Simvastatin is protective during Staphylococcus aureus pneumonia

Statin Use and Reduced Risk of Pneumonia in Patients with Melioidosis: A Lung-Specific Statin Association

Rationale: 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) use is associated with a lower risk of incident pneumonia and, less robustly, with nonpulmonary infections. Whether statin use is associated with a lower risk of pneumonia than other clinical presentations of infection with the same pathogen is unknown. Objectives: To assess whether preadmission statin use is associated with a lower risk of pneumonia than nonpneumonia presentations among patients hospitalized with Burkholderia pseudomallei infection (melioidosis). Methods: We performed a secondary analysis of a prospective multicenter cohort study of patients hospitalized with culture-confirmed B. pseudomallei infection (melioidosis). We used Poisson regression with robust standard errors to test for an association between statin use and pneumonia. We then performed several sensitivity analyses that addressed healthy user effect and indication bias. Results: Of 1,372 patients with melioidosis enrolled in the parent cohort, 1,121 were analyzed. Nine hundred eighty (87%) of 1,121 were statin nonusers, and 141 (13%) of 1,121 were statin users. Forty-six (33%) of 141 statin users presented with pneumonia compared with 432 (44%) of 980 statin nonusers. Statin use was associated with a lower risk of pneumonia in unadjusted analysis (relative risk, 0.74; 95% confidence interval, 0.58-0.95; P = 0.02) and, after adjustment for demographic variables, comorbidities, environmental exposures, and symptom duration (relative risk, 0.73; 95% confidence interval, 0.57-0.94; P = 0.02). The results of sensitivity analyses, including active comparator analysis and inverse probability of treatment weighting, were consistent with the primary analysis. Conclusions: In hospitalized patients with melioidosis, preadmission statin use was associated with a lower risk of pneumonia than other clinical presentations of melioidosis, suggesting a lung-specific protective effect of statins.

Prophylactic simvastatin increased survival during endotoxemia and inhibited granulocyte trafficking in a cell-intrinsic manner

Cross sectional studies have shown that statin-users have improved odds of surviving severe sepsis. Meanwhile controlled clinical trials failed to demonstrate improved sepsis survival with acute statin administration following hospitalization. Here, a lethal murine peritoneal lipopolysaccharide (LPS) endotoxemia model was used to assess the efficacy of chronic versus acute simvastatin on survival. Mirroring clinical observations, chronic but not acute treatment with simvastatin significantly increased survival. At a pre-mortality time point in LPS-treated mice, chronic simvastatin suppressed granulocyte trafficking in to the lungs and peritoneum without otherwise suppressing emergency myelopoiesis, myeloid cells in circulation, or inflammatory cytokines. Chronic simvastatin treatment significantly downregulated inflammatory chemokine gene signature in the lungs of LPS-treated mice. Thus, it was unclear if simvastatin was inhibiting granulocyte chemotaxis in a cell intrinsic or extrinsic manner. Adoptive transfer of fluorescently labeled granulocytes from statin and vehicle treated mice into LPS-treated mice showed that simvastatin inhibited lung-granulocyte trafficking in a cell intrinsic manner. Congruent with this, chemotaxis experiments using in vitro macrophages and ex vivo granulocytes demonstrated that simvastatin inhibited chemotaxis in a cell-intrinsic manner. Collectively, chronic but not acute simvastatin treatment improved survival in murine endotoxemia, and this was associated with cell-intrinsic inhibition of granulocyte chemotaxis.

Innovations in Evaluating Statin Benefit and Efficacy in Staphylococcus aureus Intracellular Infection Management

