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

Conventional and novel approaches to immunosuppression

Immunosuppressive therapy has contributed significantly to improved survival after solid organ transplantation. Nevertheless, treatment-related adverse events and persistently high risk of chronic graft rejection remain major obstacles to long-term survival after lung transplantation. The development of new agents, refinements in techniques to monitor immunosuppression, and enhanced understanding of transplant immunobiology are essential for further improvements in outcome. In this article, conventional immunosuppressive regimens, novel approaches to preventing graft rejection, and investigational agents for solid organ transplantation are reviewed.

Survival and quality of life of patients undergoing lung transplant

Lung transplant offers the hope of prolonged survival and significant improvement in quality of life to patients with advanced lung disease. However, the medical literature lacks strong evidence and shows conflicting information regarding the effects of lung transplantation on these outcomes. Tools that integrate survival and quality-of-life information allow for more comprehensive evaluations of the benefits and risks of lung transplant. Higher-quality information leads to improved knowledge and more-informed decision making.

Hyperlipidemia and statin use after allogeneic hematopoietic stem cell transplantation

An increased incidence of cardiovascular complications has been documented in recipients of allogeneic hematopoietic stem cell transplantation (HSCT). Despite this, little is known about the risk factors for hyperlipidemia or the role of lipid-lowering therapy early after transplantation. We performed a retrospective analysis of all patients who underwent allogeneic HSCT at the Dana-Farber Cancer Institute from 1998 to 2008 and who survived more than 100 days. The incidence of hypercholesterolemia and hypertriglyceridemia in the first 2 years after transplantation was 73.4% and 72.5%, respectively. In multivariable analysis, the development of acute graft-versus-host disease was independently associated with both hypercholesterolemia (odds ratio [OR] = 1.62) and hypertriglyceridemia (OR = 1.54) after transplantation. Statin use was instituted in 29% of patients and was associated with a significant net reduction in total cholesterol (65 mg/dL, P < .0001), triglyceride (118 mg/dL P < .0001), and LDL levels (59 mg/dL P < .0001) without any significant adverse effects. These data suggest that hyperlipidemia is common in the first 2 years after allogeneic transplantation when most patients remain under the care of the transplantation physician and lipid-lowering therapy may be underutilized. Given the cardiovascular risk associated with hyperlipidemia and the tolerability of statins, further prospective evaluation of lipid abnormalities and their treatment seems well warranted.

Anti-inflammatory effect of fluvastatin on IL-8 production induced by Pseudomonas aeruginosa and Aspergillus fumigatus antigens in cystic fibrosis

BACKGROUND

Early in life, patients with cystic fibrosis (CF) are infected with microorganisms including bacteria and fungi, particularly Pseudomonas aeruginosa and Aspergillus fumigatus. Since recent research has identified the anti-inflammatory properties of statins (besides their lipid-lowering effects), we investigated the effect of fluvastatin on the production of the potent neutrophil chemoattractant chemokine, IL-8, in whole blood from CF patients, stimulated by Pseudomonas aeruginosa (LPS) and Aspergillus fumigatus (AFA) antigens.

RESULTS

Whole blood from adult patients with CF and from healthy volunteers was collected at the Rennes University Hospital (France). Blood was pretreated for 1 h with fluvastatin (0-300 µM) and incubated for 24 h with LPS (10 µg/mL) and/or AFA (diluted 1/200). IL-8 protein levels, quantified by ELISA, were increased in a concentration-dependent manner when cells were stimulated by LPS or AFA. Fluvastatin strongly decreased the levels of IL-8, in a concentration-dependent manner, in whole blood from CF patients. However, its inhibitory effect was decreased or absent in whole blood from healthy subjects. Furthermore, the inhibition induced by fluvastatin in CF whole blood was reversed in the presence of intermediates within the cholesterol biosynthesis pathway, mevalonate, farnesyl pyprophosphate or geranylgeranyl pyrophosphate that activate small GTPases by isoprenylation.

CONCLUSIONS

For the first time, the inhibitory effects of fluvastatin on CF systemic inflammation may reveal the important therapeutic potential of statins in pathological conditions associated with the over-production of pro-inflammatory cytokines and chemokines as observed during the manifestation of CF. The anti-inflammatory effect could be related to the modulation of the prenylation of signalling proteins.

A review of bronchiolitis obliterans syndrome and therapeutic strategies

Lung transplantation is an important treatment option for patients with advanced lung disease. Survival rates for lung transplant recipients have improved; however, the major obstacle limiting better survival is bronchiolitis obliterans syndrome (BOS). In the last decade, survival after lung retransplantation has improved for transplant recipients with BOS. This manuscript reviews BOS along with the current therapeutic strategies, including recent outcomes for lung retransplantation.

The impact of high-dose statin therapy on transendothelial neutrophil migration and serum cholesterol levels in healthy male volunteers

RATIONALE

Cardiac surgery presents a risk to all major organs due to activation of the systemic inflammatory response. Patients referred for cardiac surgery are typically older, usually have comorbid conditions, and are thus at higher risk of postoperative multiorgan dysfunction. Patients demonstrating evidence of organ dysfunction require intensive postoperative management. Any means to predict and reduce the inflammatory response mounted postcardiac surgery could translate into a clinical benefit for the patient and reduce the length of stay in intensive care.

OBJECTIVE

Statins are commonly used to prevent primary and secondary cardiovascular disease through their cholesterol-lowering effects. However, they have been shown to have anti-inflammatory properties, which may help reduce postoperative mortality and morbidity for patients undergoing cardiac surgery. The purpose of this study was to analyze the in vivo effects of high-dose atorvastatin (statin) on ex vivo neutrophil migration in healthy volunteers.

