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

Management of long-term complications from immunosuppression

This review discusses long-term complications from immunosuppressants after liver transplantation and the management of these complications. Common complications of calcineurin inhibitors include nephrotoxicity and metabolic diseases. Nephrotoxicity can be managed by targeting a lower drug level and/or adding an immunosuppressant of a different class. Metabolic disorders can be managed by treating the underlying condition and targeting a lower drug level. Gastrointestinal adverse effects and myelosuppression are common complications of antimetabolites that are initially managed with dose reduction or discontinuation if adverse events persist. Mammalian targets of rapamycin inhibitors are associated with myelosuppression, proteinuria, impaired wound healing, and stomatitis, which may require dose reduction or discontinuation. Induction agents and agents used for steroid-refractory rejection or antibody-mediated rejection are reviewed. Other rare complications of immunosuppressants are discussed as well.

Nanotherapeutics targeting autophagy regulation for improved cancer therapy

The clinical efficacy of current cancer therapies falls short, and there is a pressing demand to integrate new targets with conventional therapies. Autophagy, a highly conserved self-degradation process, has received considerable attention as an emerging therapeutic target for cancer. With the rapid development of nanomedicine, nanomaterials have been widely utilized in cancer therapy due to their unrivaled delivery performance. Hence, considering the potential benefits of integrating autophagy and nanotechnology in cancer therapy, we outline the latest advances in autophagy-based nanotherapeutics. Based on a brief background related to autophagy and nanotherapeutics and their impact on tumor progression, the feasibility of autophagy-based nanotherapeutics for cancer treatment is demonstrated. Further, emerging nanotherapeutics developed to modulate autophagy are reviewed from the perspective of cell signaling pathways, including modulation of the mammalian target of rapamycin (mTOR) pathway, autophagy-related (ATG) and its complex expression, reactive oxygen species (ROS) and mitophagy, interference with autophagosome-lysosome fusion, and inhibition of hypoxia-mediated autophagy. In addition, combination therapies in which nano-autophagy modulation is combined with chemotherapy, phototherapy, and immunotherapy are also described. Finally, the prospects and challenges of autophagy-based nanotherapeutics for efficient cancer treatment are envisioned.

Treatment of newly diagnosed moderate or severe chronic graft-versus-host disease with prednisone and everolimus (PredEver first): a prospective multicenter phase IIA study

Although most patients with chronic graft-versus-host disease (cGVHD) show initial response to first-line therapy, long-term clinically meaningful success of first-line treatment remains rare. In a prospective multicentre phase II trial in 6 German centers, patients with newly diagnosed moderate or severe cGVHD received prednisone and everolimus for 12 months followed by a 1-year follow-up period. Primary endpoint was treatment success (TS) at 6 months defined as patient being alive, achieving PR or CR of cGVHD, having no relapse of underlying disease and requiring no secondary treatment for cGVHD. Of the 34 patients evaluable for efficacy, 19 (56%) had TS at 6 months with 22 and 52% of the patients in a CR and PR respectively. Overall 30 patients (88%) had a CR or PR as best response, nearly all responses (29/30) occurring within the first 6 weeks of treatment. The cumulative incidence of treatment failure at 1 year was 63%, corresponding to 37% TS. Predefined safety endpoint (thrombotic microangiopathy, pneumonitis, and avascular necrosis) were not observed in any patient. Addition of everolimus to prednisolone is well tolerated and may improve long-term treatment success. Larger studies are necessary to ascertain the possible role of everolimus in first-line treatment of cGVHD.

Pharmacokinetics of Sirolimus Eye Drops Following Topical Ocular Administration in Rabbits