An emerging therapeutic approach in the treatment of infectious disease is to augment the host response through repurposing of well-tolerated, non-antibiotic, host-directed therapeutics. Earlier retrospective studies identify a positive association between statin use and a decreased risk of death due to sepsis or bacteremia. However, more recent randomized control trials fail to detect a therapeutic benefit in these complex infection settings. It is postulated that unrecognized biases in certain observational studies may have led to an overestimation of benefit and that statin use is instead a marker for health status, wealth, and demographic characteristics which may separately affect death due to infection. What remains unresolved is that in vitro and in vivo evidence reproducibly indicates that statin pharmacology limits infection and augments immunomodulatory responses, suggesting that therapeutic benefits may be attainable in certain infection settings, such as intracellular infection by S. aureus. Carefully considering the biological mechanisms capable of driving the relationship between statins and infections and constructing a methodology to avoid potential biases in observational studies would enable the examination of protective effects against infection and limit the risk of underestimating statin efficacy. Such an approach would rely on the examination of statin use in defined infection settings based on an underlying mode-of-action and pharmacology, where the inhibition of HMG-CoA-reductase at the rate-limiting step in cholesterol biosynthesis diminishes not only cholesterol levels but also isoprenoid intermediates central to host cell invasion by S. aureus. Therapeutic benefit in such settings, if existent, may be of clinical importance.

Microbiological Status of Venous Leg Ulcers and Its Predictors: A Single-Center Cross-Sectional Study

Venous leg ulcers are frequently colonized by microbes. This can be particularly devastating if the ulcer is infected with alert pathogens, i.e., highly virulent microorganisms with well-developed mechanisms of antibiotic resistance. We analyzed the microbiological status of venous leg ulcers and identified the clinicodemographic predictors of culture-positive ulcers, especially in ulcers with colonization by alert pathogens.

METHODS

This study included 754 patients with chronic venous leg ulcers. Material for microbiological analysis was collected by swabbing only from patients who did not receive any antibiotic treatment.

RESULTS

A total of 636 (84.3%) patients presented with culture-positive ulcers. Alert pathogens, primarily Pseudomonas aeruginosa, were detected in 28.6% of the positive cultures. In a logistic regression model, culture-positive ulcers were predicted independently by age > 65 years, current ulcer duration > 12 months, and ulceration area greater than 8.25 cm². Two of these factors, duration of current ulcer > 12 months and ulceration area > 8.25 cm², were also identified as the independent predictors of colonization by alert pathogens.

CONCLUSIONS

Colonization/infection is particularly likely in older persons with chronic and/or large ulcers. Concomitant atherosclerosis was an independent predictor of culture-negative ulcers.

Pleiotropic Effects of Statins: New Therapeutic Approaches to Chronic, Recurrent Infection by Staphylococcus aureus

An emergent approach to bacterial infection is the use of host rather than bacterial-directed strategies. This approach has the potential to improve efficacy in especially challenging infection settings, including chronic, recurrent infection due to intracellular pathogens. For nearly two decades, the pleiotropic effects of statin drugs have been examined for therapeutic usefulness beyond the treatment of hypercholesterolemia. Interest originated after retrospective studies reported decreases in the risk of death due to bacteremia or sepsis for those on a statin regimen. Although subsequent clinical trials have yielded mixed results and earlier findings have been questioned for biased study design, in vitro and in vivo studies have provided clear evidence of protective mechanisms that include immunomodulatory effects and the inhibition of host cell invasion. Ultimately, the benefits of statins in an infection setting appear to require attention to the underlying host response and to the timing of the dosage. From this examination of statin efficacy, additional novel host-directed strategies may produce adjunctive therapeutic approaches for the treatment of infection where traditional antimicrobial therapy continues to yield poor outcomes. This review focuses on the opportunistic pathogen, Staphylococcus aureus, as a proof of principle in examining the promise and limitations of statins in recalcitrant infection.

Differential effects of cotreatment of the antibiotic rifampin with host-directed therapeutics in reducing intracellular Staphylococcus aureus infection

Background

Chronic infection by Staphylococcus aureus drives pathogenesis in important clinical settings, such as recurrent pulmonary infection in cystic fibrosis and relapsing infection in osteomyelitis. Treatment options for intracellular S. aureus infection are limited. Rifampin, a lipophilic antibiotic, readily penetrates host cell membranes, yet monotherapy is associated with rapid antibiotic resistance and development of severe adverse events. Antibiotic cotreatment can reduce this progression, yet efficacy diminishes as antibiotic resistance develops. ML141 and simvastatin inhibit S. aureus invasion through host-directed rather than bactericidal mechanisms.

