crescentic DDD in a patient with a normal renal function, in a short follow-up period. Considering previously reported cases, it appears that eculizumab represents a promising new approach which may prevent progression to ESRD in a subset of patients with DDD.

Functional capacity, strength, and quality of life in children and youth with familial Mediterranean fever.

PURPOSE: To examine functional capacity and muscle strength in children and youth with familial Mediterranean fever (FMF) as compared with controls, and to assess whether these factors influence quality of life (QOL) in FMF. METHODS: A total of 100 subjects with FMF and 55 control subjects (8-18 years old) without known health issues were enrolled in the study. The 6-Minute Walk Test (6MWT) was used to evaluate functional capacity. Quadriceps strength was measured with a hand-held dynamometer. Quality of life was evaluated with the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0). RESULTS: Significant differences were found between subjects with FMF and controls in the 6MWT and strength test. PedsQL scores of subjects with FMF were significantly lower than the scores of the controls. The 6MWT and quadriceps strength were weakly correlated with the PedsQL. CONCLUSION: Subjects with FMF displayed lower functional capacity and QOL than peers who are healthy. Decreased functional capacity was correlated with decreased QOL in those with FMF.

Metabolic Acidosis Is Associated With an Accelerated Decline of Allograft Function in Pediatric Kidney Transplantation.

Introduction: We investigated the relationship between metabolic acidosis over time and allograft outcome in pediatric kidney transplantation (KTx). Methods: This registry study collected data up to 10 years posttransplant. Survival analysis for a composite end point of graft loss or estimated glomerular filtration rate (eGFR) ≤ 30 ml/min per 1.73 m2 or ≥50% decline from eGFR at month 3 posttransplant was performed. The association of serum bicarbonate concentration (HCO3 -) < 22 mmol/l (metabolic acidosis) and HCO3 - < 18 mmol/l (severe metabolic acidosis) with allograft outcome was investigated using stratified Cox models and marginal structural models. Secondary analyses included the identification of risk factors for metabolic acidosis and the relationship between alkali supplementation and allograft outcome. Results: We report on 1911 patients, of whom 347 reached the composite end point. The prevalence of metabolic acidosis over time ranged from 20.4% to 38.9%. In the adjusted Cox models, metabolic acidosis (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.54-2.60) and severe metabolic acidosis (HR, 2.49; 95% CI, 1.56-3.99) were associated with allograft dysfunction. Marginal structural models showed similar results (HR, 1.75; 95% CI, 1.32-2.31 and HR, 2.09; 95% CI, 1.23-3.55, respectively). Older age was associated with a lower risk of metabolic acidosis (odds ratio [OR] 0.93/yr older; 95% CI, 0.91-0.96) and severe metabolic acidosis (OR, 0.89; 95% CI, 0.84-0.95). Patients with uncontrolled metabolic acidosis had the worst outcome compared to those without metabolic acidosis and without alkali (HR, 3.70; 95% CI, 2.54-5.40). Conclusion: The degree of metabolic acidosis is associated with allograft dysfunction.

Case report: Thrombotic microangiopathy in pediatric multisystem inflammatory syndrome associated with COVID-19: a case series.

Introduction: This report provides insight into three distinct pediatric cases exhibiting a nexus between multisystem inflammatory syndrome in children (MIS-C) and thrombotic microangiopathy (TMA) triggered by COVID-19. The aim is to underscore the range of clinical presentations and the essentiality of early interventions. Case presentations: This report presents three cases aged 10 months, 7 years, and 3 years with persistent fever, diarrhea, nausea, and vomiting. The first case, a 10-month-old girl, demonstrated acute kidney injury (AKI) and microangiopathic hemolytic anemia (MAHA) following a COVID-19 infection. Despite initial negative SARS-CoV-2 RT-PCR results, her condition escalated rapidly, presenting increased levels of LDH (peaking at 4,200 U/L) and requiring renal replacement therapy (RRT) to manage deteriorating renal function. Interventions with eculizumab and anakinra led to marked improvements, with a stable follow-up of 13 months post-hospitalization. The second case involved a 7-year-old girl who developed symptoms of MIS-C, hemolytic uremic syndrome (HUS), and posterior reversible encephalopathy syndrome (PRES) post-exposure to COVID-19, evidenced by heightened LDH levels (3,522 U/L at peak). After a precarious period of deteriorating kidney function and exacerbated hypertension, she responded positively to treatments, inclusive of IVIG, steroid therapies, and eculizumab, with a favorable 6-month follow-up showcasing stable laboratory results. The third case discusses a 3-year-old boy, without any medical history, manifesting HUS symptoms and COVID-19 infection. He exhibited increased LDH levels (peaking at 3,946 U/L) alongside elevated creatinine, marking renal impairment. He responded well to hemodialysis, IVIG, and steroid therapy, showcasing substantial recovery by the 19th day of hospitalization, which marked his discharge with a tapering steroid regimen. Conclusion: This case series underscores that MIS-C-associated TMA is a significant complication in pediatric COVID-19. Our findings illuminate the potential for treatment success but simultaneously emphasize the need for a more comprehensive understanding of the underlying pathophysiology.