Pediatric heart transplantation: Allograft rejection

The early and midterm results of pediatric heart transplantation are encouraging. The procedure has evolved from an experimental therapy to an accepted medical practice for infants and children with lethal cardiomyopathy or severe congenital heart defects. The risk of rejection, though reduced by the use of cyclosporine, continues to be a significant threat to long-term survival. Several problems of rejection have special significance in children. The requirement for lifelong immunosuppression, with longer exposure to side effects, and the difficulty of performing repeated myocardial biopsies emphasize the need for accurate noninvasive methods of recognizing rejection. There is interest in and controversy about the optimal timing for pediatric heart transplantation, especially in infants with complex congenital heart defects. Although studies have demonstrated immunological immaturity in the newborn, it remains to be seen whether this will be translated into a real long-term clinical advantage. Although the ultimate prospects for pediatric heart transplant patients remain uncertain, improvements in rejection monitoring and treatment will surely increase the prospects for long-term survival.