A pragmatic, open-label, randomized controlled trial of Plasma-Lyte-148 versus standard intravenous fluids in children receiving kidney transplants (PLUTO).

Acute electrolyte and acid-base imbalance is experienced by many children following kidney transplant. This is partly because doctors give very large volumes of artificial fluids to keep the new kidney working. When severe, fluid imbalance can lead to seizures, cerebral edema and death. In this pragmatic, open-label, randomized controlled trial, we randomly assigned (1:1) pediatric kidney transplant recipients to Plasma-Lyte-148 or standard of care perioperative intravenous fluids (predominantly 0.45% sodium chloride and 0.9% sodium chloride solutions). We then compared clinically significant electrolyte and acid-base abnormalities in the first 72 hours post-transplant. The primary outcome, acute hyponatremia, was experienced by 53% of 68 participants in the Plasma-Lyte-148 group and 58% of 69 participants in the standard fluids group (odds ratio 0·77 (0·34 - 1·75)). Five of 16 secondary outcomes differed with Plasma-Lyte-148: hypernatremia was significantly more frequent (odds ratio 3·5 (1·1 - 10·8)), significantly fewer changes to fluid prescriptions were made (rate ratio 0·52 (0·40-0·67)), and significantly fewer participants experienced hyperchloremia (odds ratio 0·17 (0·07 - 0·40)), acidosis (odds ratio 0·09 (0·04 - 0·22)) and hypomagnesemia (odds ratio 0·21 (0·08 - 0·50)). No other secondary outcomes differed between groups. Serious adverse events were reported in 9% of participants randomized to Plasma-Lyte-148 and 7% of participants randomized to standard fluids. Thus, perioperative Plasma-Lyte-148 did not change the proportion of children who experienced acute hyponatremia compared to standard fluids. However fewer fluid prescription changes were made with Plasma-Lyte-148, while hyperchloremia and acidosis were less common.

The randomized controlled trial (NAVKIDS2) of a patient navigator program created for children with chronic kidney disease.

Patient navigators enable adult patients to circumnavigate complex health systems, improving access to health care and outcomes. Here, we aimed to evaluate the effects of a patient navigation program in children with chronic kidney disease (CKD). In this multi-center, randomized controlled trial, we randomly assigned children (aged 0-16 years) with CKD stages 1-5 (including children on dialysis or with kidney transplants), from low socioeconomic status backgrounds, and/or residing in remote areas, to receive patient navigation at randomization (immediate) or at six months (waitlist). The primary outcome was self-rated health (SRH) of participating children at six months, using intention to treat analysis. Secondary outcomes included caregivers' SRH and satisfaction with health care, children's quality of life, hospitalizations, and missed school days. Repeated measures of the primary outcome from baseline to six months were analyzed using cumulative logit mixed effects models. Semi-structured interviews were thematically evaluated. Of 398 screened children, 162 were randomized (80 immediate and 82 waitlist); mean age (standard deviation) of 8.8 (4.8) years with 64.8% male. SRH was not significantly different between the immediate and wait-listed groups at six months. There were also no differences across all secondary outcomes between the two groups. Caregivers' perspectives were reflected in seven themes: easing mental strain, facilitating care coordination, strengthening capacity to provide care, reinforcing care collaborations, alleviating family tensions, inability to build rapport and unnecessary support. Thus, in children with CKD, self-rated health may not improve in response to a navigator program, but caregivers gained skills related to providing and accessing care.

Clinical conundrums in pediatric kidney transplantation: What we know about the role of angiotensin II type I receptor antibodies in pediatric kidney transplantation and the path forward.

Antibodies to angiotensin II type 1 receptor (AT1R-Abs) are among the most well-studied non-HLA antibodies in renal transplantation. These antibodies have been shown to be common in pediatric kidney transplantation and associated with antibody-mediated rejection (AMR), vascular inflammation, development of human leukocyte donor-specific antibodies (HLA DSA), and allograft loss. As AT1R-Ab testing becomes more readily accessible, evidence to guide clinical practice for testing and treating AT1R-Ab positivity in pediatric kidney transplant recipients remains limited. This review discusses the clinical complexities of evaluating AT1R-Abs given the current available evidence.

