ABO-incompatible heart transplantation in infants.

Background: Transplantation of hearts from ABO-incompatible donors is contr aindicated because of the risk of hyperacute rejection mediated by preforme d antibodies in the recipient to blood-group antigens of the donor. This co ntraindication may not apply to newborn infants, who do not yet produce ant ibodies to T-cell-independent antigens, including the major blood-group ant igens. Methods: We studied 10 infants, 4 hours to 14 months old (median, 2 months) , who had congenital heart disease or cardiomyopathy and who received heart transplants from donors of incompatible blood type between 1996 and 2000. Serum isohemagglutinin titers were measured before and after transplantatio n. Plasma exchange was performed during cardiopulmonary bypass; no other pr ocedures for the removal of antibodies were used. Standard immunosuppressiv e therapy was given, and rejection was monitored by means of endomyocardial biopsy. The results were compared with those in 10 infants who received he art transplants from ABO-compatible donors. Results: The overall survival rate among the 10 recipients with ABO-incompa tible donors was 80 percent, with 2 early deaths due to causes presumed to be unrelated to ABO incompatibility. The duration of follow-up ranged from 11 months to 4.6 years. Two infants had serum antibodies to antigens of the donor's blood group before transplantation. No hyperacute rejection occurr ed; mild humoral rejection was noted at autopsy in one of the infants with antibodies. No morbidity attributable to ABO incompatibility has been obser ved. Despite the eventual development of antibodies to antigens of the dono r's blood group in two infants, no damage to the graft has occurred. Becaus e of the use of ABO-incompatible donors, the mortality rate among infants o n the waiting list declined from 58 percent to 7 percent. Conclusions: ABO-incompatible heart transplantation can be performed safely during infancy before the onset of isohemagglutinin production; this techn ique thus contributes to a marked reduction in mortality among infants on t he waiting list. (N Engl J Med 2001;344:793-800.) Copyright (C) 2001 Massac husetts Medical Society.