Purpose: To evaluate the pharmacokinetics of sirolimus eye drops following topical instillation in rabbits. Methods: The study included 2 experiments. In single-dose pharmacokinetic study, rabbits received a single bilateral instillation of 0.05% sirolimus eye drops (0.5 mg/mL, 50 μL/eye). In repeat-dose pharmacokinetic study, 0.05% sirolimus eye drops (0.5 mg/mL, 50 μL/eye/time) were instilled into both eyes of rabbits four times a day for 6 consecutive days and one time on day 7. Whole blood, tears, aqueous humor, cornea, and conjunctiva samples were collected. Sirolimus concentration was determined by a validated liquid chromatography-tandem mass spectrometry. Results: Sirolimus was hardly detected in plasma or aqueous humor after either single or repeated dosing. The Cmax of sirolimus in tears, cornea, and conjunctiva after a single instillation was 163.34 ± 69.30 μg/g, 150.56 ± 84.98 ng/g, and 113.22 ± 49.82 ng/g, respectively. As the number of instillation elevated, the Cmax of sirolimus was increased to 486.18 ± 297.93 μg/g, 418.63 ± 41.07 ng/g, and 314.25 ± 63.74 ng/g, respectively. In repeat-dose administration, the steady state of sirolimus concentration was achieved on the third day. Ocular exposure to sirolimus after single and repeated dosing, based on AUC0-t, was highest in tears, followed by cornea and conjunctiva. Compared with single administration, a significant increase in sirolimus exposure as measured by AUC0-t was observed in tears, cornea, and conjunctiva following repeated administration. Conclusions: Topical administration of sirolimus eye drops results in extensive distribution of sirolimus in tears, cornea, and conjunctiva, while aqueous humor and systemic exposure were negligible. Repeat-dose administration increases sirolimus exposure in tears, cornea, and conjunctiva.

The impact of COVID-19 on liver transplantation: challenges and perspectives

The coronavirus disease 2019 (COVID-19) pandemic presented unique challenges to patients with decompensated cirrhosis awaiting transplant, with respect to accessing medical facilities for routine clinic visits, imaging, laboratory workup, or endoscopies. There was a delay in organ procurement that led to a decrease in the number of liver transplants (LTs) and an increase in the morality of waitlisted patients at the beginning of the pandemic. LT numbers later equalized to pre-pandemic numbers due to combined efforts and adaptability of transplant centers as well as dynamic guidelines. Due to being immunosuppressed, the demographics of LT patients were at an increased risk of infection. Although there is a higher rate of mortality and morbidity in patients with chronic liver disease, LT itself is not a risk factor for mortality in COVID-19. There was no difference in overall mortality in LT patients compared to non-LT patients, and mortality risk factors were the same: age, hypertension, diabetes, obesity, and chronic kidney disease. The most common causes of death were respiratory complications. Liver-related deaths were reported in 1.6% of patients. The optimal timing of liver transplantation post-infection depends on various factors, such as the severity of liver injury, the presence of comorbidities, and the progression of the underlying liver disease. There is not enough data available on COVID-19 cholangiopathy and the number of cases that will be seen in the future that will require LT. There are some concerns of lower immunogenicity of COVID-19 vaccines in LT patients but available evidence suggests that the vaccines are safe and well-tolerated.

Sirolimus-Induced Pulmonary Alveolar Proteinosis in the Context of Hematopoietic Stem Cells Transplant Rejection: A Case Report

Pulmonary alveolar proteinosis (PAP) is a rare parenchymal pulmonary disease, characterized by the accumulation of surfactant material in alveoli. Rare cases of pulmonary alveolar proteinosis have been reported following the use of sirolimus. All published cases have been described following solid organ transplantation, and symptoms improved quickly after treatment's cessation. We describe a case of PAP secondary to sirolimus treating graft-versus-host reaction in a patient who received a stem cell transplant for chronic lymphocytic leukemia. Pulmonary alveolar proteinosis was cured after stopping sirolimus without any other therapeutic management. PAP can be a rare but serious side effect of sirolimus. It is important to rule out other causes of primary or secondary PAP before suggesting a toxic drug cause. The main challenge is to quickly diagnose this side effect to stop exposure to the toxic agent.

Bronchoscopic Lobar Lavage in the Treatment of a Single Lung Transplant Recipient With Pulmonary Alveolar Proteinosis: A Case Report

Pulmonary alveolar proteinosis is a rare disorder that results from impaired clearance of surfactant. There are few case reports in lung transplant recipients. We report the case of a 57-year-old man with chronic hypersensitivity pneumonitis who underwent left single lung transplantation. Approximately 1 year after transplant, he was diagnosed as having pulmonary alveolar proteinosis by surgical lung biopsy. He was successfully treated with bronchoscopic lobar lavage of his allograft but later was diagnosed as having peritoneal mesothelioma. We highlight the challenges in the diagnosis, discuss potential etiologies, and describe a unique therapy of this rare disorder in lung transplant recipients.

