Low-dose calcineurin inhibitor regimen combined with mammalian target of rapamycin inhibitors preserves kidney functions in renal transplant recipients without allograft nephropathy.

OBJECTIVE: The present study was designed to investigate the effect of low-dose calcineurin inhibitor (CNI) tacrolimus combined with a mammalian target of rapamycin (mTOR) inhibitor on renal function in transplant recipients without allograft nephropathy.

PATIENTS AND METHODS: Twelve patients including seven men (58.3%) of overall mean age of 34.8 ± 14.1 years underwent renal transplantation and were switched to a new second-line treatment of low-dose CNI combined with an mTOR inhibitor, either sirolimus or everolimus.

RESULTS: The underlying cause of renal failure was not clear in half of the cases; for the others it was chronic glomerulonephritis, diabetic nephropathy, polycystic kidney disease, or hypovolemia. After 6 months of the new therapy, there was a significant increase in calculated creatinine clearance levels compared to baseline (75.5 ± 21.9 vs 89.6 ± 19.1 mL/min; P < .001), but no significant change in serum creatinine (1.3 ± 0.4 vs 1.2 ± 0.3 mg/dL) or urinary protein excretion (187.5 ± 142.0 vs 394.0 ± 326.4 mg/g). For almost all patients, proteinuria remained stable, but in two patients, it developed but responded to enalapril treatment. Dose decrement was required for four patients with hyperlipidemia (50%); one patient experienced new-onset hyperlipidemia that responded to treatment. One patient developed a urinary tract infection that responded to antibiotic treatment. None of the patients developed an acute rejection episode.

CONCLUSION: Low-dose CNI combined with an mTOR inhibitor, as a replacement for mycophenolate mofetil or enteric-coated mycophenolate sodium, seemed to prevent renal dysfunction for at least 6 months among renal transplant patients without allograft nephropathy.