immunology allergic disorders
Kidney Transplantation
Kidney donors
More than one half of donated kidneys come from previously healthy, brain-dead people. About one third of these kidneys are marginal, with physiologic or procedure-related damage, but are used because demand is so great. More kidneys from non–heart-beating donors (called donation-after-cardiac-death [DCD] grafts) are being used. These kidneys may have been damaged by ischemia before the donor's death, and their function is often impaired because of acute tubular necrosis; however, over the long term, they seem to function as well as kidneys from donors that meet standard criteria (called standard criteria donors [SCD]). The remaining donated kidneys (about another 40%) come from living donors; because of limited supply, allografts from carefully selected living unrelated donors are being increasingly used. Living donors relinquish reserve renal capacity, may put themselves at risk of procedural and long-term morbidity, and may have psychologic conflicts about donation; therefore, they are evaluated for normal bilateral renal function, absence of systemic disease, histocompatibility, emotional stability, and ability to give informed consent. Hypertension, diabetes, and cancer in prospective living donors usually preclude kidney donation. Kidney exchange programs often match a prospective donor and recipient who are incompatible with other similar incompatible pairs. When many such pairs are identified, chain exchanges are possible, greatly increasing the potential for a good match between recipient and donor. If ABO matching is not feasible, sometimes ABO-incompatible transplantation can be done; with careful selection of donors and recipients and with pretransplant treatment (plasma exchange and/or IV immune globulins [IVIG]), outcomes can be comparable to those of ABO-compatible transplantation. 