Advances in pediatric acute kidney injury pathobiology: a report from the 26th Acute Disease Quality Initiative (ADQI) conference.

BACKGROUND: In the past decade, there have been substantial advances in our understanding of the pathobiology of pediatric acute kidney injury (AKI). In particular, animal models and studies focused on the relationship between kidney development, nephron number, and kidney health have identified a number of heterogeneous pathophysiologies underlying AKI. Despite this progress, gaps remain in our understanding of the pathobiology of pediatric AKI. METHODS: During the 26th Acute Disease Quality Initiative (ADQI) Consensus conference, a multidisciplinary group of experts discussed the evidence and used a modified Delphi process to achieve consensus on recommendations for opportunities to advance translational research in pediatric AKI. The current state of research understanding as well as gaps and opportunities for advancement in research was discussed, and recommendations were summarized. RESULTS: Consensus was reached that to improve translational pediatric AKI advancements, diverse teams spanning pre-clinical to epidemiological scientists must work in concert together and that results must be shared with the community we serve with patient involvement. Public and private research support and meaningful partnerships with adult research efforts are required. Particular focus is warranted to investigate the pediatric nuances of AKI, including the effect of development as a biological variable on AKI incidence, severity, and outcomes. CONCLUSIONS: Although AKI is common and associated with significant morbidity, the biologic basis of the disease spectrum throughout varying nephron developmental stages remains poorly understood. An incomplete understanding of factors contributing to kidney health, the diverse pathobiologies underlying AKI in children, and the historically siloed approach to research limit advances in the field. The recommendations outlined herein identify gaps and outline a strategic approach to advance the field of pediatric AKI via multidisciplinary translational research.

Advances in pediatric acute kidney injury pharmacology and nutrition: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference.

BACKGROUND: In the past decade, there have been substantial advances in our understanding of pediatric AKI. Despite this progress, large gaps remain in our understanding of pharmacology and nutritional therapy in pediatric AKI. METHODS: During the 26th Acute Disease Quality Initiative (ADQI) Consensus Conference, a multidisciplinary group of experts reviewed the evidence and used a modified Delphi process to achieve consensus on recommendations for gaps and advances in care for pharmacologic and nutritional management of pediatric AKI. The current evidence as well as gaps and opportunities were discussed, and recommendations were summarized. RESULTS: Two consensus statements were developed. (1) High-value, kidney-eliminated medications should be selected for a detailed characterization of their pharmacokinetics, pharmacodynamics, and pharmaco-"omics" in sick children across the developmental continuum. This will allow for the optimization of real-time modeling with the goal of improving patient care. Nephrotoxin stewardship will be identified as an organizational priority and supported with necessary resources and infrastructure. (2) Patient-centered outcomes (functional status, quality of life, and optimal growth and development) must drive targeted nutritional interventions to optimize short- and long-term nutrition. Measures of acute and chronic changes of anthropometrics, body composition, physical function, and metabolic control should be incorporated into nutritional assessments. CONCLUSIONS: Neonates and children have unique metabolic and growth parameters compared to adult patients. Strategic investments in multidisciplinary translational research efforts are required to fill the knowledge gaps in nutritional requirements and pharmacological best practices for children with or at risk for AKI.

Neonatal hypoxic ischemic encephalopathy increases acute kidney injury urinary biomarkers in a rat model.

Hypoxic ischemic encephalopathy (HIE) is associated with acute kidney injury (AKI) in neonates with birth asphyxia. This study aimed to utilize urinary biomarkers to characterize AKI in an established neonatal rat model of HIE. Day 7 Sprague-Dawley rat pups underwent HIE using the Rice-Vannucci model (unilateral carotid ligation followed by 120 mins of 8% oxygen). Controls included no surgery and sham surgery. Weights and urine for biomarkers (NGAL, osteopontin, KIM-1, albumin) were collected the day prior, daily for 3 days post-intervention, and at sacrifice day 14. Kidneys and brains were processed for histology. HIE pups displayed histological evidence of kidney injury including damage to the proximal tubules, consistent with resolving acute tubular necrosis, and had significantly elevated urinary levels of NGAL and albumin compared to sham or controls 1-day post-insult that elevated for 3 days. KIM-1 significantly increased for 2 days post-HIE. HIE did not significantly alter osteopontin levels. Seven days post-start of experiment, controls were 81.2% above starting weight compared to 52.1% in HIE pups. NGAL and albumin levels inversely correlated with body weight following HIE injury. The AKI produced by the Rice-Vannucci HIE model is detectable by urinary biomarkers, which can be used for future studies of treatments to reduce kidney injury.

