Initial Single-Center Experience With Sirolimus After Lung Transplantation

Mammalian Target of Rapamycin Inhibitors and Kidney Function After Thoracic Transplantation: A Systematic Review and Recommendations for Management of Lung Transplant Recipients

BACKGROUND

Chronic kidney disease (CKD) after lung transplantation is common and limits the survival of transplant recipients. The calcineurin inhibitors (CNI), cyclosporine A, and tacrolimus being the cornerstone of immunosuppression are key mediators of nephrotoxicity. The mammalian target of rapamycin (mTOR) inhibitors, sirolimus and everolimus, are increasingly used in combination with reduced CNI dosage after lung transplantation.

METHODS

This systematic review examined the efficacy and safety of mTOR inhibitors after lung transplantation and explored their effect on kidney function.

RESULTS

mTOR inhibitors are often introduced to preserve kidney function. Several clinical trials have demonstrated improved kidney function and efficacy of mTOR inhibitors. The potential for kidney function improvement and preservation increases with early initiation of mTOR inhibitors and low target levels for both mTOR inhibitors and CNI. No defined stage of CKD for mTOR inhibitor initiation exists, nor does severe CKD preclude the improvement of kidney function under mTOR inhibitors. Baseline proteinuria may negatively predict the preservation and improvement of kidney function. Discontinuation rates of mTOR inhibitors due to adverse effects increase with higher target levels.

CONCLUSIONS

More evidence is needed to define the optimal immunosuppressive regimen incorporating mTOR inhibitors after lung transplantation. Not only the indication criteria for the introduction of mTOR inhibitors are needed, but also the best timing, target levels, and possibly discontinuation criteria must be defined more clearly. Current evidence supports the notion of nephroprotective potential under certain conditions.

Mammalian Target of Rapamycin Inhibitors Vs Calcineurin Inhibitors in Chronic Graft Rejection After Lung Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND

The number of lung transplantations has been rising constantly. However, use of this therapeutic resource is limited by several issues that are difficult to resolve, such as chronic graft rejection and complications secondary to immunosuppression.

METHODS

This systematic review compared mammalian target of rapamycin (mTOR) inhibitor immunosuppression associated with low-dose calcineurin inhibitors with isolated calcineurin inhibitor immunosuppression on the new-onset chronic rejection development and mortality 12 months after lung transplantation. Three controlled randomized clinical trials (SHITRIT, NOCTET, and 4EVERLUNG) were selected from electronic databases.

RESULTS

Meta-analysis of the data at 12 months postintervention showed that only 4EVERLUNG assessed chronic graft rejection, with a higher incidence in the control group; however, the difference was not statistically significant (P = .197). Significant data were related to an increase in the number of adverse events (P = .0064) and improved renal function (P < .0001) in the mTOR inhibitor-based scheme. The other outcomes indicated a trend toward greater risk of death and acute graft rejection with the use of mTORs.

CONCLUSIONS

The researchers suggest considering the use of mTOR inhibitors, whose greatest benefit is felt by patients with renal dysfunction, in association with the use of calcineurin inhibitors, because of the imminent risk of death among patients with renal failure.

Effects of prophylactic use of sirolimus on bronchiolitis obliterans syndrome development in lung transplant recipients

BACKGROUND

Sirolimus (SIR) has been shown to stabilize the lung function in lung transplant recipients with bronchiolitis obliterans syndrome (BOS). However, there is no long-term data on the prophylactic use of SIR in lung transplant recipients. This retrospective study examines the effects of SIR in the prevention of BOS.

METHODS

From 1999 to 2009, 24 lung transplant recipients whose maintenance immunosuppression regimen consisted of tacrolimus (Tac), mycophenolate mofetil (MMF) or azathioprine (AZA), and prednisone (Pred), were switched to Tac, SIR, and Pred at 1 year after transplantation. From these 24 patients, 5 developed side effects that necessitated the cessation of SIR within 1 year, while 19 patients tolerated long-term use of SIR. The clinical outcomes of these 19 patients (SIR group) were compared with 22 lung transplant recipients whose immunosuppression regimen consisted of Tac, MMF or AZA, and Pred from the time of transplant (MMF group). Survival rates and freedom from BOS were calculated by the Kaplan-Meier method.

RESULTS

The SIR group had a lower incidence of BOS and viral infection (p = 0.05), and higher survival rates (p = 0.004). The SIR group had lower levels of Tac and received less Pred. The incidences of acute rejection, carcinoma, hypertension, and diabetes were similar between both groups.

CONCLUSIONS

Results from this study suggest that conversion to SIR 1 year after lung transplantation improves survival and decreases the development of BOS. Randomized studies with higher number of patients are needed to determine the prophylactic efficacy of sirolimus in preventing the development of BOS.

Recommendations on the use of everolimus in lung transplantation

The antiproliferative effect of everolimus provides a therapeutic option in the immunosuppression therapy of lung transplantation, by reducing both the risk of acute rejection and the process of progressive fibrosis that determines chronic graft rejection. However, few data on the use of everolimus in lung transplantation have been published to date, and the specific indications of the drug, along with the most adequate time for its introduction or dosing, have not been defined yet. The aim of this article is to propose recommendations for the use of everolimus in lung transplant recipients, including indications, dosing schedules and the use of concomitant immunosuppression. This consensus document has been developed by experts of all the Spanish lung transplant groups from the review of the existing literature and the clinical experience.