Conversion to Proliferation Signal Inhibitors–Based Immunosuppressive Regimen in Kidney Transplantation: To Whom and When?

Sirolimus potentiated angioedema: A case report and review of the literature

Introduction

In the realm of organ transplantation, particularly heart transplantation, angioedema presents a significant challenge. This clinical condition ranges from minor facial edema to life-threatening swelling of vital structures. Its multifactorial etiology involves various factors and mechanisms, including C1 esterase inhibitor deficiency, food allergen hypersensitivity, and adverse drug reactions, notably involving angiotensin-converting enzyme (ACE) inhibitors and mechanistic target of rapamycin inhibitors (mTOR-Is). We present a rare case of sirolimus potentiated angioedema in a patient with long-standing ACE inhibitor therapy.

Case

A 52-year-old male with a history of heart transplant developed severe upper and lower lip edema. The patient had been on Lisinopril without any adverse events. However, sirolimus was recently added to his drug regimen. Sirolimus potentiated angioedema was suspected.

Intervention

Intravenous methylprednisolone, famotidine, and diphenhydramine were initiated, and both lisinopril and sirolimus were discontinued. The patient showed improvement and was discharged with oral antihistamines.

Lessons

Transplant physicians should be aware of the life-threatening interaction between ACE inhibitors and mTOR-Is like sirolimus. Consideration should be given to switching from an ACE inhibitor to an angiotensin-receptor blocker when initiating patients on mTOR-Is.

Everolimus-associated stomatitis in a patient who had renal transplant

Everolimus is used as an immunosuppressant in renal allograft transplant rejection and in metastatic breast cancer treatment. One side effect of everolimus is stomatitis, referred to as mammalian target of rapamycin inhibitor-associated stomatitis. This side effect can affect treatment course and contribute to discontinuation of therapy or dose reduction, previously reported in the treatment of metastatic breast cancer. Here, we present a case of everolimus-associated stomatitis with a novel management method with intralesional triamcinolone that allows for continuous course of everolimus.

Open-Label, Randomized Study of Transition From Tacrolimus to Sirolimus Immunosuppression in Renal Allograft Recipients

Calcineurin inhibitor–associated nephrotoxicity and other adverse events have prompted efforts to minimize/eliminate calcineurin inhibitor use in kidney transplant recipients.

Oscillatory mTOR inhibition and Treg increase in kidney transplantation

Intracellular metabolic pathways dependent upon the mammalian target of rapamycin (mTOR) play a key role in immune-tolerance control. In this study, we focused on long-term mTOR-dependent immune-modulating effects in kidney transplant recipients undergoing conversion from calcineurin inhibitors (CNI) to mTOR inhibitors (everolimus) in a 1-year follow-up. The conversion to everolimus is associated with a decrease of neutrophils and of CD8(+) T cells. In addition, we observed a reduced production of interferon (IFN)-γ by CD8(+) T cells and of interleukin (IL)-17 by CD4(+) T lymphocytes. An increase in CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) [regulatory T cell [(Treg)] numbers was also seen. Treg increase correlated with a higher proliferation rate of this regulatory subpopulation when compared with the CD4(+) FoxP3(-) effector counterpart. Basal phosphorylation level of S6 kinase, a major mTOR-dependent molecular target, was substantially maintained in patients treated with everolimus. Moreover, oscillations in serum concentration of everolimus were associated with changes in basal and activation-dependent S6 kinase phosphorylation of CD4(+) and CD8(+) T cells. Indeed, T cell receptor (TCR) triggering was observed to induce significantly higher S6 kinase phosphorylation in the presence of lower everolimus serum concentrations. These results unveil the complex mTOR-dependent immune-metabolic network leading to long-term immune-modulation and might have relevance for novel therapeutic settings in kidney transplants.

Conversion to everolimus in kidney transplant recipients: to believe or not believe?

INTRODUCTION

Immunosuppression with calcineurin inhibitors (CNI) in renal transplantation is associated with chronic graft dysfunction, increased cardiovascular risk, and malignancies. Everolimus (EVR) appears to permit a CNI-sparing regimen among stable kidney recipients.

AIM

The aim of this study was to analyze the efficacy and safety of conversion from CNI to EVR.

MATERIAL AND METHODS

This was a retrospective registry-based study of all kidney transplant recipients converted from CNI to EVR between 2006 and 2010. One hundred fifty-one patients, including 69.5% males and with an overall mean age of 50.2 ± 12.7 years, underwent conversion to EVR at 37.0 ± 49.8 (16) months after transplantation with 33.7% during the first 6 months. Reasons for conversion included: CNI nephrotoxicity prevention (54.3%), chronic graft dysfunction (25.8%), malignant tumors (10.6%), CNI-adverse reactions (6.6%), and biopsy-proven CNI nephrotoxicity (2.6%). During a follow-up of 17.9 ± 9.9 months (range, 6-58.5), 18 patients (11.9%) were reconverted to CNI, 2 died with functioning grafts, and 2 lost kidney function.

RESULTS

We observed a significant (P < .001) increase in estimated glomerular filtration rate-Modification of Diet in Renal Disease (eGFR-MDRD) by 11.3% within 6 months: 56.7 ± 22.1 to 64.1 ± 23.4 mL/min/1.73 m(2). At final evaluation it was 13.7%, namely, to 65.5 ± 23.0 mL/min/1.73 m(2). At the end of follow-up the proportion of patients with >300 mg/d proteinuria increased from 7.9% to 23.3% (P = .001). Dyslipidemia prevalence increased from 69.5% to 77.5% (P = not significant [NS]) and arterial hypertension increased from 49% to 65.9% (P < .001) at the end of follow-up. Other reported side effects included oral ulcers (2.6%), edema (5.3%), interstitial pneumonitis (1.3%), and toxic hepatitis (1.3%), some of them leading to EVR discontinuation.

CONCLUSION

In our population, renal function improved significantly after conversion from CNI to EVR. Although side effects were common, most were mild, withdrawal of EVR was necessary in a low percentage of cases. EVR appears to be an effective, safe alternative to CNI for maintenance therapy in selected kidney transplant recipients.

Randomized controlled trial of sirolimus conversion in cardiac transplant recipients with renal insufficiency

This randomized, comparative, multinational phase 3b/4 study of patients 1-8 years postcardiac transplantation (mean 3.9 years) evaluated the effect of conversion from a calcineurin inhibitor (CNI) to sirolimus on renal function in patients with renal insufficiency. In total, 116 patients on CNI therapy with GFR 40-90 mL/min/1.73 m(2) were randomized (1:1) to sirolimus (n = 57) or CNI (n = 59). Intent-to-treat analysis showed the 1-year adjusted mean change from baseline in creatinine clearance (Cockcroft-Gault) was significantly higher with sirolimus versus CNI treatment (+3.0 vs. -1.4 mL/min/1.73 m(2) , respectively; p = 0.004). By on-therapy analysis, values were +4.7 and -2.1, respectively (p < 0.001). Acute rejection (AR) rates were numerically higher in the sirolimus group; 1 AR with hemodynamic compromise occurred in each group. A significantly higher treatment discontinuation rate due to adverse events (AEs; 33.3% vs. 0%; p < 0.001) occurred in the sirolimus group. Most common treatment-emergent AEs significantly higher in the sirolimus group were diarrhea (28.1%), rash (28.1%) and infection (47.4%). Conversion to sirolimus from CNI therapy improved renal function in cardiac transplant recipients with renal impairment, but was associated with an attendant AR risk and higher discontinuation rate attributable to AEs.