Patient-Reported Outcomes Over 24 Months in Pediatric CKD: Findings From the MyKidneyHealth Cohort Study

RATIONALE & OBJECTIVE

The lived experience of children with chronic kidney disease (CKD) is poorly characterized. We examined the associations between patient-reported outcome (PRO) scores measuring their fatigue, sleep health, psychological distress, family relationships, and global health with clinical outcomes over time in children, adolescents, and younger adults with CKD and investigated how the PRO scores of this group compare with those of other children, adolescents, and younger adults.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

212 children, adolescentss, and adults aged 8 to 21 years with CKD and their parents recruited from 16 nephrology programs across North America.

PREDICTORS

CKD stage, disease etiology, and sociodemographic and clinical variables.

OUTCOME

PRO scores over 2 years.

ANALYTICAL APPROACH

We compared PRO scores in the CKD sample with a nationally representative general pediatric population (ages 8 to 17 years). Change of PROs over time and association of sociodemographic and clinical variables with PROs were assessed using multivariable regression models.

RESULTS

For all time points, 84% of the parents and 77% of the children, adolescents, and younger adults completed PRO surveys . The baseline PRO scores for the participants with CKD revealed a higher burden of fatigue, sleep-related impairment, psychological distress, impaired global health, and poorer family relationships compared with the general pediatric population, with median score differences≥1 SD for fatigue and global health. The baseline PRO scores did not differ by CKD stage or glomerular versus nonglomerular etiology. Over 2 years, PROs were stable with a<1-point annual change on average on each measure and intraclass correlation coefficients ranging from 0.53 to 0.79, indicating high stability. Hospitalization and parent-reported sleep problems were associated with worse fatigue, psychological health, and global health scores (all P<0.04).

LIMITATIONS

We were unable to assess responsiveness to change with dialysis or transplant.

CONCLUSIONS

Children with CKD experience a high yet stable burden of impairment across numerous PRO measures, especially fatigue and global health, independent of disease severity. These findings underscore the importance of assessing PROs, including fatigue and sleep measures, in this vulnerable population.

PLAIN-LANGUAGE SUMMARY

Children with chronic kidney disease (CKD) have many treatment demands and experience many systemic effects. How CKD impacts the daily life of a child is poorly understood. We surveyed 212 children, adolescents, and younger adults with CKD and their parents over 24 months to assess the participants' well-being over time. Among children, adolescents, and younger adults with CKD we found a very high and persistent burden of psychological distress that did not differ by degree of CKD or type of kidney disease. The participants with CKD endorsed greater impairment in fatigue and global health compared with healthy children, adolescents, and younger adults, and parent-reported sleep problems were associated with poorer patient-reported outcome (PRO) scores across all domains. These findings emphasize the importance of including PRO measures, including fatigue and sleep measures, into routine clinical care to optimize the lived experience of children with CKD.

Persistent Increase in Serum Ferritin Levels despite Converting to Permanent Vascular Access in Pediatric Hemodialysis Patients: Pediatric Nephrology Research Consortium Study

Our objective was to examine serum ferritin trends after conversion to permanent vascular access (PVA) among children who started hemodialysis (HD) using tunneled cuffed catheters (TCC). Retrospective chart reviews were completed on 98 subjects from 20 pediatric HD centers. Serum ferritin levels were collected at the creation of PVA and for two years thereafter. There were 11 (11%) arteriovenous grafts (AVG) and 87 (89%) arteriovenous fistulae (AVF). Their mean TCC use was 10.4 ± 17.3 months. Serum ferritin at PVA creation was elevated at 562.64 ± 492.34 ng/mL, increased to 753.84 ± 561.54 ng/mL (p = < 0.001) in the first year and remained at 759.60 ± 528.11 ng/mL in the second year (p = 0.004). The serum ferritin levels did not show a statistically significant linear association with respective serum hematocrit values. In a multiple linear regression model, there were three predictors of serum ferritin during the first year of follow-up: steroid-resistant nephrotic syndrome as primary etiology (p = 0.035), being from a center that enrolled >10 cases (p = 0.049) and baseline serum ferritin level (p = 0.017). Increasing serum ferritin after conversion to PVA is concerning. This increase is not associated with serum hematocrit trends. Future studies should investigate the correlation of serum transferrin saturation and ferritin levels in pediatric HD patients.