Objective

To determine whether cotreatment of ML141 or of simvastatin with rifampin would enhance rifampin efficacy.

Methods

Assays to assess host cell invasion, host cell viability, host cell membrane permeability, and bactericidal activity were performed using the human embryonic kidney (HEK) 293-A cell line infected with S. aureus (29213) and treated with vehicle control, simvastatin, ML141, rifampin, or cotreatment of simvastatin or ML141 with rifampin.

Results

We found cotreatment of ML141 with rifampin reduced intracellular infection nearly 85% when compared to the no treatment control. This decrease more than doubled the average 40% reduction in response to rifampin monotherapy. In contrast, cotreatment of simvastatin with rifampin failed to improve rifampin efficacy. Also, in contrast to ML141, simvastatin increased propidium iodide (PI) positive cells, from an average of 10% in control HEK 293-A cells to nearly 20% in simvastatin-treated cells, indicating an increase in host cell membrane permeability. The simvastatin-induced increase was reversed to control levels by cotreatment of simvastatin with rifampin.

Conclusion

Taken together, rifampin efficacy is increased through host-directed inhibition of S. aureus invasion by ML141, while efficacy is not increased by simvastatin. Considerations regarding novel therapeutic approaches may be dependent on underlying differences in pharmacology.

Repurposing of drugs approved for cardiovascular diseases: Opportunity or mirage?

Drug repurposing is a promising way in drug discovery to identify new therapeutic uses -different from the original medical indication- for existing drugs. It has many advantages over traditional approaches to de novo drug discovery, since it can significantly reduce healthcare costs and development timeline. In this review, we discuss the possible repurposing of drugs approved for cardiovascular diseases, such as β-blockers, angiotensin converting enzyme inhibitors (ACE-Is), angiotensin II receptor blockers (ARBs), statins, aspirin, cardiac glycosides and low-molecular-weight heparins (LMWHs). Indeed, numerous experimental and epidemiological studies have reported promising anti-cancer activities for these drugs. It is worth mentioning, however, that the results of these studies are often controversial and very few data were obtained by controlled prospective clinical trials. Therefore, no final conclusion has yet been reached in this area and no final recommendations can be made. Moreover, β-blockers, ARBs and statins showed promising results in randomised controlled trials (RCTs) where pathological conditions other than cancer were considered. The results obtained have led or may lead to new indications for these drugs. For each drug or class of drugs, the potential molecular mechanisms of action justifying repurposing, results obtained in vitro and in animal models and data from epidemiological and randomized studies are described.

Statins: a viable candidate for host-directed therapy against infectious diseases

Statins were first identified over 40 years ago as lipid-lowering drugs and have been remarkably effective in treating cardiovascular diseases. As research advanced, the protective effects of statins were additionally attributed to their anti-inflammatory, antioxidative, anti-thrombotic and immunomodulatory functions rather than lipid-lowering abilities alone. By promoting host defence mechanisms and inhibiting pathological inflammation, statins increase survival in human infectious diseases. At the cellular level, statins inhibit the intermediates of the host mevalonate pathway, thus compromising the immune evasion strategies of pathogens and their survival. Here, we discuss the potential use of statins as an inexpensive and practical alternative or adjunctive host-directed therapy for infectious diseases caused by intracellular pathogens, such as viruses, protozoa, fungi and bacteria.

Atorvastatin increases the production of proinflammatory cytokines and decreases the survival of Escherichia coli-infected mice

To assess whether the immunosuppressive effects of atorvastatin outweigh its antibacterial ones in an infection, mice were infected with Escherichia coli and administered atorvastatin; survival rates were then monitored. Mice treated with atorvastatin post-infection showed a remarkable decrease in their survival rate. On the other hand, the higher the level of serum IFN-γ in the infected mice treated with atorvastatin, the lower was the survival rate. Levels of IL-4 were markedly depressed in all groups infected with E. coli and treated with atorvastatin. Since atorvastatin inhibits IFN-γ expression in the absence of bacterial infection, we examined whether bacterial lipopolysaccharide (LPS) was the element capable of overriding this inhibition. Mouse peripheral blood mononuclear cells were treated with atorvastatin and lipopolysaccharide ex vivo then proinflammatory (IFN-γ, TNFα, IL-6) and prohumoral/regulatory (IL-4, IL-13, IL-10) cytokine levels were analyzed in culture supernatants. While proinflammatory cytokine levels were decreased upon treatment with atorvastatin alone, their levels were markedly elevated by treatment with LPS, bacterial lysate or bacterial culture supernatant. On the other hand, atorvastatin exerted an inhibitory effect on production of the prohumoral/regulatory cytokines. Our data indicates that any consideration for statins as antimicrobial treatment should assess the possible adverse outcomes.