Advances and potential of regenerative medicine in pediatric nephrology.

The endogenous capacity of the kidney to repair is limited, and generation of new nephrons after injury for adequate function recovery remains a need. Discovery of factors that promote the endogenous regenerative capacity of the injured kidney or generation of transplantable kidney tissue represent promising therapeutic strategies. While several encouraging results are obtained after administration of stem or progenitor cells, stem cell secretome, or extracellular vesicles in experimental kidney injury models, very little data exist in the clinical setting to make conclusions about their efficacy. In this review, we provide an overview of the cutting-edge knowledge on kidney regeneration, including pre-clinical methodologies used to elucidate regenerative pathways and describe the perspectives of regenerative medicine for kidney patients.

Fifteen-year temporal changes in rates of acute kidney injury among children in Denmark.

BACKGROUND: We aimed to examine temporal changes in the annual rate of acute kidney injury (AKI) in Danish children and associated changes in patient characteristics including potential underlying risk factors. METHODS: In this population-based cohort study, we used plasma creatinine measurements from Danish laboratory databases to identify AKI episodes in children aged 0-17 years from 2007 to 2021. For each child, the first AKI episode per calendar year was included. We estimated the annual crude and sex- and age-standardized AKI rate as the number of children with an AKI episode divided by the total number of children as reported by census numbers. Using Danish medical databases, we assessed patient characteristics including potential risk factors for AKI, such as use of nephrotoxic medication, surgery, sepsis, and perinatal factors. RESULTS: In total, 14,200 children contributed with 16,345 AKI episodes over 15 years. The mean annual AKI rate was 148 (95% CI: 141-155) per 100,000 children. From 2007 to 2021, the annual AKI rate demonstrated minor year-to-year variability without any discernible overall trend. The highest AKI rate was recorded in 2007 at 174 (95% CI: 161-187) per 100,000 children, while the lowest rate occurred in 2012 at 129 (95% CI: 118-140) per 100,000 children. In 2021, the AKI rate was 148 (95% CI: 141-155) per 100,000 children. Characteristics of children with AKI were similar throughout the study period. CONCLUSION: The rate of AKI among Danish children was stable from 2007 to 2021 with little variation in patient characteristics over time.

Basal knowledge in the field of pediatric nephrology and its enhancement following specific training of ChatGPT-4 "omni" and Gemini 1.5 Flash.

BACKGROUND: We aimed to evaluate the baseline performance and improvement of ChatGPT-4 "omni" (ChatGPT-4o) and Gemini 1.5 Flash (Gemini 1.5) in answering multiple-choice questions related to pediatric nephrology after specific training. METHODS: Using questions from the "Educational Review" articles published by Pediatric Nephrology between January 2014 and April 2024, the models were tested both before and after specific training with Portable Data Format (PDF) and text (TXT) file formats of the Educational Review articles removing the last page containing the correct answers using a Python script. The number of correct answers was recorded. RESULTS: Before training, ChatGPT-4o correctly answered 75.2% of the 1395 questions, outperforming Gemini 1.5, which answered 64.9% correctly (p < 0.001). After training with PDF files, ChatGPT-4o's accuracy increased to 77.8%, while Gemini 1.5 improved significantly to 84.7% (p < 0.001). Training with TXT files showed similar results, with ChatGPT-4o maintaining 77.8% accuracy and Gemini 1.5 further improving to 87.6% (p < 0.001). CONCLUSIONS: The study highlights that while ChatGPT-4o has strong baseline performance, specific training does not significantly enhance its accuracy. Conversely, Gemini 1.5, despite its lower initial performance, shows substantial improvement with training, particularly with TXT files. These findings suggest Gemini 1.5's superior ability to store and retrieve information, making it potentially more effective in clinical applications, albeit with a dependency on additional data for optimal performance.

