Cardiac transplantation in infancy: a model for dissecting immunological function

Abstract: Infants with heart transplants are generally subjected to thymectomy and T cell depletion. In principle, these manipulations should bring about an enduring defect in the structure and function of the T cell compartment. Consistent with that concept, we found that children with heart transplants have profound contraction of the T cell repertoire and higher levels of herpes viruses following infection. Still, these children are generally free of opportunistic infections and other complications expected of those with immunodeficiency. Here we consider these observations and the implications they offer for understanding immune physiology.