Non Cognate Function of B cells in Transplantation

How B cells affect the outcome of transplants is a question of enduring interest. Initial efforts to answer that question suggested, wrongly, that B cells have no impact on transplantation. Now, however, B cells are known to influence the outcome of vascularized grafts through the production of anti-donor antibodies and the competence of cellular immunity through a number of physiologic functions. In this communication, we explain why the importance of B cells was overlooked in the past and consider the range of non-cognate functions of B cells that may determine the outcome of transplants.