Sequential Stem Cell-Kidney Transplantation in Schimke Immuno-osseous Dysplasia

Lifelong immunosuppression is required for allograft survival after kidney transplantation but may not ultimately prevent allograft loss resulting from chronic rejection. We developed an approach that attempts to abrogate immune rejection and the need for post-transplantation immunosuppression in three patients with Schimke immuno-osseous dysplasia who had both T-cell immunodeficiency and renal failure. Each patient received sequential transplants of αβ T-cell-depleted and CD19 B-cell-depleted haploidentical hematopoietic stem cells and a kidney from the same donor. Full donor hematopoietic chimerism and functional ex vivo T-cell tolerance was achieved, and the patients continued to have normal renal function without immunosuppression at 22 to 34 months after kidney transplantation. (Funded by the Kruzn for a Kure Foundation.).

Safety and efficacy of sucroferric oxyhydroxide in pediatric patients with chronic kidney disease

BACKGROUND

Pediatric patients with advanced chronic kidney disease (CKD) are often prescribed oral phosphate binders (PBs) for the management of hyperphosphatemia. However, available PBs have limitations, including unfavorable tolerability and safety.

METHODS

This phase 3, multicenter, randomized, open-label study investigated safety and efficacy of sucroferric oxyhydroxide (SFOH) in pediatric and adolescent subjects with CKD and hyperphosphatemia. Subjects were randomized to SFOH or calcium acetate (CaAc) for a 10-week dose titration (stage 1), followed by a 24-week safety extension (stage 2). Primary efficacy endpoint was change in serum phosphorus from baseline to the end of stage 1 in the SFOH group. Safety endpoints included treatment-emergent adverse events (TEAEs).

RESULTS

Eighty-five subjects (2-18 years) were randomized and treated (SFOH, n = 66; CaAc, n = 19). Serum phosphorus reduction from baseline to the end of stage 1 in the overall SFOH group (least squares [LS] mean ± standard error [SE]) was - 0.488 ± 0.186 mg/dL; p = 0.011 (post hoc analysis). Significant reductions in serum phosphorus were observed in subjects aged ≥ 12 to ≤ 18 years (LS mean ± SE - 0.460 ± 0.195 mg/dL; p = 0.024) and subjects with serum phosphorus above age-related normal ranges at baseline (LS mean ± SE - 0.942 ± 0.246 mg/dL; p = 0.005). Similar proportions of subjects reported ≥ 1 TEAE in the SFOH (75.8%) and CaAc (73.7%) groups. Withdrawal due to TEAEs was more common with CaAc (31.6%) than with SFOH (18.2%).

CONCLUSIONS

SFOH effectively managed serum phosphorus in pediatric patients with a low pill burden and a safety profile consistent with that reported in adult patients.

Predictors of time to first cannulation for arteriovenous fistula in pediatric hemodialysis patients: Midwest Pediatric Nephrology Consortium study

BACKGROUND

Permanent vascular access (PVA) is preferred for long-term hemodialysis. Arteriovenous fistulae (AVF) have the best patency and the lowest complication rates compared to arteriovenous grafts (AVG) and tunneled cuffed catheters (TCC). However, AVF need time to mature. This study aimed to investigate predictors of time to first cannulation for AVF in pediatric hemodialysis patients.

METHODS

Data on first AVF and AVG of patients at 20 pediatric dialysis centers were collected retrospectively, including demographics, clinical information, dialysis markers, and surgical data. Statistical modeling was used to investigate predictors of outcome.

