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.

A case of crescentic glomerulonephritis with exacerbation of pre-existing IgA nephropathy after COVID-19

BACKGROUND

Relapses or new-onset IgA nephropathy (IgAN) have been documented in patients after vaccination against SARS-CoV-2; however, only one adult patient has been reported in whom pre-existing IgAN worsened during coronavirus disease 2019 (COVID-19).

CASE

We present the first pediatric case with biopsy-proven IgAN and genetically confirmed Alport syndrome, who developed end-stage kidney disease after an exacerbation of IgAN associated with COVID-19. The patient`s basal serum creatinine was 0.7-0.9 mg/dL before infection. He had not been vaccinated against COVID-19. He was admitted to the hospital with edema, hypertension, an elevated serum creatinine of 4.7 mg/ dL, and massive proteinuria. Three months before admission, he had been admitted to another hospital with COVID -19 and an elevated serum creatinine (1.9 mg/dL), but no biopsy had been performed at that time. The kidney biopsy revealed IgAN with 50% fibrocellular crescents with sclerosed glomeruli, tubular atrophy, and interstitial fibrosis. His serum creatinine did not decrease even after five administrations of pulse steroids, and hemodialysis was initiated.

CONCLUSION

In conclusion, COVID -19 may pose a high risk for exacerbation of pre-existing glomerular disease. It is therefore necessary to closely monitor the kidney function of patients with underlying glomerulonephritis during and after COVID-19 and consider an early biopsy if serum creatinine does not return to baseline levels. In addition, this case report highlights the clinical importance of the co-occurence of IgAN and Alport syndrome.

A novel homozygous missense variant in TBC1D31 in a consanguineous family with congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) is the leading cause of chronic kidney disease in the first three decades of life. Until now, more than 180 monogenic causes of isolated or syndromic CAKUT have been described. In addition, copy number variants (CNV) have also been implicated, however, all of these causative factors only explain a small fraction of patients with CAKUT, suggesting that additional yet-to-be-discovered novel genes are present. Herein, we report three siblings (two of them are monozygotic twin) of a consanguineous family with CAKUT. Whole-exome sequencing identified a homozygous variant in TBC1D31. Three dimensional protein modeling as well as molecular dynamics simulations predicted it as pathogenic. We therefore showed for the first time an association between a homozygous TBC1D31 variant with CAKUT in humans, expanding its genetic spectrum.

Cardiometabolic Risk Factors in Pediatric Kidney Transplant Recipients

OBJECTIVE

There is an increased risk of obesity and metabolic syndrome among kidney transplant recipients, which adversely affects cardiovascular and renal outcomes in these patients. The present study aims to investigate the prevalence of metabolic syndrome in pediatric kidney transplant recipients and the associations of metabolic syndrome with cardiovascular disease and graft function.

MATERIALS AND METHODS

This cross-sectional, single-center study included 52 kidney transplant recipients (27 males) transplanted before 18 years of age. All subjects underwent a comprehensive assessment that included anthropometric and blood pressure measurements and laboratory tests. Metabolic syndrome was defined based on the recent recommendations of the Pediatric Renal Nutrition Taskforce. Left ventricular hypertrophy was assessed as a risk factor for cardiovascular disease, and estimated glomerular filtration rate was assessed to determine graft function.

RESULTS

The median age of patients was 15.9 (13.8;18.4) years, and the median follow-up time was 35.5 (20.0;62;0) months after transplantation. Nineteen patients (36.5%) were obese or overweight, 43 (83%) had hypertension or controlled hypertension, 23 (44%) had dyslipidemia, and 9 (17%) had hyperglycemia. Ten patients (19.2%) were diagnosed with metabolic syndrome. Twenty-eight patients (54%) had left ventricular hypertrophy. The prevalence of left ventricular hypertrophy was higher in patients with metabolic syndrome than in those without metabolic syndrome (90% vs. 45%, P = .014), whereas estimated glomerular filtration rate did not differ between the 2 groups.

CONCLUSION

Cardiometabolic risk factors are common in pediatric kidney transplant recipients. Approximately one-fifth of patients have metabolic syndrome, and left ventricular hypertrophy is much more common among patients with metabolic syndrome. However, there is no relationship between metabolic syndrome and graft dysfunction.

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".

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.

MATERIALS AND 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.

CONCLUSION

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.