Achromobacter denitrificans pneumonia in a kidney transplant recipient - dose-dependent decrease of phagocytic activity as a potential mechanism for everolimus pulmonary toxicity

Mammalian target of rapamycin (mTOR) inhibitors inclusive regimens are associated with increased risk of pulmonary toxicity, but the underlying mechanism has not been elucidated so far.

We present the case of a 68-year-old man, after deceased-donor kidney transplantation (KTx), maintained on de novo everolimus (EVR) based immunosuppression, who developed Achromobacter denitrificans pneumonia 3 months after KTx. There was clinical improvement with antibiotic treatment, but without a radiological resolution. An additional reduction of the EVR dose resulted only in partial resolution of radiological abnormalities. We performed a functional analysis of peripheral blood neutrophils and monocytes. The ability of phagocytosis and oxidative burst generation against A. denitrificans and Escherichia coli was significantly decreased on EVR treatment as compared to the control healthy person, and significantly improved after 3 weeks of EVR absence. Additionally, these processes were significantly affected by increasing doses of EVR in vitro in the control healthy donor in a dose-dependent manner. EVR discontinuation, with no additional antibiotic treatment, resulted in complete recovery and resolution of pulmonary infiltrates.

Our findings suggest that dose-dependent impairment of neutrophil/monocyte phagocytic activity and oxidative burst generation might be a potential mechanism for EVR pulmonary toxicity.

An overview of the efficacy and safety of everolimus in adult solid organ transplant recipients

As the risk of graft loss due to acute rejection has declined, the goal of post-transplant management has switched to long-term preservation of organ function. Minimizing calcineurin inhibitor (CNI)-related nephrotoxicity is a key component of this objective. Everolimus is a mammalian target of rapamycin inhibitor/proliferation-signal inhibitor with potent immunosuppressive and anti-proliferative effects. It has been widely investigated in large randomized clinical studies that have shown it to have similar anti-rejection efficacy compared with standard-of-care regimens across organ transplant indications. With demonstrated potential to facilitate the reduction of CNI therapy and preserve renal function, everolimus is an alternative to the current standard-of-care CNI-based regimens used in de novo and maintenance solid organ transplantation recipients. Here, we provide an overview of the evidence from the everolimus clinical study program across kidney, liver, heart, and lung transplants, as well as other key data associated with its use in CNI reduction strategies in adult transplant recipients.

Ageing mechanisms that contribute to tissue remodeling in lung disease

Age is a major risk factor for chronic respiratory diseases such as idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and certain phenotypes of asthma. The recent COVID-19 pandemic also highlights the increased susceptibility of the elderly to acute respiratory distress syndrome (ARDS), a diffuse inflammatory lung injury with often long-term effects (ie parenchymal fibrosis). Collectively, these lung conditions are characterized by a pathogenic reparative process that, rather than restoring organ function, contributes to structural and functional tissue decline. In the ageing lung, the homeostatic control of wound healing following challenge or injury has an increased likelihood of being perturbed, increasing susceptibility to disease. This loss of fidelity is a consequence of a diverse range of underlying ageing mechanisms including senescence, mitochondrial dysfunction, proteostatic stress and diminished autophagy that occur within the lung, as well as in other tissues, organs and systems of the body. These ageing pathways are highly interconnected, involving localized and systemic increases in inflammatory mediators and damage associated molecular patterns (DAMPs); along with corresponding changes in immune cell function, metabolism and composition of the pulmonary and gut microbiomes. Here we comprehensively review the roles of ageing mechanisms in the tissue remodeling of lung disease.

