DONOR CELL CHIMERISM PERMITTED BY IMMUNOSUPPRESSIVE DRUGS - A NEW VIEW OF ORGAN-TRANSPLANTATION

One line of thought in organ transplantation feels that immunosuppress ive drugs can lead to tolerance induction by allowing a previously unr ecognized common mechanism of cell migration and microchimerism to occ ur, persist, and in some cases, become drug independent. It has been r ecognized that there is a spectrum of susceptibility of different orga ns to cellular rejection and that the variable ability of these organs to induce donor-specific nonreactivity reflects their comparative con tent of migratory leukocytes. Here, Thomas Starzl and colleagues discu ss how many of the enigmas of transplantation immunology can be explai ned by this chimerism.