On chain lengths, domino-paired and unbalanced altruistic kidney donations

Kidney transplantations with living related and unrelated donors are the optimal option for patients with end-stage renal disease. For patients with a willing--but blood-type or HLA incompatible donor--a living-donor kidney exchange program could be an opportunity. In Asia, the United States and Europe, kidney exchange programs were developed under different conditions, with different exchange algorithms, and with different match results. The easiest way to organize a living-donor kidney exchange program is to enlist national or regional cooperation, initiated by an independent organization that is already responsible for the allocation of deceased donor organs. For logistic reasons, the optimal maximum chain length should be three pairs. To optimize cross-match procedures a central laboratory is recommended. Anonymity between the matched pairs depends on the culture and logistics of the various countries. For incompatible donor-recipient pairs who have been unsuccessful in finding suitable matches in an exchange program, domino-paired kidney transplantations triggered by Good Samaritan donors is the next alternative. To expand transplantations with living donors, we advise integrating such a program into a national exchange program under supervision of an independent allocation authority. If no Good Samaritan donors are available, an unbalanced kidney paired-exchange program with compatible and incompatible pairs is another strategy that merits future development.