Indications and Effectiveness of the Mammalian Target of Rapamycin in Liver Transplantation

Abstract

Background The mammalian target of rapamycin (mTOR) inhibitors are new immunosuppressive drugs for organ transplantation. They are interesting for liver transplantation because of their absence of nephrotoxicity and potential antitumor effects, because calcineurin inhibitors (CNI) are associated with renal dysfunction post-CNI and tumors. We sought to analyze the indications, safety, and efficacy of mTOR among liver transplant patients at our center. Methods We retrospectively identified patients who were treated with mTOR for their indications for liver transplantation, type of immunosuppressive therapy, acute rejection episodes, and evolution of kidney function. Results We identified 43 (19.02%) patients treated with mTOR including 35 (81.4%) males and 8 (18.6%) females of overall average age of 56.7 (range, 44–68). In 30% of patients, the drug was introduced for kidney failure, and in 23% for actual or a high risk of hepatocellular carcinoma (HCC) recurrence. The average time to introduction of the mTOR was 6.4 months (range, 1–46). The final immunosuppressive regimen was mTOR alone (73%), or mTOR plus CNI (23%), or mTOR plus mycophenolate mofetil (4%). The average values of creatinine and urea were lower after conversion to mTOR ( P < .05) with a 6.9% incidence of acute rejection episodes. Conclusion The mTOR immunosuppressive drugs are safe for liver transplant patients, effectively controlling renal dysfunction. They can be used in other indications, such as neurotoxicity, de novo tumors, and high risk of HCC recurrence. More studies are needed to clarify their long-term effectiveness.