Pediatric Nephrology最新文献

Background: In patients with steroid-resistant nephrotic syndrome (SRNS), the presence of monogenic variants influences therapeutic strategies. Large cohort studies reported the detection of monogenic variants in approximately 30% of patients with SRNS. However, these cohorts included many patients, such as those with symptomatic proteinuria, who did not meet the strict diagnostic criteria for pediatric nephrotic syndrome (NS). Therefore, we investigated the proportion of causative monogenic variants detected in patients who strictly met the diagnostic criteria of SRNS and explored their clinical characteristics.

Methods: We examined pediatric SRNS cases with genetic analysis conducted in our hospital. Cases satisfying all of the following criteria were included: (1) age at onset 1-18 years, (2) serum albumin at onset ≤ 2.5 g/dl, (3) persistent heavy proteinuria, and (4) no complete remission after 4 weeks of steroid monotherapy.

Results: The proportion of detected monogenic variants was 12% (22/185) among all patients. The proportion was only 7% (9/129) in patients with edema at disease onset compared with 38% (9/24) in those without (p < 0.0001). Monogenic variants were rare in patients with acute kidney injury associated with NS (1% (1/11)) or a history of complete remission (4% (2/51)).

Conclusions: Our study revealed a monogenic cause in 12% of individuals with strictly defined SRNS, a much smaller proportion than previously reported. The presence or absence of edema at the onset was an important factor to distinguish SRNS with monogenic cause from SRNS without. Our results provide further evidence of the SRNS types attributable to monogenic causes.

Background: Access to pediatric dialysis is challenged in low-resource settings due to high costs, scarcity of equipment, and the lack of qualified personnel availability. We demonstrated the manual single lumen alternating micro-batch (mSLAMB) device can remove small solutes in vitro without the need for electricity, batteries, or pumps. We developed a new version (Kirpa Kit™) to address some of the technical limitations of mSLAMB. Here, we compare the in vitro clearance performance and ease of use of the Kirpa Kit™ with that of prior mSLAMB configurations.

Methods: A mixture of expired packed red blood cells, 0.9% NaCl, urea, and heparin was used to test the efficiency of two mSLAMB configurations and the Kirpa Kit™ in removing potassium and urea. Clearance was evaluated by measuring percent reduction after 25-min sessions with each device. A survey was used to evaluate the ease of use of each configuration.

Results: The Kirpa Kit™ achieved a median urea reduction of 82.4% and potassium reduction of 82.1%, which were higher than those achieved with the best-performing mSLAMB configuration (urea 71.9%, potassium 75.4%). The Kirpa Kit™ was easier to use with a shorter perceived time of use than the mSLAMB.

Conclusions: The Kirpa Kit™, evolution of mSLAMB, is easy to use and may have improved efficacy, making it an optimal candidate for in vivo testing.

Background: Nephronophthisis (NPH) comprises a heterogeneous group of inherited renal ciliopathies clinically characterized by progressive kidney failure. So far, definite diagnosis is based on molecular testing only. Here, we studied the feasibility of NPHP1 and NPHP4 immunostaining of nasal epithelial cells to secure and accelerate the diagnosis of NPH.

Methods: Samples of 86 individuals with genetically determined renal ciliopathies were analyzed for NPHP1 localization using immunofluorescence microscopy (IF). A sub-cohort of 35 individuals was also analyzed for NPHP4 localization. Western blotting was performed to confirm IF results.

Results: NPHP1 and NPHP4 were both absent in all individuals with disease-causing NPHP1 variants including one with a homozygous missense variant (c.1027G > A; p.Gly343Arg) formerly classified as a "variant of unknown significance." In individuals with an NPHP4 genotype, we observed a complete absence of NPHP4 while NPHP1 was severely reduced. IF results were confirmed by immunoblotting. Variants in other genes related to renal ciliopathies did not show any impact on NPHP1/NPHP4 expression. Aberrant immunostaining in two genetically unsolved individuals gave rise for a further genetic workup resulting in a genetic diagnosis for both with disease-causing variants in NPHP1 and NPHP4, respectively.

Conclusions: IF of patient-derived respiratory epithelial cells may help to secure and accelerate the diagnosis of nephronophthisis-both by verifying inconclusive genetic results and by stratifying genetic diagnostic approaches. Furthermore, we provide in vivo evidence for the interaction of NPHP1 and NPHP4 in a functional module.

Background: Cardiac surgery associated acute kidney injury (CS-AKI) is common. Urine response to loop diuretic and urine neutrophil gelatinase associated lipocalin (uNGAL) are separately associated with CS-AKI. We aimed to determine whether urine response to loop diuretic and uNGAL together were associated with postoperative day 2-4 CS-AKI.

Methods: Two-center prospective observational study (ages 0-18 years). uNGAL (8-12 h after admission) (ng/mL) and urine response to loop diuretic (6 h for bolus furosemide and 12 h for infusion bumetanide) (mL/kg/hr) were measured. All diuretic doses were converted to furosemide equivalents. The primary outcome was day 2-4 CS-AKI. Patients were sub-phenotyped using a priori cutoffs (uNGAL +  ≥ 100 ng/mL and UOP +  < 1.5 mL/kg/hr) and optimal cutoffs (uNGAL +  ≥ 127 ng/mL and UOP +  ≤ 0.79 mL/kg/hr): 1) uNGAL-/UOP-, 2) uNGAL-/UOP + , 3) uNGAL + /UOP-, and 4) uNGAL + /UOP + . Multivariable regression was used to assess the association of uNGAL, UOP and each sub-phenotype with outcomes.

