Rejection

Abstract

The mammalian immune system is specialized for the discrimination between self and nonself. The appearance of new macromolecules (or antigens) normally signifies a threat, such as an infection or malignant tumor. In these settings, the prompt destruction of antigen-bearing cells is a valuable adaptation. Unfortunately, the same defense mechanisms are also efficiently invoked by the clinical transplantation of potentially lifesaving organs. © 2008 Springer New York.