Consensus-Based Recommendations on Priority Activities to Address Acute Kidney Injury in Children: A Modified Delphi Consensus Statement.

Importance: Increasing evidence indicates that acute kidney injury (AKI) occurs frequently in children and young adults and is associated with poor short-term and long-term outcomes. Guidance is required to focus efforts related to expansion of pediatric AKI knowledge. Objective: To develop expert-driven pediatric specific recommendations on needed AKI research, education, practice, and advocacy. Evidence Review: At the 26th Acute Disease Quality Initiative meeting conducted in November 2021 by 47 multiprofessional international experts in general pediatrics, nephrology, and critical care, the panel focused on 6 areas: (1) epidemiology; (2) diagnostics; (3) fluid overload; (4) kidney support therapies; (5) biology, pharmacology, and nutrition; and (6) education and advocacy. An objective scientific review and distillation of literature through September 2021 was performed of (1) epidemiology, (2) risk assessment and diagnosis, (3) fluid assessment, (4) kidney support and extracorporeal therapies, (5) pathobiology, nutrition, and pharmacology, and (6) education and advocacy. Using an established modified Delphi process based on existing data, workgroups derived consensus statements with recommendations. Findings: The meeting developed 12 consensus statements and 29 research recommendations. Principal suggestions were to address gaps of knowledge by including data from varying socioeconomic groups, broadening definition of AKI phenotypes, adjudicating fluid balance by disease severity, integrating biopathology of child growth and development, and partnering with families and communities in AKI advocacy. Conclusions and Relevance: Existing evidence across observational study supports further efforts to increase knowledge related to AKI in childhood. Significant gaps of knowledge may be addressed by focused efforts.

Global and Regional White Matter Fractional Anisotropy in Children with Chronic Kidney Disease.

OBJECTIVE: To investigate the associations between neurocognition and white matter integrity in children with chronic kidney disease (CKD). STUDY DESIGN: This cross-sectional study included 17 boys (age 6-16 years) with a diagnosis of mild to moderate (stages 1-3, nondialysis/nontransplant) CKD because of congenital anomalies of the kidney and urinary tract and 20 typically developing community controls. Participants underwent 3T neuroimaging and diffusion-weighted magnetic resonance imaging to assess white matter fractional anisotropy. Multivariable linear regression models were used to evaluate the impact of each group (controls vs CKD) on white matter fractional anisotropy, adjusting for age. Associations between white matter fractional anisotropy and neurocognitive abilities within the CKD group were also evaluated using regression models that were adjusted for age. The false discovery rate was used to account for multiple comparisons; wherein false discovery values <0.10 were considered significant. RESULTS: Global white matter fractional anisotropy was reduced in patients with CKD relative to controls (standardized estimate = -0.38, 95% CI -0.69:-0.07), driven by reductions within the body of the corpus callosum (standardized estimate = -0.44, 95% CI -0.75:-0.13), cerebral peduncle (SE = -0.37, 95% CI -0.67:-0.07), cingulum (hippocampus) (standardized estimate = -0.45, 95% CI -0.75:-0.14), and posterior limb of the internal capsule (standardized estimate = -0.46, 95% CI -0.76:-0.15). Medical variables and neurocognitive abilities were not significantly associated with white matter fractional anisotropy. CONCLUSIONS: White matter development is vulnerable in children with CKD because of congenital causes, even prior to the need for dialysis or transplantation.

Severe Acute Kidney Injury and Mortality in Extremely Low Gestational Age Neonates.