METHODS

Thirteen healthy male volunteers consented and were placed on high-dose (40 mg) statin therapy for 2 weeks. At week 0 and week 2, full blood count, liver function, serum cholesterol and creatine kinase were assessed, as was neutrophil migration.

RESULTS

Neutrophil migration of healthy volunteers was significantly reduced after 2 weeks of high-dose statin therapy (p = 0.002), as was serum cholesterol (p <0.001). There was no change in liver function during statin treatment.

CONCLUSION

Statins have an established role as cholesterol-lowering agents, and this study demonstrates that they also potentially have an anti-inflammatory effect in healthy male volunteers.

Chronic allograft dysfunction

Chronic, progressive, and irreversible loss of lung function is the major medium-term and long-term complication after lung transplantation and the leading cause of death. Over the past decade, progress has been made in understanding the pathogenesis of bronchiolitis obliterans. Alloimmune factors and nonalloimmune factors may contribute to its development. Understanding the precise mechanism of each type of chronic allograft dysfunction may open up the field for new preventive and therapeutic interventions. This article reviews major new insights into the clinical aspects, pathophysiology, risk factors, diagnosis, and management of chronic allograft dysfunction after lung transplantation.

Role of statins in the treatment of multiple sclerosis: an update

SUMMARY This article discusses the role of statins in the treatment of multiple sclerosis. Statins are promising agents as adjunctive therapies in immune-mediated disorders such as multiple sclerosis owing to their immunomodulatory, anti-inflammtory and neuroprotective characteristics. On the other hand, there are some conflicting data that warrant further investigation before sound conclusions can be made. Clinical trials are planned and being conducted to help shed more light on the potential benefit and the optimal dose of statins in treating multiple sclerosis.

Aerosolized tacrolimus: a case report in a lung transplant recipient

Long-term outcomes after lung transplantation remain poor mainly to the development of bronchiolitis obliterans syndrome (BOS). Currently, treatment options for BOS are very limited. Strategies to prevent and treat this complication include the use of aerosolized therapy with only cyclosporine used in patients to date. We describe the use of aerosolized tacrolimus in a lung transplant recipient with BOS. The patient demonstrated clinical improvement in functional capacity and oxygenation while receiving tacrolimus by nebulization. Further research is needed to study whether aerosolized tacrolimus is beneficial in lung transplant recipients with BOS.

The contribution of airway ischemia and vascular remodelling to the pathophysiology of bronchiolitis obliterans syndrome and chronic lung allograft dysfunction

PURPOSE OF REVIEW

Chronic allograft dysfunction continues to limit the enduring success of lung transplantation. Increasingly it is recognized that events very early post-transplant such as primary graft dysfunction can be linked to poor clinical outcomes at much later time points. In this article we review a number of the different processes that predispose the allograft to ischemia early post-transplant and explore how these events may contribute to obliterative bronchiolitis, the histological correlate of chronic lung allograft dysfunction.

RECENT FINDINGS

Allograft ischemia may arise during explantation (warm ischemia), at implantation (in the absence of bronchial arterial reanastomosis) or at later time points (small airway microvascular damage). We describe how allograft ischemia may result in a hypoxic inflammatory milieu within the lung allograft that is conducive to vascular remodelling and angiogenesis.

SUMMARY

Whilst the published literature for vascular remodelling in post-transplant obliterative bronchiolitis is not as extensive as that for asthma, a disease also characterized by airway pathology, there are clear parallels and shared pathophysiological pathways between the two diseases. An understanding of the complex interaction between ischemia, vascular remodelling and chronic lung allograft dysfunction may lead to the future development of therapeutic strategies that can unravel this association.

Optimizing post-transplant outcomes in lung transplantation

Lung transplant recipients are at risk of numerous complications, which range from early events, such as primary graft dysfunction, to late events, including opportunistic infection or graft loss caused by chronic rejection. Although lung transplantation is often the only therapeutic option that can improve quality of life and prolong survival for many forms of end-stage lung disease, survival following lung transplantation is significantly worse than survival following transplantation of other solid organs. Carefully choosing potential recipients for listing, maximizing the likelihood that donor organs will function well following implantation, appropriate use of immunosuppressive agents to prevent allograft rejection, prophylactic or pre-emptive strategies to prevent allograft infection and appropriate surveillance to detect significant complications are key to maximizing the likelihood of prolonged graft and patient survival while avoiding significant complications following lung transplantation. Post-transplant outcomes will be optimized by a team approach to comprehensive management of the lung transplantation recipient combined with vigilant surveillance to detect complications in a timely fashion.

Extracorporeal photopheresis in patients with refractory bronchiolitis obliterans developing after allo-SCT

Extracorporeal photopheresis (ECP) has been shown to be a promising treatment for chronic graft-versus-host disease; however, only a few case reports are available that examine the effectiveness of ECP for bronchiolitis obliterans (BO) after allo-SCT. Because of the poor response to traditional therapies, ECP has been explored as a possible therapeutic option for severe BO after allo-SCT. Nine patients received ECP between July 2008 and August 2009 after a median follow-up of 23 months (range 9-93 months) post transplant. The primary indication for ECP was the development of BO in patients who had failed prior multidrug regimens. The median number of drugs used for BO management before ECP was 5 (range 2-7); this included immunosuppressive therapy. Six of nine (67%) patients responded to ECP after a median of 25 days (range 20-958 days). No ECP-related complications occurred. ECP seemed to stabilize rapidly declining pulmonary function tests in about two-thirds of patients with severe and heavily pretreated BO that developed after allo-SCT. This finding supports the need for a larger prospective study to confirm the impact of ECP on BO, and to consider earlier intervention with ECP to improve the outcome of BO after allo-SCT.