Acute kidney injury requiring dialysis in children: a multicentric, emerging country perspective.

BACKGROUND: Acute kidney injury (AKI) is a life-threatening condition, especially in extreme age groups and when kidney replacement therapy (KRT) is necessary. Studies worldwide report mortality rates of 10-63% in pediatric patients undergoing KRT. METHODS: Over 13 years, this multicenter study analyzed data from 693 patients with AKI, all receiving KRT, across 74 hospitals and medical facilities in Rio de Janeiro, Brazil. RESULTS: The majority were male (59.5%), under one year old (55.6%), and treated in private hospitals (76.5%). Sixty-six percent had comorbidities. Pneumonia and congenital heart disease were the most common admission diagnoses (21.5% and 20.2%, respectively). The mortality rate was 65.2%, with lower rates in patients over 12 years (50%). Older age was protective (HR: 2.35, IQR [1.52-3.62] for neonates), and primary kidney disease had a three-fold lower mortality rate. ICU team experience (HR: 0.74, IQR [0.60-0.91]) correlated with lower mortality, particularly in hospitals treating 20 or more patients. Among the deceased, 40% died within 48 h of KRT initiation, suggesting possible late referral or treatment futility. CONCLUSIONS: This study confirms the high mortality in pediatric dialytic AKI in middle-income countries, underlining early mortality and offering critical insights for improving outcomes.

Responding to the workforce crisis: consensus recommendations from the Second Workforce Summit of the American Society of Pediatric Nephrology.

IMPORTANCE: Pediatric patients with complex medical problems benefit from pediatric sub-specialty care; however, a significant proportion of children live greater than 80 mi. away from pediatric sub-specialty care. OBJECTIVE: To identify current knowledge gaps and outline concrete next steps to make progress on issues that have persistently challenged the pediatric nephrology workforce. EVIDENCE REVIEW: Workforce Summit 2.0 employed the round table format and methodology for consensus building using adapted Delphi principles. Content domains were identified via input from the ASPN Workforce Committee, the ASPN's 2023 Strategic Plan survey, the ASPN's Pediatric Nephrology Division Directors survey, and ongoing feedback from ASPN members. Working groups met prior to the Summit to conduct an organized literature review and establish key questions to be addressed. The Summit was held in-person in November 2023. During the Summit, work groups presented their preliminary findings, and the at-large group developed the key action statements and future directions. FINDINGS: A holistic appraisal of the effort required to cover inpatient and outpatient sub-specialty care will help define faculty effort and time distribution. Most pediatric nephrologists practice in academic settings, so work beyond clinical care including education, research, advocacy, and administrative/service tasks may form a substantial amount of a faculty member's time and effort. An academic relative value unit (RVU) may assist in creating a more inclusive assessment of their contributions to their academic practice. Pediatric sub-specialties, such as nephrology, contribute to the clinical mission and care of their institutions beyond their direct billable RVUs. Advocacy throughout the field of pediatrics is necessary in order for reimbursement of pediatric sub-specialist care to accurately reflect the time and effort required to address complex care needs. Flexible, individualized training pathways may improve recruitment into sub-specialty fields such as nephrology. CONCLUSIONS AND RELEVANCE: The workforce crisis facing the pediatric nephrology field is echoed throughout many pediatric sub-specialties. Efforts to improve recruitment, retention, and reimbursement are necessary to improve the care delivered to pediatric patients.

Assessing bias in GFR estimating equations: improper GFR stratification can yield misleading results.

