Four cases of sirolimus-associated interstitial pneumonitis: identification of risk factors

Effective low-dose sirolimus regimen for kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon in young infants

AIMS

Management of kaposiform haemangioendotheliomas (KHE) with Kasabach-Merritt phenomenon is challenging in young infants who are subjected to developmental pharmacokinetic changes. Sirolimus, sometimes combined with corticosteroids, can be used as an effective treatment of KHE. Simultaneously, toxicities such as interstitial pneumonitis related to the use of sirolimus may be fatal. As infants have a very low CYP3-enzyme expression at birth, which rises during ageing, we hypothesize that a reduced metabolization of sirolimus might lead to high sirolimus serum levels and low dose may be sufficient without the side effects.

METHODS

A case series of 5 infants with kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon was analysed retrospectively. All infants were treated with sirolimus 0.2 mg/m2 every 24 or 48 hours according to their age. Prednisone was added to the therapy for additional effect in 4 patients.

RESULTS

In all patients, low dose of sirolimus led to therapeutic sirolimus levels (4-6 ng/mL). All infants (aged 4 days-7 months) had a complete haematological response, without serious adverse events. In all patients, the Kasabach-Merritt phenomenon resolved, the coagulation profile normalized and tumour size reduction was seen.

CONCLUSION

Low-dose sirolimus treatment is safe for infants with kaposiform haemangioendothelioma and Kasabach-Merritt phenomenon. It is essential to realize that during the first months of life, metabolism is still developing and enzymes necessary to metabolise drugs like sirolimus still have to mature. To avoid toxic levels, the sirolimus dosage should be based on age and the associated pharmacological developments.

Patients with Congenital Low-Flow Vascular Malformation Treated with Low Dose Sirolimus

INTRODUCTION

Patients with congenital vascular malformations often suffer from an impaired quality of life (QoL) because of pain and functional disabilities. Previous studies have shown that the mTOR inhibitor sirolimus can reduce complaints and improve QoL in some patients. High target levels of sirolimus of 10-15 ng/ml were well tolerated; however, in a relative high percentage of patients sirolimus caused serious adverse events (AEs).

METHODS

A case series of 12 patients with therapy-resistant low-flow vascular malformations was treated with sirolimus, using low target levels of 4-10 ng/ml. Efficacy of sirolimus was evaluated in regard to pain symptoms using the visual analogue scale/numeric rating scale and patients reported QoL. To rule out a placebo effect of sirolimus, sirolimus was stopped after a certain time point and reintroduced as soon as complaints returned. Adverse events were closely monitored and graded using the Common Terminology Criteria for Adverse Events (CTCAE) grading.

RESULTS

An improvement in symptoms was seen in 92% (n = 11/12) of patients. In nine patients pain complaints returned. Seven out of nine of them (78%) again experienced a reduction of symptoms after restarting sirolimus treatment. Despite low target levels, these response rates are comparable to those found in the literature using higher target levels of sirolimus. However, significantly less serious AEs were observed with low dose sirolimus, suggesting low dose sirolimus might be safer. Unfortunately, young adolescent female patients developed serious menstrual disturbances during treatment with low dose sirolimus. We describe this adverse event for the first time in patients with congenital vascular malformations and this might be specifically related to low dose sirolimus.

CONCLUSIONS

Low dose sirolimus showed a high efficacy in patients with therapy-resistant and low-flow malformation, with a lower incidence of serious adverse events. At the same time a new adverse event, namely menstrual cycle disturbance, was observed in young adolescents, indicating the need for caution when sirolimus is given. This is extremely relevant to patients with low-flow vascular malformation, who are likely to require lifelong treatment for their condition.

