Sirolimus and ACE-inhibitors: a note of caution

Sirolimus and mTOR Inhibitors: A Review of Side Effects and Specific Management in Solid Organ Transplantation

Inhibitors of mechanistic target of rapamycin (mTOR inhibitors) are used as antiproliferative immunosuppressive drugs and have many clinical applications in various drug combinations. Experience in transplantation studies has been gained regarding the side effect profile of these drugs and the potential benefits and limitations compared with other immunosuppressive agents. This article reviews the adverse effects of mTOR inhibitors in solid organ transplantation, with special attention given to mechanisms hypothesized to cause adverse events and their management strategies.

Effect of Sirolimus on Disease Progression in Patients with Autosomal Dominant Polycystic Kidney Disease and CKD Stages 3b-4

BACKGROUND AND OBJECTIVES

The effect of mammalian target of rapamycin (mTOR) inhibitors has never been tested in patients with autosomal dominant polycystic kidney disease (ADPKD) and severe renal insufficiency.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this academic, prospective, randomized, open label, blinded end point, parallel group trial (ClinicalTrials.gov no. NCT01223755), 41 adults with ADPKD, CKD stage 3b or 4, and proteinuria ≤0.5 g/24 h were randomized between September of 2010 and March of 2012 to sirolimus (3 mg/d; serum target levels of 5-10 ng/ml) added on to conventional therapy (n=21) or conventional treatment alone (n=20). Primary outcome was GFR (iohexol plasma clearance) change at 1 and 3 years versus baseline.

RESULTS

At the 1-year preplanned interim analysis, GFR fell from 26.7±5.8 to 21.3±6.3 ml/min per 1.73 m(2) (P<0.001) and from 29.6±5.6 to 24.9±6.2 ml/min per 1.73 m(2) (P<0.001) in the sirolimus and conventional treatment groups, respectively. Albuminuria (73.8±81.8 versus 154.9±152.9 μg/min; P=0.02) and proteinuria (0.3±0.2 versus 06±0.4 g/24 h; P<0.01) increased with sirolimus. Seven patients on sirolimus versus one control had de novo proteinuria (P=0.04), ten versus three patients doubled proteinuria (P=0.02), 18 versus 11 patients had peripheral edema (P=0.04), and 14 versus six patients had upper respiratory tract infections (P=0.03). Three patients on sirolimus had angioedema, 14 patients had aphthous stomatitis, and seven patients had acne (P<0.01 for both versus controls). Two patients progressed to ESRD, and two patients withdrew because of worsening of proteinuria. These events were not observed in controls. Thus, the independent data and safety monitoring board recommend early trial termination for safety reasons. At 1 year, total kidney volume (assessed by contrast-enhanced computed tomography imaging) increased by 9.0% from 2857.7±1447.3 to 3094.6±1519.5 ml on sirolimus and 4.3% from 3123.4±1695.3 to 3222.6±1651.4 ml on conventional therapy (P=0.12). On follow-up, 37% and 7% of serum sirolimus levels fell below or exceeded the therapeutic range, respectively.

CONCLUSIONS

Finding that sirolimus was unsafe and ineffective in patients with ADPKD and renal insufficiency suggests that mTOR inhibitor therapy may be contraindicated in this context.

Oedema, solid organ transplantation and mammalian target of rapamycin inhibitor/proliferation signal inhibitors (mTOR-I/PSIs)

Mammalian target of rapamycin inhibitor (mTOR-I)/proliferation signal inhibitors (PSI) including sirolimus and everolimus represent a new class of drugs increasingly used in solid-organ transplantation as alternatives to calcineurin inhibitors for patients with renal dysfunction, transplant coronary arterial vasculopathy or malignancy. The most frequently occurring mTOR-I/PSI-related adverse events are similar to those associated with other immunosuppressive therapies, but some side effects are more characteristic of proliferation signal inhibitors (e.g. lymphocele, arthralgia, oedema and hyperlipidaemia). The present paper review incidence, clinical presentation and mechanism of oedema within the clinical experience of mTOR-I/PSI in solid organ transplantation.