Biotechnological Production of Statins: Metabolic Aspects and Genetic Approaches

Statins are drugs used for people with abnormal lipid levels (hyperlipidemia) and are among the best-selling medications in the United States. Thus, the aspects related to the production of these drugs are of extreme importance for the pharmaceutical industry. Herein, we provide a non-exhaustive review of fungal species used to produce statin and highlighted the major factors affecting the efficacy of this process. The current biotechnological approaches and the advances of a metabolic engineer to improve statins production are also emphasized. The biotechnological production of the main statins (lovastatin, pravastatin and simvastatin) uses different species of filamentous fungi, for example Aspergillus terreus. The statins production is influenced by different types of nutrients available in the medium such as the carbon and nitrogen sources, and several researches have focused their efforts to find the optimal cultivation conditions. Enzymes belonging to Lov class, play essential roles in statin production and have been targeted to genetic manipulations in order to improve the efficiency for Lovastatin and Simvastatin production. For instance, Escherichia coli strains expressing the LovD have been successfully used for lovastatin production. Other examples include the use of iRNA targeting LovF of A. terreus. Therefore, fungi are important allies in the fight against hyperlipidemias. Although many studies have been conducted, investigations on bioprocess optimization (using both native or genetic- modified strains) still necessary.

Statins improve the long-term prognosis in patients who have survived sepsis: A nationwide cohort study in Taiwan (STROBE complaint)

Most patients diagnosed with sepsis died during their first episode, with the long-term survival rate upon post-sepsis discharge being low. Major adverse cardiovascular events and recurrent infections were regarded as the major causes of death. No definite medications had proven to be effective in improving the long-term prognosis. We aimed to examine the benefits of statins on the long-term prognosis of patients who had survived sepsis.Between 1999 and 2013, a total of 220,082 patients who had been hospitalized due to the first episode of sepsis were included, with 134,448 (61.09%) of them surviving to discharge. The surviving patients who were subsequently prescribed statins at a concentration of more than 30 cumulative Defined Daily Doses (cDDDs) during post-sepsis discharge were defined as the users of statin.After a propensity score matching ratio of 1:5, a total of 7356 and 36,780 surviving patients were retrieved for the study (statin users) and comparison cohort (nonstatin users), respectively. The main outcome was to determine the long-term survival rate during post-sepsis discharge.HR with 95% CI was calculated using the Cox regression model to evaluate the effectiveness of statins, with further stratification analyses according to cDDDs.The users of statins had an adjusted HR of 0.29 (95% CI, 0.27-0.31) in their long-term mortality rate when compared with the comparison cohort. For the users of statins with cDDDs of 30-180, 180-365, and >365, the adjusted HRs were 0.32, 0.22, and 0.16, respectively, (95% CI, 0.30-0.34, 0.19-0.26, and 0.12-0.23, respectively), as compared with the nonstatins users (defined as the use of statins <30 cDDDs during post-sepsis discharge), with the P for trend <.0001. In the sensitivity analysis, after excluding the surviving patients who had died between 3 and 6 months after post-sepsis discharge, the adjusted HR for the users of statins remained significant (0.35, 95% CI 0.32-0.37 and 0.42, 95% CI 0.39-0.45, respectively).Statins may have the potential to decrease the long-term mortality of patients who have survived sepsis. However, more evidence, including clinical and laboratory data, is necessary in order to confirm the results of this observational cohort study.Trial registration: CMUH104-REC2-115.

