Multicenter experience of ABO-incompatible pediatric cardiac transplantation

Although ABO blood group incompatible cardiac transplantation in neonates and infants reduces waiting list mortality without compromising outcome, the technique has not been adopted by all centers, and to date Toronto remains the only center to have published results from a large case series. We present a review of ABO-incompatible heart transplantation in the United Kingdom (UK) where current recipient selection criteria differ somewhat from those used in the United States (US) and Canada. Between February 2000 and November 2006, 21 ABO-incompatible cardiac transplants were performed in children aged 2-40 months (median 10.0). Immunosuppression followed standard regimens. Pretransplant donor-specific isohemagglutinins of >1:4, (the UNOS cutoff), were present in five patients and reduced by plasma exchange. After transplantation, 19/21 recipients demonstrated persisting deficiency of donor-specific isohemagglutinins. Significant donor-specific isohemagglutinins levels were detected repeatedly in 2/21 recipients who have shown no clinical or biopsy evidence of rejection. All recipients survive without retransplantation and there have been no episodes of humoral rejection. We conclude it is possible for other centers to replicate the excellent results achieved in Toronto and that ABO-incompatible transplantation may be performed successfully in some patients beyond infancy with established isohemagglutinin production providing preoperative antibody removing strategies are used.