Characterization of Cytokines in Lung Transplant Recipients with Elevated Donor-derived Cell-free DNA

Document Type

Conference Proceeding

Publication Date

2025

Publication Title

American Journal of Respiratory and Critical Care Medicine

Abstract

Rationale: Elevated levels of both plasma donor-derived cell-free DNA (dd-cfDNA) and various cytokines in bronchoalveolar lavage fluid (BALF) have been associated with acute lung allograft dysfunction (ALAD) in lung transplant recipients and predict worse long-term outcomes. Data regarding the association between dd-cfDNA and BALF cytokines is lacking. We sought to compare select BALF cytokines in lung transplant recipients with marked elevations in dd-cfDNA levels to those with stable allograft and normal dd-cfDNA.

Methods: BALF from 11 patients (14 samples) with high (>3.0%) dd-cfDNA at time of collection were matched with 14 control recipients with normal (< 1%) dd-cfDNA based on age and time post-transplant. Plasma dd-cfDNA was measured with the Prospera (Natera) assay. Values for single lung transplant recipients were adjusted by doubling the measured percentage. A multiplex assay was performed for the quantitative analysis of eight cytokines (MIP-1a, IL-1b, IP-10, IL-6, IL-8, IL-17a, RANTES, TNFa) in BALF using the Luminex MAGPIX system and a custom Thermo Fisher Scientific 8-plex panel on a 96-well plate. Sterile saline, used the perform the lavages, was used as the background media for the assay. Analysis was performed with paired T-test.

Results: The high dd-cfDNA group included 5 males, median age 68 (range: 41-74), nine bilateral transplants with median post-transplant interval of 11 months (range: 2-36). Median dd-cfDNA was 5.3% (range: 3.1-14.2). The clinical diagnoses at the time of BAL were infection in 11 cases (4 aspergillus, 3 COVID, 2 other viral, 2 bacterial), two acute cellular rejection and one fibrothorax. The control group included nine males, median age 67 (range: 35-74) with median post-operative time of 12 months (range: 1-84). All were bilateral transplants with normal bronchoscopy findings and stable pulmonary function. Median dd-cfDNA was 0.25% (range: 0.08-0.81). BALF cytokine profiling in the elevated dd-cfDNA compared with the control group demonstrated elevated concentrations of IL-6 (33.6 pg/mL vs. 11.2 pg/mL; P=0.04) and MIP-1α (31.7 pg/mL vs. 12.3 pg/mL; P=0.04). Strong trends were noted for higher IP-10 (P=0.06) and IL-8 (P=0.1). RANTES, IL-1β, IL-17α and TNFα were numerically greater in the high dd-cfDNA group but not significant.

Conclusions: IL-6, MIP-1α, IP-10 and IL-8 are elevated in BALF of lung transplant recipients with high dd-cfDNA compared with subjects with low dd-cfDNA. Additional research is required to further characterize the BALF cytokine profile associated with ALAD and injury indicated by dd-cfDNA. There is potential to use cytokine profiles in conjunction with dd-cfDNA testing to improve diagnostic performance.

Volume

211

First Page

A1878

Last Page

A1878

Comments

American Thoracic Society International Conference, May 16-21, 2025, San Francisco, CA

DOI

10.1164/ajrccm.2025.211.Abstracts.A1878

ISSN

1535-4970

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