Statin therapy in patients with community-acquired pneumonia

Community-acquired pneumonia (CAP) is the leading cause of death from infection in developed countries. There is evidence of an association between improved survival from infection and statin use. The possible beneficial effects of statins are complicated by the common use of macrolide antibiotics for pneumonia, with current guidance suggesting that concurrent macrolide and statin use is contraindicated.We conducted an observational study of statin use in patients with CAP. Of 2,067 patients with CAP, 30.4% were on statin therapy at admission. Statin users were more likely to survive the admission (p<0.001). In addition, we conducted a survey of doctors and found that knowledge regarding concurrent macrolide and statin use was lacking.These data suggest a potential role of statins in the management of CAP. Further research using high-dose statins is required to assess their safe use in subjects with mild to moderate infections.

The Use of Statins and Risk of Community-Acquired Pneumonia

PURPOSE OF THE REVIEW

Community-acquired pneumonia (CAP) is still associated with a large burden and causes significant morbidity and mortality. Besides universal vaccination and antibiotic treatment, statins as adjunctive therapy may also have a beneficial role in the prevention and treatment of CAP. Our goal from this review is to discuss the epidemiology of CAP, and role of statins as adjunctive therapy in the development of CAP.

RECENT FINDINGS

Statins are lipid-lowering medications characterized by their ability to control hypercholesterolemia in addition to other pleiotropic effects that could explain their role in the pathogenesis of CAP. While most observational studies have shown that statins reduce risk of pneumonia in the general population, patients with diabetes, and recently in patients with myocardial infarction, no randomized controlled trial (RCT) to date has been conducted to assess the efficacy of statins to prevent development of CAP. Given the paucity of robust randomized evidence to assess statin use and the development of CAP, and considering conflicting results of the observational studies, we are not in favor of initiation of statins for either the prevention or treatment of CAP.

Roles of the Mevalonate Pathway and Cholesterol Trafficking in Pulmonary Host Defense

The mevalonic acid synthesis pathway, cholesterol, and lipoproteins play fundamental roles in lung physiology and the innate immune response. Recent literature investigating roles for cholesterol synthesis and trafficking in host defense against respiratory infection was critically reviewed. The innate immune response and the cholesterol biosynthesis/trafficking network regulate one another, with important implications for pathogen invasion and host defense in the lung. The activation of pathogen recognition receptors and downstream cellular host defense functions are critically sensitive to cellular cholesterol. Conversely, microorganisms can co-opt the sterol/lipoprotein network in order to facilitate replication and evade immunity. Emerging literature suggests the potential for harnessing these insights towards therapeutic development. Given that >50% of adults in the U.S. have serum cholesterol abnormalities and pneumonia remains a leading cause of death, the potential impact of cholesterol on pulmonary host defense is of tremendous public health significance and warrants further mechanistic and translational investigation.

Is There Potential for Repurposing Statins as Novel Antimicrobials?

Statins are members of a class of pharmaceutical widely used to reduce high levels of serum cholesterol. In addition, statins have so-called "pleiotropic effects," which include inflammation reduction, immunomodulation, and antimicrobial effects. An increasing number of studies are emerging which detail the attenuation of bacterial growth and in vitro and in vivo virulence by statin treatment. In this review, we describe the current information available concerning the effects of statins on bacterial infections and provide insight regarding the potential use of these compounds as antimicrobial therapeutic agents.

Impact of statins on ALI/ARDS: A meta-analysis

BACKGROUND

Statins may be beneficial in treating acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), but their application remains controversial.

OBJECTIVES

This meta-analysis of published studies investigated their potential benefit in ALI/ARDS treatment.

METHODS

PubMed, EMBASE, Google Scholar and Cochrane databases were searched and all randomized controlled trials (RCT) and cohort studies with head-to-head comparison between statin and standard care were included.

RESULTS

Three RCTs and six cohort studies were included. Overall, statins treatment had no significant effect on mortality compared with placebo (RCTs: OR = 0.99, 95% CI = 0.72, 1.37; cohorts: OR = 0.99, 95% CI = 0.71, 1.37). In addition, ventilator-free days were comparable between the two groups (RCTs: SMD = 0.08, 95% CI = -0.03, 0.19; cohorts: SMD = 0.06, 95% CI = -0.17, 0.29). The one-way sensitivity analysis confirmed the stability of results.

