Sirolimus-induced pneumonitis complicated by pentamidine-induced phospholipidosis in a renal transplant recipient: a case report

Post-CMV Organizing Pneumonia - An Unusual Presentation 10 years after Kidney Transplantation

A 45-year-old gentleman underwent kidney transplantation in March 2010. He remained apparently healthy for the next 10 years when he developed anorexia and weight loss. Diagnostic workup revealed cytomegalovirus (CMV) pneumonia. While viremia resolved within 3 weeks of initiation of valganciclovir, he developed progressive breathlessness and hypoxia on exertion. Imaging of thorax revealed central peri-bronchovascular consolidation and fine reticulations with peripheral sparing. Computed tomography (CT)-guided percutaneous lung biopsy revealed organizing intra-alveolar exudates, suggestive of organizing pneumonia, with no evidence of active infection on biopsy as well as bronchoalveolar lavage (BAL) cytology. This atypical pattern of central distribution of opacities is not typical of organizing pneumonia where peripheral subpleural distribution is more common. Patient responded dramatically following escalation of steroids, with complete resolution of infiltrates on follow-up imaging.

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.

Long-term Outcomes of Kidney Transplantation in Fabry Disease

BACKGROUND

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene that obliterate or markedly reduce α-galactosidase A activity. This results in the systemic accumulation of its glycosphingolipid substrates in body fluids and organs, including the kidney. Fabry nephropathy can lead to end-stage renal disease requiring kidney transplantation. Little is known about its long-term outcomes and the overall patient survival after kidney transplantation.

METHODS

Here, we report 17 Fabry patients (15 male and 2 female subjects) who received kidney transplants and their long-term treatment and follow-up at 4 specialized Fabry centers.

RESULTS

The posttransplant follow-up ranged to 25 years, with a median of 11.5 (range, 0.8-25.5] years. Graft survival was similar, and death-censored graft survival was superior to matched controls. Fabry patients died with functioning kidneys, mostly from cardiac causes. In 2 male subjects 14 and 23 years posttransplant, the grafts had a few typical FD lamellar inclusions, presumably originating from invading host macrophages and vascular endothelial cells.

CONCLUSIONS

We conclude that kidney transplantation has an excellent long-term outcome in FD.

Inhibition of mTOR ameliorates bleomycin-induced pulmonary fibrosis by regulating epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) plays a pivotal role in idiopathic pulmonary fibrosis (IPF). In bleomycin-induced pulmonary fibrosis mice, we observed that inhibition of mTOR (mammalia target of rapamycin) attenuated IPF. Rapamycin suppressed the down-regulation of E-cadherin and up-regulation of fibronectin in bleomycin-induced pulmonary fibrosis mice. In addition, dual immunofluorescence staining for E-cadherin and fibronectin demonstrated that rapamycin pretreatment decreased the proportions of AECs undergoing EMT in bleomycin-induced pulmonary fibrosis, indicating that mTOR inhibition suppressed EMT in vivo. In the setting of transforming growth factor (TGF)-β1-induced EMT in AECs, we found that mTOR inhibitor attenuated TGF-β1-induced EMT in AECs. This EMT was characterized by morphology and cell skeleton changes and the expression of EMT phenotype markers. Finally, mTOR blockade decreased S6k and TGF-β1-induced Smad2/3 phosphorylation. Bleomycin induced pulmonary fibrosis and EMT in mice, while mTOR repression inhibited bleomycin-induced pulmonary fibrosis and attenuated EMT in vivo. Hence, our study provided evidence of a novel mechanism by which mTOR inhibitor ameliorates pulmonary fibrosis. Suppression of mTOR and EMT may be a target for treatment of pulmonary fibrosis.

