ABSTRACT
Introduction: Malignancies are a major complication of heart transplant (HT). Noninvasive surveillance after HT using gene expression (GEP) profiling and donor derived cell free DNA (dd-cfDNA) are noninferior to biopsy and are widely utilized. The interpretation of % dd-cfDNA, is not well understood in malignancies with a conceptual increase in the recipient fraction. The effect of chemotherapy on GEP in the setting of post-HT surveillance has not been described to the best of our knowledge. Hypothesis: Induction of chemotherapy will cause global transcriptional reduction in GEP. Method(s): GEP was performed with AlloMap (AM, CareDx), which evaluates expression levels of 11 mononuclear cell genes, involved in lymphocyte activation, T-cell priming, cell migration, hematopoietic proliferation, steroid sensitivity, and platelet activation. Scores range from 0-40, higher scores have a stronger correlation with rejection. At our center a total of 995 draws were analyzed from 2019-2022. In parallel dd-cfDNA, which informs about graft injury was analyzed using AlloSure (AS, CareDx). Case Events: A 71-year-old male HT recipient for nonischemic cardiomyopathy and no rejection history was diagnosed with metastatic gastric adenocarcinoma at 16 months post-HT. Following diagnosis, mycophenolic acid was stopped, prednisone 5 mg was started, and tacrolimus trough goal was gradually lowered to 4-6 given infectious complications. Palliative chemotherapy with folinic acid, fluorouracil (5-FU), oxaliplatin (FOLFOX) was initiated at 18 months post-HT with planned dose reduction of oxaliplatin and holding of 5-FU bolus to reduce risk of myelosuppression given comorbidities. Oxaliplatin was stopped at 18 months post HT. Due to COVID he last received 5-FU at 33 months post-HT. Graft function remained stable and DSA negative. At 36 months post-HT, he developed a bowel obstruction without surgical options for interventions and expired shortly thereafter. Result(s): With initiation of prednisone and following chemotherapy there was a drastic decrease in AM scores (Fig. A). Steroid therapy led to an 18% decline in AM scores, the greatest decrease occurred with chemotherapy, with 67% decline from the mean when compared to all center patients (Fig B). Dd-cfDNA levels remained stable during the course aside from one early elevation. Conclusion(s): To the best of our knowledge this is the first published case on the effect of chemotherapy on GEP profiling in the setting of post-HT surveillance. This case advises caution when interpreting GEP in the setting of chemotherapy showing great reduction in GEP scores. While dd-cfDNA levels remained relatively stable after malignancy diagnosis and treatment initiation further studies will need to inform on the use of both GEP and dd-cfDNA in these patients.Copyright © 2022