Abstract 13110: Pediatric Heart Transplantation in Pre-Sensitized Recipients: A Current Perspective

Introduction: Anti-HLA antibodies (Ab) are increasingly prevalent in pediatric patients (pts) awaiting heart transplant (HT) and may result in a significant delay in time to HT because of the need to wait for a negative prospective donor HLA crossmatch (XM). Methods: Data from pts in the Pediatric HT Study transplanted between 2010-2014 were analyzed to determine the association of pre-HT percent reactive anti-HLA Ab (PRA) detected by flow cytometry with retrospective donor XM results and outcomes after HT. Sensitization was defined as a PRA >20%. Results: HT was performed in 1,596 pts, 1,459 had a PRA calculated and 1,419 had XM results available. Sensitization was present in 32% of pts; 25% were sensitized against Class I and 20% were sensitized against Class II Ab (p Conclusions: In the current era, 32% of pediatric HT pts are sensitized, with a higher incidence seen in pts with CHD compared to those with CM. Although, increasing PRA levels were associated with a higher likelihood of a positive retrospective XM, 68% of pts with a pre-HT PRA >50% had a negative XM. XM was positive in 9% of pts with a PRA between 1-20%. Sensitized pts with a positive XM had a higher incidence of rejection than all other pts. Better methods of identifying pts at risk for a positive XM are needed to refine the indications for a prospective XM in pediatric pts listed for HT.