BACKGROUND: Assessing bias (estimated - measured) is key to evaluating glomerular filtration rate (GFR). Stratification by subgroups can indicate where equations perform differently. However, there is a fallacy in the assessment of two instruments (e.g., eGFR and mGFR) when stratifying on the level of only one of those instruments. Here, we present statistical aspects of the problem and a solution for GFR stratification along with an empirical investigation using data from the CKiD study. METHODS: Compared and contrasted biases (eGFR relative to mGFR) with 95% confidence intervals within strata of mGFR only, eGFR only, and the average of mGFR and eGFR using data from the Chronic Kidney Disease in Children (CKiD) study. RESULTS: A total of 304 participants contributed 843 GFR studies with a mean mGFR of 48.46 (SD = 22.72) and mean eGFR of 48.67 (SD = 22.32) and correlation of 0.904. Despite strong agreement, eGFR significantly overestimated mGFR when mGFR < 30 (+ 6.2%; 95%CI + 2.9%, + 9.7%) and significantly underestimated when mGFR > 90 (-12.2%; 95%CI - 17.3%, - 7.0%). Significant biases in opposite direction were present when stratifying by eGFR only. In contrast, when stratifying by the average of eGFR and mGFR, biases were not significant (+ 1.3% and - 1.0%, respectively) congruent with strong agreement. CONCLUSIONS: Stratifying by either mGFR or eGFR only to assess eGFR biases is ubiquitous but can lead to inappropriate inference due to intrinsic statistical issues that we characterize and empirically illustrate using data from the CKiD study. Using the average of eGFR and mGFR is recommended for valid inferences in evaluations of eGFR biases.

PHYOX2: a pivotal randomized study of nedosiran in primary hyperoxaluria type 1 or 2.

Nedosiran is an investigational RNA interference agent designed to inhibit expression of hepatic lactate dehydrogenase, the enzyme thought responsible for the terminal step of oxalate synthesis. Oxalate overproduction is the hallmark of all genetic subtypes of primary hyperoxaluria (PH). In this double-blind, placebo-controlled study, we randomly assigned (2:1) 35 participants with PH1 (n = 29) or PH2 (n = 6) with eGFR ≥30 mL/min/1.73 m2 to subcutaneous nedosiran or placebo once monthly for 6 months. The area under the curve (AUC) of percent reduction from baseline in 24-hour urinary oxalate (Uox) excretion (primary endpoint), between day 90-180, was significantly greater with nedosiran vs placebo (least squares mean [SE], +3507 [788] vs -1664 [1190], respectively; difference, 5172; 95% CI 2929-7414; P < 0.001). A greater proportion of participants receiving nedosiran vs placebo achieved normal or near-normal (<0.60 mmol/24 hours; <1.3 × ULN) Uox excretion on ≥2 consecutive visits starting at day 90 (50% vs 0; P = 0.002); this effect was mirrored in the nedosiran-treated PH1 subgroup (64.7% vs 0; P < 0.001). The PH1 subgroup maintained a sustained Uox reduction while on nedosiran, whereas no consistent effect was seen in the PH2 subgroup. Nedosiran-treated participants with PH1 also showed a significant reduction in plasma oxalate versus placebo (P = 0.017). Nedosiran was generally safe and well tolerated. In the nedosiran arm, the incidence of injection-site reactions was 9% (all mild and self-limiting). In conclusion, participants with PH1 receiving nedosiran had clinically meaningful reductions in Uox, the mediator of kidney damage in PH.

Longitudinal assessment of the health-related quality of life of children and adolescents with chronic kidney disease.