Role of Fluorodeoxyglucose Positron Emission Tomogram Scan in Sirolimus-Induced Lung Toxicity: A Rare Case Report

Lung toxicity is a rare but serious side effect of sirolimus, a mammalian target of rapamycin inhibitor used as an immunosuppressive agent in solid-organ transplant recipients. We report a case of 67-year-old man who had living-related renal transplant 12 years previously that was complicated by chronic allograft dysfunction. He presented with fever, cough, and shortness of breath, and his chest imaging showed bilateral patchy and ground glass opacities. Before symptoms of lung toxicity, the patient's sirolimus levels were in the range of high normal. Bronchoalveolar lavage ruled out infection, and a transbronchial biopsy was inconclusive. A fluorodeoxyglucose positron emission tomogram scan showed high uptake in the area of lung opacities with a standard uptake value of 4.7. His symptoms improved after he was switched from sirolimus to tacrolimus, and a thoracic computed tomography scan after 6 weeks showed complete resolution. Pulmonary toxicity should be considered in any patient on sirolimus with respiratory symptoms and opacities on chest imaging. The role of fluorodeoxyglucose positron emission tomogram scan in evaluation of sirolimus-induced lung toxicity has not been previously described, and this is the first report of this type of scan finding indicating intense inflammation in this condition.

A Pediatric Case of Sirolimus-Associated Pneumonitis After Kidney Transplantation

Sirolimus is an immunosuppressive medication often used in solid organ transplantation. It has been associated with severe side effects, including pulmonary toxicity. In adult patients, a single center study found that 14% of those treated with sirolimus developed pulmonary pneumonitis; however, the incidence in the pediatric population is not known. Most reports in adult patients indicate that elevated drug concentrations and a prolonged duration of use are associated with pulmonary toxicity. We report a case of a 17-year-old male kidney transplant recipient who developed rapid-onset respiratory failure, necessitating mechanical ventilation and acute renal replacement therapy for ultrafiltration secondary to sirolimus-induced pneumonitis. He had been treated for acute rejection with corticosteroids 17 days prior to the development of pneumonitis. His symptoms developed within 1 week of initiation of sirolimus and with a serum concentration of 1.1 ng/mL. Sirolimus was discontinued, and, following aggressive diuresis and ventilatory support, his respiratory status returned to baseline. Sirolimus-induced pneumonitis is an important diagnosis to be considered in any transplant recipient receiving sirolimus with new onset fever, cough, or dyspnea without an identifiable source, especially if there is a preceding history of treatment with high-dose corticosteroids.

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.

A Case of Sirolimus-Induced Interstitial Lung Disease After Liver Transplantation

Mammalian target of rapamycin inhibitors (mTORis) are immunosuppression agents that are commonly used in solid organ transplantation. Available mTORis include sirolimus and everolimus. Interstitial lung disease (ILD) is an uncommon side effect of mTORis in liver transplantation. A high index of suspicion is needed, and timely intervention can reverse the disease. We present a case of sirolimus-induced ILD that improved after discontinuation of sirolimus.

Sirolimus-induced interstitial lung disease following pediatric stem cell transplantation

Sirolimus-induced ILD is a known but rare complication in adults who have undergone SOT. However, little is known about this adverse effect in children. Diagnosis of sirolimus-induced ILD can be challenging, especially in patients who have difficulty participating in lung function testing. We present a case of presumed sirolimus-induced ILD in a pediatric stem cell transplant patient who developed polycythemia and hypoxemia. To our knowledge, no other cases of sirolimus-induced pulmonary toxicity in children after HCT have been reported.

Interstitial Lung Disease Associated with mTOR Inhibitors in Solid Organ Transplant Recipients: Results from a Large Phase III Clinical Trial Program of Everolimus and Review of the Literature

Interstitial lung disease (ILD) has been reported with the use of mammalian target of rapamycin inhibitors (mTORi). The clinical and safety databases of three Phase III trials of everolimus in de novo kidney (A2309), heart (A2310), and liver (H2304) transplant recipients (TxR) were searched using a standardized MedDRA query (SMQ) search for ILD followed by a case-by-case medical evaluation. A literature search was conducted in MEDLINE and EMBASE. Out of the 1,473 de novo TxR receiving everolimus in Phase III trials, everolimus-related ILD was confirmed in six cases (one kidney, four heart, and one liver TxR) representing an incidence of 0.4%. Everolimus was discontinued in three of the four heart TxR, resulting in ILD improvement or resolution. Outcome was fatal in the kidney TxR (in whom everolimus therapy was continued) and in the liver TxR despite everolimus discontinuation. The literature review identified 57 publications on ILD in solid organ TxR receiving everolimus or sirolimus. ILD presented months or years after mTORi initiation and symptoms were nonspecific and insidious. The event was more frequent in patients with a late switch to mTORi. In most cases, ILD was reversed after prompt mTORi discontinuation. ILD induced by mTORi is an uncommon and potentially fatal event warranting early recognition and drug discontinuation.