Liposomes Loaded with Everolimus and Coated with Hyaluronic Acid: A Promising Approach for Lung Fibrosis

Chronic lung allograft dysfunction (CLAD) and interstitial lung disease associated with collagen tissue diseases (CTD-ILD) are two end-stage lung disorders in which different chronic triggers induce activation of myo-/fibroblasts (LFs). Everolimus, an mTOR inhibitor, can be adopted as a potential strategy for CLAD and CTD-ILD, however it exerts important side effects. This study aims to exploit nanomedicine to reduce everolimus side effects encapsulating it inside liposomes targeted against LFs, expressing a high rate of CD44. PEGylated liposomes were modified with high molecular weight hyaluronic acid and loaded with everolimus (PEG-LIP(ev)-HA400kDa). Liposomes were tested by in vitro experiments using LFs derived from broncholveolar lavage (BAL) of patients affected by CLAD and CTD-ILD, and on alveolar macrophages (AM) and lymphocytes isolated, respectively, from BAL and peripheral blood. PEG-LIP-HA400kDa demonstrated to be specific for LFs, but not for CD44-negative cells, and after loading everolimus, PEG-LIP(ev)-HA400kDa were able to arrest cell cycle arrest and to decrease phospho-mTOR level. PEG-LIP(ev)-HA400kDa showed anti-inflammatory effect on immune cells. This study opens the possibility to use everolimus in lung fibrotic diseases, demonstrating that our lipids-based vehicles can vehicle everolimus inside cells exerting the same drug molecular effect, not only in LFs, but also in immune cells.

Sirolimus-induced interstitial lung disease and resolution after conversion to everolimus

Mammalian target of rapamycin inhibitors (mTORi) are used to treat a variety of malignancies and have an established role in organ transplantation. Interstitial lung disease (ILD) is one of the complications of mTORi and is believed to be a class effect. More cases of ILD have been reported with sirolimus than with everolimus in the literature, possibly due to earlier introduction and wider use of sirolimus. We report the case of a kidney transplant recipient who developed ILD secondary to sirolimus and improved rapidly after switching to everolimus.

Immunosuppressive strategies in lung transplantation

Lung transplantation is a viable option for those with end-stage lung disease which is evidenced by the continued increase in the number of lung transplantations worldwide. However, patients and clinicians are constantly faced with acute and chronic rejection, infectious complications, drug toxicities, and malignancies throughout the lifetime of the lung transplant recipient. Conventional maintenance immunosuppression therapy consisting of a calcineurin inhibitor (CNI), anti-metabolite, and corticosteroids have become the standard regimen but newer agents and modalities continue to be developed. Here we will review induction agents, maintenance immunosuppressives, adjunctive therapies and other strategies to improve long-term outcomes.

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.

Reversible sirolimus-induced pulmonary alveolar proteinosis in a renal transplant patient

Pulmonary alveolar proteinosis (PAP) is characterized by accumulation of surfactant-like lipoprotein material within distal bronchioles and alveoli due to impaired clearance. Clinically, PAP presents with dyspnea and cough. A 58-year-old Hispanic man presented with 6 months of productive cough, weight loss, and progressively worsening dyspnea. He reported a long history of poorly controlled type 2 diabetes that led to diabetic nephropathy. The patient had a strong passive smoking history for over 30 years and exposure to woodsmoke. He had pulmonary tuberculosis in 2007 and 2012. In 2011, he was diagnosed with renal failure, was dialyzed for a year, and received a renal transplant in 2012. His posttransplant medication regimens included tacrolimus, mycophenolic acid, and prednisone. Six months after the transplant, he suffered graft rejection, managed with steroids and switching from tacrolimus to sirolimus. His physical examination demonstrated scattered inspiratory crackles, and a chest X-ray showed bilateral perihilar ground-glass opacities. PAP was diagnosed through lung biopsy, which showed eosinophilic granular infiltrate withing the alveoli. Sirolimus was switched back to tacrolimus 2 mg in September 2018. PAP diagnosis included hematoxylin and eosin and PAS. Clinical follow-up included oxygen saturation with pulse oximeter and chest X-rays. A 2-month follow-up showed only partial improvement in both symptoms and radiological findings. In January 2019, a follow-up showed complete radiological and symptomatologic resolution. After 5 months, the patient remains asymptomatic with adequate exertion tolerance. PAP remains a diagnosis of exclusion in patients undergoing immunomodulatory therapy with sirolimus and pulmonary symptoms. Reversal can be achieved by switching agents.

