Immunological risks of minimization strategies.

During the past 10 years, minimization strategies have been legitimately initiated to decrease the many toxicities of calcineurin inhibitors, especially nephrotoxicity which was considered to be responsible for the majority of graft losses. Even though CNI-induced nephrotoxicity is undeniable, we have learned in the past 10 years that DSAs detected with solid-phase assays are excellent prognostic biomarkers in kidney transplantation (and in other organ transplantations as well) and that chronic antibody-mediated rejection has become the leading cause of graft loss. In this review, we will focus on the immunological risks linked to various strategies aiming at decreasing CNI doses either at time of transplantation or later in the course of follow-up. Some of these interventions are associated with an increase in acute cellular rejection rates but also with an improvement in renal function. The effects on antibody-mediated rejection and occurrence of de novo donor-specific antibodies are still under-reported. We are currently missing long-term data to appreciate the influence of these minimization strategies on graft and patient survival. This then leads to a cautious attitude regarding reducing immunosuppression.