Liquid biopsies: non-invasive rejection detection after heart transplantation

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L.S.M. Hofste, A. Vink, J. van Kuik, E. Siera-de Koning, F. Ahmadi, N. de Jonge, R.A. de Weger, M.M.H. Huibers

Chair(s): Prof. dr. F.J. Bemelman & prof. dr. R. Goldschmeding

Thursday 9 march 2017

9:12 - 9:24h at Hendrik Marsmanzaal

Categories: Parallel - Basaal

Parallel session: Parallelsessie IX – Basaal 2 - Biomarkers gerelateerd aan rejectie na orgaantransplantatie

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After heart transplantation (HTx) acute cellular rejection (ACR) can damage the allograft which leads to the release of donor cell free DNA (cfDNA) into the circulation of the recipient. The amount of donor cfDNA in the recipients blood (liquid biopsies) can be measured using digital PCR. The aim of our study is to implement this non-invasive liquid biopsy technique for donor cfDNA detection post-HTx.

50 HTx patients were selected with at least one year follow-up. Within this cohort 37 patients experienced ACR. The 13 non-ACR patients are used as controls. Eight common SNPs were used for the recipient-donor genotyping with qPCR. cfDNA was isolated from EDTA plasma from the recipients pre-HTx and at multiple timepoints post-HTx. With digital PCR the amount of donor cfDNA was measured in the recipients plasma by targeting the specific SNP of the donor. 

Pilot data of 15 patients were gathered and post-HTx we detect donor cfDNA in the recipient plasma samples. A limit of detection (LOD) for every SNP was determined during validation of the assays. In the first month post-HTx the amount of cfDNA of both the donor and the recipient is fluctuating. The amount of donor cfDNA decreases to a baseline (BL) level after one month. In all plasma samples of the patients post-HTx elevated levels of donor cfDNA were detected after the biopsy proven ACR and in some patients the elevated levels of donor cfDNA also matched the biopsy proven ACR. Other clinical events explained peaks in cfDNA levels.

The eight SNPs were sufficient for typing the HTx recipients and donors. We can detect donor cfDNA in the recipients plasma post-HTx. Because cfDNA fluctuates within the first month, endomyocardial biopsies (EMBs) are still crucial in this period. After the first month liquid biopsies show promising results to limit the amount of EMBs, however this remains challenging as other medical issues might be interfering.