New immunosuppressive protocols with the advent of novel biological drugs

Long-term results in renal transplantation are not as good as it has been expected. Thus, there is increasing interest in new immunosuppressive drugs and strategies. Among such strategies, antithymocyte globulin, particularly in calcineurin inhibitor-free protocols, may allow generation of regulatory T cells (Tregs), a cell population with suppressor properties that has been associated with donor-specific cellular hyporesponse and suppression of B-cell response by inhibiting T-cell help. Interestingly, belatacept despite targeting the main costimularory signal for Tregs survival does not abrogated generation of Tregs. Belatacept has excellent short-term results in calcineurin inhibitor-free protocols. On the other hand, it has been recently shown that CD40-C40L is critical to develop donor-specific antibodies. Perhaps, association of T-cell depleting agents with CD40-CD40L blockade may avoid both cellular rejection and, more interestingly, human leukocyte antigen sensitization.