BACKGROUND AND OBJECTIVES: AKI is associated with poor short- and long-term outcomes. Questions remain about the frequency and timing of AKI, and whether AKI is a cause of death in extremely low gestational age neonates. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Recombinant Erythropoietin for Protection of Infant Kidney Disease Study examines the kidney outcomes of extremely low gestational age neonates enrolled in the Preterm Epo Neuroprotection study, a randomized, placebo-controlled trial of recombinant human erythropoietin. We included 900 of 941 patients enrolled in Preterm Epo Neuroprotection. Baseline characteristics were compared by primary exposure (severe AKI versus none/stage 1 AKI) using unadjusted logistic regression models. Cox regression models estimated the relationship between severe AKI and death after adjustment for potential confounders. Time-dependent AKI was modeled as a binary outcome and a categorical variable by stage of AKI. We fit Cox models using time-dependent AKI status lagged by <7 days before death. Landmark analyses examined the relationship of death with development of severe AKI. RESULTS: Severe AKI occurred in 168 of 900 (19%, 95% confidence interval, 17% to 20%) neonates, and stage 3 AKI occurred in 60 (7%, 95% confidence interval, 5% to 8%). Stage 3 AKI occurring 7 days before death (hazard ratio, 3.88; 95% confidence interval, 1.26 to 11.96), intraventricular hemorrhage (hazard ratio, 2.01; 95% confidence interval, 1.01 to 3.99) and sepsis (hazard ratio, 2.85; 95% confidence interval, 1.12 to 7.22) were all independently associated with death. Severe AKI occurring 7 days before death (hazard ratio, 2.21; 95% confidence interval, 0.92 to 5.26) was associated with death but not statistically significant. In a landmark analysis, after adjusting for potential confounders, late (after day 14 and before day 28) severe AKI was strongly associated with higher hazard of death (hazard ratio, 4.57; 95% confidence interval, 1.82 to 11.5). CONCLUSIONS: Severe AKI occurs frequently in extremely low gestational age neonates. Stage 3 AKI is associated with mortality, and this association is present 7 days before death.

Case Report: Novel Dietary Supplementation Associated With Kidney Recovery and Reduction in Proteinuria in a Dialysis Dependent Patient Secondary to Steroid Resistant Minimal Change Disease.

Minimal change disease (MCD) is the most common cause of nephrotic syndrome worldwide. For decades, the foundation of the treatment has been corticosteroids. However, relapse rate is high and up to 40% of patients develop frequent relapsing/steroid dependent course and one third become steroid resistant. This requires treatment with repeated courses of corticosteroids, and second and third line immunomodulators increasing the incidence of drug related adverse effects. More recently, there have been reports of a very small subset of Nephrotic Syndrome (NS) patients who are initially steroid sensitive and later become secondarily steroid resistant. The disease course in this small subset is often protracted leading ultimately to end stage kidney disease requiring dialysis or kidney transplantation. Unfortunately, patients with this disease course do not do well post transplantation because 80% of them will develop disease recurrence that will ultimately lead to graft failure. Few approaches have been tried over many years to reduce the frequency of relapses, and steroid dependence and there is absolutely no therapeutic intervention for patients who develop secondary steroid resistance. Nonetheless, their therapeutic index is low, evidencing the need of a safer complementary treatment. Several hypotheses, including an oxidative stress-mediated mechanism, and immune dysregulation have been proposed to date to explain the underlying mechanism of Minimal Change Disease (MCD) but its specific etiology remains elusive. Here, we report a case of a 54-year-old man with steroid and cyclosporine resistant MCD. The patient rapidly progressed to end stage kidney disease requiring initiation of chronic dialysis. Intradialytic parenteral nutrition (IDPN), albumin infusion along with a proprietary dietary supplement, as part of the supportive therapy, led to kidney function recovery and complete remission of MCD without relapses.

Early pediatric chronic kidney disease is associated with brain volumetric gray matter abnormalities.

BACKGROUND: The impact of pediatric chronic kidney disease (pCKD) on the brain remains poorly defined. The objective of this study was to compare brain morphometry between children with early-stage pCKD and typically developing peers using structural magnetic resonance imaging (MRI). METHODS: The sample age range was 6-16 years. A total of 18 children with a diagnosis of pCKD (CKD stages 1-3) due to congenital anomalies of the kidney and urinary tract and 24 typically developing peers were included. Volumetric data from MRI and neurocognitive testing were compared using linear models including pCKD status, age, maternal education level, and socioeconomic status. RESULTS: Cerebellar gray matter volume was significantly smaller in pCKD, t(38) = -2.71, p = 0.01. In contrast, cerebral gray matter volume was increased in pCKD, t(38) = 2.08, p = 0.04. Reduced cerebellum gray matter volume was associated with disease severity, operationalized as estimated glomerular filtration rate (eGFR), t(14) = 2.21, p = 0.04 and predicted lower verbal fluency scores in the pCKD sample. Enlarged cerebral gray matter in the pCKD sample predicted lower scores on mathematics assessment. CONCLUSIONS: This study provides preliminary evidence for a morphometric underpinning to the cognitive deficits observed in pCKD. IMPACT: The impact of pediatric chronic kidney disease (CKD) on the brain remains poorly defined, with no data linking brain morphometry and observed cognitive deficits noted in this population. We explored the relationship between brain morphometry (using structural magnetic resonance imaging), cognition, and markers of CKD. Cerebellar and cerebral gray matter volumes are different in early CKD. Volumetric decreases in cerebellar gray matter are predicted by lower eGFR, suggesting a link between disease and brain morphometry. Reduced cerebellar gray matter predicted lower verbal fluency for those with pCKD. Enlarged cerebral gray matter in the pCKD sample predicted lower mathematics performance.