In this multi-center longitudinal cohort study conducted in Australia and New Zealand, we assessed the trajectories of health-related quality of life (HRQoL) in children with chronic kidney disease (CKD) over time. A total of 377 children (aged 6-18 years) with CKD stages 1-5 (pre-dialysis), dialysis, or transplant, were followed biennially for four years. Multi Attribute Utility (MAU) scores of HRQoL were measured at baseline and at two and four years using the McMaster Health Utilities Index Mark 3 tool, a generic multi-attribute, preference-based system. A multivariable linear mixed model was used to assess the trajectories of HRQoL over time in 199 children with CKD stage 1-5, 43 children receiving dialysis and 135 kidney transplant recipients. An interaction between CKD stage at baseline and follow-up time indicated that the slopes of the HRQoL scores differed between children by CKD stage at inception. Over half of the cohort on dialysis at baseline had received a kidney transplant by the end of year four and the MAU scores of these children increased by a meaningful amount averaging 0.05 (95% confidence interval 0.01 to 0.09) per year in comparison to those who were transplant recipients at baseline. The mean difference between baseline and year two MAU scores was 0.09 (95% confidence interval -0.05, 0.23), (Cohen's d effect size 0.31). Thus, improvement in HRQoL over time of children on dialysis at baseline was likely to have been driven by their transition from dialysis to transplantation. Additionally, children with CKD stage 1-5 and transplant recipients at baseline had no changes in their disease stage or treatment modality and experienced stable HRQoL over time.

Development of an adaptive clinical web-based prediction tool for kidney replacement therapy in children with chronic kidney disease.

Clinicians need improved prediction models to estimate time to kidney replacement therapy (KRT) for children with chronic kidney disease (CKD). Here, we aimed to develop and validate a prediction tool based on common clinical variables for time to KRT in children using statistical learning methods and design a corresponding online calculator for clinical use. Among 890 children with CKD in the Chronic Kidney Disease in Children (CKiD) study, 172 variables related to sociodemographics, kidney/cardiovascular health, and therapy use, including longitudinal changes over one year were evaluated as candidate predictors in a random survival forest for time to KRT. An elementary model was specified with diagnosis, estimated glomerular filtration rate and proteinuria as predictors and then random survival forest identified nine additional candidate predictors for further evaluation. Best subset selection using these nine additional candidate predictors yielded an enriched model additionally based on blood pressure, change in estimated glomerular filtration rate over one year, anemia, albumin, chloride and bicarbonate. Four additional partially enriched models were constructed for clinical situations with incomplete data. Models performed well in cross-validation, and the elementary model was then externally validated using data from a European pediatric CKD cohort. A corresponding user-friendly online tool was developed for clinicians. Thus, our clinical prediction tool for time to KRT in children was developed in a large, representative pediatric CKD cohort with an exhaustive evaluation of potential predictors and supervised statistical learning methods. While our models performed well internally and externally, further external validation of enriched models is needed.

Blood Pressure Classification Status in Children With CKD Following Adoption of the 2017 American Academy of Pediatrics Guideline.

RATIONALE & OBJECTIVE: Accurate detection of hypertension is crucial for clinical management of pediatric chronic kidney disease (CKD). The 2017 American Academy of Pediatrics (AAP) clinical practice guideline for childhood hypertension included new normative blood pressure (BP) values and revised definitions of BP categories. In this study, we examined the effect of applying the AAP guideline's normative data and definitions to the Chronic Kidney Disease in Children (CKiD) cohort compared with use of normative data and definitions from the 2004 Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: Children and adolescents in the CKiD cohort. EXPOSURE: Clinic BP measurements. OUTCOME: BP percentiles and hypertension stages calculated using the 2017 AAP guideline and the Fourth Report from 2004. ANALYTICAL APPROACH: Agreement analysis compared the estimated percentile and prevalence of high BP based on the 2017 guideline and 2004 report to clinic and combined ambulatory BP readings. RESULTS: The proportion of children classified as having normal clinic BP was similar using the 2017 and 2004 systems, but the use of the 2017 normative data classified more participants as having stages 1-2 hypertension (22% vs 11%), with marginal reproducibility (κ=0.569 [95% CI, 0.538-0.599]). Those identified as having stage 2 hypertension by the 2017 guideline had higher levels of proteinuria compared with those identified using the 2004 report. Comparing use of the 2017 guideline and the 2004 report in terms of ambulatory BP monitoring categories, there were substantially more participants with white coat (3.5% vs 1.5%) and ambulatory (15.5% vs 7.9%) hypertension, but the proportion with masked hypertension was lower (40.2% vs 47.8%, respectively), and the percentage of participants who were normotensive was similar (40.9% vs 42.9%, respectively). Overall, there was good reproducibility (κ=0.799 [95% CI, 0.778-0.819]) of classification by ambulatory BP monitoring. LIMITATIONS: Relationship with long-term progression and target organ damage was not assessed. CONCLUSIONS: A greater percentage of children with CKD were identified as having hypertension based on both clinic and ambulatory BP when using the 2017 AAP guideline versus the Fourth Report from 2004, and the 2017 guideline better discriminated those with higher levels of proteinuria. The substantial differences in the classification of hypertension when using the 2017 guideline should inform clinical care.

