The effects of mammalian target of rapamycin inhibitors on serum uric acid levels in renal transplant patients

Backgrounds/Aims Elevated uric acid (UA) levels are frequently observed after renal transplantation. We investigated the consequences of shifting from calcineurin inhibitors (CNI) to mammalian target of rapamycin inhibitors (mTORi) on UA levels and graft functions. Methods Ninety-six patients were enrolled. Main points of interest were changes in UA and glomerular filtration rate (GFR). Results Mean age of the whole population was 39 ± 11 years (18–73), and 64.2 % were male. Patients were stratified into two groups according to their CNI type prior to the switch as cyclosporin A (CsA) or tacrolimus (Tac). Patients that were switched from CsA had a mean GFR of 49 ± 18 ml/min and serum UA level of 7.4 ± 1.8 mg/dl at the pre-switch period. Mean GFR increased to 53 ± 22 ml/min ( p = 0.03), and UA levels decreased to 6.2 ± 1.6 mg/dl at the final visit ( p