Retrospective evaluation of clinical and laboratory data of renal transplant recipients using mammalian target of rapamycin (mTOR) therapy

Chronic kidney disease (CKD) is defined as irreversible alternations of function and structure of the kidney over months or years due to many diseases. A glomerular filtration rate (GFR) of less than 15 mL/min per 1•73m² is referred as end stage kidney disease (ESKD). Treatment options for patients with ESKD are kidney replacement therapy (dialysis or kidney transplantation) or conservative care. Kidney transplantation is the preferred treatment for ESKD because it is the closest thing to having normal kidneys. Patients with renal transplantation should receive immunosuppressive therapy as long as the graft function is maintained. Immunosupression is almost always includes a combination of drugs. In this combination, corticosteroids, calcineurin inhibitors (CNI), antimetabolites and mammalian target of rapamycin (mTOR) inhibitors are used. The most common immunosuppressive treatment protocol among renal transplant patients is the combination of antimetabolite agents and CNIs. Nephrotoxicity, chronic allograft nephropathy and graft loss may be seen with the long term use of CNI. Mammalian target of rapamycin (mTOR) is a protein serine/threonine kinase that plays a central role in the regulation of cell growth, metabolism and proliferation. mTOR inhibitors act as immunospressant by blocking the signaling pathway of T cell growth factors and thus inhibit the proliferation of antigen-activated T cells. mTOR inhibitors are used as an alternative to calcineurin inhibitors for long-term immunosuppression in renal transplant patients, especially because of their relative lack of nephrotoxicity. However, relatively high drug discontinuation rates have limited the more broad introduction of mTOR inhibitors in kidney transplantation. The primary reason for drop outs were side effects, such as bone marrow suppression, mucositis, acne, proteinurea and peripheral edema. In this study, we evaluated the clinical and laboratory data of renal transplant patients receiving mTOR inhibitors (including interruption and withdrawn) in our center.