Results: 476 patients were included. CS-AKI occurred in 52 (10.9%). uNGAL was associated with 2.59-fold greater odds (95%CI: 1.52-4.41) of CS-AKI. UOP was not associated with CS-AKI. Compared with uNGAL + alone, uNGAL + /UOP + improved prediction of CS-AKI using a priori and optimal cutoffs respectively (AUC 0.70 vs. 0.75). Both uNGAL + /UOP + (IQR OR:4.63, 95%CI: 1.74-12.32) and uNGAL + /UOP- (IQR OR:5.94, 95%CI: 2.09-16.84) were associated with CS-AKI when compared with uNGAL-/UOP-.

Conclusions: uNGAL is associated with CS-AKI. The sub-phenotype association was largely driven by uNGAL. Future studies standardizing diuretic dose and timing may be needed to refine the combined performance for clinical decision making.

A 6-month-old girl, previously diagnosed with cystic fibrosis (CF), was admitted to hospital for nephrolithiasis. Her parents were first-degree cousins. The patient underwent endoscopic stone management. Despite no family history of stones and medical treatment with potassium citrate, the patient developed recurrent renal stones and atypical urinary tract infections during follow-up. Basic investigations were all normal. Due to consanguinity and early presentation of nephrolithiasis, metabolic causes such as cystinuria and hyperoxaluria were considered. Cystinuria was excluded due to normal cystine levels. High urinary oxalate excretion was found as expected due to absorptive (secondary) hyperoxaluria in CF patients. An early stone burden in the patient with a history of medical treatment and consanguinity led us to perform a genetic testing. Genetic testing revealed a missense homozygous variant in exon 1 of the AGXT gene. The patient was diagnosed with primary hyperoxaluria type 1. Two rare life-threatening genetic diseases were found together in the same child.

There is no specific treatment for proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID), a disease that is very rare in the pediatric population. We report the case of a 15-year-old boy who presented with mildly reduced kidney function and nephrotic syndrome. Kidney biopsy revealed PGNMID with monoclonal deposits of IgG3 with kappa light chain restriction. Flow cytometry showed a significant CD38 plasma cell population in the peripheral blood in the absence of other signs of hematological malignancy. The patient was treated with a 6-month course of daratumumab, a monoclonal antibody targeting CD38. There was a significant reduction in proteinuria and normalization of kidney function. Based on positive experience with adults, daratumumab should also be studied in children with PGNMID.

Background: Social media platforms such as TikTok™ are key sources of health information for young patients and caregivers. Misinformation is prevalent on TikTok™ across healthcare fields, which can perpetuate false beliefs about medical care. Limited data exists on the reliability of pediatric nephrology TikTok™ content. This study aimed to describe the quality of medical content of TikTok™ Videos (TTVs), related to pediatric kidney disease and transplant.

Methods: TTVs were selected using specific search terms and categorized into pediatric kidney disease and kidney transplant, excluding duplicate and adult-related content. The top 100 TTVs in each category, based on views, were analyzed. TTV characteristics were stratified by account type (physician, non-physician healthcare professional (HCP), non-HCP) and video aim (personal story, education, entertainment). DISCERN scoring, a validated questionnaire evaluating health information reliability, was conducted by 4 independent raters. Inter-rater reliability was assessed using a 2-way random effects model, and differences between content creator types were evaluated using one-way ANOVA and post-Hoc Tukey test.

Results: TTVs had a total of 12.5 million likes and 113.1 million views. Over 70% of videos were created by non-HCPs (n = 147/200). DISCERN scoring revealed low reliability of medical information across content creator types. TTVs created by physicians and non-physician HCPs about kidney disease had significantly higher mean DISCERN scores compared to those created by non-HCPs (2.85, p < 0.001 and 2.48, p = 0.005, respectively).

Conclusions: Educators within the pediatric nephrology community must keep in mind the lack of reliability of medical information available on TikTok™ and coordinate collective efforts to consider utilizing TikTok™ for patient education.

Phosphate is essential for numerous biological processes, and serum levels are tightly regulated to accomplish these functions. The regulation of serum phosphate in a narrow physiological range is a well-orchestrated process and involves the gastrointestinal (GI) tract, bone, kidneys, and several hormones, namely, parathyroid hormone, fibroblast growth factor 23 (FGF23), and 1,25-dihydroxyvitamin D (1,25 Vitamin D). Although primarily synthesized in the bone, FGF23, an endocrine FGF, acts on the kidney to regulate phosphate and Vitamin D homeostasis by causing phosphaturia and reduced levels of 1,25 Vitamin D. Recent studies have highlighted the complex regulation of FGF23 including transcriptional and post-translational modification and kidney-bone cross talk. Understanding FGF23 biology has led to the identification of novel therapeutic agents to treat diseases that disrupt phosphate metabolism secondary to FGF23. The focus of this review is to provide an overview of phosphate homeostasis, FGF23 biology, and the role of FGF23 in phosphate balance.