Photopheresis in Antibody Mediated Rejection: A Single Center Experience

Abstract

<h3>Purpose</h3> Antibody mediated rejection (AMR) remains a major source of morbidity and mortality for heart transplant (HT) recipients with diverse treatment strategies across transplant centers. The role of extracorporeal photopheresis (ECP), a cellular immunotherapy, as a potential adjunctive therapy for AMR in HT remains controversial. <h3>Methods</h3> A retrospective analysis was performed of all HT patients at our institution who received at least 3 months ECP for AMR between 09/2011-09/2020. Clinical response to ECP and outcomes within 1 year of therapy are described. Endomyocardial biopsy (EMB) grading of AMR was defined per 2013 ISHLT nomenclature. Donor specific antibodies (DSA) were considered positive if identified de-novo, at mean fluorescence intensity (MFI) greater than 4000. <h3>Results</h3> Results are reported in Table 1. The analysis included 19 HT recipients treated with ECP for AMR at a median of 723 days (IQR 112.5, 1749) post HT. At diagnosis, 7/19 (36.8%) had pAMR1I+, 11/19 (57.9%) had decline in left ventricular ejection fraction (LVEF) by at least 10%, and 13/19 (68.4%) had presence of DSA. Following initial immunosuppressive therapy for AMR, 6/11 (54.5%) had at least a 10% improvement in LVEF, 4/7 (57.1 %) had resolution of AMR on EMB, and 6/13 (46.1%) had reduction in DSA below threshold MFI. In patients without improvement in LVEF, EMB, or DSA following initial treatment; 3 patients (75%) had improvement in LVEF by at least 10% and 2 patients (33.3%) had reduction in DSA after 6 months of ECP. All 3 patients (100%) with persistent pAMR1I+ had resolution of biopsy-confirmed AMR after 3 months of ECP. In patients with clinical improvement following initial therapy, 3 (60%) patients maintained or improved LVEF and 4 (80%) maintained reduction in DSA after 6 months of ECP. <h3>Conclusion</h3> In this retrospective cohort, ECP was well tolerated with improvement and maintenance in LVEF, decrease in DSA positivity, and resolution of AMR on EMB. This modality may be a reasonable adjunctive therapy following initial treatment for AMR after HT.