A prospective multi-center quality improvement initiative (NINJA) indicates a reduction in nephrotoxic acute kidney injury in hospitalized children.

Nephrotoxic medication (NTMx) exposure is a common cause of acute kidney injury (AKI) in hospitalized children. The Nephrotoxic Injury Negated by Just-in time Action (NINJA) program decreased NTMx associated AKI (NTMx-AKI) by 62% at one center. To further test the program, we incorporated NINJA across nine centers with the goal of reducing NTMx exposure and, consequently, AKI rates across these centers. NINJA screens all non-critically ill hospitalized patients for high NTMx exposure (over three medications on the same day or an intravenous aminoglycoside over three consecutive days), and then recommends obtaining a daily serum creatinine level in exposed patients for the duration of, and two days after, exposure ending. Additionally, substitution of equally efficacious but less nephrotoxic medications for exposed patients starting the day of exposure was recommended when possible. The main outcome was AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) serum creatinine criteria (increase of 50% or 0.3 mg/dl over baseline). The primary outcome measure was AKI episodes per 1000 patient-days. Improvement was defined by statistical process control methodology and confirmed by Autoregressive Integrated Moving Average (ARIMA) modeling. Eight consecutive bi-weekly measure rates in the same direction from the established baseline qualified as special cause change for special process control. We observed a significant and sustained 23.8% decrease in NTMx-AKI rates by statistical process control analysis and by ARIMA modeling; similar to those of the pilot single center. Thus, we have successfully applied the NINJA program to multiple pediatric institutions yielding decreased AKI rates.

Children with vesicoureteric reflux have joint hypermobility and occasional tenascin XB sequence variants.

INTRODUCTION: To consider alternative mechanisms that give rise to a refluxing ureterovesical junction (UVJ), we hypothesized that children with a common heritable urinary tract defect, vesicoureteric reflux (VUR), may have a defect in the extracellular matrix composition of the UVJ and other tissues that would be revealed by assessment of the peripheral joints. Hypermobile joints can arise from defects in the extracellular matrix within the joint capsule that affect proteins, including tenascin XB (TNXB). METHODS: We performed an observational study of children with familial and non-familial VUR to determine the prevalence of joint hypermobility, renal scarring, and DNA sequence variants in TNXB. RESULTS: Most children (27/44) exhibited joint hypermobility using the Beighton scoring system. This included 15/26 girls (57.7%) and 12/18 boys (66.7%), which is a significantly higher prevalence for both sexes when compared to population controls (p<0.005). We found no association between joint hypermobility and renal scarring. Seven of 49 children harbored rare pathogenic sequence variants in TNXB, and two also exhibited joint hypermobility. No sequence variants in TNXB were identified in 25/27 children with VUR and joint hypermobility. Due to the observational design of the study, there was missing data for joint hypermobility scores in six children and for dimercaptosuccinic acid (DMSA) scans in 17 children. CONCLUSIONS: We observed a high prevalence of VUR and joint hypermobility in children followed within a tertiary care pediatric urology clinic. While mutations in TNXB have been reported in families with VUR and joint hypermobility, we identified only two children with these phenotypes and pathogenic variants in TNXB. We, therefore, speculate that VUR and joint hypermobility may be due to mutations in other extracellular matrix genes.

Incidence and Risk Factors of Early Onset Neonatal AKI.