Improving Clinical Care for Children With CKD: A Report From a National Kidney Foundation Scientific Workshop.

Development of clinical guidelines and recommendations to address the care of pediatric patients with chronic kidney disease (CKD) has rarely included the perspectives of providers from a variety of health care disciplines or the patients and parents themselves. Accordingly, the National Kidney Foundation hosted an in-person, one and a half-day workshop that convened a multidisciplinary group of physicians, allied health care professionals, and pediatric patients with CKD and their parents, with the goal of developing key clinical recommendations regarding best practices for the clinical management of pediatric patients living with CKD. The key clinical recommendations pertained to 5 broad topics: addressing the needs of patients and parents/caregivers; modifying the progression of CKD; clinical management of CKD-mineral and bone disorder and growth retardation; clinical management of anemia, cardiovascular disease, and hypertension; and transition and transfer of pediatric patients to adult nephrology care. This report describes the recommendations generated by the participants who attended the workshop.

Humoral immune response and live-virus neutralization of the SARS-CoV-2 omicron (BA.1) variant after COVID-19 mRNA vaccination in children and young adults with chronic kidney disease.

BACKGROUND: Data on humoral immune response to standard COVID-19 vaccination are scarce in adolescent patients and lacking for children below 12 years of age with chronic kidney disease including kidney transplant recipients. METHODS: We therefore investigated in this retrospective two-center study (DRKS00024668; registered 23.03.2021) the humoral immune response to a standard two-dose mRNA vaccine regimen in 123 CKD patients aged 5-30 years. A live-virus assay was used to assess the serum neutralizing activity against the SARS-CoV-2 omicron (BA.1) variant. RESULTS: Children aged 5-11 years had a comparable rate and degree of immune response to adolescents despite lower vaccine doses (10 µg vs. 30 µg BNT162b2). Treatment with two (odds ratio 9.24) or three or more (odds ratio 17.07) immunosuppressants was an independent risk factor for nonresponse. The immune response differed significantly among three patient cohorts: 48 of 77 (62.3%) kidney transplant recipients, 21 of 26 (80.8%) patients on immunosuppressive therapy, and 19 of 20 (95.0%) patients with chronic kidney disease without immunosuppressive therapy responded. In the kidney transplant recipients, immunosuppressive regimens comprising mycophenolate mofetil, an eGFR of < 60 mL/min/1.73 m2, and female sex were independent risk factors for nonresponse. Two of 18 (11.1%) and 8 of 16 (50.0%) patients with an anti-S1-RBD IgG of 100-1411 and > 1411 BAU/mL, respectively, showed a neutralization activity against the omicron variant. CONCLUSION: A standard mRNA vaccine regimen in immunosuppressed children and adolescents with kidney disease elicits an attenuated humoral immune response with effective live virus neutralization against the omicron variant in approximately 10% of the patients, underlying the need for omicron-adapted vaccination. A higher resolution version of the Graphical abstract is available as Supplementary information.

Longitudinal changes of health-related quality of life in childhood chronic kidney disease.

