Late Antibody-Mediated Rejection After Heart . Transplantation Following the Development of De Novo Donor-Specific Human Leukocyte Antigen Antibody

Antibody-mediated rejection (AMR) is an important problem after heart transplantation. Most cases seem to occur in sensitized recipients with preformed donor-specific human leukocyte antigen antibody (DSA) early after transplantation. Few data exist on AMR in patients who form de novo DSA. We describe the clinical features and treatment outcome for late AMR secondary to de novo DSA. This was a retrospective, observational cohort study. All heart transplant patients treated for symptomatic AMR secondary to de novo DSA between November 2005 and August 2011. Fifteen patients were treated for AMR giving an incidence of 3.1 cases per 1000 person years and a prevalence of 1.4%. All had evidence of heart failure on presentation and de novo DSA at diagnosis. There was a spectrum of histologic and immunohistochemical findings. Despite treatment with immunepheresis, intravenous immunoglobulin, and rituximab, and in some cases total lymph node irradiation (n=3) and bortezomib (n=2), clinical outcomes were poor. DSA antibody levels, measured using Labscreen single antigen kits, were reduced by a mean of 76% with a median of 77% and a range of 35% to 99%, but were not eliminated. Forty-six percent had persistent cardiac allograft dysfunction. Mean and median survival was 1.3 and 0.8 years after diagnosis of AMR. Only 40% were alive at the end of the study period. Late cardiac AMR caused by de novo DSA was an uncommon but serious problem. Despite treatment consistent with current best practice, 46% of patients developed persistent cardiac dysfunction and their medium-term survival was poor.