BACKGROUND AND OBJECTIVES: Neonatal AKI is associated with poor short- and long-term outcomes. The objective of this study was to describe the risk factors and outcomes of neonatal AKI in the first postnatal week. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The international retrospective observational cohort study, Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN), included neonates admitted to a neonatal intensive care unit who received at least 48 hours of intravenous fluids. Early AKI was defined by an increase in serum creatinine >0.3 mg/dl or urine output <1 ml/kg per hour on postnatal days 2-7, the neonatal modification of Kidney Disease: Improving Global Outcomes criteria. We assessed risk factors for AKI and associations of AKI with death and duration of hospitalization. RESULTS: Twenty-one percent (449 of 2110) experienced early AKI. Early AKI was associated with higher risk of death (adjusted odds ratio, 2.8; 95% confidence interval, 1.7 to 4.7) and longer duration of hospitalization (parameter estimate: 7.3 days 95% confidence interval, 4.7 to 10.0), adjusting for neonatal and maternal factors along with medication exposures. Factors associated with a higher risk of AKI included: outborn delivery; resuscitation with epinephrine; admission diagnosis of hyperbilirubinemia, inborn errors of metabolism, or surgical need; frequent kidney function surveillance; and admission to a children's hospital. Those factors that were associated with a lower risk included multiple gestations, cesarean section, and exposures to antimicrobials, methylxanthines, diuretics, and vasopressors. Risk factors varied by gestational age strata. CONCLUSIONS: AKI in the first postnatal week is common and associated with death and longer duration of hospitalization. The AWAKEN study demonstrates a number of specific risk factors that should serve as "red flags" for clinicians at the initiation of the neonatal intensive care unit course.

Model for Medical Student Introductory Telemedicine Education.

Background: Several medical specialty organizations and the American Telemedicine Association have developed specialty-specific guidelines and tips for optimal telemedicine use. Formal introductory education for medical students appears to lag behind these other developments. Introduction: Leaders at the University of Iowa Hospitals and Clinics recognized that students would benefit from an introductory educational program pertinent across all specialties to prepare them for future telemedicine use. The program objective was to introduce a short educational intervention highlighting basic principles to improve knowledge and help students gain confidence with telemedicine technology. Materials and Methods: The program consists of three modules, a video, and a simulation session. The first module presents telemedicine history, current uses, terminology, Medicare-Medicaid rules, and legal issues. The second addresses efficacy, ethical concerns, and best practices. The third reviews steps for success, including environment (sound, lighting, color, and camera placement), communication tips, documentation, and follow-up. The video demonstrates an ideal telemedicine visit. A short quiz follows each module. A 1-h simulation session utilizes case scenarios, telemedicine software, and peripheral equipment. A retrospective pretest and posttest were used to gauge success. Results: One hundred fifty-three second year medical students completed the program during 2017. Ninety-three (60%) completed the questionnaire. Posttest results showed higher (positive) mean scores for all questions addressed in the program regarding basic telemedicine knowledge and confidence issues. Conclusion: This program model was effective in improving basic knowledge and confidence in telemedicine among second-year medical students. We speculate that they are more informed and prepared for future telemedicine rotations and practices.

Late onset neonatal acute kidney injury: results from the AWAKEN Study.

BACKGROUND: Most studies of neonatal acute kidney injury (AKI) have focused on the first week following birth. Here, we determined the outcomes and risk factors for late AKI (>7d). METHODS: The international AWAKEN study examined AKI in neonates admitted to an intensive care unit. Late AKI was defined as occurring >7 days after birth according to the KDIGO criteria. Models were constructed to assess the association between late AKI and death or length of stay. Unadjusted and adjusted odds for late AKI were calculated for each perinatal factor. RESULTS: Late AKI occurred in 202/2152 (9%) of enrolled neonates. After adjustment, infants with late AKI had higher odds of death (aOR:2.1, p = 0.02) and longer length of stay (parameter estimate: 21.9, p < 0.001). Risk factors included intubation, oligo- and polyhydramnios, mild-moderate renal anomalies, admission diagnoses of congenital heart disease, necrotizing enterocolitis, surgical need, exposure to diuretics, vasopressors, and NSAIDs, discharge diagnoses of patent ductus arteriosus, necrotizing enterocolitis, sepsis, and urinary tract infection. CONCLUSIONS: Late AKI is common, independently associated with poor short-term outcomes and associated with unique risk factors. These should guide the development of protocols to screen for AKI and research to improve prevention strategies to mitigate the consequences of late AKI.