Lessons from transplantation and future perspectives.

Organ transplantation is now a routine treatment for a number of chronic kidney, heart, lung, and liver diseases. We have accumulated much knowledge about these treatments in the respective disciplines, and it seems appropriate to reflect on some general "across-the-border" lessons that may be important for medicine as a whole. The natural history of several diseases has been extended; however, we have also learned much about temporary organ replacement, with the possibility of treating and, perhaps, also preventing some diseases in ways that were not possible in the past. This study explores the phenomenon of temporary organ replacement, whereby organs that are in danger in losing their function may recover in quiescence. It raises the question of whether there might be a common, underlying mechanism-such as apoptosis-for some very different diseases. Pharmacological interventions designed to modulate apoptosis are being developed that will hopefully reduce the amount of time needed for organs to recover their function. We have learned some lessons, but are there more possibilities that need to be explored?