Related Experiment Video
Updated: May 2, 2026
Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS
Published on: November 8, 2015
Conversion to mTOR-inhibitor-based immunosuppression: which patients and when?
Abstract:
Mammalian target of rapamycin (mTOR) inhibitors are currently considered an alternative immunosuppressive treatment that can prevent the nephrotoxicity, viral infections and malignancies that are associated with calcineurin inhibitor-based immunosuppressive regimens. However, the side effects of mTOR-inhibitor-based regimens lead to frequent treatment discontinuations, and not all patients seem to have the same benefits from conversion to mTOR inhibitors. This review focuses on long-term results of trials that have assessed early and late conversion to sirolimus or everolimus. The renal benefit of late conversion (≥1 year post transplantation) is limited, except in patients with good renal function and without proteinuria. Early conversion to mTOR inhibitors in the first 6 months, in combination with mycophenolate mofetil, could be an appropriate strategy for maintenance therapy in renal transplant recipients with a low immunological risk after careful screening at the time of conversion. Good renal function (glomerular filtration rate >40 ml/ minute), weak proteinuria (<1 g/day), an absence of previous acute rejection and subclinical rejection, and appearance of donor-specific anti-human leukocyte antigen antibodies appear to be the most important criteria in identifying patients for whom conversion to an mTOR inhibitor may improve renal function at 5 years.
Insights
Mammalian target of rapamycin (mTOR) inhibitors offer an alternative immunosuppression post-transplant. Early conversion to mTOR inhibitors benefits select renal transplant recipients, improving long-term renal function.
Area of Science:
- Nephrology
- Immunosuppression
- Transplantation
Background:
- Calcineurin inhibitor (CNI)-based immunosuppression is associated with nephrotoxicity, infections, and malignancies.
- Mammalian target of rapamycin (mTOR) inhibitors are an alternative immunosuppressive strategy.
- mTOR inhibitor regimens can cause side effects leading to treatment discontinuation and variable patient benefits.
Purpose of the Study:
- To review long-term results of early and late conversion to mTOR inhibitors (sirolimus or everolimus).
- To identify criteria for optimal patient selection for mTOR inhibitor conversion in renal transplantation.
Main Methods:
- Review of clinical trials assessing early (<6 months) and late (≥1 year) conversion to mTOR inhibitors.
- Analysis of patient characteristics and outcomes, focusing on renal function and proteinuria.
Main Results:
- Late conversion (≥1 year) offers limited renal benefit, except in patients with preserved renal function and low proteinuria.
- Early conversion (within 6 months) in combination with mycophenolate mofetil may be suitable for low immunological risk renal transplant recipients.
- Key criteria for successful conversion include good renal function (GFR >40 ml/min), low proteinuria (<1 g/day), absence of rejection, and no donor-specific antibodies.
Conclusions:
- Early conversion to mTOR inhibitors, with careful patient selection, can be an effective maintenance strategy for renal transplant recipients.
- Identifying patients with specific criteria is crucial for maximizing the renal benefits of mTOR inhibitor therapy at 5 years post-transplantation.
Related Concept Videos
01:27Tumor Immunotherapy
01:29Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents
03:03mTOR Signaling and Cancer Progression
The mTOR pathway or the...