CONCLUSION

The results did not show that statins had effects on mortality and ventilator-free days among ALI/ARDS patients. However, this meta-analysis is limited by the number of RCTs included.

Modulating antibiotic activity towards respiratory bacterial pathogens by co-medications: a multi-target approach

Non-antibiotic drugs can modulate bacterial physiology and/or antibiotic activity, opening perspectives for innovative therapeutic strategies. Focusing on respiratory pathogens and considering in vitro, in vivo, and clinical data, here we examine the effect of these drugs on the expression of resistance mechanisms, biofilm formation, and intracellular survival, as well as their influence on the activity of antibiotics on bacteria. Beyond the description of the effects observed, we also comment on concentrations that are active and discuss the mechanisms of drug-drug or drug-target interactions. This discussion should be helpful in defining useful targets for adjuvant therapy and establishing the corresponding pharmacophores for further drug fine-tuning.

Preoperative statin therapy and infectious complications in cardiac surgery

AIM

To assess whether preoperative statin therapy is associated with the risk of postoperative infection in patients undergoing cardiac surgery.

METHODS

520 patients undergoing cardiac surgery in 2010 were retrospectively examined. Data regarding statin and antibiotic use prior to and after surgery were available from the hospital pharmacy information system. Cultures and clinical data of patients on postoperative antibiotics other than standard prophylactic therapy were studied to identify postoperative infections up to 30 days from day of surgery.

RESULTS

370 (71.2 %) patients were on preoperative statin therapy. Overall, 82 patients (15.8 %) suffered from postoperative infection of which 11 were surgical site infections. In multivariable regression analysis, statin therapy was associated with a reduced risk of postoperative infection (adjusted odds ratio: 0.329, 95 %: CI 0.19-0.57; P < 0.001).

CONCLUSIONS

Preoperative statin use was associated with a considerable reduced risk of postoperative infections following cardiac surgery. Randomised controlled trials are required to clarify the role of statin therapy in the prevention of postoperative infections.

Influenza virus A/Anhui/1/2013 (H7N9) replicates efficiently in the upper and lower respiratory tracts of cynomolgus macaques

In March 2013, three fatal human cases of infection with influenza A virus (H7N9) were reported in China. Since then, human cases have been accumulating. Given the public health importance of this virus, we performed a pathogenicity study of the H7N9 virus in the cynomolgus macaque model, focusing on clinical aspects of disease, radiographic, histological, and gene expression profile changes in the upper and lower respiratory tracts, and changes in systemic cytokine and chemokine profiles during infection. Cynomolgus macaques developed transient, mild to severe disease with radiographic evidence of pulmonary infiltration. Virus replicated in the upper as well as lower respiratory tract, with sustained replication in the upper respiratory tract until the end of the experiment at 6 days after inoculation. Virus shedding occurred mainly via the throat. Histopathological changes in the lungs were similar to those observed in humans, albeit less severe, with diffuse alveolar damage, infiltration of polymorphonuclear cells, formation of hyaline membranes, pneumocyte hyperplasia, and fibroproliferative changes. Analysis of gene expression profiles in lung lesions identified pathways involved in tissue damage during H7N9 infection as well as leads for development of therapeutics targeting host responses rather than virus replication. Overall, H7N9 infection was not as severe in cynomolgus macaques as in humans, supporting the possible role of underlying medical complications in disease severity as discussed for human H7N9 infection (H. N. Gao et al., N. Engl. J. Med. 368:2277–2285, 2013, doi:10.1056/NEJMoa1305584).

Influenza A virus H7N9 emerged early in 2013, and human cases have continued to emerge since then. Although H7N9 virus-induced disease in humans is often very severe and even lethal, the majority of reported H7N9 cases occurred in older people and people with underlying medical conditions. To better understand the pathogenicity of this virus, healthy cynomolgus macaques were inoculated with influenza A virus H7N9. Cynomolgus macaques were used as a model because the receptor distribution for H7N9 virus in macaques was recently shown to be more similar to that in humans than that of other frequently used animal models. From comparison with previous studies, we conclude that the emerging H7N9 influenza virus was more pathogenic in cynomolgus macaques than seasonal influenza A viruses and most isolates of the pandemic H1N1 virus but less pathogenic than the 1918 Spanish influenza virus or highly pathogenic avian influenza (HPAI) H5N1 virus.

