Approaching tolerance in transplantation

Basic research has provided substantial encouragement that tolerance proces ses may be harnessed to the benefit of organ transplants. The goal of achie ving mixed chimerism to ensure a robust tolerance, however elegant, may yet prove to be too complex and, consequently, risky as a procedure to compens ate for the breadth of genetic differences, and prior immunological experie nces of donor and host. Tolerance through regulation may prove to be easier to generate, but insufficiently robust to maintain. In the end the chosen protocol will be one that is simple, cheap and can guarantee patient compli ance. Pragmatically, such a protocol need not be one aimed at clear-cut dru g-free tolerance, but rather one which is trouble free. This could end up a s a combination of partial tolerance (where tolerance processes have been h arnessed) induced through a short-term treatment, in conjunction with easil y tolerated maintenance therapy with select immunosuppressive drugs. Perhap s to the patient, the holy grail of tolerance is not as important as the co mplete assurance that the graft will survive and continue to function in al l circumstances. Copyright (C) 2001 S. Karger AG, Basel.