Antibody-Mediated Rejection in Heart Transplant Recipients Detected Through Donor-Derived DNA: Presented at CEOT

By Vicki Moore, PhD

PHOENIX, Ariz -- February 13, 2018 -- Presence of cell-free donor-derived DNA (dd-cfDNA) shows potential to screen for antibody-mediated rejection (AMR) in patients with heart transplants, according to a study presented here at the 2018 Annual Cutting Edge of Transplantation (CEOT) Meeting.

Measurement of dd-cfDNA has been shown to reveal AMR in patients with transplanted kidneys, but so far blood tests to identify AMR in heart transplant recipients have been lacking, according to Jignesh Patel, MD, Cedars-Sinai Heart Institute, Los Angeles, California, and colleagues.

The researchers investigated whether an approach similar to the kidney dd-cfDNA test could detect AMR in patients with heart transplants.

The research team evaluated presence of dd-cfDNA in sensitised patients with heart transplants (n = 40), with sensitisation confirmed by circulating antibodies. Mean patient age was 53.8 + 12.0 years. Between 2015 and 2017 the researchers extracted DNA from blood samples from the patients and compared results with endomyocardial biopsies (EMBs). Mixed rejection cases were omitted from this study to avoid recipient inflammation contributing to the recipient cell-free DNA (recipient-cfDNA) pools.

There were 7 cases of AMR in 5 patients, with 4 of them graded as AMR grade 1 and 3 of them graded as AMR 2 according to EMBs.

Percent of dd-cfDNA divided by recipient-cfDNA in patients with AMR was compared with percent of dd-cfDNA divided by recipient-cfDNA from patients with samples lacking AMR (AMR 0).

The researchers reported results for amounts of dd-cfDNA allocated to samples from AMR 0 status (n = 127), AMR 1 status (n = 4), and AMR 2 status (n = 3). The mean dd-cfDNA percentage with AMR 0 was 0.51% + 0.95%, with AMR 1 it was 2.56% + 3.15%, and with AMR 2 it was 1.50% + 2.03% (P = .001).

The dd-cfDNA assay appeared capable of aiding in detection of AMR in the patients with heart transplants in this study. However, as the authors noted, it is appropriate to replicate this analysis with larger sample sizes.

[Presentation title: Donor-Derived Cell Free DNA May Detect Antibody-Mediated Rejection After Heart Transplantation. Abstract P-23]

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