What is the purpose of CNI minimization or avoidance strategies?
These strategies are meant to avoid the long-term toxicities associated with CNI use—in particular, nephrotoxicity. This must be individualized to the patient and their immune risk for rejection. Various strategies include switching to a lower drug level target for tacrolimus in combination with an mTOR inhibitor with or without steroids. CNIs can be completely switched out for an mTOR inhibitor or Belatacept with an antimetabolite and steroids as well. There is some increased risk of rejection, particularly in high-risk populations when CNIs are minimized. The other concern that has come to light more recently is that CNI nephrotoxicity might not be the main culprit limiting long-term graft survival, but rather chronic alloimmune damage. If this is the case, it might be better to keep a patient on a CNI and not aggressively try to reduce the CNI exposure. Additional studies are needed.