Abstract 13048: Do Anti-HLA Antibodies Pre-heart Transplant Truly Impact Post-transplant Outcomes?

Abstract

Introduction: Antibody-mediated rejection (AMR) continues to be a major barrier to favorable long-term outcomes and long-term survival. Sensitized pre-heart transplant (HTx) patients, those with anti-HLA antibodies, have previously demonstrated increased post-HTx rejection risk as well as increased mortality. In the current era, there is contention as to whether pre-HTx antibodies result in poor outcome after HTx. Methods: Between 2010 and 2015, 580 HTx patients were assessed for pre-HTx panel reactive antibodies (PRA). PRA levels were measured by the Luminex Single Antigen assay. Patients were divided into 5 groups of PRA levels including 0%, n=423 (Control); PRA 1-10%, n= 21; PRA 11-25%, n=24; PRA 26-50%, n=49; PRA 51-75%, n=32; and PRA >75%, n=35. Endpoints included 5-year survival, freedom from cardiac allograft vasculopathy (CAV), freedom from non-fatal major adverse cardiac events (NF-MACE), freedom from donor specific antibody (DSA) development, and freedom from LV dysfunction (LV ejection fraction ≤40%) and 1-year freedom from rejection (any treated rejection (ATR), acute cellular rejection (ACR), AMR). Results: All groups with PRA >10% had significantly lower 1-year freedom from AMR and 5-year freedom from DSA compared to the control, worsening with higher the PRA group. There was no significant difference in 5-year survival, 5-year freedom from CAV, NF-MACE, or LV dysfunction and 1-year freedom from ATR or ACR. Conclusions: Patients with increased anti-HLA antibody levels pre-HTx do not appear to have lower 5-year survival compared to patients without anti-HLA antibody levels. However, the development of 1-year AMR and 5-year DSA increased progressively with higher the PRA group. Further studies and longer follow-up are needed to better understand the effects of elevated pre-HTx PRA, immune therapies (desensitization) and post-HTx outcomes.