Tapering immunosuppression in recipients of living donor kidney transplants.

We have previously suggested that the in vitro donor-specific cytotoxic T-lymphocyte precursor (CTLp) assay can guide us to identify patients in which the immunosuppressive load can be tapered. In a clinical trial we had observed that a low (<10/10(6) PBMC) frequency of these CTLp was predictive for an uneventful rejection-free clinical course in patients that were converted from calcineurin inhibitors to mycophenolate mofetil or azathiopine. In the present prospective study in 81 stable kidney transplant recipients, already converted from calcineurin inhibitors, we measured CTLp frequencies and reduced the immunosuppressive load on a routine basis when CTLp were