Ischemia and reperfusion injury

Organ allografts, particularly from less than optimal donors, may not be biologically inert at the time of transplantation but may trigger or amplify subsequent host responses against the foreign tissues. These potentially activated organs may provoke a continuum between the inflammatory changes evoked in the recipient by initial nonspecific, antigen-independent insults and the later onset of antigen-dependent, immunologic alloresponsiveness. Older donors, hypertension and other donor factors, the peripheral events surrounding brain death, the use of non-heart-beating donors, and ischemia-reperfusion injury may all contribute to initial graft injuries. These in turn may provoke the eventual onset of progressive chronic graft dysfunction. The effects of these insults, with special reference to cardiac transplants, are reviewed.