Pathology of small airways disease

CONTEXT

The term small airways disease encompasses a generally poorly understood group of lung diseases that may arise primarily within the small airways or secondarily from diseases primarily affecting the bronchi or lung parenchyma. Their histology may be confusing; however, because treatments and prognoses vary, correct pathologic diagnosis is important.

OBJECTIVE

To present a nonexhaustive review of the pathology of primary and secondary small airways diseases, including small airways disease related to tobacco; to various other exposures, including mineral dusts; to diseases involving other areas of the lung with secondary bronchiolar involvement; and to recently described bronchiolitic disorders.

DATA SOURCES

Current literature is reviewed.

CONCLUSIONS

Small airways diseases include a wide variety of diseases of which the pathologist must consider. Uncommon conditions such as diffuse idiopathic neuroendocrine cell hyperplasia and diffuse panbronchiolitis may show relatively specific diagnostic features histologically; however, most small airways diseases exhibit nonspecific histologic features. Conditions not considered primary pulmonary diseases, such as collagen vascular diseases, bone marrow transplantation, and inflammatory bowel disease, must also be considered in patients with small airways changes histologically. Clinical and radiologic correlation is important for obtaining the best possible diagnosis.

Lovastatin decreases acute mucosal inflammation via 15-epi-lipoxin A4

The widespread use of statins for hypercholesterolemia has uncovered pleiotropic anti-inflammatory properties that were unexpected based on the drugs' original design; yet, mechanisms for these protective actions remain uncertain. In this study lovastatin triggered biosynthesis of the anti-inflammatory and pro-resolving mediator 15-epi-lipoxin A(4) (15-epi-LXA(4)). During interactions between human neutrophils and airway epithelial cells, the statin-induced increase in 15-epi-LXA(4) was associated with increased 14,15-epoxyeicosatrienoic acid (14,15-EET) generation. When added to activated neutrophils, 14,15-EET enhanced 15-epi-LXA(4) biosynthesis. In a murine model of airway mucosal injury and inflammation, lovastatin increased 15-epi-LXA(4) formation in vivo and markedly decreased acute lung inflammation. Administration of 15-epi-LXA(4) also inhibited lung inflammation in an additive manner with lovastatin. Together, these results indicate that statin-triggered 15-epi-LXA(4) generation during human leukocyte-airway epithelial cell interactions is an endogenous mechanism for statin-mediated tissue protection at mucosal surfaces that may also be relevant in the statins' ability to stimulate the resolution of inflammation.

Statin therapy ameliorates renal allograft function

BACKGROUND

Statins have proven ability as antilipidemic agents and benefit cardiovascular survival in transplant recipients. The pleiotropic effects of statins on renal function in renal allograft recipients are still undetermined.

METHODS

Statin therapy was initiated according to guidelines for cardiovascular protection. Serum creatinine concentration and estimated glomerular filtration rate (eGFR) were analyzed before and after introduction of statins. The 73 patients who were retrospectively studied included those who were dialysis-dependent. Mean changes in eGFR and lipid profile were compared before and after commencing statins using chi(2) tests.

RESULTS

Mean serum creatinine concentration 18 months before starting statin therapy was 160.13 mumol/L, and 24 months after starting statin therapy was 172.22 mumol/L. Mean eGFR was 53.40 mL/min 18 months before starting statin therapy, and decreased to 49.43 mL/min after starting statin therapy. This represented a decline in renal function of 0.22 mL/min/mo over 18 months. The eGFR at 12 months after beginning statin therapy was 52.67 mL/min, and at 24 months was 49.06 mL/min. The rate of decline of eGFR after starting statin therapy was significantly lower: 0.02 mL/min/mo over 24 months (P < .001). Total cholesterol and low-density lipoprotein cholesterol concentrations were significantly decreased after starting statin therapy (P < .001). Four of 73 patients developed graft failure within 24 months.

CONCLUSION

Statin therapy in our setting was associated with a lower rate of decline in renal function in renal allograft recipients within 2 years of starting treatment.

HMG-CoA reductase inhibitors in kidney transplant recipients receiving tacrolimus: statins not associated with improved patient or graft survival

Background

The beneficial effects of early statin use in kidney transplant recipients, especially those on tacrolimus-based immunosuppression, are not well established. We evaluated the predictors of statin use following kidney transplantation and examined its association with patient and allograft survival.

Methods

We examined 615 consecutive patients who underwent kidney transplant at our institution between January 1998 and January 2002. Statin use was assessed at baseline and 3, 6, 9, and 12 months following kidney transplant. Patients were followed for allograft and patient survival.

Results

36% of the 615 kidney transplant recipients were treated with statin treatment. Statin use increased over the course of the study period. Older age, elevated body mass index, higher triglyceride levels, hypercholesterolemia, diabetes, history of myocardial infarction were associated with higher rates of statin use; elevated alkaline phosphatase levels and CMV IgG seropositivity were associated with less statin use. Older age, elevated BMI and hypercholesterolemia remained significant predictors of increased statin use after accounting for covariates using multiple regression. The early use of statins was not associated with improvements in unadjusted patient survival [HR 0.99; 95%CI 0.72-1.37] or graft survival [HR 0.97; 95% CI 0.76-1.24]. The risks of death and graft survival were not consistently reduced with exposure to statin using either adjusted models or propensity scores in Cox Proportional Hazards models.

