Risk Factors Associated With Mammalian Target of Rapamycin Inhibitor Withdrawal in Kidney Transplant Recipients

Mammalian target of rapamycin inhibitors (mTORi) play an essential role as novel immunosuppressive agents in kidney transplantation (KT). Treatment cessation usually occurs after adverse effects occur. We investigated the risk factors associated with withdrawal of mTORi in KT recipients and evaluated the outcomes related to the withdrawal.

The study enrolled KT recipients being followed up in a medical center in southern Taiwan from January 1999 through December 2014.

Risk factors associated with mTORi withdrawal were initial proteinuria level, higher initial serum creatinine level posttransplantation, and history of glomerulonephritis as the primary etiology of renal failure. mTORi withdrawal was associated with increased risk of graft failure (hazard ratio [HR], 9.97 [95% confidence interval (CI), 1.03-96.8]; P = .047). Higher body mass index (HR, 11.2 [95% CI, 1.63-76.6]; P = .01) and tacrolimus usage (HR, 8.30 [95% CI, 1.14-60.7]; P = .037) were associated with increased risk of new-onset diabetes after transplantation in mTORi withdrawal groups.

Proteinuria, poor graft function, and primary glomerulonephritis were associated with cessation of mTORi treatment. Earlier identification of these risk factors may prevent further adverse events and optimize transplantation outcomes after mTORi conversion.