Temsirolimus induces surfactant lipid accumulation and lung inflammation in mice

Interstitial lung disease (ILD) is a well-known adverse effect of mammalian target of rapamycin (mTOR) inhibitors. However, it remains unknown how lung toxicities are induced by mTOR inhibitors. Here, we constructed a mouse model of mTOR inhibitor-induced ILD using temsirolimus and examined the pathogenesis of the disease. Male ICR mice were treated with an intraperitoneal injection of different doses of temsirolimus (3 or 30 mg·kg−1·wk−1) or vehicle. Temsirolimus treatment increased capillary-alveolar permeability and induced neutrophil infiltration and fibrinous exudate into the alveolar space, indicating alveolar epithelial and/or endothelial injury. It also induced macrophage depletion and the accumulation of excessive surfactant phospholipids and cholesterols. Alveolar macrophage depletion is thought to cause surfactant lipid accumulation. To further examine whether temsirolimus has cytotoxic and/or cytostatic effects on alveolar macrophages and alveolar epithelial cells, we performed in vitro experiments. Temsirolimus inhibited cell proliferation and viability in both alveolar macrophage and alveolar epithelial cells. Temsirolimus treatment caused some signs of pulmonary inflammation, including upregulated expression of several proinflammatory cytokines in both bronchoalveolar lavage cells and lung homogenates, and an increase in lymphocytes in the bronchoalveolar lavage fluid. These findings indicate that temsirolimus has the potential to induce alveolar epithelial injury and to deplete alveolar macrophages followed by surfactant lipid accumulation, resulting in pulmonary inflammation. This is the first study to focus on the pathogenesis of mTOR inhibitor-induced ILD using an animal model.

Monitoring of nonsteroidal immunosuppressive drugs in patients with lung disease and lung transplant recipients: American College of Chest Physicians evidence-based clinical practice guidelines

OBJECTIVES

Immunosuppressive pharmacologic agents prescribed to patients with diffuse interstitial and inflammatory lung disease and lung transplant recipients are associated with potential risks for adverse reactions. Strategies for minimizing such risks include administering these drugs according to established, safe protocols; monitoring to detect manifestations of toxicity; and patient education. Hence, an evidence-based guideline for physicians can improve safety and optimize the likelihood of a successful outcome. To maximize the likelihood that these agents will be used safely, the American College of Chest Physicians established a committee to examine the clinical evidence for the administration and monitoring of immunosuppressive drugs (with the exception of corticosteroids) to identify associated toxicities associated with each drug and appropriate protocols for monitoring these agents.

METHODS

Committee members developed and refined a series of questions about toxicities of immunosuppressives and current approaches to administration and monitoring. A systematic review was carried out by the American College of Chest Physicians. Committee members were supplied with this information and created this evidence-based guideline.

CONCLUSIONS

It is hoped that these guidelines will improve patient safety when immunosuppressive drugs are given to lung transplant recipients and to patients with diffuse interstitial lung disease.

Sirolimus-induced pneumonitis after renal transplantation: a single-center experience

PURPOSE

Sirolimus is a potent immunosuppressive agent used with increasing frequency in kidney transplantation. However, sirolimus can increase the rate of unexplained interstitial pneumonitis. The aim of this study was to evaluate the clinical characteristics of sirolimus-induced pneumonitis and the therapeutic results in renal transplant recipients.

PATIENTS AND METHODS

Seventy-two patients received sirolimus, conversion or de novo regimen, at our center between January 2007 and April 2011. Twelve of the 72 patients (16.7%) developed interstitial pneumonitis. The patients were divided into three groups according to the following indications of sirolimus use: de novo, early conversion, and late conversion groups.

