Calcineurin inhibitor-free protocols: risks and benefits.

The nephrotoxic and extra-renal adverse effects associated with calcineurin inhibitor (CNI) therapies appear to have a negative impact on long-term graft survival. Several CNI minimization protocols have been recently studied. These protocols involve either early CNI avoidance or CNI withdrawal. CNI withdrawal strategies are associated with a significant improvement in renal function and graft survival on both a short and long-term basis. Delayed and progressive withdrawal appears to be safer. Maintaining a high mycophenolate mofetil (MMF) or sirolimus (SIR) exposure minimizes the risk of acute rejection. CNI avoidance regimens using maintenance mono-therapy or combination therapies without induction appear to be immunologically risky and unsafe. In contrast, the combination of SIR + MMF with induction therapy reduces markedly the incidence of acute rejection and chronic allograft nephropathy (CAN). Two year patient and graft survival levels were comparable. CAN as well as the incidence and the risk for cancer in addition to blood pressure profiles and uric acid levels were overall lower in the SIR-based treatment. In contrast, hyperlipidemia, delayed wound healing, lymphocele, arthralgias, thrombocytopenia and study protocol deviations were reported more frequently in the SIR-maintenance protocols. Longer-term follow-ups are definitely needed to determine whether these avoidance strategies will result in a significant improvement in long-term patient and graft survival. Outcome differences among various protocols within the same CNI elimination strategy are probably related to study design, patient selection criteria, immunosuppression monitoring methods, indications for graft biopsies, environmental, and both genetic and ethnic factors. All monitoring techniques are unreliable short of a graft biopsy. Preliminary results on drug lymphocyte binding may offer new guidelines for tailoring immunosuppression. Whether these protocols based on SIR or SIR + MMF can also be extended to high risk patients is currently unknown. These encouraging results allow speculation but with caution that the use of the combination of non-nephrotoxic immunosuppression such as SIR and MMF, might change dramatically the natural course of CAN and may influence long-term patient survival.

Cyclosporine lymphocyte maximum level monitoring in de novo kidney transplant patients: a prospective study.

OBJECTIVES: To determine prospectively the temporal variations of cyclosporine-A lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count in patients with de novo kidney transplantation. MATERIALS AND METHODS: Lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count were prospectively measured in 35 patients at 1, 2, and 3 months after kidney transplantation. Two groups--a biopsy-proven acute rejection group (REJ+) and a rejection-free group (REJ-)--were compared. RESULTS: Both groups had similar lymphocyte maximum levels, whole blood maximum concentrations, and total lymphocyte counts at the first month after transplantation. REJ+ patients had significantly lower lymphocyte maximum levels at 2 and 3 months (59+/-34 and 33+/-9 pg/Lc) and higher total lymphocyte counts (0.00204+/-0.00078x10(9)/L and 0.00203+/-0.00022x10(9)/L) when compared with their REJ- counterparts (87+/-56 and 63+/-30 pg/Lc, P<.05 and P<.007) and (0.00137+/-0.00074x10(9)/L and 0.0015+/-0.0006x10(9)/L, P<.02 and P<.003) respectively. Whole blood maximum concentrations were significantly higher in patients in the REJ+ group (2050+/-623 vs 1414+/-536 ng/mL, P<.02) at 2 months. At 3 months, the 2 groups were comparable (1158+/-340 vs 1365+/-525 ng/mL, P=NS). CONCLUSIONS: These results suggest that acute rejection is associated with a relatively low cyclosporine- A lymphocyte maximum level and high total lymphocyte count in the early posttransplant period. Cyclosporine-A whole blood maximum concentration failed to correlate with clinical outcome. Cyclosporine-A lymphocyte maximum level seems to offer a more reliable alternative than does whole blood maximum concentration for cyclosporine-A monitoring in patients with kidney transplantation.