Sirolimus-associated pericardial effusion with cardiac tamponade and interstitial pneumonitis in a hematopoietic stem cell transplant recipient

Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, is a potent immunosuppressant that is increasingly used in prevention and treatment of graft-vs-host disease (GVHD) in allogeneic hematopoietic stem cell transplant (HSCT) patients. However, data regarding its adverse effects in HSCT patients remain limited. We describe an 18-year-old HSCT patient with a history of invasive fungal infection, who developed pericardial effusion with cardiac tamponade and interstitial pneumonitis while receiving sirolimus for GVHD prophylaxis. Our case illustrates potentially life-threatening complications of sirolimus use in allogeneic HSCT patients.

Pneumonia in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the AST Infectious Diseases Community of Practice review the diagnosis and management of pneumonia in the post-transplant period. Clinical presentations and differential diagnosis for pneumonia in the solid organ transplant recipient are reviewed. A two-tier approach is proposed based on the net state of immunosuppression and the severity of presentation. With a lower risk of opportunistic, hospital-acquired, or exposure-specific pathogens and a non-severe presentation, empirical therapy may be initiated under close clinical observation. In all other patients, or those not responding to the initial therapy, a more aggressive diagnostic approach including sampling of tissue for microbiological and pathological testing is warranted. Given the broad range of potential pathogens, a microbiological diagnosis is often key for optimal care. Given the limited literature comparatively evaluating diagnostic approaches to pneumonia in the solid organ transplant recipient, much of the proposed diagnostic algorithm reflects clinical experience rather than evidence-based data. It should serve as a template which may be modified according to local needs. The same holds true for the suggested empiric therapies, which need to be adapted to the local resistance patterns. Further study is needed to comparatively evaluate diagnostic and empiric treatment strategies in SOT recipients.

Infection in Kidney Transplant Recipients

In organ transplant recipients, impaired inflammatory responses suppress the clinical and radiologic findings of infection. The possible etiologies of infection are diverse, ranging from common bacterial and viral pathogens that affect the entire community to opportunistic pathogens that cause invasive disease only in immunocompromised hosts. Antimicrobial therapies required to treat established infection are often complex, with accompanying risks for drug toxicities and drug interactions with the immunosuppressive agents used to maintain graft function. Rapid and specific diagnosis is essential for successful therapy. The risk of serious infections in the organ transplant patient is largely determined by the interaction between two factors: the patient’s epidemiologic exposures and the patient’s net state of immunosuppression. The epidemiology of infection includes environmental exposures and nosocomial infections, organisms derived from donor tissues, and latent infections from the recipient activated with immunosuppression. The net state of immune suppression is a conceptual framework that measures those factors contributing to risk for infection: the dose, duration, and temporal sequence of immunosuppressive drugs; the presence of foreign bodies or injuries to mucocutaneous barriers; neutropenia; metabolic abnormalities including diabetes; devitalized tissues, hematomas, or effusions postsurgery; and infection with immunomodulating viruses. Multiple factors are present in each host. A timeline exists to aid in the development of a differential diagnosis for infection. The timeline for each patient is altered by changes in prophylaxis and immunosuppressive drugs. For common infections, new microbiologic assays, often nucleic acid based, are useful in the diagnosis and management of opportunistic infections.

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.

Everolimus induced pneumonitis in a lung transplant recipient

Everolimus is a mechanistic target of rapamycin inhibitor used for the treatment of various cancers and prevention of allograft rejection in solid organ transplantation. We present a case of a lung transplant recipient on everolimus who was admitted with generalized weakness, hypoxia and new onset bilateral pulmonary infiltrates on imaging. Extensive workup revealed no infectious etiology and high levels of serum everolimus levels. Her condition deteriorated over the hospital course with symptoms and signs of systemic everolimus toxicity. She was treated with high-dose steroids with significant improvement. Follow-up imaging showed resolution of infiltrates. Everolimus induced pneumonitis is seldom reported in the lung transplant literature. It is important to recognize early signs of toxicity to intervene and preserve the lung allograft.

