Abstracts

INTRAVENOUS IMMUNOGLOBULIN (IVIG): EFFECTIVE FOR REDUCTION OF ALLOANTIBODY IN SENSITIZED HEART TRANSPLANTATION (HT) CANDIDATES

Eric Quivers, Susan Miller, Victor Morell, Adriana Zeevi, Steven Webber Cardiology, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA

Background and Methods: An elevated panel reactive antibody (PRA) indicates prior human leukocyte antigen (HLA) sensitization and represents a significant risk for severe early allograft rejection and dysfunction in organ transplantation. Treatment of HT candidates with IVIG has been recommended in this setting. The efficacy of this practice remains unclear. We reviewed our experience with IVIG therapy in children listed for HT with DTT-treated PRA levels of > 10%.

Results: We identified 7 children listed for HT who were treated with IVIG, 4 M and 3 F with an average age of 4.8 +/- 3.4 years (range 0.5 to 10.2 years) at the time of evaluation. 6/7 had congenital heart disease (CHD) and had undergone a median of 2 open heart procedures (range 1 to 4). The 6 CHD patients had homograft material implanted during prior surgery. The last patient had dilated cardiomyopathy and received multiple blood products on ECMO. Initial median PRA values were 50% (range 25 to 96%) without DTT and 50% (range 21 to 89%) with DTT. The number of IVIG (2g/kg) treatments given: 1 treatment (2 pts), 2 (3 pts), 5 (1 pt) and 8 (1 pt). Concurrent treatments included: mycophenolate mofetil (2 pts) and cytogam (1 pt). The response to IVIG therapy for each individual was unpredictable. Overall, median % change in DTT-treated PRA after first treatment was 0% (range 79 to + 86%) and % change at latest follow-up from baseline was -3% (range 58 to + 105%). DTT-treated PRA at latest follow-up was median 43%, range 29-86%. No patient achieved a reduction in PRA value to the acceptable level of 10% or less.

Conclusions: The use of IVIG does not reliably result in the reduction of elevated PRA in allosensitized pediatric HT candidates. We speculate that this failure is due to presence of ongoing antigenic stimulation from homograft material used as part of their prior surgical palliation for CHD. Other strategies will be required to decrease allosensitization in this population.