Inclusive ABO-Incompatible Listing for Pediatric Heart Transplantation Results in Comparable Post-Transplant...

ABO-incompatible (ABOi) heart transplantation (HT) has increased organ availability for infants with end-stage heart failure. Despite increasing adoption of ABOi listing for HT, data remain limited regarding pre- and post-HT immunologic profiles to guide listing practices and post-HT follow-up. Thus, the purpose of this study was to evaluate post-HT outcomes at a single center employing inclusive ABOi listing irrespective of pre-HT isohemagglutinin titers. All HT recipients listed at less than 24 months of age at our institution from 2010-2020 were included. Pre- and post-operative variables were compared for ABOi and ABO-compatible (ABOc) recipients. Separate iso-IgG and iso-IgM titers were monitored pre- and post-HT. Primary outcomes were compared between ABOi versus ABOc groups at mid-term follow-up. 51 HTs were performed on 50 patients from 2010-2020 (ABOi, N = 13; ABOc, N = 38). Six ABOi recipients received intra-operative plasma exchange for elevated titers (greater than 1:8 for IgG or IgM or reverse type greater than 2 +). Treated rejection, DSA, CAV, primary graft failure, need for re-HT, and survival were comparable between ABOi and ABOc groups at mid-term follow-up. An inclusive approach to ABOi HT listing for infants less than 24 months of age results in comparable post-transplant rejection-free survival, CAV, and prevalence of DSA at mid-term follow-up. These data define a potential role for specific IgM and IgG testing to promote understanding of risk stratification in pediatric ABOi listing, and support an inclusive strategy irrespective of high pre-HT titers to expand the number of available donor hearts for infants and older children awaiting HT.