Conclusions

In a kidney transplant population primarily receiving tacrolimus-based immunosuppression, early statin use was not associated with significantly improved graft or patient survival.

Tolerability of pravastatin in pediatric hematopoietic stem cell transplant patients with bronchiolitis obliterans

Pravachol and other statins have immune modulatory effects and have been shown to decrease the incidence of bronchiolitis obliterans (BrOb) in lung transplant recipients. It may also be useful in the treatment or prevention of hematopoietic stem cell transplant (HSCT) associated bronchiolitis obliterans. However, the safety of pravachol has not been shown in pediatric patients with BrOb after HSCT. We report on the safety and tolerability in 5 pediatric HSCT patients with established BrOb. All participants tolerated the drug without difficulty and there were no pravachol-associated adverse effects. Changes in creatine kinase (CK) and transaminases were minimal in 4 patients. One patient experienced increased CK and alanine aminotransferase, and a decrease in platelet count in the setting of severe systemic illness. No other patient had a clinically relevant change in white blood cell count, platelet count, or hemoglobin. Pravachol was well tolerated and safe in this group of patients, and merits further study in this patient population.

Non-atheroprotective effects of statins: a systematic review

Since the introduction of HMG-CoA reductase inhibitors (statins) for lowering lipids, a large amount of data has been published demonstrating their potential benefits in conditions as varied as cancer, osteoporosis, and Alzheimer's dementia. We reviewed the published literature on MEDLINE from articles between 1950 and 2008 on the non-atheroprotective effects of statins and noted consistent benefits of statin use in improving outcomes of ventricular arrhythmias, sudden cardiac death, cardiac transplant rejection, chronic obstructive pulmonary disease, and sepsis. However, for these conditions, the level of evidence was inadequate to recommend statin use. The evidence for improving outcomes in atrial fibrillation, mortality in heart failure, contrast-induced nephropathy, cataract, age-related macular degeneration, sub-arachnoid hemorrhage, osteoporosis, dementia, and cancer incidence was conflicting and inconclusive. Furthermore, we found that most of the literature consists of small observational studies and their conclusions are often not corroborated by results from larger or randomized studies. Pending large, well designed, randomized trials, we conclude that there is no definite evidence for the use of statins in any condition besides hyperlipidemia and atherosclerosis.

[Medical complications of lung transplantation]

In 2010, lung transplantation is a valuable therapeutic option for a number of patients suffering from of end-stage non-neoplastic pulmonary diseases. The patients frequently regain a very good quality of life, however, long-term survival is often hampered by the development of complications such as the bronchiolitis obliterans syndrome, metabolic and infectious complications. As the bronchiolitis obliterans syndrome is the first cause of death in the medium and long term, an intense immunosuppressive treatment is maintained for life in order to prevent or stabilize this complication. The immunosuppression on the other hand induces a number of potentially severe complications including metabolic complications, infections and malignancies. The most frequent metabolic complications are arterial hypertension, chronic renal insufficiency, diabetes, hyperlipidemia and osteoporosis. Bacterial, viral and fungal infections are the second cause of mortality. They are to be considered as medical emergencies and require urgent assessment and targeted therapy after microbiologic specimens have been obtained. They should not, under any circumstances, be treated empirically and it has also to be kept in mind that the lung transplant recipient may present several concomitant infections. The most frequent malignancies are skin cancers, the post-transplant lymphoproliferative disorders, Kaposi's sarcoma and some types of bronchogenic carcinomas, head/neck and digestive cancers. Lung transplantation is no longer an exceptional procedure; thus, the pulmonologist will be confronted with such patients and should be able to recognize the symptoms and signs of the principal non-surgical complications. The goal of this review is to give a general overview of the most frequently encountered complications. Their assessment and treatment, though, will most often require the input of other specialists and a multidisciplinary and transversal approach.

Bronchiolitis obliterans syndrome after allogeneic hematopoietic stem cell transplantation-an increasingly recognized manifestation of chronic graft-versus-host disease

Bronchiolitis obliterans syndrome (BOS) is a progressive, insidious, and often fatal lung alloreaction that can occur following allogeneic hematopoietic stem cell transplantation (HSCT) or allogeneic lung transplantation. Current estimates in the literature suggest that approximately 2% to 3% of all allogeneic HSCT recipients and 6% of patients who develop chronic graft-versus-host disease (cGVHD) will develop this syndrome. However, based on newer data it is likely that the true incidence of BOS is higher. Unfortunately, the survival and treatment of patients with BOS after HSCT has not improved over the last 20 years. Attempts at clinical trials have been hindered by the lack of uniform diagnostic criteria and inability to detect the syndrome at a reversible stage in its natural history. Recently, the National Institutes of Health (NIH) consensus project for criteria in cGVHD has made recommendations regarding the diagnosis of BOS and monitoring of lung disease among long-term survivors. Although a rare and poorly understood manifestation of cGVHD, BOS occurs commonly after lung transplantation and is similar in pathology, clinical presentation, radiographic presentation, and presumed immunologic pathogenesis. This review describes the current understanding of the epidemiology and pathogenesis of BOS and presents information on evaluations and therapies for patients with BOS after HSCT.

Bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation

With improvements in supportive care, both long-term survival following allogeneic hematopoietic stem cell transplantations (HSCTs) and the indications for this procedure have increased. As a result, the number of patients living with long-term toxic effects due to HSCT has increased. A once rare condition of the donor immune cells attacking healthy host tissues, termed chronic graft-vs-host disease, has become a more common phenomenon. When chronic graft-vs-host disease affects the lung tissue, bronchiolitis obliterans syndrome ensues. Recent data suggest that bronchiolitis obliterans syndrome may affect up to 6% of HSCT recipients and dramatically alters survival, with overall survival of only 13% at 5 years. These statistics have not improved since the first presentation of this disease over 20 years ago. Challenges to the progress of medical management of bronchiolitis obliterans syndrome include difficulties and delays in diagnosis and a paucity of data on pathogenesis to direct new therapies. This article critically evaluates the current diagnostic criteria for bronchiolitis obliterans syndrome and reviews the epidemiology, pathogenesis, and available treatments. Improvements in survival will likely require early disease recognition, allowing for therapeutic modulation of disease prior to the development of irreversible airway obliteration.

Associations between statins and COPD: a systematic review

Background

Statins have anti-inflammatory and immunomodulating properties which could possibly influence inflammatory airways disease. We assessed evidence for disease modifying effects of statin treatment in patients with chronic obstructive pulmonary disease (COPD).

Methods

A systematic review was conducted of studies which reported effects of statin treatment in COPD. Data sources searched included MEDLINE, EMBASE and reference lists.

Results

Eight papers reporting nine original studies met the selection criteria. One was a randomized controlled trial (RCT), one a retrospective nested case-control study, five were retrospective cohort studies of which one was linked with a case-control study, and one was a retrospective population-based analysis. Outcomes associated with treatment with statins included decreased all-cause mortality in three out of four studies (OR/HR 0.48–0.67 in three studies, OR 0.99 in one study), decreased COPD-related mortality (OR 0.19–0.29), reduction in incidence of respiratory-related urgent care (OR 0.74), fewer COPD exacerbations (OR 0.43), fewer intubations for COPD exacerbations (OR 0.1) and attenuated decline in pulmonary function. The RCT reported improvement in exercise capacity and dyspnea after exercise associated with decreased levels of C-reactive protein and Interleukin-6 in statin users, but no improvement of lung function.

Conclusion

There is evidence from observational studies and one RCT that statins may reduce morbidity and/or mortality in COPD patients. Further interventional studies are required to confirm these findings.

Targeting allograft injury and inflammation in the management of post-lung transplant bronchiolitis obliterans syndrome

Chronic allograft dysfunction, manifesting as bronchiolitis obliterans syndrome (BOS), is the major cause of morbidity and mortality in human lung transplant recipients. While alloimmunity has a definite role, there is increasing interest in overall allograft injury and subsequent inflammation and remodeling. This review deals with nonalloimmune factors that may potentiate alloimmune injury. We discuss infection and reflux/aspiration as examples of allograft injury, which may lead to chronic loss of graft function and BOS. Surgical and nonsurgical treatments aimed at preventing these insults and improving survival are considered. The need for further evidence, including randomized-controlled trials, to evaluate the role of medical and surgical therapies is emphasized by the current literature.

Ezetimibe and atorvastatin both immunoregulate CD4+ T cells from cardiac transplant recipients invitro

BACKGROUND

Statins are LDL lowering agents that reduce cardiac allograft vasculopathy (CAV) incidence after cardiac transplantation. Furthermore, 'pleiotropic effects' including immunomodulation have been demonstrated by statins following transplantation. It has also been previously suggested that ezetimibe may exert specific effects on the innate immune system in vitro. We compared the effects of ezetimibe and atorvastatin on T lymphocytes in vitro on the justification that these cells are implicated in the pathogenesis of atherosclerosis, allograft rejection and CAV.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from 30 cardiac transplant recipients and co-cultured with the study drug (or placebo) over 48 h. In total, 150 cultures were performed (5 per patient). Drug concentrations were calculated to simulate 10 mg or 100 mg daily in a 70 kg adult. Flow cytometry was performed to analyse T lymphocyte counts and functional characteristics.

RESULTS

Ezetimibe reduced the standard CD3+CD4+ T cell count and CD3+CD4+CD45ro T memory count by dose linear effect (p < 0.001). Atorvastatin also reduced the CD3+CD4+ T cell count and CD3+CD4+CD45ro T memory count by dose linear effect (p = 0.005). Neither drug affected CD3+CD8+ cytotoxic T cells.

DISCUSSION

Both atorvastatin and ezetimibe may have selective immunomodulatory properties independent of their mechanisms of LDL lowering, given that both drugs affect CD4 T helper cells but have no effect on CD8 cytotoxic lymphocytes in vitro. Although speculative, both of these agents could potentially offer benefits to the transplant patient by modulating important components of the adaptive immune system. CD4+ cells in particular are implicated in both CAV and rejection processes.

Bronchiolitis obliterans syndrome: alloimmune-dependent and -independent injury with aberrant tissue remodeling

Long-term success in lung transplantation continues to be challenged by chronic graft dysfunction, which is manifest as bronchiolitis obliterans syndrome (BOS). The mechanisms of BOS involve both immune-mediated pathways (rejection, autoimmune-like mechanisms), and alloimmune-independent pathways (infection, aspiration, ischemia, primary graft failure), which lead to a fibroproliferative responses. BOS correlates histologically with obliterative bronchiolitis in terminal bronchioles and evidence of aberrant remodeling in the airway epithelium, vasculature, stroma, and lymphoid system. A potentially important mechanism that supports the progressive and therapy-resistant nature of BOS is a continuous cycle of ongoing injury and aberrant remodeling. Namely, anatomical and functional abnormalities induce and exacerbate immune-mediated and alloimmune-independent pathways through various mechanisms (e.g., epithelial remodeling decreases mucociliary clearance that exacerbates aspiration-related injury). From this viewpoint, we review current therapeutic strategies and revisit the role of transplant surgeons in attenuating the initial transplant-related injuries to prevent the lung grafts from entering the remodeling-injury cycle.

