Recipients of ventricular assist devices (VADR) have a higher incidence to develop antibodies (Abs) against human leukocyte antigens (HLA). Non-HLA antibodies like major histocompatibility complex class I-related chain A (MICA) and autoantibodies against angiotensin type 1 receptor (AT1R) and endothelin receptor A (ETAR) are also implicated in the pathogenesis of acute rejection and allograft vasculopathy. We monitored non-HLA- and HLA-Abs in VADR up to one year after implantation.