BACKGROUND: Few longitudinal studies have evaluated the impact of chronic kidney disease (CKD) duration on health-related quality of life (HRQOL). The study's aim was to determine how HRQOL changes over time in childhood CKD. METHODS: Study participants were children in the chronic kidney disease in children (CKiD) cohort who completed the pediatric quality of life inventory (PedsQL) on three or more occasions over the course of two or more years. Generalized gamma (GG) mixed-effects models were applied to assess the effect of CKD duration on HRQOL while controlling for selected covariates. RESULTS: A total of 692 children (median age = 11.2) with a median of 8.3 years duration of CKD were evaluated. All subjects had a GFR greater than 15 ml/min/1.73 m2. GG models with child self-report PedsQL data indicated that longer CKD duration was associated with improved total HRQOL and the 4 domains of HRQOL. GG models with parent-proxy PedsQL data indicated that longer duration was associated with better emotional but worse school HRQOL. Increasing trajectories of child self-report HRQOL were observed in the majority of subjects, while parents less frequently reported increasing trajectories of HRQOL. There was no significant relationship between total HRQOL and time-varying GFR. CONCLUSIONS: Longer duration of the disease is associated with improved HRQOL on child self-report scales; however, parent-proxy results were less likely to demonstrate any significant change over time. This divergence could be due to greater optimism and accommodation of CKD in children. Clinicians can use these data to better understand the needs of pediatric CKD patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

Lessons learned from regional training of paediatric nephrology fellows in Africa.

BACKGROUND: Access to care for children with kidney disease is limited in less well-resourced regions of the world and paediatric nephrology (PN) workforce development with good practical skills is critical. METHODS: Retrospective review of a PN training program and trainee feedback from 1999 to 2021, based at Red Cross War Memorial Children's Hospital (RCWMCH), University of Cape Town. RESULTS: A regionally appropriate 1-2-year training program enrolled 38 fellows with an initial 100% return rate to their country of origin. Program funding included fellowships from the International Pediatric Nephrology Association (IPNA), International Society of Nephrology (ISN), International Society of Peritoneal Dialysis (ISPD), and the African Paediatric Fellowship Program (APFP). Fellows were trained on both in- and out-patient management of infants and children with kidney disorders. "Hands-on skills" training included examination, diagnosis and management skills, practical insertion of peritoneal dialysis catheters for management of acute kidney injury and kidney biopsies. Of 16 trainees who completed > 1 year of training, 14 (88%) successfully completed subspecialty exams and 9 (56%) completed a master's degree with a research component. PN fellows reported that their training was appropriate and enabled them to make a difference in their respective communities. CONCLUSIONS: This training program has successfully equipped African physicians with the requisite knowledge and skills to provide PN services in resource-constrained areas for children with kidney disease. The provision of funding from multiple organizations committed to paediatric kidney disease has contributed to the success of the program, along with the fellows' commitment to build PN healthcare capacity in Africa. A higher resolution version of the Graphical abstract is available as Supplementary information.

NSAID-associated acute kidney injury in hospitalized children - a prospective Pediatric Nephrology Research Consortium study.

BACKGROUND: Acute kidney injury (AKI) in children has serious short-term and long-term consequences. We sought 1) to prospectively describe NSAID-associated AKI in hospitalized children; 2) to determine if NSAID-associated AKI was more severe in younger children < 5 years; and 3) to follow outcomes after hospitalization for NSAID-associated AKI. METHODS: This was a prospective, multi-center study in hospitalized children 1 month to 18 years. Parents/guardians were given a brief questionnaire to determine the dosing, duration, and type of NSAIDs given. Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria were used to stage AKI severity. Patients with other causes of AKI were excluded (e.g., other nephrotoxins, sepsis, malignancy, etc.). RESULTS: We identified 25 patients with NSAID-associated AKI, accounting for 3.1% of AKI. All 25 had AKI upon hospital presentation. The median age was 15.5 years, and 20/25 (80%) had volume depletion. Median duration of NSAID use was 2 days, and 63% of patients took the normal recommended NSAID dose. Median hospital length of stay was 4 days, and none required dialysis. At the most recent estimated glomerular filtration rate (eGFR) after discharge (available in 17/25 patients), only 4/17 (24%) had eGFR ≥ 90 ml/min/1.73 m2, and 13/17 (76%) had eGFR 60 to < 90 ml/min/1.73 m2, indicative of abnormal kidney function. CONCLUSIONS: NSAID-associated AKI usually occurs with recommended NSAID dosing in the setting of dehydration. Follow-up after AKI showed a substantial rate of CKD. Therefore, we recommend that NSAIDs should not be used in dehydrated children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Using Machine Learning to Identify Metabolomic Signatures of Pediatric Chronic Kidney Disease Etiology.