Simvastatin attenuates release of neutrophilic and remodeling factors from primary bronchial epithelial cells derived from stable lung transplant recipients

Obliterative bronchiolitis (OB), the major cause of chronic lung allograft dysfunction, is characterized by airway neutrophilia, inflammation, and remodeling, with progressive fibroproliferation and obliteration of small airways that ultimately leads to patient death. Statins have potential anti-inflammatory effects and have been demonstrated to confer a survival advantage in lung transplant patients. We postulated that the beneficial effects of simvastatin in lung transplantation are in part due to inhibition of the epithelial production of key mediators of neutrophil chemotaxis, inflammation, and airway remodeling. Our objective was to assess the effect of simvastatin on a unique population of primary bronchial epithelial cells (PBECs) derived from stable lung allografts, with specific reference to airway neutrophilia and remodeling. PBEC cultures were stimulated with IL-17 or transforming growth factor (TGF)-β, with and without simvastatin. Supernatant levels of factors critical to driving airway neutrophilia and remodeling were measured. IL-17 upregulated IL-8, IL-6, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), and VEGF, whereas TGF-β increased IL-6, GM-CSF, matrix metalloproteinase (MMP)-2, and MMP-9. Simvastatin attenuated effects of both IL-17 and TGF-β. We have demonstrated the ability of simvastatin to attenuate release of airway neutrophilic and remodeling mediators and to inhibit their upregulation by TGF-β and IL-17. These data illustrate the potential of simvastatin to alleviate neutrophilic airway inflammation and remodeling in the transplanted lung and may have additional relevance to other neutrophilic airway conditions, such as chronic obstructive pulmonary disease.

Reversal of elastase-induced pulmonary emphysema and promotion of alveolar epithelial cell proliferation by simvastatin in mice

Besides lowering cholesterol, statins exert multiple effects, such as anti-inflammatory activity and improvement of endothelial cell function. We examined whether simvastatin (SS) protects against the development of elastase-induced pulmonary emphysema in mice by using mean linear intercepts of alveoli (Lm) as a morphometric parameter of emphysema. After injection of intratracheal elastase on day 0, C57BL/6 mice were treated daily with SS (SS+ group) or PBS (SS- group) for 2 wk. A 21% decrease in Lm on day 7 was observed in the SS+ group vs. the SS- group. Anti-inflammatory effects of SS were observed as a decrease in percentage of neutrophils up to day 3, and in hydroxyproline concentration on day 3, in bronchoalveolar lavage fluid (BALF). SS also increased the number of proliferating cell nuclear antigen (PCNA)-positive alveolar epithelial cells between days 3 and 14. To confirm the role of statins in promoting proliferation of alveolar cells, mice were treated with SS (SS+) vs. PBS (SS-) for 12 days, starting 3 wk after elastase administration. After SS treatment, Lm decreased by 52% and PCNA-positive alveolar epithelial cells increased compared with the SS- group. Concentrations of vascular endothelial growth factor in BALF and endothelial nitric oxide synthase protein expression in pulmonary vessels tended to be higher in the SS+ group vs. the SS- group in this protocol. In conclusion, SS inhibited the development of elastase-induced pulmonary emphysema in mice. This therapeutic effect was due not only to anti-inflammation but also to the promotion of alveolar epithelial cell regeneration, partly mediated by restoring endothelial cell functions.

Angiogenesis: a potentially critical part of remodelling in chronic airway diseases?

Angiogenesis is a prominent feature of the structural tissue remodelling that occurs in the chronic airway diseases of asthma, Bronchiolitis Obliterans Syndrome (BOS, post-lung transplantation), and in smoking-related Chronic Obstructive Pulmonary Disease (COPD). For each, we have explored the relationship between angiogenesis and underlying chronic inflammatory processes--are the hypervascular changes secondary to inflammation, or do they occur in parallel? What are the likely growth factors which stimulate the angiogenic process? We discuss the relationships that have been studied between angiogenesis and the physiological impairment of airflow obstruction. The pattern that emerges is complex and variable. In asthma, there is strong evidence to suggest that Vascular Endothelial Growth Factor (VEGF) and its receptor system is upregulated in the airway. Local production of VEGF has also been implicated as a major driver of angiogenesis in the airway component of COPD, though paradoxically emphysema seems to be due to lack of VEGF in the lung parenchyma. In BOS, the evidence suggests that VEGF is lacking in the airway: other mediators and especially C-X-C chemokines such as Interleukin (IL)-8, are likely to be more important in angiogenesis. The physiological consequences of angiogenesis are likely to be important in asthma (especially during acute episodes of deterioration), and probably also in COPD, although data is equivocal. In BOS, increased airway vascularity appears to occur early, but is not progressive. In terms of therapy, evidence for anti-angiogenic effectiveness is strongest for Inhaled Corticosteroid (ICS) and Long Acting Beta-Agonists (LABA) in asthma.

