Blood type incompatible cardiac transplantation in young infants.

OBJECTIVE: Donor organ shortage in pediatric heart transplantation (HTx) is causing mortality rates of 30-50% on the waiting list. Due to immaturity of the immune system of newborns and infants, ABO-incompatible HTx may be an option to increase donor availability. We present our experience with ABO-incompatible HTx.
METHODS: Three infants were transplanted ABO-incompatible since 12/2004: (1) hypoplastic left heart complex, (2) restrictive hypertrophic cardiomyopathy, (3) dilative cardiomyopathy. Age at HTx was 7, 5, and 3.5 months. All recipients had blood type O, donors were A, A, and B. Informed consent was given by parents, the ethics committee, and Eurotransplant.
RESULTS: Preoperative isohemagglutinin titers were low (Patient 1: 1:4 for anti-A1, A2, B, Patient 2: 1:4, 1:1, 1:4 for anti-A1, A2, B, respectively, and Patient 3: 0 for all, but quick spin 1+ for all). Intraoperatively, plasma was separated from red blood cells and discarded up to six times until antibodies were eliminated. Immunosuppressive induction with ATG was started for 5 days. Basic immunosuppression consisted of tacrolimus, mycophenolate mofetil, and prednisone. Extubation was performed on days 15, 2, and 1, respectively. After a follow-up of 17, 16, and 12 months all patients are well, ventricular function is excellent without any acute rejection periods; Patient 1 is still on dialysis. Isohemagglutinin titers against donor blood type have disappeared in follow-up.
CONCLUSIONS: ABO-incompatible cardiac transplantation shows good short-term results in young infants and seems to be a safe procedure to lower the mortality on the waiting list.