BACKGROUND: Untargeted plasma metabolomic profiling combined with machine learning (ML) may lead to discovery of metabolic profiles that inform our understanding of pediatric CKD causes. We sought to identify metabolomic signatures in pediatric CKD based on diagnosis: FSGS, obstructive uropathy (OU), aplasia/dysplasia/hypoplasia (A/D/H), and reflux nephropathy (RN). METHODS: Untargeted metabolomic quantification (GC-MS/LC-MS, Metabolon) was performed on plasma from 702 Chronic Kidney Disease in Children study participants (n: FSGS=63, OU=122, A/D/H=109, and RN=86). Lasso regression was used for feature selection, adjusting for clinical covariates. Four methods were then applied to stratify significance: logistic regression, support vector machine, random forest, and extreme gradient boosting. ML training was performed on 80% total cohort subsets and validated on 20% holdout subsets. Important features were selected based on being significant in at least two of the four modeling approaches. We additionally performed pathway enrichment analysis to identify metabolic subpathways associated with CKD cause. RESULTS: ML models were evaluated on holdout subsets with receiver-operator and precision-recall area-under-the-curve, F1 score, and Matthews correlation coefficient. ML models outperformed no-skill prediction. Metabolomic profiles were identified based on cause. FSGS was associated with the sphingomyelin-ceramide axis. FSGS was also associated with individual plasmalogen metabolites and the subpathway. OU was associated with gut microbiome-derived histidine metabolites. CONCLUSION: ML models identified metabolomic signatures based on CKD cause. Using ML techniques in conjunction with traditional biostatistics, we demonstrated that sphingomyelin-ceramide and plasmalogen dysmetabolism are associated with FSGS and that gut microbiome-derived histidine metabolites are associated with OU.

Inflammation in Children with CKD Linked to Gut Dysbiosis and Metabolite Imbalance.

BACKGROUND: CKD is characterized by a sustained proinflammatory response of the immune system, promoting hypertension and cardiovascular disease. The underlying mechanisms are incompletely understood but may be linked to gut dysbiosis. Dysbiosis has been described in adults with CKD; however, comorbidities limit CKD-specific conclusions. METHODS: We analyzed the fecal microbiome, metabolites, and immune phenotypes in 48 children (with normal kidney function, CKD stage G3-G4, G5 treated by hemodialysis [HD], or kidney transplantation) with a mean±SD age of 10.6±3.8 years. RESULTS: Serum TNF-α and sCD14 were stage-dependently elevated, indicating inflammation, gut barrier dysfunction, and endotoxemia. We observed compositional and functional alterations of the microbiome, including diminished production of short-chain fatty acids. Plasma metabolite analysis revealed a stage-dependent increase of tryptophan metabolites of bacterial origin. Serum from patients on HD activated the aryl hydrocarbon receptor and stimulated TNF-α production in monocytes, corresponding to a proinflammatory shift from classic to nonclassic and intermediate monocytes. Unsupervised analysis of T cells revealed a loss of mucosa-associated invariant T (MAIT) cells and regulatory T cell subtypes in patients on HD. CONCLUSIONS: Gut barrier dysfunction and microbial metabolite imbalance apparently mediate the proinflammatory immune phenotype, thereby driving the susceptibility to cardiovascular disease. The data highlight the importance of the microbiota-immune axis in CKD, irrespective of confounding comorbidities.