In Vitro Identification of New Transcriptomic and miRNomic Profiles Associated with Pulmonary Fibrosis Induced by High Doses Everolimus: Looking for New Pathogenetic Markers and Therapeutic Targets

The administration of Everolimus (EVE), a mTOR inhibitor used in transplantation and cancer, is often associated with adverse effects including pulmonary fibrosis. Although the underlying mechanism is not fully clarified, this condition could be in part caused by epithelial to mesenchymal transition (EMT) of airway cells. To improve our knowledge, primary bronchial epithelial cells (BE63/3) were treated with EVE (5 and 100 nM) for 24 h. EMT markers (α-SMA, vimentin, fibronectin) were measured by RT-PCR. Transepithelial resistance was measured by Millicell-ERS ohmmeter. mRNA and microRNA profiling were performed by Illumina and Agilent kit, respectively. Only high dose EVE increased EMT markers and reduced the transepithelial resistance of BE63/3. Bioinformatics showed 125 de-regulated genes that, according to enrichment analysis, were implicated in collagen synthesis/metabolism. Connective tissue growth factor (CTGF) was one of the higher up-regulated mRNA. Five nM EVE was ineffective on the pro-fibrotic machinery. Additionally, 3 miRNAs resulted hyper-expressed after 100 nM EVE and able to regulate 31 of the genes selected by the transcriptomic analysis (including CTGF). RT-PCR and western blot for MMP12 and CTGF validated high-throughput results. Our results revealed a complex biological network implicated in EVE-related pulmonary fibrosis and underlined new potential disease biomarkers and therapeutic targets.

Individualizing immunosuppression in lung transplantation

Immunosuppression management after lung transplantation continues to evolve, with an increasing number of agents available for use in various combinations allowing for more choice and individualization of immunosuppressive therapy. Therapeutic developments have led to improved outcomes including lower acute rejection rates and improved survival. However, a one size fits all approach for any immunosuppressive strategy may not be best suited to the individual patient and ultimately patient specific factors must be considered when designing the immunosuppressive regimen. Recipient factors including age, race, co-morbidities, immunologic risk, genetic polymorphisms, concomitant and previous pharmacotherapy, and overall immunosuppression burden should be considered. There are several significant drug-drug interactions with select immunosuppressive agents utilized in lung transplant pharmacotherapy that must be considered when choosing and devising a dosing strategy for an individual immunosuppressive agent. Herein, considerations for immunosuppression management in the individual patient will be reviewed.

Rapamycin Eye Drops Suppress Lacrimal Gland Inflammation In a Murine Model of Sjögren's Syndrome

Purpose

To evaluate the efficacy of topical rapamycin in treating autoimmune dacryoadenitis in a mouse model of Sjögren's syndrome.

Methods

We developed rapamycin in a poly(ethylene glycol)-distearoyl phosphatidylethanolamine (PEG-DSPE) micelle formulation to maintain solubility. Rapamycin or PEG-DSPE eye drops (vehicle) were administered in a well-established Sjögren's syndrome disease model, the male nonobese diabetic (NOD) mice, twice daily for 12 weeks starting at 8 weeks of age. Mouse tear fluid was collected and tear Cathepsin S, a putative tear biomarker for Sjögren's syndrome, was measured. Lacrimal glands were retrieved for histological evaluation, and quantitative real-time PCR of genes associated with Sjögren's syndrome pathogenesis. Tear secretion was measured using phenol red threads, and corneal fluorescein staining was used to assess corneal integrity.

Results

Lymphocytic infiltration of lacrimal glands from rapamycin-treated mice was significantly (P = 0.0001) reduced by 3.8-fold relative to vehicle-treated mice after 12 weeks of treatment. Rapamycin, but not vehicle, treatment increased tear secretion and decreased corneal fluorescein staining after 12 weeks. In rapamycin-treated mice, Cathepsin S activity was significantly reduced by 3.75-fold in tears (P < 0.0001) and 1.68-fold in lacrimal gland lysates (P = 0.003) relative to vehicle-treated mice. Rapamycin significantly altered the expression of several genes linked to Sjögren's syndrome pathogenesis, including major histocompatibility complex II, TNF-α, IFN-γ, and IL-12a, as well as Akt3, an effector of autophagy.

Conclusions

Our findings suggest that topical rapamycin reduces autoimmune-mediated lacrimal gland inflammation while improving ocular surface integrity and tear secretion, and thus has potential for treating Sjögren's syndrome–associated dry eye.