Exploiting the therapeutic potential of ready-to-use drugs: Repurposing antibiotics against amyloid aggregation in neurodegenerative diseases

Neurodegenerative diseases are chronic and progressive disorders that affect specific regions of the brain, causing gradual disability and suffering that results in a complete inability of patients to perform daily functions. Amyloid aggregation of specific proteins is the most common biological event that is responsible for neuronal death and neurodegeneration in various neurodegenerative diseases. Therapeutic agents capable of interfering with the abnormal aggregation are required, but traditional drug discovery has fallen short. The exploration of new uses for approved drugs provides a useful alternative to fill the gap between the increasing incidence of neurodegenerative diseases and the long-term assessment of classical drug discovery technologies. Drug re-profiling is currently the quickest possible transition from bench to bedside. In this way, experimental evidence shows that some antibiotic compounds exert neuroprotective action through anti-aggregating activity on disease-associated proteins. The finding that many antibiotics can cross the blood-brain barrier and have been used for several decades without serious toxic effects makes them excellent candidates for therapeutic switching towards neurological disorders. The present review is, to our knowledge, the first extensive evaluation and analysis of the anti-amyloidogenic effect of different antibiotics on well-known disease-associated proteins. In addition, we propose a common structural signature derived from the antiaggregant antibiotic molecules that could be relevant to rational drug discovery.

Enhancing the Enrichment of Pharmacophore-Based Target Prediction for the Polypharmacological Profiles of Drugs

PharmMapper is a web server for drug target identification by reversed pharmacophore matching the query compound against an annotated pharmacophore model database, which provides a computational polypharmacology prediction approach for drug repurposing and side effect risk evaluation. But due to the inherent nondiscriminative feature of the simple fit scores used for prediction results ranking, the signal/noise ratio of the prediction results is high, posing a challenge for predictive reliability. In this paper, we improved the predictive accuracy of PharmMapper by generating a ligand-target pairwise fit score matrix from profiling all the annotated pharmacophore models against corresponding ligands in the original complex structures that were used to extract these pharmacophore models. The matrix reflects the noise baseline of fit score distribution of the background database, thus enabling estimation of the probability of finding a given target randomly with the calculated ligand-pharmacophore fit score. Two retrospective tests were performed which confirmed that the probability-based ranking score outperformed the simple fit score in terms of identification of both known drug targets and adverse drug reaction related off-targets.

Rapamycin increases CCN2 expression of lung fibroblasts via phosphoinositide 3-kinase

Excessive production of connective tissue growth factor (CTGF, CCN2) and increased motor ability of the activated fibroblast phenotype contribute to the pathogenesis of idiopathic pulmonary fibrosis (IPF). However, molecules and signal pathways regulating CCN2 expression and migration of lung fibroblasts are still elusive. We hypothesize that rapamycin, via binding and blocking mammalian target of rapamycin (mTOR) complex (mTORC), affects CCN2 expression and migration of lung fibroblasts in vitro. Primary normal and fibrotic human lung fibroblasts were isolated from lung tissues of three patients with primary spontaneous pneumothorax and three with IPF. Cells were incubated with regular medium, or medium containing rapamycin, human recombinant transforming growth factor (TGF)-β1, or both. CCN2 and tissue inhibitor of metalloproteinase (TIMP)-1 expression in cells or supernatant was detected. Wound healing and migration assay was used to measure the migratory potential. TGF-β type I receptor (TβRI)/Smad inhibitor, SB431542 and phosphoinositide 3-kinase (PI3K) inhibitor, LY294002 were used to determine rapamycin's mechanism of action. We demonstrated that rapamycin amplified basal or TGF-β1-induced CCN2 mRNA and protein expression in normal or fibrotic fibroblasts by Smad-independent but PI3K-dependent pathway. Additionally, rapamycin also enhanced TIMP-1 expression as indicated by ELISA. However, wound healing and migrating assay showed rapamycin did not affect the mobility of fibroblasts. Collectively, this study implies a significant fibrogenic induction activity of rapamycin by activating AKT and inducing CCN2 expression in vitro and provides the possible mechanisms for the in vivo findings which previously showed no antifibrotic effect of rapamycin on lung fibrosis.

Fatal rituximab-associated lung injury syndrome in a patient treated with rituximab for recurrence of post-transplant nephrotic syndrome

Rituximab (anti-B CD20 ab.) in recently widely used in renal transplantation.

