Donor-Derived Cell-Free DNA in Stable Pediatric Kidney Transplant Recipients: Influence of Donor Obesity and Recipient Size.

Document Type

Article

Publication Date

8-2026

Publication Title

Pediatric Transplantation

Abstract

BACKGROUND: Donor-derived cell-free DNA (dd-cfDNA) is increasingly used as a noninvasive marker of kidney allograft injury, but adult-derived cutoffs may not be applicable to pediatric recipients, particularly in the setting of donor-recipient size mismatch. We evaluated dd-cfDNA levels in stable pediatric kidney transplant (KT) recipients and assessed variation by recipient weight and donor body mass index (BMI).

METHODS: Retrospective data were collected from seven U.S. pediatric KT centers. Clinically stable recipients <  18 years of age (no de novo donor specific antibody, biopsy-proven rejection or BK viremia/nephropathy), with ≥ 2 dd-cfDNA measurements per year were included. Recipients were stratified by weight at dd-cfDNA collection (<  20 kg, 20-50 kg, > 50 kg). Donor BMI was categorized as underweight (≤ 18.5), normal (18.6-24.9), overweight (25-29.9), or obese (≥ 30). Comparisons were performed using linear mixed-effects models.

RESULTS: Among 178 recipients, mean dd-cfDNA did not differ by recipient weight (<  20 kg: 0.51 ± 0.44; 20-50 kg: 0.65 ± 1.28; > 50 kg: 0.49 ± 0.70). Median dd-cfDNA was similar across donor BMI categories. However, among obese donors, recipients <  20 kg had 1.3-fold higher dd-cfDNA (p = 0.044). Donor-recipient body surface area mismatch > 1.5 was associated with 1.083-fold higher dd-cfDNA up to 5 years post-transplant (p = 0.016).

CONCLUSIONS: In stable pediatric KT recipients, dd-cfDNA levels were well below the adult-derived 1% cutoff, reinforcing the generalizability of this cutoff to the pediatric population. Recipients < 20 kg with donor BMI > 30 kg/m2 or in the setting of a donor-recipient BSA mismatch > 1.5 were associated with higher dd-cfDNA levels.

Volume

30

Issue

8

First Page

e70416

Last Page

e70416

Comments

Helen DeVos Children's Hospital

DOI

10.1111/petr.70416

ISSN

1399-3046

PubMed ID

42606109

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