Increased incidence of angioedema with ACE inhibitors in combination with mTOR inhibitors in kidney transplant recipients

BACKGROUND AND OBJECTIVE

The clinical manifestation of angioedema ranges from minor facial edema up to life-threatening swelling of mouth and throat. Hereditary defects, drugs, and food allergies may play a role in the development of angioedema. We systematically investigated the incidence of angioedema in renal allograft recipients treated with mTOR inhibitors (mTORis).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All patients in the authors' electronic database who had received mTORis (n = 309) between 2000 and 2008 were identified. Of these, 137 were additionally treated with angiotensin-converting enzyme inhibitors (ACEis).

RESULTS

Nine patients (6.6%, 3.8 per 100 treatment years) developed angioedema after a mean period of 123 days under combined therapy with mTORi and ACEi. Among the remaining 172 patients on mTORi, including 119 patients treated with angiotensin-receptor blockers, only two developed angioedema (1.2%, 0.5 per 100 treatment years, P = 0.01). In patients receiving mycophenolate and ACEi (n = 462), 10 instances of angioedema were found (2.1%, 0.8 per 100 treatment years, P = 0.004).

CONCLUSIONS

This systematic investigation demonstrated a noticeable incidence of 6.6% angioedema under combined therapy with mTORi and ACEi in kidney transplant recipients. Treatment with either ACEi or mTORi alone resulted in a significantly lower incidence of angioedema, suggesting that this combination should be avoided.

Angioedema in Renal Transplant Recipients on Sirolimus

BACKGROUND

Most drug-associated angioedemas are induced by angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, or nonsteroidal anti-inflammatory drugs. Recently, the responsibility of immunosuppressive agents given to transplant recipients in the development of angioedema has been discussed.

OBJECTIVE

To describe, in detail, angioedema episodes in renal transplant recipients (RTRs) on sirolimus.

METHODS

A cross-sectional study in a university hospital. Eighty consecutive RTRs on sirolimus were studied.

RESULTS

Angioedema without urticaria occurred a mean of 5 times in 12/80 (15%) RTRs taking sirolimus. It was predominantly located on the face (83%), with mucous membrane involvement in 7 (58%) patients, and was life threatening in 1. Another putative cofactor for angioedema without urticaria was identified in 9 (75%) patients: drugs (n=8), food allergy or physical activity (n=3). Tacrolimus intake was significantly associated with sirolimus-associated angioedema.

CONCLUSION

Our results suggested a causal relationship between sirolimus and angioedema in RTRs.

Onychopathie associée au sirolimus chez les transplantés rénaux

INTRODUCTION

A large number of drugs may be responsible for the development of nail changes. Sirolimus is an immunosuppressive drug recently developed in organ transplantation. Herein, we evaluate sirolimus-induced nail abnormalities in renal transplant recipients.

PATIENTS AND METHODS

The nails of 80 consecutive renal transplant recipients receiving sirolimus have been evaluated in a systematic dermatological study in 2003. The patients were mainly men (60%) with a mean age of 48 years. The mean duration of the graft was 6 years and of sirolimus treatment 18 months. Mycophenolate mofetil and steroids were combined with sirolimus in 86% of patients.

RESULTS

Fifty-seven patients (74%) complained for nail alterations. The most frequent anomalies (88%) were matrix alterations including slow growth, onychomalacia, onychorrexis, and leukonychia. Nail bed alterations (onycholysis), vascular phenomenon (erythema, splinter hemorrhages), and periungual anomalies (mainly pyogenic granulomas) were observed in 42, 42 and 19% of cases respectively. One observation of type 1 photo-onycholysis was described.

DISCUSSION

This study reports a new drug-induced onychopathy. Responsibility of sirolimus is highly suggested. The main pathogenesis hypothesis to explain these nail alterations is inhibition of EGF (epidermal growth factor) pathway by sirolimus.