CASE HISTORY

A 10-yr-old patient with end-stage renal failure due to multidrug-resistant NS was transplanted with renal graft from deceased donor and presented immediate recurrence of NS. PF was started on day 3 and patient received MP pulses, however with no effect. Rituximab (4 × 375 mg/m(2)) was administered. Chest radiographs taken at that time were normal. Partial remission was achieved and the patient was discharged in good condition. Sequential recurrence appeared two wk afterward. Twelve sessions of PF were performed and six pulses of MP were given, effecting a partial remission. Three months after the last dose of rituximab, patient was admitted with increasing respiratory failure, requiring mechanical ventilation. Infectious background, including CMV, BKV, mycoplasma, and pneumocystis, was not confirmed. The patient was treated with MP pulses, IVIG, and a variety of antibiotics. Ground-glass opacity was confirmed on lung CT images. Respiratory failure worsened, despite aggressive ventilation and patient passed away after three wk at ICU. A destruction of alveolar epithelium and extended pulmonary fibrosis was confirmed in the autopsy report. The case represents a fatal RALI.

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.

Sirolimus-induced bronchiolitis obliterans organizing pneumonia in a kidney transplant recipient; a case report and review of literature

BACKGROUND

Sirolimus is immunosuppressive drug used to prevent rejection in kidney transplantation. Pulmonary problems are one of the serious complications which may be seen after administration of this drug and it is believed that it could be life threatening.

CASE PRESENTATION

Here in this paper we presented a 49-years-old man with bronchiolitis obliterans organizing pneumonia (BOOP) induced by chronic use of Sirolimus. The disease was diagnosed and successfully treated.

CONCLUSIONS

Sirolimus uses after kidney transplantation may lead to lung complications, especially BOOP, and the prompt diagnosis would allow earlier treatment.

Di-22:6-bis(monoacylglycerol)phosphate: A clinical biomarker of drug-induced phospholipidosis for drug development and safety assessment

The inability to routinely monitor drug-induced phospholipidosis (DIPL) presents a challenge in pharmaceutical drug development and in the clinic. Several nonclinical studies have shown di-docosahexaenoyl (22:6) bis(monoacylglycerol) phosphate (di-22:6-BMP) to be a reliable biomarker of tissue DIPL that can be monitored in the plasma/serum and urine. The aim of this study was to show the relevance of di-22:6-BMP as a DIPL biomarker for drug development and safety assessment in humans. DIPL shares many similarities with the inherited lysosomal storage disorder Niemann-Pick type C (NPC) disease. DIPL and NPC result in similar changes in lysosomal function and cholesterol status that lead to the accumulation of multi-lamellar bodies (myeloid bodies) in cells and tissues. To validate di-22:6-BMP as a biomarker of DIPL for clinical studies, NPC patients and healthy donors were classified by receiver operator curve analysis based on urinary di-22:6-BMP concentrations. By showing 96.7-specificity and 100-sensitivity to identify NPC disease, di-22:6-BMP can be used to assess DIPL in human studies. The mean concentration of di-22:6-BMP in the urine of NPC patients was 51.4-fold (p ≤ 0.05) above the healthy baseline range. Additionally, baseline levels of di-22:6-BMP were assessed in healthy non-medicated laboratory animals (rats, mice, dogs, and monkeys) and human subjects to define normal reference ranges for nonclinical/clinical studies. The baseline ranges of di-22:6-BMP in the plasma, serum, and urine of humans and laboratory animals were species dependent. The results of this study support the role of di-22:6-BMP as a biomarker of DIPL for pharmaceutical drug development and health care settings.

Pulmonary toxicity in a renal transplant recipient treated with amiodarone and everolimus: a case of hypothetical synergy and a proposal for a screening protocol

Pneumotoxic drugs like amiodarone and m-TOR inhibitors (m-TORi) may be administered contemporaneously in therapy for patients who had renal transplants. We present a case of amiodarone pulmonary toxicity (APT) in a patient treated with amiodarone and everolimus. A 57-year-old Caucasian male, under treatment with both everolimus (for 3 years) and amiodarone (for 2 months), presented with fever, dyspnoea and a negative chest X-ray after his second kidney transplant with suboptimal serum creatinine (3 mg/dl). A non-contrastive high-resolution CT scan showed bilateral interstitial lung disease with an associated reduction in carbon monoxide diffusing capacity. Bronchoalveolar lavage (BAL) was negative for an infection, but BAL cytology was suitable for APT (50% of ‘foamy’ macrophages). A complete recovery was achieved after amiodarone interruption and an oral steroid therapy increase. Everolimus was continued. His kidney function remained unchanged in the upcoming months. In conclusion, we suggest a possible synergistic effect between m-TORi and amiodarone. Furthermore, we propose a diagnostic algorithm that can be used as a surveillance tool to identify a potential initial lung damage in patients treated with 1 or more pneumotoxic drugs.

Strategies for the management of adverse events associated with mTOR inhibitors

Mammalian target of rapamycin (mTOR) inhibitors are used as potent immunosuppressive agents in solid-organ transplant recipients (everolimus and sirolimus) and as antineoplastic therapies for various cancers (eg, advanced renal cell carcinoma; everolimus, temsirolimus, ridaforolimus). Relevant literature, obtained from specific PubMed searches, was reviewed to evaluate the incidence and mechanistic features of specific adverse events (AEs) associated with mTOR inhibitor treatment, and to present strategies to effectively manage these events. The AEs examined in this review include stomatitis and other cutaneous AEs, wound-healing complications (eg, lymphocele, incisional hernia), diabetes/hyperglycemia, dyslipidemia, proteinuria, nephrotoxicity, delayed graft function, pneumonitis, anemia, hypertension, gonadal dysfunction, and ovarian toxicity. Strategies for selecting appropriate patients for mTOR inhibitor therapy and minimizing the risks of AEs are discussed, along with best practices for identifying and managing side effects. mTOR inhibitors are promising therapeutic options in immunosuppression and oncology; most AEs can be effectively detected and managed or reversed with careful monitoring and appropriate interventions.

Clinical efficacy and management of temsirolimus in patients with relapsed or refractory mantle cell lymphoma

Most patients with mantle cell lymphoma (MCL) relapse within a few years of treatment. Conventional agents provide little benefit, thus identification of new therapies is critical to improve patient outcomes. Temsirolimus, an inhibitor of mammalian target of rapamycin, is an effective, well-tolerated option authorized in Europe for treatment of patients with relapsed/refractory MCL. Intravenous temsirolimus has been extensively studied in MCL and has consistently demonstrated single-agent antitumor activity. In the pivotal phase III trial, treatment with temsirolimus 175 mg weekly for 3 weeks followed by 75 mg weekly (175/75 mg) resulted in significant improvements in progression-free survival (P = .0009) and objective response rate (P = .002) vs. investigator's choice of therapy. Hematologic toxicities (thrombocytopenia, neutropenia) were the principal grade 3/4 adverse events associated with temsirolimus 175/75 mg. Other toxicities included increases in serum cholesterol and triglycerides, hyperglycemia, fatigue, and dyspnea. Overall, the safety profile of temsirolimus is acceptable in this setting, and most toxicities are manageable with dose modification or medical intervention. Clinical studies of temsirolimus in relapsed or refractory MCL patients aim to clarify the optimal treatment schedule and to assess rational combinations with other therapeutic agents, such as rituximab or chemotherapy. Practical considerations are discussed for the clinical use of temsirolimus in patients with MCL.

Short-term treatment with rapamycin and dietary restriction have overlapping and distinctive effects in young mice

Because rapamycin, an inhibitor of the nutrient sensor mammalian target of rapamycin, and dietary restriction both increase life span of mice, it has been hypothesized that they act through similar mechanisms. To test this hypothesis, we compared various biological parameters in dietary restriction mice (40% food restriction) and mice fed rapamycin (14 ppm). Both treatments led to a significant reduction in mammalian target of rapamycin signaling and a corresponding increase in autophagy. However, we observed striking differences in fat mass, insulin sensitivity, and expression of cell cycle and sirtuin genes in mice fed rapamycin compared with dietary restriction. Thus, although both treatments lead to significant downregulation of mammalian target of rapamycin signaling, these two manipulations have quite different effects on other physiological functions suggesting that they might increase life span through a common pathway as well as pathways that are altered differently by dietary restriction and rapamycin.