RESULTS

First PVA was created in 117 children: 103 (88%) AVF and 14 (12%) AVG. Mean age at AVF creation was 15.0 ± 3.3 years. AVF successfully matured in 89 children (86.4%), and mean time to first cannulation was 3.6 ± 2.5 months. In a multivariable regression model, study center, age, duration of non-permanent vascular access (NPVA), and Kt/V at AVF creation predicted time to first cannulation, with study center as the strongest predictor (p < 0.01). Time to first cannulation decreased with increasing age (p = 0.03) and with increasing Kt/V (p = 0.01), and increased with duration of NPVA (p = 0.03). Secondary failure occurred in 10 AVF (11.8%). Time to first cannulation did not predict secondary failure (p = 0.29), but longer time to first cannulation tended towards longer secondary patency (p = 0.06).

CONCLUSIONS

Study center is the strongest predictor of time to first cannulation for AVF and deserves further investigation. Time to first cannulation is significantly shorter in older children, with more efficient dialysis treatments, and increases with longer NPVA duration.

Kidney Support in Children using an Ultrafiltration Device: A Multicenter, Retrospective Study

BACKGROUND AND OBJECTIVES

Provision of kidney replacement therapy (KRT) to manage kidney injury and volume overload in critically ill neonates and small children is technically challenging. The use of machines designed for adult-sized patients, necessitates large catheters, a high extracorporeal volume relative to patient size, and need for blood priming. The Aquadex FlexFlow System (CHF Solutions Inc., Eden Prairie, MN) is an ultrafiltration device designed for fluid removal in adults with diuretic resistant heart failure. It has an extracorporeal volume of 33 ml, which can potentially mitigate some complications seen at onset of KRT in smaller infants.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this multicenter, retrospective case series of children who received KRT with an ultrafiltration device (n=119 admissions, 884 circuits), we report demographics, circuit characteristics, complications, and short- and long-term outcomes. Patients were grouped according to weight (<10, 10-20, and >20 kg), and received one of three modalities: slow continuous ultrafiltration, continuous venovenous hemofiltration (CVVH), or prolonged intermittent KRT. Our primary outcome was survival to end of KRT.

RESULTS

Treatment patterns and outcomes varied between the groups. In patients who weighed <10 kg, the primary indication was AKI in 40%, volume overload in 46%, and ESKD in 14%. These patients primarily received CVVH (66%, n=48) and prolonged intermittent KRT (21%, n=15). In the group weighing >20 kg, volume overload was the primary indication in 91% and slow continuous ultrafiltration was the most common modality. Patients <10 kg had lower KRT survival than those >20 kg (60% versus 97%), more volume overload at onset, and received KRT for a longer duration. Cardiovascular complications at initiation were seen in 3% of treatments and none were severe. Complications during therapy were seen in 15% treatments and most were vascular access-related.

CONCLUSIONS

We report the first pediatric experience using an ultrafiltration device to provide a range of therapies, including CVVH, prolonged intermittent KRT, and slow continuous ultrafiltration. We were able to initiate KRT with minimal complications, particularly in critically ill neonates. There is an unmet need for devices specifically designed for younger patients. Having size-appropriate machines will improve the care of smaller children who require kidney support.

Correction to: Predictors of patency for arteriovenous fistulae and grafts in pediatric hemodialysis patients

The original version of this article unfortunately contained a mistake. The name of Vimal Chadha was presented incorrectly. The corrected author list is given above.

Neutral pH and low-glucose degradation product dialysis fluids induce major early alterations of the peritoneal membrane in children on peritoneal dialysis

The effect of peritoneal dialysates with low-glucose degradation products on peritoneal membrane morphology is largely unknown, with functional relevancy predominantly derived from experimental studies. To investigate this, we performed automated quantitative histomorphometry and molecular analyses on 256 standardized peritoneal and 172 omental specimens from 56 children with normal renal function, 90 children with end-stage kidney disease at time of catheter insertion, and 82 children undergoing peritoneal dialysis using dialysates with low-glucose degradation products. Follow-up biopsies were obtained from 24 children after a median peritoneal dialysis of 13 months. Prior to dialysis, mild parietal peritoneal inflammation, epithelial-mesenchymal transition and vasculopathy were present. After up to six and 12 months of peritoneal dialysis, blood microvessel density was 110 and 93% higher, endothelial surface area per peritoneal volume 137 and 95% greater, and submesothelial thickness 23 and 58% greater, respectively. Subsequent peritoneal changes were less pronounced. Mesothelial cell coverage was lower and vasculopathy advanced, whereas lymphatic vessel density was unchanged. Morphological changes were accompanied by early fibroblast activation, leukocyte and macrophage infiltration, diffuse podoplanin presence, epithelial mesenchymal transdifferentiation, and by increased proangiogenic and profibrotic cytokine abundance. These transformative changes were confirmed by intraindividual comparisons. Peritoneal microvascular density correlated with peritoneal small-molecular transport function by uni- and multivariate analysis. Thus, in children on peritoneal dialysis neutral pH dialysates containing low-glucose degradation products induce early peritoneal inflammation, fibroblast activation, epithelial-mesenchymal transition and marked angiogenesis, which determines the PD membrane transport function.