A Case of Interstitial Lung Disease Probably Related to Rituximab Treatment

A 44-year-old male developed interstitial lung disease (ILD) during treatment with rituximab (375 mg/m² weekly intravenous × 4 weeks) for the management of immune thrombocytopenia (ITP). After 1 month of treatment he developed dyspnea, fever (38.9 °C), an increase of C-reactive protein (CRP) and white blood cells with hypoxemia, and decreased platelets. Chest X-ray and high-resolution computed tomography revealed diffuse bilateral lung infiltrates. He was diagnosed with severe ILD; rituximab was discontinued, and treatment with fluticasone combined with salmeterol, methylprednisolone, and omeprazole was started, with an improvement of symptoms over 15 days with normalization in CRP at 30 days. A Naranjo assessment score of 6 was obtained, indicating a probable relationship between the patient's symptoms and the suspect drug. In conclusion, in ITP patients treated with rituximab, we suggest evaluating pulmonary endpoints through pharmaco-epidemiological observational studies.

Lung Transplant Recipient with Pulmonary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is a progressive lung disease characterized by accumulated surfactant-like lipoproteinaceous material in the alveoli and distal bronchioles. This accumulation is the result of impaired clearance by alveolar macrophages. PAP has been described in 11 solid organ transplant recipients, 9 of whom were treated with mammalian target of rapamycin inhibitors. We report a case of a lung transplant recipient treated with prednisone, mycophenolate mofetil (MMF), and tacrolimus who ultimately developed PAP, which worsened when MMF was replaced with everolimus.

The mTORC1 inhibitor everolimus has antitumor activity in vitro and produces tumor responses in patients with relapsed T-cell lymphoma

Everolimus is an oral agent that targets the mammalian target of rapamycin (mTOR) pathway. This study investigated mTOR pathway activation in T-cell lymphoma (TCL) cell lines and assessed antitumor activity in patients with relapsed/refractory TCL in a phase 2 trial. The mTOR pathway was activated in all 6 TCL cell lines tested and everolimus strongly inhibited malignant T-cell proliferation with minimal cytotoxic effects. Everolimus completely inhibited phosphorylation of ribosomal S6, a raptor/mTOR complex 1 (mTORC1) target, without a compensatory activation of the rictor/mTORC2 target Akt (S475). In the clinical trial, 16 patients with relapsed TCL were enrolled and received everolimus 10 mg by mouth daily. Seven patients (44%) had cutaneous (all mycosis fungoides); 4 (25%) had peripheral T cell not otherwise specified; 2 (13%) had anaplastic large cell; and 1 each had extranodal natural killer/T cell, angioimmunoblastic, and precursor T-lymphoblastic leukemia/lymphoma types. The overall response rate was 44% (7/16; 95% confidence interval [CI]: 20% to 70%). The median progression-free survival was 4.1 months (95% CI, 1.5-6.5) and the median overall survival was 10.2 months (95% CI, 2.6-44.3). The median duration of response for the 7 responders was 8.5 months (95% CI, 1.0 to not reached). These studies indicate that everolimus has antitumor activity and provide proof-of-concept that targeting the mTORC1 pathway in TCL is clinically relevant. This trial was registered at www.clinicaltrials.gov as #NCT00436618.

mTOR, a new potential target for chronic pain and opioid-induced tolerance and hyperalgesia

Chronic pain is a major public health problem with limited treatment options. Opioids remain a routine treatment for chronic pain, but extended exposure to opioid therapy can produce opioid tolerance and hyperalgesia. Although the mechanisms underlying chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia remain to be uncovered, mammalian target of rapamycin (mTOR) is involved in these disorders. The mTOR complex 1 and its triggered protein translation are required for the initiation and maintenance of chronic pain (including cancer pain) and opioid-induced tolerance/hyperalgesia. Given that mTOR inhibitors are FDA-approved drugs and an mTOR inhibitor is approved for the treatment of several cancers, these findings suggest that mTOR inhibitors will likely have multiple clinical benefits, including anticancer, antinociception/anti-cancer pain, and antitolerance/hyperalgesia. This paper compares the role of mTOR complex 1 in chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia.