Statin use is associated with improved function and survival of lung allografts

The Evaluation and Management of Coronary Artery Disease in the Lung Transplant Patient

Lung transplantation can greatly improve quality of life and extend survival in those with end-stage lung disease. In order to derive the maximal benefit from such a procedure, patients must be carefully selected and be otherwise healthy enough to survive a high-risk surgery and sometimes prolonged immunosuppressive therapy following surgery. Patients therefore must be critically assessed prior to being listed for transplantation with close attention paid towards assessment of cardiovascular health and operative risk. One of the biggest dictators of this is coronary artery disease. In this review article, we discuss the assessment and management of coronary artery disease in the potential lung transplant candidate.

Impact of statin treatment and exposure on the risk of chronic allograft dysfunction in Chinese lung transplant recipients

PURPOSE

Chronic lung allograft dysfunction (CLAD) was a common complication following lung transplantation that contributed to long-term morbidity and mortality. Statin therapy had been suggested to attenuate recipient inflammation and immune response, potentially reducing the risk and severity of CLAD. This study aimed to evaluate the impact of statin use and in vivo exposure on the incidence of CLAD in lung transplant recipients (LTRs), as well as their effects on immune cells and inflammatory factors.

METHODS

A retrospective cohort study was conducted on patients who underwent lung transplantation between January 2017 and December 2020. The incidence of CLAD, as per the 2019 ISHLT criteria, was assessed as the clinical outcome. The plasma concentrations of statin were measured using a validated UPLC-MS/MS method, while inflammation marker levels were determined using ELISA kits.

RESULTS

The statin group exhibited a significantly lower rate of CLAD (P = 0.002). Patients receiving statin therapy showed lower CD4+ T-cell counts, total T-lymphocyte counts, and IL-6 levels (P = 0.017, P = 0.048, and P = 0.038, respectively). Among the CLAD groups, the atorvastatin level (2.51 ± 1.31 ng/ml) was significantly lower than that in the non-CLAD group (OR = 1.438, 95%CI (1.007-2.053), P = 0.046).

CONCLUSION

Statin therapy significantly reduced the incidence of CLAD, as well as immune cell counts and inflammatory cytokine levels in LTRs. Although the statin exposure was significantly lower in CLAD patients, it was not associated with the incidence of CLAD.

Statin Use May Be Associated With a Lower Risk of Invasive Aspergillosis in Lung Transplant Recipients

BACKGROUND

Statins are competitive inhibitors of 3-hydroxy-3methylglutaryl coenzyme A reductase (HMG-CoA reductase) that catalyses HMG-CoA conversion to mevalonate, a process involved in synthesizing cholesterol in humans and ergosterol in fungi. The effect of statin use on the risk of development of invasive aspergillosis (IA) in lung transplant recipients (LTRs) is not well documented.

METHODS

This retrospective study included LTRs from 2010 to 2017 who were followed for one-year post-transplant. Proven or probable IA was diagnosed as per ISHLT criteria. We performed a multivariable Cox proportional hazards model of the association between IA and statin use (minimum of 2 weeks duration prior to IA), adjusting for other known IA risk factors.

RESULTS

We identified 785 LTRs, 44% female, mean age 53 years old, the most common underlying disease being pulmonary fibrosis (23.8%). In total, 451 LTRs (57%) received statins post-transplant, atorvastatin was the most commonly used statin (68%). The mean duration of statins post-transplant was 347 days (interquartile range [IQR]: 305 to 346). And 55 (7%) LTRs developed IA in the first-year post-transplant. Out of these 55 LTRs, 9 (16.3%) had received statin before developing IA. In multivariable analysis, statin use was independently associated with a lower risk of IA (P = .002, SHR 0.30, 95% confidence interval [CI] 95% .14-.64). Statin use was also associated with a lower incidence of post-transplant Aspergillus colonization, 114 (34%) in the no statin group vs 123 (27%) in the statin group (P = .038).

CONCLUSIONS

The use of statin for a minimum of two weeks during the first-year post-transplant was associated with a 70% risk reduction of IA in LTRs.

Perioperative statin medication impairs pulmonary outcome after abdomino-thoracic esophagectomy

Background

Although surgery is the curative option of choice for patients with locally advanced esophageal cancer, morbidity, especially the rate of pulmonary complications, and consequently mortality of patients undergoing abdomino-thoracic esophagectomy remain unacceptably high. Causes for developing post-esophagectomy pulmonary complications are trauma to the lung and thoracic cavity as well as systemic inflammatory response. Statins are known to influence inflammatory pathways, but whether perioperative statin medication impacts on inflammatory response and pulmonary complication development after esophagectomy had not been investigated, yet.

Methods

Retrospective analysis and propensity score matching of patients, who either received perioperative statin medication [statin( +)] or not [statin( −)], with regard to respiratory impairment (PaO₂/FiO₂ < 300 mmHg), pneumonia development, and inflammatory serum markers after abdomino-thoracic esophagectomy.

Results

Seventy-eight patients who underwent abdomino-thoracic esophagectomy for cancer were included into propensity score pair-matched analysis [statin( +): n = 26 and statin( −): n = 52]. Although no differences were seen in postoperative inflammatory serum markers, C-reactive protein values correlated significantly with the development of pneumonia beyond postoperative day 3 in statin( −) patients. This effect was attenuated under statin medication. No difference was seen in cumulative incidences of respiratory impairment; however, significantly higher rate (65.4% versus 38.5%, p = 0.0317, OR 3.022, 95% CI 1.165–7.892) and higher cumulative incidence (p = 0.0468) of postoperative pneumonia were seen in statin( +) patients, resulting in slightly longer postoperative stay on intensive care unit (p = 0.0612) as well as significantly prolonged postoperative in-hospital stay (p = 0.0185).

Conclusions

Development of pulmonary complications after abdomino-thoracic esophagectomy is multifactorial but frequent. The establishment of preventive measures into the perioperative clinical routine is mandatory for an improved patient outcome. Perioperative medication with statins might influence pneumonia development in the highly vulnerable lung after abdomino-thoracic esophagectomy. Perioperative interruption of statin medication might be beneficial in appropriate patients; however, further clinical trials and translational studies are needed to prove this hypothesis.

Pharmacotherapy of chronic lung allograft dysfunction post lung transplantation

Chronic lung allograft dysfunction (CLAD) remains the primary cause of death in lung transplant recipients (LTRs) in spite of improvements in immunosuppression management. Despite advances in knowledge regarding the pathogenesis of CLAD, treatments that are currently available are usually ineffective and delay progression of disease at best. There are currently no evidence-based guidelines for the optimal treatment of CLAD, and management varies widely across transplant centers. Additionally, there are minimal publications available to summarize data for currently available therapies and outcomes in LTRs. We identified the major domains of the medical management of CLAD and conducted a comprehensive search of PubMed and Embase databases to identify articles published from inception to December 2021 related to CLAD in LTRs. Studies published in English pertaining to the pharmacologic prevention and treatment of CLAD were included; highest priority was given to prospective, randomized, controlled trials if available. Prospective observational and retrospective controlled trials were prioritized next, followed by retrospective uncontrolled studies, case series, and finally case reports if the information was deemed to be pertinent. Reference lists of qualified publications were also reviewed to find any other publications of interest that were not found on initial search. In the absence of literature published in the aforementioned databases, additional articles were identified by reviewing abstracts presented at the International Society for Heart and Lung Transplantation and American Transplant Congress annual meetings between 2010-2021. This document serves to provide a comprehensive review of the literature and considerations for the prevention and medical management of CLAD. This article is protected by copyright. All rights reserved.

Management of long-term cardiovascular risk factors post organ transplant

PURPOSE OF REVIEW

Cardiovascular disease is one of the leading causes of death in solid organ transplant (SOT) recipients. Early identification of cardiovascular risk factors and their adequate management in this population is key for prevention and improved outcomes.

RECENT FINDINGS

Approximately 80% of SOT present one or more cardiovascular risk factors, with increasing prevalence with time posttransplantation. They are due to the interplay of pretransplant conditions and metabolic consequences of immunosuppressive agents, mainly corticosteroids and calcineurin inhibitors. Among the pharmacological management strategies, statins have shown an important protective effect in SOT.

SUMMARY

Strict surveillance of cardiovascular risk factors is recommended in SOT due to their high prevalence and prognostic implications. Further studies on the best managements strategies in this population are needed.

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.

Effect of HMG CoA reductase inhibitors on the development of chronic lung allograft dysfunction

Lung transplant recipients (LRs) have a reduced median 5-year survival of approximately 55% primarily due to chronic lung allograft dysfunction (CLAD). Statins have anti-inflammatory and immunomodulatory effects that may facilitate CLAD prevention. This study sought to evaluate statin effect on CLAD development. Adult bilateral LRs from January 2004 to October 2013 were included. Statin group included recipients with early statin use and continued for minimum 6 months. Propensity score matching was performed for age, gender, and native lung disease to select matched nonstatin group. Competing risk approach was used to evaluate statin effect on CLAD development at 3 years while controlling for acute rejection and CMV pneumonitis. A total of 130 patients were included in each group. CLAD cumulative incidence at 3 years for statin and nonstatin groups was 20.6% (CI: 11.8%-33.5%) and 22.4% (CI: 12.2%-27.3%). Statin use was not associated with a decreased risk of CLAD (subdistribution hazard ratio [SHR]: 0.93, 95% CI: 0.55-1.59, P = .80) but was associated with a decreased risk of death (SHR: 0.45, CI: 0.22-0.90, P = .024). At 3 years, patient survival was 81.7% in statin group and 68.3% in nonstatin group (P = .012). Statins did not significantly delay the time to development of CLAD in LR but did demonstrate a benefit in patient survival.

Prevention of chronic rejection after lung transplantation

Long-term survival after lung transplantation (LTx) is limited by chronic rejection (CR). Therapeutic strategies for CR have been largely unsuccessful, making prevention of CR an important and challenging therapeutic approach. In the current review, we will discuss current clinical evidence regarding prevention of CR after LTx.

Statin therapy for preventing cardiovascular diseases in patients treated with tacrolimus after kidney transplantation

Background

Lipid abnormalities are prevalent in tacrolimus-treated patients. The aim of the study was to evaluate the preventive effects of statin therapy on major adverse cardiovascular events (MACE) in patients treated with tacrolimus-based immunosuppression after kidney transplantation (KT), and to identify the risk factors.

Methods

This observational cohort study included adult patients who underwent KT and were treated with tacrolimus. Patients who received any lipid-lowering agents except statins, or had a history of immunosuppressant use before transplantation were excluded. The primary outcome was the adjusted risk of the first occurrence of MACE. The secondary outcomes included the risk of individual cardiovascular disease (CVD) and changes in cholesterol level. Subgroup analyses were performed in the statin-user group according to the dosage and/or type of statin.

Results

Compared with the control group (n=73), the statin-users (n=92) had a significantly reduced risk of MACE (adjusted HR, 0.31; 95% CI, 0.13–0.74). In the Cox regression analysis, old age, history of CVD, and comorbid hypertension were identified as independent factors associated with increased MACE. The total cholesterol levels were not significantly different between the two groups. Subjects with higher cumulative defined daily dose of statins had significantly lower risks of MACE.

Conclusion

Statin therapy in patients treated with tacrolimus after KT significantly lowered the risk of MACE. Long-term statin therapy is clearly indicated in older kidney transplant recipients for secondary prevention.

Atorvastatin has a protective effect in a mouse model of bronchial asthma through regulating tissue transglutaminase and triggering receptor expressed on myeloid cells-1 expression

Airway remodeling in asthma contributes to airway hyperreactivity, loss of lung function and persistent symptoms. Current therapies do not adequately treat the structural airway changes associated with asthma. Statin drugs have improved respiratory health and their therapeutic potential in asthma has been tested in clinical trials. However, the mechanism of action of statins in this context has remained elusive. The present study hypothesized that atorvastatin treatment of ovalbumin-exposed mice attenuates early features of airway remodeling via a mevalonate-dependent mechanism. BALB/c mice were sensitized with ovalbumin and atorvastatin was delivered via oral gavage prior to each ovalbumin exposure. Reverse transcription-semi-quantitative polymerase chain reaction (RT-semi-qPCR), ELISA and western blot analysis were used to assess the expression of a number of relevant genes, including tissue transglutaminase (tTG), triggering receptor expressed on myeloid cells (TREM)-1, nuclear factor erythroid 2-related factor (Nrf) 2, hypoxia-inducible factor (HIF)-1α, transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-9 and tissue inhibitors of metalloproteinases (TIMP)-1 in lung tissue. α-Smooth muscle actin (α-SMA) activity was measured by immunohistochemistry. Airway hyperresponsiveness, lung collagen deposition, airway wall area, airway smooth muscle thickness and lung pathology were also assessed. Atorvastatin treatment led to downregulation of tTG and TREM-1 expression in lung tissue after ovalbumin sensitization, blocked the activity of MMP-9, vascular endothelial growth factor, nuclear factor-κB p65, α-SMA, HIF-α and TGF-β1 and up-regulated Nrf2 expression. Furthermore, the number of lymphocytes and eosinophils in the atorvastatin group was significantly lower than that in the control group. In addition, airway hyperresponsiveness, lung collagen deposition, airway wall area, airway smooth muscle thickness and pathological changes in the lung were significantly decreased in the atorvastatin group, and tumor necrosis factor-α, interleukin (IL)-8, IL-13 and IL-17 in serum were significantly decreased. Histological results demonstrated the attenuating effect of atorvastatin on ovalbumin-induced airway remodeling in asthma. In conclusion, the present study indicated that atorvastatin significantly alleviated ovalbumin-induced airway remodeling in asthma by downregulating tTG and TREM-1 expression. The marked protective effects of atorvastatin suggest its therapeutic potential in ovalbumin-induced airway remodeling in asthma treatment.

Pleiotropic and Adverse Effects of Statins-Do Epigenetics Play a Role?

Statins are widely used to prevent major cardiovascular events by lowering serum cholesterol. There is evidence that statins have pleiotropic effects-that is, cholesterol-independent effects-that may also confer protection from cardiovascular disease and potentially numerous other pathologies, including cancer. Statins also have a number of well described adverse effects, including myopathy, rhabdomyolysis, liver damage, and type 2 diabetes. This paper examines the evidence of epigenetic modifications as a contributory factor to the pleiotropic and adverse effects of statins. In vitro and animal studies have shown that statins can inhibit histone deacetylase activity and increase histone acetylation. Similarly, there is evidence that statins may inhibit both histone and DNA methyltransferases and subsequently demethylate histone residues and DNA, respectively. These changes have been shown to alter expression of various genes, including tumor suppressor genes and genes thought to have anti-atherosclerotic actions. Statins have also been shown to influence the expression of numerous microRNAs that suppress the translation of proteins involved in tumorigenesis and vascular function. Whether the adverse effects of statins may also have an epigenetic component has been less widely studied, although there is evidence that microRNA expression may be altered in statin-induced muscle and liver damage. As epigenetics and microRNAs influence gene expression, these changes could contribute to the pleiotropic and adverse effects of statins and have long-lasting effects on the health of statin users.

Effect of statins on disease-related outcomes in patients with idiopathic pulmonary fibrosis

BACKGROUND

Data are conflicting regarding the possible effects of statins in patients with idiopathic pulmonary fibrosis (IPF). This post hoc analysis assessed the effects of statin therapy on disease-related outcomes in IPF.

METHODS

Patients randomised to placebo (n=624) in three controlled trials of pirfenidone in IPF (CAPACITY 004 and 006, ASCEND) were categorised by baseline statin use. Outcomes assessed during the 1-year follow-up included disease progression, mortality, hospitalisation and composite outcomes of death or ≥10% absolute decline in FVC and death or ≥50 m decline in 6-minute walk distance (6MWD).

RESULTS

At baseline, 276 (44%) patients were statin users versus 348 (56%) non-users. Baseline characteristics were similar between groups, except statin users were older and had higher prevalence of cardiovascular disease and risk factors. In multivariate analyses adjusting for differences in baseline characteristics, statin users had lower risks of death or 6MWD decline (HR 0.69; 95% CI 0.48 to 0.99, p=0.0465), all-cause hospitalisation (HR 0.58; 95% CI 0.35 to 0.94, p=0.0289), respiratory-related hospitalisation (HR 0.44; 95% CI 0.25 to 0.80, p=0.0063) and IPF-related mortality (HR 0.36; 95% CI 0.14 to 0.95, p=0.0393) versus non-users. Non-significant treatment effects favouring statin use were observed for disease progression (HR 0.75; 95% CI 0.52 to 1.07, p=0.1135), all-cause mortality (HR 0.54; 95% CI 0.24 to 1.21, p=0.1369) and death or FVC decline (HR 0.71; 95% CI 0.48 to 1.07, p=0.1032).

CONCLUSIONS

This post hoc analysis supports the hypothesis that statins may have a beneficial effect on clinical outcomes in IPF. Prospective clinical trials are required to validate these observations.

TRIAL REGISTRATION NUMBERS

NCT01366209, NCT00287729 and NCT00287716.

Influenza Vaccine Antibody Responses in Lung Transplant Recipients

Context

Lung transplant recipients are at high risk of morbidity and mortality from influenza infection because of altered lung physiology and immunosuppression. Annual influenza immunization is recommended, but the ability to mount an antibody response may be limited by immunosuppressant medications.

Objective

To compare the antibody response rate to influenza vaccine in lung transplant recipients to healthy controls.

Design

Open label study

Setting

Lung transplant clinic and General Clinical Research Center at a university hospital.

Subjects

Sixty-eight single and bilateral lung transplant recipients and 35 healthy controls were enrolled in October and November 2002.

Methods

Each individual underwent blood sampling before receiving the 2002–2003 influenza vaccine and 4 weeks later. Influenza antibody concentrations were measured by hemagglutination inhibition assay. Vaccine response rates (antibody concentration >40 hemagglutination units and at least 4-fold increase in antibody concentration) were compared using χ2. The influence of specific immunosuppressants on vaccine response was compared.

Results

The influenza vaccine response rate for lung transplant recipients was 29/68 (43%) and 22/35 (63%) for the healthy individuals ( Pž < .05; χ2). Among the recipients, mycophenolate mofetil was associated with poorer influenza vaccine antibody response (> 40 hemagglutination units) (62% vs 91%; Pž = .01), whereas sirolimus (91% vs 63%; Pž = .02) was associated with better influenza antibody response compared to those not taking mycophenolate mofetil or sirolimus, respectively.

Conclusion

Lung transplant recipients had lower influenza vaccine response rates than healthy individuals. Influenza vaccine antibody response is influenced by concomitant administration of mycophenolate mofetil or sirolimus. Future studies should measure protection from influenza infection conferred by immunization and alternative vaccination strategies.

[Small airway diseases and immune deficiency]

INTRODUCTION

Innate or acquired immune deficiency may show respiratory manifestations, often characterized by small airway involvement. The purpose of this article is to provide an overview of small airway disease across the major causes of immune deficiency.

BACKGROUND

In patients with common variable immune deficiency, recurrent lower airway infections may lead to bronchiolitis and bronchiectasis. Follicular and/or granulomatous bronchiolitis of unknown origin may also occur. Bronchiolitis obliterans is the leading cause of death after the first year in patients with lung transplantation. Bronchiolitis obliterans also occurs in patients with allogeneic haematopoietic stem cell transplantation, especially in the context of systemic graft-versus-host disease.

VIEWPOINT AND CONCLUSION

Small airway diseases have different clinical expression and pathophysiology across various causes of immune deficiency. A better understanding of small airways disease pathogenesis in these settings may lead to the development of novel targeted therapies.

[Therapeutic Drug Management for Transplanted Women with a Planned Pregnancy: About Two Cases of Lung and Heart-lung Transplantation]

Advances in lung transplantation allow the women of childbearing age to consider becoming mothers. When planning to become pregnant, a therapeutic drug management of immunosuppressive drugs and associated therapies is required. It must take into account teratogenic and fetotoxic drugs, as well as pharmacokinetic changes encountered during pregnancy. Increasingly data are currently available on the management of immunosuppressive drugs and associated therapies during pregnancy. We report the case management of drug therapy before and during pregnancy in two patients after a lung or heart-lung transplantation. To prevent the emergence of complications for mother and child, a literature review has been necessary to manage drug therapies of each patient.

What's new in clinical solid organ transplantation by 2013

Innovative and exciting advances in the clinical science in solid organ transplantation continuously realize as the results of studies, clinical trials, international conferences, consensus conferences, new technologies and discoveries. This review will address to the full spectrum of news in transplantation, that verified by 2013. The key areas covered are the transplantation activity, with particular regards to the donors, the news for solid organs such as kidney, pancreas, liver, heart and lung, the news in immunosuppressive therapies, the news in the field of tolerance and some of the main complications following transplantation as infections and cancers. The period of time covered by the study starts from the international meetings held in 2012, whose results were published in 2013, up to the 2013 meetings, conferences and consensus published in the first months of 2014. In particular for every organ, the trends in numbers and survival have been reviewed as well as the most relevant problems such as organ preservation, ischemia reperfusion injuries, and rejections with particular regards to the antibody mediated rejection that involves all solid organs. The new drugs and strategies applied in organ transplantation have been divided into new way of using old drugs or strategies and drugs new not yet on the market, but on phase Ito III of clinical studies and trials.

Recent advances in the management of acute bronchiolitis

Acute bronchiolitis is characterized by acute wheezing in infants or children and is associated with signs or symptoms of respiratory infection; it is rarely symptomatic in adults and the most common etiologic agent is respiratory syncytial virus (RSV). Usually it does not require investigation, treatment is merely supportive and a conservative approach seems adequate in the majority of children, especially for the youngest ones (<3 months); however, clinical scoring systems have been proposed and admission in hospital should be arranged in case of severe disease or a very young age or important comorbidities. Apnea is a very important aspect of the management of young infants with bronchiolitis. This review focuses on the clinical, radiographic, and pathologic characteristics, as well as the recent advances in management of acute bronchiolitis.

Simvastatin Increases the Ability of Roflumilast N-oxide to Inhibit Cigarette Smoke-Induced Epithelial to Mesenchymal Transition in Well-differentiated Human Bronchial Epithelial Cells in vitro

BACKGROUND

Cigarette smoking contributes to epithelial-mesenchymal transition (EMT) in COPD small bronchi as part of the lung remodeling process. We recently observed that roflumilast N-oxide (RNO), the active metabolite of the PDE4 inhibitor roflumilast, prevents cigarette smoke-induced EMT in differentiated human bronchial epithelial cells. Further, statins were shown to protect renal and alveolar epithelial cells from EMT.

OBJECTIVES

To analyze how RNO and simvastatin (SIM) interact on CSE-induced EMT in well-differentiated human bronchial epithelial cells (WD-HBEC) from small bronchi in vitro.

METHODS

WD-HBEC were stimulated with CSE (2.5%). The mesenchymal markers vimentin, collagen type I and α-SMA, the epithelial markers E-cadherin and ZO-1, as well as β-catenin were quantified by real time quantitative PCR or Western blotting. Intracellular reactive oxygen species (ROS) were measured using the H2DCF-DA probe. GTP-Rac1 and pAkt were evaluated by Western blotting.

RESULTS

The combination of RNO at 2 nM and SIM at 100 nM was (over) additive to reverse CSE-induced EMT. CSE-induced EMT was partially mediated by the generation of ROS and the activation of the PI3K/Akt/β-catenin pathway. Both RNO at 2 nM and SIM at 100 nM partially abrogated this pathway, and its combination almost abolished ROS/ PI3K/Akt/β-catenin signaling and therefore EMT.

CONCLUSIONS

The PDE4 inhibitor roflumilast N-oxide acts (over)additively with simvastatin to prevent CSE-induced EMT in WD-HBEC in vitro.

Immunosuppression in lung transplantation

Lung transplantation can be a life-saving procedure for those with end-stage lung diseases. Unfortunately, long term graft and patient survival are limited by both acute and chronic allograft rejection, with a median survival of just over 6 years. Immunosuppressive regimens are employed to reduce the rate of rejection, and while protocols vary from center to center, conventional maintenance therapy consists of triple drug therapy with a calcineurin inhibitor (cyclosporine or tacrolimus), antiproliferative agents [azathioprine (AZA), mycophenolate, sirolimus (srl), everolimus (evl)], and corticosteroids (CS). Roughly 50% of lung transplant centers also utilize induction therapy, with polyclonal antibody preparations [equine or rabbit anti-thymocyte globulin (ATG)], interleukin 2 receptor antagonists (IL2RAs) (daclizumab or basiliximab), or alemtuzumab. This review summarizes these agents and the data surrounding their use in lung transplantation, as well as additional common and novel therapies in lung transplantation. Despite the progression of the management of lung transplant recipients, they continue to be at high risk of treatment-related complications, and poor graft and patient survival. Randomized clinical trials are needed to allow for the development of better agents, regimens and techniques to address above mentioned issues and reduce morbidity and mortality among lung transplant recipients.

Immunosuppression and allograft rejection following lung transplantation: evidence to date

The enduring success of lung transplantation is built on the use of immunosuppressive drugs to stop the immune system from rejecting the newly transplanted lung allograft. Most patients receive a triple-drug maintenance immunosuppressive regimen consisting of a calcineurin inhibitor, an antiproliferative and corticosteroids. Induction therapy with either an antilymphocyte monoclonal or an interleukin-2 receptor antagonist are prescribed by many centres aiming to achieve rapid inhibition of recently activated and potentially alloreactive T lymphocytes. Despite this generic approach acute rejection episodes remain common, mandating further fine-tuning and augmentation of the immunosuppressive regimen. While there has been a trend away from cyclosporine and azathioprine towards a preference for tacrolimus and mycophenolate mofetil, this has not translated into significant protection from the development of chronic lung allograft dysfunction, the main barrier to the long-term success of lung transplantation. This article reviews the problem of lung allograft rejection and the evidence for immunosuppressive regimens used both in the short- and long-term in patients undergoing lung transplantation.

Simvastatin for the prevention of exacerbations in moderate-to-severe COPD

BACKGROUND

Retrospective studies have shown that statins decrease the rate and severity of exacerbations, the rate of hospitalization, and mortality in chronic obstructive pulmonary disease (COPD). We prospectively studied the efficacy of simvastatin in preventing exacerbations in a large, multicenter, randomized trial.

METHODS

We designed the Prospective Randomized Placebo-Controlled Trial of Simvastatin in the Prevention of COPD Exacerbations (STATCOPE) as a randomized, controlled trial of simvastatin (at a daily dose of 40 mg) versus placebo, with annual exacerbation rates as the primary outcome. Patients were eligible if they were 40 to 80 years of age, had COPD (defined by a forced expiratory volume in 1 second [FEV1] of less than 80% and a ratio of FEV1 to forced vital capacity of less than 70%), and had a smoking history of 10 or more pack-years, were receiving supplemental oxygen or treatment with glucocorticoids or antibiotic agents, or had had an emergency department visit or hospitalization for COPD within the past year. Patients with diabetes or cardiovascular disease and those who were taking statins or who required statins on the basis of Adult Treatment Panel III criteria were excluded. Participants were treated from 12 to 36 months at 45 centers.

RESULTS

A total of 885 participants with COPD were enrolled for approximately 641 days; 44% of the patients were women. The patients had a mean (±SD) age of 62.2±8.4 years, an FEV1 that was 41.6±17.7% of the predicted value, and a smoking history of 50.6±27.4 pack-years. At the time of study closeout, the low-density lipoprotein cholesterol levels were lower in the simvastatin-treated patients than in those who received placebo. The mean number of exacerbations per person-year was similar in the simvastatin and placebo groups: 1.36±1.61 exacerbations and 1.39±1.73 exacerbations, respectively (P=0.54). The median number of days to the first exacerbation was also similar: 223 days (95% confidence interval [CI], 195 to 275) and 231 days (95% CI, 193 to 303), respectively (P=0.34). The number of nonfatal serious adverse events per person-year was similar, as well: 0.63 events with simvastatin and 0.62 events with placebo. There were 30 deaths in the placebo group and 28 in the simvastatin group (P=0.89).

CONCLUSIONS

Simvastatin at a daily dose of 40 mg did not affect exacerbation rates or the time to a first exacerbation in patients with COPD who were at high risk for exacerbations. (Funded by the National Heart, Lung, and Blood Institute and the Canadian Institutes of Health Research; STATCOPE ClinicalTrials.gov number, NCT01061671.).

Statins in the treatment of asthma

PURPOSE

Current evidence on statin agents as potential alternatives or adjuncts to corticosteroid therapy for asthma is reviewed.

SUMMARY

Research showing antiinflammatory and antioxidant effects of statins in animal models suggested that the cholesterol-lowering drugs might be useful in mitigating the adverse effects of long-term corticosteroid therapy in patients with asthma, but studies in humans have yielded mixed results. Two small placebo-controlled clinical trials indicated that statins were not effective in combating asthmatic inflammatory processes, and trials of statins as adjunctive therapy have indicated minimal steroid-sparing benefits. In two studies involving a total of more than 1000 current and former smokers with asthma, statin use correlated with reduced acute asthma exacerbations and a slower decline of lung function in some patients. A large population-based study (n = 3965) found that statin therapy was associated with a significantly reduced risk of hospitalization for asthma after an average follow-up period of about 4.5 years; a smaller U.S. retrospective cohort study indicated a significantly lower 1-year rate of asthma-related emergency room visits among patients receiving statins relative to those not using statins (9.08% versus 4.18%). Much of the research on statins and asthma has not controlled for confounding influences such as patient comorbidities and concomitant medication use.

CONCLUSION

Clinical trials have shown that statin therapy is not superior to and does not enhance the beneficial effects of inhaled corticosteroids for the treatment of asthma. Some evidence suggests that statins may help preserve lung function in cigarette smokers with obstructive pulmonary disease and reduce hospitalizations in asthmatic smokers and nonsmokers.

Simvastatin attenuates neutrophil recruitment in one-lung ventilation model in rats

PURPOSE

To investigate the anti-inflammatory effects of simvastatin in rats undergoing one-lung ventilation (OLV) followed by lung re-expansion.

METHODS

Male Wistar rats (n=30) were submitted to 1-h OLV followed by 1-h lung re-expansion. Treated group received simvastatin (40 mg/kg for 21 days) previous to OLV protocol. Control group received no treatment or surgical/ventilation interventions. Measurements of pulmonary myeloperoxidase (MPO) activity, pulmonary protein extravasation, and serum levels of cytokines and C-reactive protein (CRP) were performed.

RESULTS

OLV significantly increased the MPO activity in the collapsed and continuously ventilated lungs (31% and 52% increase, respectively) compared with control (p<0.05). Treatment with simvastatin significantly reduced the MPO activity in the continuously ventilated lung but had no effect on lung edema after OLV. The serum IL-6 and CRP levels were markedly higher in OLV group, but simvastatin treatment failed to affect the production of these inflammatory markers. Serum levels of IL-1β, TNF-α and IL-10 remained below the detection limit in all groups.

CONCLUSIONS

In an experimental one-lung ventilation model pre-operative treatment with simvastatin reduces remote neutrophil infiltration in the continuously ventilated lung. Our findings suggest that simvastatin may be of therapeutic value in OLV-induced pulmonary inflammation deserving clinical investigations.

Experimental evaluation of analgesic and anti-inflammatory activity of simvastatin and atorvastatin

Aim:

The aim of this study is to evaluate the analgesic and anti-inflammatory activities of atorvastatin and simvastatin in different experimental models in mice and rats.

Materials and Methods:

Analgesic activity of simvastatin and atorvastatin was assessed in tail flick model in rats (n = 6), where it was compared with aspirin and tramadol and in acetic acid induced writhing in mice (n = 6), where it was compared with aspirin. Anti-inflammatory activity of statins was evaluated using carrageenin induced paw edema and formalin induced arthritis in rats.

Results:

In the tail flick method, analgesic effect of tramadol was significantly more than the other drugs except at two observation times, when it was comparable to simvastatin and atorvastatin. Effect of simvastatin was found to be comparable to aspirin. In acetic acid induced writhing method, analgesic activity of simvastatin was comparable to that of aspirin while that of atorvastatin was significantly less. In carrageenin induced paw edema in rats, both simvastatin and atorvastatin showed anti-inflammatory activity which was comparable to aspirin. Both the statins exhibited significant anti-inflammatory activity (P < 0.01) in formalin induced arthritis model though less than aspirin (P < 0.05).

Conclusion:

The results of this study if substantiated by further experimental and clinical research suggest that simvastatin and atorvastatin may play an adjuvant role, which may be particularly beneficial in the treatment of inflammatory disorders, especially when there is coexisting dyslipidemia.

Managing bronchiolitis obliterans syndrome (BOS) and chronic lung allograft dysfunction (CLAD) in children: what does the future hold?

The success of pediatric lung transplantation continues to be limited by long-term graft dysfunction. Historically this has been characterized as an obstructive spirometric defect in the form of the bronchiolitis obliterans syndrome (BOS). It is recognized, however, that this does not reflect many of the other acknowledged etiologies of chronic lung dysfunction-noting it is the sum of the parts that contribute to respiratory morbidity and mortality after transplant. The term chronic lung allograft dysfunction (CLAD) has been coined to reflect these other entities and, in particular, a group of relatively recently described lung disorders called the restrictive allograft syndrome (RAS). RAS is characterized by a restrictive spirometric defect. Although these entities have not yet been studied in a pediatric setting their association with poor compliance, antibody-mediated rejection (AMR), and post-infectious lung damage (particularly viral) warrants attention by pediatric lung transplant teams. Current therapy for the BOS subset of CLAD is otherwise limited to changing immunosuppressants and avoiding excessive infectious risk by avoiding over-immunosuppression. Long-term macrolide therapy in lung transplantation is not of proven efficacy. Reviewing previous BOS studies to explore restrictive spirometric cases and joint projects via groups like the International Pediatric Lung Transplant Collaborative will be the way forward to solve this pressing problem.

Pretransplant dyslipidaemia determines outcome in lung transplant recipients

Background

There is little knowledge about the effect of dyslipidaemia on the outcome after lung transplantation. Thus, the aim of this retrospective single centre study was to analyse the impact of the plasma lipid profile on mortality in lung transplant recipients. From January 2000 to December 2008 the charts of 172 consecutive lung transplantation recipients were analysed. At baseline and after one year lipid profiles were routinely collected. During the follow-up major cardiovascular events (MCE; beginning of dialysis, cerebrovascular insult or myocardial infarction) were recorded. The follow-up period ended December 2010.

Findings

Over all total cholesterol (4.3 ± 1.6 vs. 5.4 ± 1.3 mmol/l, p < 0.0001), triglycerides (1.2 ± 0.7 vs. 2.4 ± 1.3 mmol/l, p < 0.0001), HDL (1.5 ± 0.6 vs. 1.7 ± 0.6 mmol/l, p = 0.003) and TC/HDL ratio (3.0 ± 1.0 vs. 3.6 ± 1.2, p = 0.002) increased significantly after 1 year.

During the observational period 6.9% (10 patients) suffered a major cardiac event. In univariate analysis MCE was associated with baseline TC: on average the event-group had a 33% higher baseline TC (5.6 vs. 4.2 mmol/l, OR 1.6, CI 1.1 – 2.2, p = 0.02). The total mortality in the observational period was 25% (36 patients overall). In univariate analysis mortality was associated with increased TC/HDL ratio. The non-survivors had on average a 22% higher baseline TC/HDL ratio (3.6 vs. 2.8, HR 2.8, CI 1.2 – 3.5, p = 0.001). There was no association between mortality and TC (p = 0.33), triglycerides (p = 0.34), HDL (p = 0.78) and creatinine (p = 0.73). In a multivariate model the hazard ratio was 1.5 (1.2 – 1.9, p = 0.001) per increase of 0.4 TC/HDL ratio.

Conclusions

This study shows that the total cholesterol before transplantation is associated with the incidence of MCE and the cholesterol/HDL ratio with mortality in lung transplanted recipients.

The potassium channel KCa3.1 as new therapeutic target for the prevention of obliterative airway disease

BACKGROUND

The calcium-activated potassium channel KCa3.1 is critically involved in T-cell activation as well as in the proliferation of smooth muscle cells and fibroblasts. We sought to investigate whether KCa3.1 contributes to the pathogenesis of obliterative airway disease (OAD) and whether knockout or pharmacologic blockade would prevent the development of OAD.

METHODS

Tracheas from CBA donors were heterotopically transplanted into the omentum of C57Bl/6J wild-type or KCa3.1 mice. C57Bl/6J recipients were either left untreated or received the KCa3.1 blocker TRAM-34 (120 mg/kg/day). Histopathology and immunologic assays were performed on postoperative day 5 or 28.

RESULTS

Subepithelial T-cell and macrophage infiltration on postoperative day 5, as seen in untreated allografts, was significantly reduced in the KCa3.1 and TRAM-34 groups. Also, systemic Th1 activation was significantly and Th2 mildly reduced by KCa3.1 knockout or blockade. After 28 days, luminal obliteration of tracheal allografts was reduced from 89%±21% in untreated recipients to 53%±26% (P=0.010) and 59%±33% (P=0.032) in KCa3.1 and TRAM-34-treated animals, respectively. The airway epithelium was mostly preserved in syngeneic grafts, mostly destroyed in the KCa3.1 and TRAM-34 groups, and absent in untreated allografts. Allografts triggered an antibody response in untreated recipients, which was significantly reduced in KCa3.1 animals. KCa3.1 was detected in T cells, airway epithelial cells, and myofibroblasts. TRAM-34 dose-dependently suppressed proliferation of wild-type C57B/6J splenocytes but did not show any effect on KCa3.1 splenocytes.

CONCLUSIONS

Our findings suggest that KCa3.1 channels are involved in the pathogenesis of OAD and that KCa3.1 blockade holds promise to reduce OAD development.

Statins as a novel therapeutic strategy in acute lung injury

Acute lung injury (ALI) is a devastating clinical condition associated with pulmonary and systemic inflammation and characterized by incompetence of the pulmonary microvascular barrier culminating in noncardiogenic pulmonary edema. An understanding of the mechanisms underlying endothelial barrier dysfunction in ALI has been facilitated by study of the effects of statins in relevant cellular and animals models. Many of the pleotropic properties of these drugs, including direct effects on endothelial cell (EC) cytoskeletal rearrangement, NADPH oxidase, and nitric oxide activity, as well as effects on differential EC gene expression, are relevant to the pathobiology of ALI and suggest a potential therapeutic role for statins in this context. Moreover, results from preclinical studies and observations in relevant patient populations support the protective potential of statins in ALI, paving the way now for definitive clinical trials.

Chronic obstructive pulmonary disease: an update of treatment related to frequently associated comorbidities

Chronic obstructive pulmonary disease (COPD) is associated with a pulmonary inflammatory response to inhaled substances, and individuals with COPD often have raised levels of several circulating inflammatory markers indicating the presence of systemic inflammation. Recently, there has been increasing interest in comorbidities associated with COPD such as skeletal muscle dysfunction, cardiovascular disease, osteoporosis, diabetes and lung cancer. These conditions are associated with a similar inflammation-based patho-physiology to COPD, and may represent a lung inflammatory 'overspill' to distant organs. Cardiovascular disease is a significant cause of mortality in COPD, and the concepts of an inflammatory link raise the possibility that treatment for one organ may show benefits to comorbidities in other organs. When considering treatment of COPD and its comorbidities, one approach is to target the pulmonary inflammation and hence reduce any 'overspill' effect of inflammatory mediators systemically as suggested by response to inhaled corticosteroids. Alternatively, treatment targeted towards comorbid organs may alter features of pulmonary disease as statins, angiotensin-converting enzyme (ACE) inhibitors and peroxisome proliferator-activated receptor (PPAR) agonists may have beneficial effects on COPD by reducing exacerbations and mortality. Newer anti-inflammatory treatments, such as phosphodiesterase 4 (PDE4), nuclear factor(NF)-kB, and p38 mitogen-activated protein kinase (MAPK) inhibitors, are given systemically and may confer benefits to both COPD and its comorbidities. With common inflammatory pathways it might be expected that successful anti-inflammatory therapy in one organ may also influence others. In this review we explore the concepts of systemic inflammation in COPD and current evidence for treatment of its related comorbidities.

Therapeutic potential of growth factors in pulmonary emphysematous condition

Pulmonary emphysema is a major manifestation of chronic obstructive pulmonary disease (COPD), which is characterized by progressive destruction of alveolar parenchyma with persistent inflammation of the small airways. Such destruction in the distal respiratory tract is irreversible and irreparable. All-trans-retinoic acid was suggested as a novel therapy for regeneration of lost alveoli in emphysema. However, profound discrepancies were evident between studies. At present, no effective therapeutic options are available that allow for the regeneration of lost alveoli in emphysematous human lungs. Recently, some reports on rodent's models have suggested the beneficial effects of various growth factors toward alveolar maintenance and repair processes.

Advances in immunosuppression after lung transplantation

Immunosuppression in transplantation has experienced changes in recent years as a result of the introduction of new drugs that act upon the different pathways of the host immune response with the purpose of securing more individualized immune suppression, with fewer side effects. Although following in the steps of other solid organ transplant modalities, lung transplantation, because of its special characteristics, has not yielded similar middle- and long-term results. Improved understanding of the underlying rejection mechanisms, the pharmacodynamic control of drugs, new administration routes designed to reduce the side effects, and new drug substances or immune modulating processes will all contribute to improve the expectations associated to lung transplantation in the near future.

Emerging roles for cholesterol and lipoproteins in lung disease

Dyslipidemia, the condition of elevated serum triglycerides, elevated low-density lipoprotein cholesterol, and/or low high-density lipoprotein cholesterol, is a public health problem of growing concern. Dyslipidemia clusters with other disorders of the metabolic syndrome that together influence, and may derive from, chronic inflammation. While best recognized as a risk factor for atherosclerotic cardiovascular disease, lipid dysregulation has recently been shown to influence a variety of disease processes in several organ systems. This review highlights our current understanding of the role of cholesterol and its homeostatic trafficking in pulmonary physiology and pathophysiology. Gene-targeted mice deficient in regulatory proteins that govern reverse cholesterol transport (e.g., ATP Binding Cassette transporter G1, apolipoprotein E) have recently been shown to have abnormal lung physiology, including dysregulated pulmonary innate and adaptive immune responses to the environment. It has also recently been shown that diet-induced dyslipidemia alters trafficking of immune cells to the lung in a manner that may have important implications for the pathogenesis of acute lung injury, asthma, pneumonia, and other lung disorders. Conversely, cholesterol-targeting pharmacologic agents, such as statins, apolipoprotein mimetic peptides, and Liver X Receptor agonists, have shown early promise in the treatment of several lung disorders. An improved understanding of the precise molecular mechanisms by which cholesterol and its trafficking modify pulmonary immunity will be required before the full implications of dyslipidemia as a lung disease modifier, and the full potential of lipid-targeting agents as pulmonary therapeutics, can be realized.

Effect of simvastatin on development of obliterative airway disease: an experimental study

BACKGROUND

Obliterative bronchiolitis after lung transplantation is characterized by airway inflammation leading to obliteration of small airways. Statins are known to have lipid-independent immunomodulatory properties. We investigated the effect of simvastatin treatment on innate and adaptive immune responses and the development of obliterative airway disease (OAD).

METHODS

In fully MHC-mismatched rat tracheal allograft recipients, we used simvastatin at different doses (0.1 to 20 mg/kg/day orally) to assess its effect on OAD development. No immunosuppressive treatment was administered. Histologic, immunohistochemical and real-time RT-PCR analyses were performed 3, 10 and 30 days after transplantation.

RESULTS

Simvastatin treatment with doses ranging from 0.5 to 20 mg/kg/day significantly enhanced early epithelial recovery and reduced the development of OAD. No dose response was observed. Simvastatin treatment markedly reduced IL-23 mRNA and lymphocyte chemokine CCL20 production, and the infiltration of CD4(+) and CD8(+) T cells into allografts already at 3 days. At 10 days, simvastatin significantly attenuated the production of pro-inflammatory cytokines, IL-1β, TNF-α, MCP-1 and IP-10, and Th17-polarizing cytokines, IL-6 and IL-17e, and inhibited allograft infiltration by inflammatory cells. The protective effects of simvastatin on inflammation and OAD were partially mediated through nitric oxide synthase.

CONCLUSIONS

Simvastatin treatment inhibited adaptive T-cell alloimmune activation as depicted by reduced expression of lymphocyte chemokine and pro-inflammatory cytokine mRNA and reduced allograft infiltration by inflammatory cells. Importantly, simvastatin inhibits the development of OAD and this effect is partially mediated by increased nitric oxide activity. These results suggest a role for simvastatin in the prevention of obliterative bronchiolitis.

Impact of lung transplantation on serum lipids in COPD

BACKGROUND

Severe chronic obstructive pulmonary disease is associated with high HDL cholesterol (HDL-C). We sought to examine the effect of lung transplantation on lipid profiles in patients with COPD.

METHODS

We analyzed 101 lung transplant recipients in a retrospective cohort of patients from two centers in whom lipid values were available both before as well as after transplantation. Sixty-one subjects were transplanted for severe COPD (93% GOLD stage 4).

RESULTS

Eighty-nine percent of subjects with COPD exhibited a decline in HDL-C. Median decline for the COPD cohort was 25 mg/dL (IQR 12-38 mg/dL, p < 0.0001). Non-COPD subjects exhibited no significant changes in HDL-C. Other lipid changes in the COPD cohort included a rise in triglycerides of 70 mg/dL (IQR 35 to 140, p < 0.0001). Decreases in HDL-C levels were independent from the rise in triglyceride levels. Neither LDL-C nor non-HDL-C demonstrated significant changes. Subjects with greater increases in prednisone exposure post-transplant exhibited lesser declines in HDL-C. Compared with tacrolimus, cyclosporine had no effect on observed changes in HDL-C or triglycerides, but was associated with a greater median rise in LDL-C.

CONCLUSIONS

In patients with COPD, lung transplantation results in reductions in the serum levels of HDL-C. These changes are not observed in patients undergoing lung transplantation for diagnoses other than COPD.

[Bronchiolitis obliterans postallogeneic stem cell transplantation: what is new?]

Bronchiolitis obliterans (BO) is a severe complication of hematopoietic stem cell transplantation (HSCT). It is considered as a respiratory manifestation of chronic graft-versus-host disease. It is quite similar to the bronchiolitis obliterans after lung transplantation. Classical therapy associates steroids and immunosuppressive drugs, however theses procedure showed a modest efficacy and have an important morbidity. Recent progresses in the physiopathology of BO post-HSCT allow to use new treatments: mTOR inhibitors, immunotherapy, extra-corporeal photochemotherapy, and bronchial anti-inflammatory effects of azithromycin, statins or antileucotriens. This review will focus on the use of these new therapies in BO post-HSCT.

Simvastatin inhibits TGFβ1-induced fibronectin in human airway fibroblasts

Background

Bronchial fibroblasts contribute to airway remodelling, including airway wall fibrosis. Transforming growth factor (TGF)-β1 plays a major role in this process. We previously revealed the importance of the mevalonate cascade in the fibrotic response of human airway smooth muscle cells. We now investigate mevalonate cascade-associated signaling in TGFβ1-induced fibronectin expression by bronchial fibroblasts from non-asthmatic and asthmatic subjects.

Methods

We used simvastatin (1-15 μM) to inhibit 3-hydroxy-3-methlyglutaryl-coenzyme A (HMG-CoA) reductase which converts HMG-CoA to mevalonate. Selective inhibitors of geranylgeranyl transferase-1 (GGT1; GGTI-286, 10 μM) and farnesyl transferase (FT; FTI-277, 10 μM) were used to determine whether GGT1 and FT contribute to TGFβ1-induced fibronectin expression. In addition, we studied the effects of co-incubation with simvastatin and mevalonate (1 mM), geranylgeranylpyrophosphate (30 μM) or farnesylpyrophosphate (30 μM).

Results

Immunoblotting revealed concentration-dependent simvastatin inhibition of TGFβ1 (2.5 ng/ml, 48 h)-induced fibronectin. This was prevented by exogenous mevalonate, or isoprenoids (geranylgeranylpyrophosphate or farnesylpyrophosphate). The effects of simvastatin were mimicked by GGTI-286, but not FTI-277, suggesting fundamental involvement of GGT1 in TGFβ1-induced signaling. Asthmatic fibroblasts exhibited greater TGFβ1-induced fibronectin expression compared to non-asthmatic cells; this enhanced response was effectively reduced by simvastatin.

Conclusions

We conclude that TGFβ1-induced fibronectin expression in airway fibroblasts relies on activity of GGT1 and availability of isoprenoids. Our results suggest that targeting regulators of isoprenoid-dependent signaling holds promise for treating airway wall fibrosis.