Efficacy and safety of sevelamer carbonate in hyperphosphatemic pediatric patients with chronic kidney disease

BACKGROUND

Treatment for hyperphosphatemia in chronic kidney disease (CKD) involves dietary control of phosphorus intake, dialysis, and treatment with oral phosphate binders, none of which were approved by the Federal Food and Drug Administration in pediatric patients at the time of this study.

METHODS

This was a phase 2, multicenter study (NCT01574326) with a 2-week, randomized, placebo-controlled, fixed-dose period (FDP) followed by a 6-month, single-arm, open-label, dose-titration period (DTP), with the aim to evaluate the safety and efficacy of sevelamer carbonate (SC) in hyperphosphatemic pediatric patients with CKD. Following a 2-4 week screening phase, pediatric patients with a serum phosphorus level higher than age-appropriate levels were randomized to receive either SC or placebo as powder/tablets in 0.4-1.6 g doses, based on body surface area. The primary efficacy outcome was the change in serum phosphorus from baseline to end of the FDP in the SC versus placebo arms (analysis of covariance). The secondary outcome was mean change in serum phosphorus from baseline to end of DTP by treatment group and overall. Treatment-emergent/serious adverse events (AEs) were recorded.

RESULTS

Of 101 enrolled patients (29 centers), 66 completed the study. The majority of patients were adolescents (74%; mean age 14.1 years) and on dialysis (77%). Renal transplant was the main reason for discontinuation. SC significantly reduced serum phosphorus from baseline levels (7.16 mg/dL) during the FDP compared to placebo (least square mean difference - 0.90 mg/dL, p = 0.001) and during the DTP (- 1.18 mg/dL, p < 0.0001). The safety and tolerability of SC and placebo were similar during the FDP, with patients in both groups reporting mild/moderate gastrointestinal AEs during the DTP.

CONCLUSIONS

Sevelamer carbonate significantly lowered serum phosphorus levels in hyperphosphatemic children with CKD, with no serious safety concerns identified.

An open-label study to evaluate a single-dose of cinacalcet in pediatric dialysis subjects

BACKGROUND

There is limited knowledge of the effectiveness and safety profile of cinacalcet in pediatric patients with secondary hyperparathyroidism (sHPT) treated with dialysis.

METHODS

This was an open-label, single-dose study conducted on 12 pediatric subjects with chronic kidney disease treated with dialysis. Subjects were stratified by four age cohorts and given a single 15-mg oral dose of cinacalcet. Multiple blood samples were collected up to 72 h post-dose for the assessment of serum calcium (Ca), serum intact parathyroid hormone (iPTH), and plasma cinacalcet concentrations.

RESULTS

Overall, cinacalcet was well tolerated with no serious adverse events. Mean (standard deviation) percentage change in serum Ca over the first 12 h post-dose was -2.93 % (5.70 %) with a nadir of -4.34 % (6.04 %) at 8 h; Ca values returned to baseline by 48 h post-dose. Mean percentage change in iPTH over the first 12 h post-dose was 57.94 % (71.82 %) with a nadir of -35.65 % (55.82 %) at 2 h. There was an inverse relationship between peak serum Ca concentration and body surface area (BSA) (r (2) = 0.41), although no relationship was found between area under the curve and age or BSA.

CONCLUSIONS

These data support future analysis to determine the therapeutic starting dose of cinacalcet for pediatric patients with sHPT on dialysis.