Utilization of Donor-Derived Cell-Free DNA (ddcfDNA) in Lung Transplant Recipients

Document Type

Conference Proceeding

Publication Date

4-1-2025

Publication Title

J Heart Lung Transplant

Abstract

Purpose: The purpose of this study is to assess the utility of noninvasive monitoring with ddcfDNA in detecting acute rejection (AR), including acute cellular rejection (ACR) and antibody-mediated rejection (AMR). Methods: This is a single center, retrospective, observational, cohort analysis of lung transplant recipients. DdcfDNA samples were collected between 4/18/2022 and 7/11/2024 and included if patients had 3 or more samples and a corresponding transbronchial biopsy (TBBX). Samples were categorized based on biopsy results: stable, ACR, subclinical AMR, or AMR. Median and IQR, Wilcoxon sign-rank, and Friedman ANOVA tests were utilized. The primary outcome was to assess the trend of ddcfDNA before and after AR treatment. Secondary outcomes assessed the trend of FEV1 before and after AR treatment, and the correlation between ddcfDNA and change in FEV1. Results: Seventy patients were included. The median (IQR) of ddcfDNA at time of TBBX was 0.71 (0.32-1.1) in stable, 0.69 (0.2-1.1) in ACR, 0.43 in subclinical AMR, and 0.78 in AMR, p< 0.05. There were 50 episodes of biopsy-proven ACR (62% were routine and 38% for-cause TBBX). The median ddcfDNA was noted to increase two-fold at time of ACR (pre-level 3) from the previous level (Figure 1). Among those treated, 97.2% received steroids and 2.8% received antithymocyte globulin (ATG). Of note, the patient who received ATG for steroid-refractory ACR had a ddcfDNA of 3.3% at time of ACR, a five-fold increase from their previous level. The mean FEV1 was 2.08 L before and 2.13 L after AR treatment. There was not a significant correlation between ddcfDNA and change in FEV1 in AR patients (rho= -0.036, p= 0.08). Conclusion: Trending ddcfDNA may provide a more useful tool as compared to a single value at time of ACR, as a doubling of median % ddcfDNA was noted at time of biopsy-proven acute rejection. A decrease back to pre-ACR ddcfDNA levels were also noted after treatment along with corresponding improvement in FEV1. [Formula presented]

Volume

44

Issue

4

First Page

S761

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