Ethical issues in increasing living kidney donations by expanding kidney paired exchange programs

In 1997, Ross et al. proposed to increase the supply of living kidney donations by using kidneys from living ABO-incompatible donors through an exchange arrangement between two living kidney donor-recipient pairs. Although many transplant centers are exploring this option, only a small fraction of potential donor-recipient pairs are eligible for an exchange on the basis of ABO incompatibility. In this article, we explore three variations that have potentially great clinical relevance. The three potential variations discussed are: (1) altruistically unbalanced living donor-recipient exchanges; (2) an indirect exchange (an exchange between a living donor-recipient pair with a cadaveric donor-recipient pair) on the basis of a positive crossmatch; and (3) an indirect exchange on the basis of ABO incompatibility. The goal of kidney paired exchange programs is to increase the supply of kidneys available for transplantation ethically. We acknowledge that all exchanges increase the potential for coercion, and we currently reject the proposal of altruistically unbalanced exchanges because of the potential for coercion. However, we believe that voluntary consent can be achieved for indirect exchanges. The indirect ABO-compatible exchange creates no new ethical concerns to our original living paired exchange program and we support its implementation. The indirect ABO-incompatible exchange does create a new ethical concern because it may increase the vulnerability of O blood group recipients. If mechanisms can be developed to avoid increasing the waiting time for blood group O recipients, we would support the implementation of the indirect ABO-incompatible exchange.