RESULTS

The mean duration of follow-up was 11.0 ± 11.5 months. The mean blood level of sirolimus measured by microparticulate enzyme immunoassay was 16.5 ± 7.4 ng/mL at the time of diagnosis. The mean time from the start of sirolimus to pneumonitis onset was 14.7 ± 8.0 months. The clinical presentation included fever, cough, dyspnea, general weakness, and periorbital edema. In most cases, radiological imaging tests revealed bilateral lower-lobe involvement. Bronchoalveolar lavage was performed in three patients and two patients showed lymphocytic alveolitis. Sirolimus was discontinued or reduced for the treatment of pneumonitis. All cases of pneumonitis were resolved within 2 to 4 weeks.

CONCLUSION

Sirolimus blood level should be monitored tightly and early intervention is important when sirolimus-induced pneumonitis is suspected.

Histological spectrum of pulmonary manifestations in kidney transplant recipients on sirolimus inclusive immunosuppressive regimens

Background

After the introduction of novel effective immunosuppressive therapies, kidney transplantation became the treatment of choice for end stage renal disease. While these new therapies lead to better graft survival, they can also cause a variety of complications. Only small series or case reports describe pulmonary pathology in renal allograft recipients on mTOR inhibitor inclusive therapies. The goal of this study was to provide a systematic review of thoracic biopsies in kidney transplant recipients for possible association between a type of immunosuppressive regimen and pulmonary complications.

Methods

A laboratory database search revealed 28 of 2140 renal allograft recipients (18 males and 10 females, 25 to 77 years old, mean age 53 years) who required a biopsy for respiratory symptoms. The histological features were correlated with clinical findings including immunosuppressive medications.

Results

The incidence of neoplasia on lung biopsy was 0.4% (9 cases), which included 3 squamous cell carcinomas, 2 adenocarcinomas, 1 diffuse large B-cell lymphoma, 1 lymphomatoid granulomatosis, and 2 post transplant B-cell lymphoproliferative disorders. Diffuse parenchymal lung disease was identified in 0.4% (9 cases), and included 5 cases of pulmonary hemorrhage, 3 cases of organizing pneumonia and 1 case of pulmonary alveolar proteinosis. Five (0.2%) cases showed histological features indicative of a localized infectious process. Patients on sirolimus had neoplasia less frequently than patients on other immunosuppressive combinations (12.5% vs. 58.3%, p = 0.03). Lung biopsies in 4 of 5 patients with clinically suspected sirolimus toxicity revealed pulmonary hemorrhage as the sole histological finding or in combination with other patterns.

Conclusions

Our study documents a spectrum of neoplastic and non-neoplastic lesions in renal allograft recipients on current immunosuppressive therapies. Sirolimus inclusive regimens are associated with increased risk of pulmonary toxicity but may be beneficial in cases of posttransplant neoplasia.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3320012126569395.

Interstitial pneumonitis is a frequent complication in liver transplant recipients treated with sirolimus

BACKGROUND

Sirolimus is a powerful immunosuppressive drug which is being used increasingly after liver transplantation because of its renal sparing and anti-tumour effects. It has been associated with uncommon, but potentially fatal, interstitial pneumonitis.

AIM

To determine the frequency and outcome of sirolimus-associated pneumonitis following liver transplantation.

METHODS

Retrospective study in an adult liver transplant centre.

RESULTS

We identified five patients with siromimus-associated pneumonitis, three of whom were transplanted at our centre. Between 1999 and 2008 a total of 522 liver transplants were performed, in our unit, and 45 patients were switched from calcineurin inhibitors to sirolimus. Three of these 45 patients subsequently developed pneumonitis (6.7%). The most common presenting symptoms were cough and dyspnea. The duration of use of sirolimus before diagnosis of pneumonitis varied between 4 and 16 months. Trough serum sirolimus levels were elevated in 3/5 patients with pneumonitis. Sirolimus was withdrawn in all five patients with complete resolution of symptoms and radiological findings.

CONCLUSIONS

Pneumonitis is a relatively common side effect of sirolimus in liver transplant patients and can occur despite normal therapeutic blood levels. It is reversible on stopping the medication. Early recognition is important to prevent unnecessary investigations and prolonged morbidity.

