Use of dd-cfDNA in Real World Practice: Single Center Experience

Purpose Gene expression profiling testing (GEP; AlloMap) and donor-derived cell free DNA (dd-cfDNA; AlloSure) each provide non-invasive means to detect possible heart allograft rejection, including acute cellular rejection (ACR). This report describes the largest single center use of dd-cfDNA to date. Methods Post heart transplant (HT) management is standardized at our center such that endomyocardial biopsy is used for rejection surveillance in the early period with crossover to GEP testing at day 56. Elevated GEP (≥34) prompts biopsy. dd-cfDNA was utilized in conjunction with biopsy or in lieu of biopsy (barrier to biopsy). A cohort of 26 HT patients underwent dd-cfDNA testing, including 3 multiorgan (same donor) and 5 retransplant patients. The dd-cfDNA (%, AlloSure) and GEP (AlloMap, score 0-40) results were correlated patient survival. Results Among 26 HT patients there was a total 70 dd-cfDNA tests (mean 2.7 per pt). dd-cfDNA usage was due to inability to biopsy (33%), anticoagulation (22%), elevated GEP (26%), with graft dysfunction, prior rejection, biopsy refusal, tricuspid regurgitation and critically ill status comprising 4% each. Mean day post HT for first dd-cfDNA test was 201 (IQR 90-517), with earliest at day 7 post HT. Mean dd-cfDNA was 0.3 ± 0.5%. Mean GEP score was 32.8 ± 5.3. There were no deaths in this cohort. One patient had confirmed AMR2 (dd-cfDNA 0.25%). Mean LVEF 54% ± 5. Conclusion In surveillance of heart allograft recipients for rejection, consideration of dd-cfDNA levels may improve patient management decisions particularly when endomyocardial biopsy may not be feasible.