Hyperlipidemia is associated with accelerated chronic kidney disease progression after lung transplantation

Hyperlipidemia is associated with faster progression of chronic kidney disease (CKD) in the general public. We sought to investigate this association after lung transplantation. Data was retrospectively collected on 230 lung recipients transplanted between January 1997 and December 2003. Estimated glomerular filtration rates (eGFR) and lipid levels were recorded at regular intervals posttransplant. Independent associations between lipid levels early posttransplant and pertinent renal endpoints were investigated. Baseline LDL was 110 +/- 35 mg/dL and remained unchanged at 6 months. A faster decline in eGFR was seen in those with 6 month LDLs > versus < the mean level of 110 mg/dL (p = 0.05). By 6 months posttransplant eGFRs were lower in the 6 month LDL > versus < 110 mg/dL group (53 +/- 23 vs. 62 +/- 29 mL/min/1.73 m2, p = 0.01), a difference that persisted at 60 months (39 +/- 24 vs. 73 +/- 57 mL/min/1.73 m2, p = 0.05). On univariate analysis, a 6 month LDL in the highest quartile, i.e. >140 mg/dL, predicted faster progression to CKD, defined as declining to an eGFR < 30 mL/min/1.73 m2 (HR 1.5, p = 0.01). This finding persisted in the multivariate Cox-proportional model (HR 1.4, p = 0.02). Hyperlipidemia predicts faster decline in renal function after lung transplant. Prospective trials are needed to confirm this finding.

The use of statins and lung function in current and former smokers

BACKGROUND

Smokers are affected by a variety of inflammatory diseases, including COPD. Statins, 3-hydroxy-3-methyl-glutaryl-coenzyme-A reductase inhibitors, are used for their lipid-lowering characteristics but also appear to have antiinflammatory and immunomodulatory activities. We assessed their ability to preserve lung function in current and former smokers.

METHODS

All smokers and ex-smokers seen at the Oklahoma City VA hospital in 2005 with abnormal baseline spirometry findings and two or more pulmonary function tests done 6 months apart were classified into obstructive and restrictive groups based on the initial PFT result. Statin use, annual decline in FEV(1) and FVC, and need for respiratory-related urgent care (emergency department or inpatient) were compared.

RESULTS

Approximately one half, 215 of 418 patients, were receiving a statin. Compared to the control group, statin users had a lower decline in FEV(1) (- 0.005 +/- 0.20 L/yr vs 0.085 +/- 0.17 L/yr, p < 0.0001) and FVC (- 0.046 +/- 0.45 L/yr vs 0.135 +/- 0.32 L/yr, p < 0.0001) [mean +/- SD]. This difference remained significant irrespective of whether the patient had obstructive (n = 319), or restrictive (n = 99) disease, and regardless of whether the patient continued or stopped smoking. In patients with an obstructive spirometry finding, we found a lower incidence of respiratory-related urgent care in favor of the statin group (0.12 +/- 0.29 patient-years vs 0.19 +/- 0.32/patient-years; p = 0.02).

CONCLUSION

In smokers and former smokers, statins are associated with a slower decline in pulmonary function, independent of the underlying lung disease.

CLINICAL IMPLICATION

Prospective, randomized trials are needed to study the effect of statins on lung function.

Lung transplantation for cystic fibrosis: Current concepts and one center's experience

BACKGROUND

Although new approaches to the treatment of patients with cystic fibrosis (CF) are significantly prolonging their lives, most patients will eventually develop respiratory failure due to progressive bronchiectasis caused by chronic lung infection and inflammation and die from to respiratory failure. We examined our center's (University of Wisconsin Hospital and Clinics) experience with lung transplantation for patients with CF and reviewed the literature to examine current and evolving approaches to transplantation for this indication.

METHODS

We reviewed all published literature pertaining to lung transplantation for CF through 2006, and we reviewed all aspects of transplantation for patients with CF at our institution from 1994 to 2005.

RESULTS

Major complications following lung transplantation include acute rejection, bacterial infection, and bronchiolitis obliterans. Five-year survival at UWHC (Kaplan-Meier) is 67%, and survival was not adversely affected by transplanting patients receiving mechanical ventilation. The major cause of death for transplant recipients was bronchiolitis obliterans syndrome (BOS).

CONCLUSIONS

Lung transplantation for CF is associated with acceptable survival rates and can improve quality of life. Lung transplant should be offered to all patients with advanced CF lung disease if they meet currently accepted inclusion and exclusion criteria.

Statin use reduces decline in lung function: VA Normative Aging Study

RATIONALE

Decreased lung function has been linked to increased inflammation and oxidative stress. Statins have demonstrated antiinflammatory and antioxidant properties.

OBJECTIVES

We investigated the effect of statin use on decline in lung function in the elderly, and whether smoking modified this effect.

METHODS

Our study population included 2,136 measurements on 803 elderly men from the Normative Aging Study whose lung function (FVC and FEV(1)) was measured two to four times between 1995 and 2005. Subjects indicated statin use and smoking history at each visit. We used mixed linear models to estimate the effects of each covariate, adjusting for subject and possible confounders.

MEASUREMENTS AND MAIN RESULTS

For those not using statins, the estimated decline in FEV(1) was 23.9 ml/year (95% confidence interval [CI], -27.8 to -20.1 ml/yr), whereas those taking statins had an estimated 10.9-ml/year decline in FEV(1) (95% CI, -16.9 to -5.0 ml/yr). We also examined the effect of statins with smoking by dividing the cohort into four groups: never-smokers, longtime quitters (quit >or= 10 yr ago), recent quitters (quit < 10 yr ago), and current smokers. We found a significant three-way interaction between time since first visit, statin use, and smoking status (P < 0.001). Within each smoking category, the effect of statins was always estimated to be beneficial, but the size of the improvement in the decline rate varied among smoking groups. We found similar results for FVC decline.