Sirolimus in pediatric renal transplantation

SRL, an mTOR inhibitor that inhibits cell cycle progression, represents an important alternative to CNIs, which are still the cornerstones of pediatric solid organ tx. Because there are still limited data on SRL use among pediatric solid organ recipients, further studies are needed to verify the efficacy and safety of SRL. It has unique pharmacokinetic characteristics concerning dosing intervals and reduction of the dose in combination with other immunosuppressants. SRL also has antineoplastic, antiviral, and antiatherogenic advantages over other immunosuppressive agents. The adverse effects of SRL including thrombocytopenia, hyperlipidemia, proteinuria, impaired wound healing, mouth ulcers, edema, male hypogonadism, TMA, and interstitial pneumonitis must be considered carefully in pediatric population. This article reviews the most recent data on SRL application in the field of pediatric renal tx.

Noninfectious pneumonitis after everolimus therapy for advanced renal cell carcinoma

RATIONALE

Noninfectious pneumonitis is a known class effect of mammalian target of rapamycin (mTOR) inhibitors.

OBJECTIVES

To assess the incidence, radiographic patterns, management, and outcome of pneumonitis in patients with advanced renal cell carcinoma receiving everolimus.

METHODS

Clinical study data from 416 patients, randomized to receive everolimus versus placebo, were analyzed for adverse events of pneumonitis. Radiographic studies performed every 8 weeks were subject to a prospective, independent, blinded central review for the presence of findings indicative of pneumonitis.

MEASUREMENTS AND MAIN RESULTS

Of 274 patients receiving everolimus, clinical pneumonitis was suspected for 37 patients (13.5%) (none with placebo). Nine cases (3.3%) were grade 1 (asymptomatic), 18 (6.6%) were grade 2 (not interfering with daily living), and 10 (3.6%) were grade 3 (interfering with daily living or oxygen indicated). No grade 4 (life-threatening) pneumonitis was observed. Of the 10 patients with grade 3 pneumonitis, 5 had baseline radiological evidence of pneumonitis before everolimus therapy. Twenty of the 37 cases (54.0%) were reversible within the follow-up period; resolution followed dose reduction for 20 patients and treatment discontinuation in 10 patients. Corticosteroid therapy was initiated in 16 cases. Dedicated radiological review of available serial radiographic studies (245 patients receiving everolimus and 132 receiving placebo) found a higher percentage of new radiographic findings even in patients without a diagnosis of clinical pneumonitis who were receiving everolimus versus placebo (38.9 vs. 15.2%).

CONCLUSIONS

Early recognition, prompt intervention, and a conservative approach are important in managing the risk associated with noninfectious pneumonitis in association with everolimus. Clinical trial registered with www.clinicaltrials.gov (NCT 00410124).

VEGF inhibitors for the treatment of neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world for those patients aged 50 years or older. Neovascular AMD, a subtype characterized by the growth of new, pathologic blood vessels, results in most of the cases of severe and rapid vision loss associated with AMD. A critical activator of angiogenesis in neovascular AMD is VEGF. Several therapies have been and are now being developed for neovascular AMD, with the goal of inhibiting VEGF. These VEGF inhibitors include the RNA aptamer pegaptanib, partial and full-length antibodies ranibizumab and bevacizumab, VEGF receptor decoy VEGF Trap, small interfering RNA-based therapies bevasiranib and AGN211745, sirolimus, and tyrosine kinase inhibitors including vatalanib, pazopanib, TG100801, TG101095, AG013958 and AL39324. At present, established therapies have met with great success in reducing the vision loss associated with neovascular AMD, whereas those still investigational in nature offer the potential for further advances.

Sirolimus-related pulmonary toxicity mimicking 'asthma like' symptoms

Sirolimus is an immunosuppressant with expanding use in pediatric organ transplantation, dermatology and rheumatology. We report two cases of children who developed asthma like symptoms and were diagnosed with interstitial lung disease, which responded to discontinuation of sirolimus. Pediatricians should be aware about the pulmonary side effects of sirolimus.