Atorvastatin as a stable treatment in bronchiectasis: a randomised controlled trial

BACKGROUND

Bronchiectasis is characterised by chronic cough, sputum production, and recurrent chest infections. Pathogenesis is poorly understood, but excess neutrophilic airway inflammation is seen. Accumulating evidence suggests that statins have pleiotropic effects; therefore, these drugs could be a potential anti-inflammatory treatment for patients with bronchiectasis. We did a proof-of-concept randomised controlled trial to establish if atorvastatin could reduce cough in patients with bronchiectasis.

METHODS

Patients aged 18-79 years were recruited from a secondary-care clinic in Edinburgh, UK. Participants had clinically significant bronchiectasis (ie, cough and sputum production when clinically stable) confirmed by chest CT and two or more chest infections in the preceding year. Individuals were randomly allocated to receive either high-dose atorvastatin (80 mg) or a placebo, given orally once a day for 6 months. Sequence generation was done with a block randomisation of four. Random allocation was masked to study investigators and patients. The primary endpoint was reduction in cough from baseline to 6 months, measured by the Leicester Cough Questionnaire (LCQ) score, with a lower score indicating a more severe cough (minimum clinically important difference, 1·3 units). Analysis was done by intention-to-treat. The trial is registered with ClinicalTrials.gov, number NCT01299181.

FINDINGS

Between June 23, 2011, and Jan 30, 2011, 82 patients were screened for inclusion in the study and 22 were excluded before randomisation. 30 individuals were assigned atorvastatin and 30 were allocated placebo. The change from baseline to 6 months in LCQ score differed between groups, with a mean change of 1·5 units in patients allocated atorvastatin versus -0·7 units in those assigned placebo (mean difference 2·2, 95% CI 0·5-3·9; p=0·01). 12 (40%) of 30 patients in the atorvastatin group improved by 1·3 units or more on the LCQ compared with five (17%) of 30 in the placebo group (difference 23%, 95% CI 1-45; p=0·04). Ten (33%) patients assigned atorvastatin had an adverse event versus three (10%) allocated placebo (difference 23%, 95% CI 3-43; p=0·02). No serious adverse events were recorded.

INTERPRETATION

6 months of atorvastatin improved cough on a quality-of-life scale in patients with bronchiectasis. Multicentre studies are now needed to assess whether long-term statin treatment can reduce exacerbations.

FUNDING

Chief Scientist's Office.

Short term statin treatment improves survival and differentially regulates macrophage-mediated responses to Staphylococcus aureus

Staphylococcus aureus is the most prevalent etiologic agent of sepsis. Statins, primarily prescribed for their cholesterol-lowering capabilities, may be beneficial for treating sepsis due to their anti-inflammatory properties. This study examined the effect of low dose, short term simvastatin pretreatment in conjunction with antibiotic treatment on host survival and demonstrated that pretreatment with simvastatin increased survival of C57BL/6 mice in response to S. aureus infection. In vitro studies revealed that short term simvastatin pretreatment did not reduce S. aureus-stimulated expression of surface proteins necessary for macrophage presentation of antigen to T cells, such as MHC Class II and costimulatory molecules CD80 and CD86, but did reduce both basal and S. aureus-stimulated levels of C5aR. Additionally, this work demonstrated the ability of simvastatin to dampen macrophage responses initiated not only by bacteria directly but by membrane vesicles shed in response to infection, revealing a new mechanism of immune modulation by statins. These data demonstrate the ability of short term simvastatin pretreatment to modulate immune responses and identify new insights into the underlying mechanisms of the anti-inflammatory properties of simvastatin that may decrease the pathophysiological effects leading to sepsis.

The immunomodulatory effects of statins in community-acquired pneumonia: a systematic review

OBJECTIVE

To evaluate the potential immunomodulatory effects of statins in community-acquired pneumonia.

