Kidney Outcomes and Hypertension in Survivors of Wilms Tumor: A Prospective Cohort Study.

2020

2020 Dec 05

1097-6833

<p>Supported by a Pilot Grant from the Children's Hospital of Philadelphia Center for Pediatric Clinical Effectiveness (to D.C.). D.C. is also supported by the NIH/NIDDK (K23 DK125670). G.T. was supported by the NIH/NIDDK (K23 DK106428). Ja.G. was supported by NIH/NIDDK (K08 DK110536). M.D. was supported by the NIH/NIDDK (K23 DK093556). The NIH and NIDDK had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript. The views expressed in this article are those of the authors and do not necessarily represent the official view of the NIDDK nor NIH. G.T. serves on the scientific advisory boards for Allena Pharmaceuticals, Novome Biotechnology, and Dicerna Pharmaceuticals and serves as a consultant for Alnylam Pharmaceuticals, all of which are unrelated to this work. M.D. receives research funding from Mallinckrodt unrelated to this work. The other authors declare no conflicts of interest. Portions of this study were presented at the Pediatric Academic Society annual meeting, May 5-8, 2020, Toronto, Canada.</p>

<p><strong>OBJECTIVE: </strong>To assess the prevalence of therapy-related kidney outcomes in survivors of Wilms tumor (WT).</p>

<p><strong>STUDY DESIGN: </strong>This prospective cohort study included survivors of WT who were ≥5 years old and ≥1 year from completing therapy, excluding those with pre-existing hypertension, prior dialysis or kidney transplant. Participants completed 24-hour ambulatory blood pressure monitoring (ABPM). Abnormal blood pressure (BP) was defined as ≥90 percentile. Masked hypertension was defined as having normal office BP and abnormal ABPM findings. Urine was analyzed for KIM-1, IL-18, EGF, albumin, and creatinine. Estimated glomerular filtration rate (eGFR) was calculated using the bedside CKiD equation. Recent kidney ultrasounds and echocardiograms were reviewed for contralateral kidney size and left ventricular hypertrophy (LVH), respectively. Clinical follow-up data was collected for approximately 2 years following study enrollment.</p>

<p><strong>RESULTS: </strong>Thirty-two participants (median age 13.6 [IQR: 10.5-16.3] years; 75% ≥Stage 3 WT) were evaluated at a median of 8.7 years (IQR: 6.5-10.8) post-therapy; 29 participants underwent unilateral radical nephrectomy, two bilateral partial nephrectomy, and one radical and contralateral partial nephrectomy. 72% received kidney radiotherapy and 75% received doxorubicin. Recent median eGFR was 95.6 ml/min/1.73m (IQR: 84.6-114.0; 11 (34%) had an eGFR &lt;90). Abnormal ABPM results were found in 22/29 participants (76%), masked hypertension in 10/29 (34%), and microalbuminuria in 2/32 (6%). 22/32 (69%) participants had abnormal EGF; few had abnormal KIM-1 or IL-18. Seven participants with previous unilateral nephrectomy lacked compensatory contralateral kidney hypertrophy. None had LVH.</p>

<p><strong>CONCLUSION: </strong>In survivors of WT, adverse kidney outcomes were common and should be closely monitored.</p>

10.1016/j.jpeds.2020.12.005

J Pediatr

33290810

Using Electronic Health Record Data to Rapidly Identify Children with Glomerular Disease for Clinical Research.

2019

2427-2435

2019 Dec

1533-3450

<p><strong>BACKGROUND: </strong>The rarity of pediatric glomerular disease makes it difficult to identify sufficient numbers of participants for clinical trials. This leaves limited data to guide improvements in care for these patients.</p>

<p><strong>METHODS: </strong>The authors developed and tested an electronic health record (EHR) algorithm to identify children with glomerular disease. We used EHR data from 231 patients with glomerular disorders at a single center to develop a computerized algorithm comprising diagnosis, kidney biopsy, and transplant procedure codes. The algorithm was tested using PEDSnet, a national network of eight children's hospitals with data on &gt;6.5 million children. Patients with three or more nephrologist encounters (=55,560) not meeting the computable phenotype definition of glomerular disease were defined as nonglomerular cases. A reviewer blinded to case status used a standardized form to review random samples of cases (=800) and nonglomerular cases (=798).</p>

<p><strong>RESULTS: </strong>The final algorithm consisted of two or more diagnosis codes from a qualifying list or one diagnosis code and a pretransplant biopsy. Performance characteristics among the population with three or more nephrology encounters were sensitivity, 96% (95% CI, 94% to 97%); specificity, 93% (95% CI, 91% to 94%); positive predictive value (PPV), 89% (95% CI, 86% to 91%); negative predictive value, 97% (95% CI, 96% to 98%); and area under the receiver operating characteristics curve, 94% (95% CI, 93% to 95%). Requiring that the sum of nephrotic syndrome diagnosis codes exceed that of glomerulonephritis codes identified children with nephrotic syndrome or biopsy-based minimal change nephropathy, FSGS, or membranous nephropathy, with 94% sensitivity and 92% PPV. The algorithm identified 6657 children with glomerular disease across PEDSnet, ≥50% of whom were seen within 18 months.</p>

<p><strong>CONCLUSIONS: </strong>The authors developed an EHR-based algorithm and demonstrated that it had excellent classification accuracy across PEDSnet. This tool may enable faster identification of cohorts of pediatric patients with glomerular disease for observational or prospective studies.</p>

10.1681/ASN.2019040365

J. Am. Soc. Nephrol.

31732612

Variability in measures of mineral metabolism in children on hemodialysis: impact on clinical decision-making.

2017

2311-2318

2017 Dec

1432-198X

<p><strong>BACKGROUND: </strong>Variability in measures of mineral metabolism has not been studied in pediatric end stage kidney disease. We sought to determine the intra-individual variability in measures of mineral metabolism in children on hemodialysis (HD) and its impact on clinical decision-making.</p>

<p><strong>METHODS: </strong>We conducted a prospective single-center study of children (3.6-17.3 years old) on chronic HD. Serial twice weekly measures of serum calcium, phosphate and intact parathyroid hormone (PTH), as well as weekly measures of fibroblast growth factor 23 (FGF23) and vitamin D metabolites, were obtained over a 12-week period in 10 children. Samples (n = 226) were assayed in a single batch at the end of the study.</p>

<p><strong>RESULTS: </strong>The median intra-individual coefficient of variation (CV) calculated by 4-week blocks was 5.1-6.5% for calcium, 9.5-14.9% for phosphate and 32.7-33.4% for PTH. The median overall CV for FGF23 was 44.4%. Using the first value of each block as a reference, subsequent values would dictate a discrepant management decision 33-56%, 19-28%, and 30-33% of the time for calcium, phosphate, and PTH, respectively. Adjusting for sex and age, most of the variability in phosphate and PTH was attributable to within-participant variability. For calcium, 49% of the variability was attributable to day of blood collection (Monday vs. Friday). The median (range) of an individual participant's values within clinical target ranges was 55% (26-86%) for calcium, 58% (0-96%) for phosphate, and 21% (0-64%) for PTH.</p>

<p><strong>CONCLUSIONS: </strong>There is considerable intra-individual variability in measures of mineral metabolism that serve as surrogate markers for bone health in children on HD. Within a 4-week period, at least 20-30% of measures would dictate a discrepant decision from the referent measure of that month. These findings have important implications for clinical decision-making and underscore the need to base therapeutic decisions on trends rather than single measurements.</p>

10.1007/s00467-017-3730-4

Pediatr. Nephrol.

28667458