We previously reported the short-term feasibility of Calcineurin-Inhibitor (CNI) elimination in kidney transplant recipients. We now report the long-term clinical impact on renal allograft function after conversion from tacrolimus (Tac) to sirolimus (SRL) in a prednisone-free regimen.

Methods:

In a prospective, randomized, single center trial, 200 kidney transplant recipients were induced with Alemtuzumab and placed on a prednisone-free regimen with Tac and Mycophenolate Mofetil (MMF). At 1 year post transplantation, patients were randomized 2:1 to SRL (n=135) or maintained on Tac (n=65). Intention to treat analysis included 64 in the Tac group and 117 in the SRL group. Patients with a recent (<3 months) episode of acute rejection or more than 0.5g/day of proteinuria were excluded.

Results:

There were no statistical differences in recipient demographics, donor age, number of mismatched antigens, DGF or PRA. Mean time of conversion to SRL was 12.6 months. Mean follow time was 63.9 months in the SRL group and 65.9 months in the Tac group. There was no significant difference in the number of deaths (n=3 in Tac group, n=9 in SRL group: p value= 0.5437) or eGFR by MDRD (Fig 1) in the two groups. However, the combined outcome of acute rejection and graft loss was worse in patients converted to SRL compared to those who remained on Tac (Fig 2).

Conclusion:

Conversion from CNI to mTor inhibitor in kidney transplant recipients on a prednisone free immunosuppression regimen may lead to worse clinical outcomes. Mechanistic studies are underway to investigate possible predictors of poor outcomes in the SRL converted group.

« Back to 2015 American Transplant Congress