CONCLUSIONS

Our results indicate that statin use attenuates decline in lung function in the elderly, with the size of the beneficial effect modified by smoking status.

Emerging drugs in lung transplantation

The balance between immunosuppression to ensure graft tolerance while preventing emergence of infectious complications is key in lung transplantation. Although opportunistic infection may appear to be the most important of these complications, malignancies and severe drug toxicities significantly affect the short- and long-term outcomes of the patients. The present practice is combination therapy using drugs with complementary immunosuppressive action, to achieve synergistic immunosuppression with the lowest possible toxicity. Components of immunosuppression include induction and maintenance regimens. Primary graft failure remains an important cause of mortality and morbidity in the immediate post-transplant period. Acute rejection is a common complication after lung transplant, but responds well to augmented immunosuppression and immunomodulation. Chronic rejection still is the major cause of mortality in patients who survive the initial year post-transplantation. Several new drugs have shown promise in decreasing the rate of loss of graft function. This review discusses the current and emerging therapeutic regimens.

American Society of Transplantation executive summary on pediatric lung transplantation

Lung transplantation in children poses distinctly different challenges from those seen in the adult population. This consensus statement reviews the experience in the field of pediatric lung transplantation and highlights areas that deserve further investigation.

Early detection of chronic pulmonary allograft dysfunction by exhaled biomarkers

RATIONALE

Early detection of bronchiolitis obliterans syndrome (BOS) is important because therapies are more likely to be effective if employed early in the disease process.

OBJECTIVES

To compare the performance of exhaled NO and CO (which reflect airway inflammation) and the slope of the alveolar plateau for helium (which reflects heterogeneity of ventilation distribution) for detection of BOS stages 0-p and 1.

METHODS

Recipients of bilateral (n=64) and single (n=1) lung grafts were prospectively monitored for 1,249 days; the helium slope was derived from single-breath washouts and exhaled NO and CO were measured by chemiluminescence on 933 occasions.

MEASUREMENTS AND MAIN RESULTS

At the end of follow-up, 9 patients were in stage 0-p and 16 patients were in BOS stage 1 or higher; 21 patients had at least one measurement made in BOS stage 0-p. All markers increased in BOS stage 0-p, but only the helium slope increased in BOS stage 1. The helium slope had better sensitivity for detection of stages 0-p and 1 than either exhaled NO or CO, but considering exhaled NO and CO together improved their sensitivity; the best sensitivity was found with the three markers in combination. The biomarkers had high negative predictive values, but low specificity and positive predictive values.

CONCLUSIONS

After lung transplantation, (1) the helium slope and exhaled NO, but also exhaled CO, increase in BOS stage 0-p, (2) the helium slope has better sensitivity than exhaled NO and CO for the detection of BOS stages 0-p and 1, and (3) exhaled biomarkers have high negative predictive values, but low specificity and positive predictive values.

Simvastatin does not exhibit therapeutic anti-inflammatory effects in asthma

BACKGROUND

Statins lower cholesterol and also exhibit anti-inflammatory properties. In vitro and animal studies have suggested they may be useful for the treatment of a number of inflammatory conditions.

OBJECTIVE

To evaluate the in vivo therapeutic potential of simvastatin as an anti-inflammatory agent in patients with asthma.

METHODS

Potential signal from treatment effect was optimized by withdrawing all anti-inflammatory treatment for the duration of the study. Participants received 1 month of daily simvastatin and 1 month of daily placebo in a randomized, double-blind crossover trial. A total of 16 patients completed per protocol. Asthmatic inflammation was evaluated by measuring exhaled tidal nitric oxide, alveolar nitric oxide, sputum and peripheral eosinophil count, methacholine hyperresponsiveness, salivary eosinophilic cationic protein, and C-reactive protein. Measurements of dynamic and static lung volumes and of cholesterol were also made.

RESULTS

After initial withdrawal of usual asthma medication, there was a 1.43 geometric mean fold increase (ie, 43% difference) in fraction of exhaled nitric oxide (95% CI, 1.15 to 1.78; P = .004). Compared with placebo, simvastatin led to a 0.86 geometric mean fold decrease (95% CI, 0.7 to 1.04; P = .15) in exhaled nitric oxide (ie, a 14% difference), and a -0.18 doubling dilution shift (95% CI, -1.90 to 1.55; P = 1.0) in methacholine hyperresponsiveness. There were no significant differences in other inflammatory outcomes, lung volumes, or airway resistance between simvastatin and placebo. Treatment with simvastatin led to a significant reduction (P < .005) of total and low-density lipoprotein cholesterol.

CONCLUSION

There is no evidence to suggest simvastatin has anti-inflammatory activity in patients with asthma.

CLINICAL IMPLICATIONS

Simvastatin is not useful for the treatment of asthma.

Bronchiolitis obliterans following lung transplantation

Bronchiolitis obliterans syndrome (BOS) is the main and late chronic complication after lung transplantation. It remains a major impediment to long-term outcome. Unfortunately, the survival rate of lung transplant recipients lags behind that of other organ transplant recipients, and BOS accounts for more than 30% of all mortality after the third year following lung transplantation. Most recent studies suggest that immune injury is the main pathogenic event in small airway obliteration and the development of BOS. Early detection of BOS is possible as well as essential because prompt initiation of treatment may halt the progress of the disease and the development of chronic graft failure. Current treatment of BOS is disappointing despite advances in surgical techniques and improvements in immunosuppressive therapies. Therefore, a clear understanding of the pathogenesis of BOS plays a major role in the search for new and effective therapeutic strategies for better long-term survival and quality of life after lung transplantation.