METHODS

We performed a systematic review of available literature on experimental and clinical studies. We used a PubMed/MEDLINE and EMBASE search to identify potential articles.

RESULTS

We identified 34 original studies, 17 experimental and 17 clinical studies, published up to March 2013.

CONCLUSIONS

Statins attenuated pulmonary inflammation by modulating neutrophil function, by reducing cytokine expression and release, and by protecting against disruption of pulmonary integrity. However, additional experimental studies are needed to fully elucidate the exact mechanisms. Several clinical studies suggested a decreased risk of CAP or a reduction in mortality due to CAP for current statin users, but the mostly observational design of these studies hampers the interpretation of their results. Therefore, appropriately designed studies, such as randomised controlled trials, are required to demonstrate the usefulness of statins in the prevention and treatment of CAP.

Host cell invasion by Staphylococcus aureus stimulates the shedding of microvesicles

During severe sepsis, microvesicles that are positive for tissue factor (TF) are at increased levels within blood and in pulmonary lavage. These microvesicles potentially disperse TF, the major initiator of the coagulation cascade, throughout multiple organ systems, initiating fibrin deposition and resultant ischemia. The source of these microvesicles has remained incompletely defined. Although TF(+) microvesicles are shed from cells that express nascent TF transcript in response to injury, recent findings revealed that circulating, full-length TF protein is detectable prior to these nascent transcripts. This finding suggested that the protein is released from constitutive sources as an acute response. We examined whether Staphylococcus aureus, the Gram-positive bacteria that is emerging as one of the most common etiologic agents in sepsis, is capable of stimulating the release of TF(+) microvesicles from a pulmonary cell line that constitutively expresses TF protein. We found that host cell invasion stimulated an acute release of TF(+) microvesicles and that these microvesicles mediated the transfer of the protein to TF-negative endothelial cells. We also found that transfer was inhibited by cholesterol-lowering simvastatin. Taken together, our findings reveal that S. aureus pathogenesis extends to the acute release of TF(+) microvesicles and that inhibiting dispersal by this mechanism may provide a therapeutic target.

Impact of oral simvastatin therapy on acute lung injury in mice during pneumococcal pneumonia

Background

Recent studies suggest that the reported protective effects of statins (HMG-CoA reductase inhibitors) against community-acquired pneumonia (CAP) and sepsis in humans may be due to confounders and a healthy user-effect. To directly test whether statins are protective against Streptococcus pneumoniae, the leading cause of CAP, we examined the impact of prolonged oral simvastatin therapy at physiologically relevant doses in a mouse model of pneumococcal pneumonia. BALB/c mice were placed on rodent chow containing 0 mg/kg (control), 12 mg/kg (low simvastatin diet [LSD]; corresponds to 1.0 mg/kg/day), or 120 mg/kg (high simvastatin diet [HSD]; corresponds to 10 mg/kg/day) simvastatin for four weeks, infected intratracheally with S. pneumoniae serotype 4 strain TIGR4, and sacrificed at 24, 36, or 42 h post-infection for assessment of lung histology, cytokine production, vascular leakage and edema, bacterial burden and bloodstream dissemination. Some mice received ampicillin at 12-h intervals beginning at 48 h post-infection and were monitored for survival. Immunoblots of homogenized lung samples was used to assess ICAM-1 production.

Results

Mice receiving HSD had reduced lung consolidation characterized by less macrophage and neutrophil infiltration and a significant reduction in the chemokines MCP-1 (P = 0.03) and KC (P = 0.02) and ICAM-1 in the lungs compared to control mice. HSD mice also had significantly lower bacterial titers in the blood at 36 (P = 0.007) and 42 (P = 0.03) hours post-infection versus controls. LSD had a more modest effect against S. pneumoniae but also resulted in reduced bacterial titers in the lungs and blood of mice after 42 h and a reduced number of infiltrated neutrophils. Neither LSD nor HSD mice had reduced mortality in a pneumonia model where mice received ampicillin 48 h after challenge.

Conclusions

Prolonged oral simvastatin therapy had a strong dose-dependent effect on protection against S. pneumoniae as evidenced by reduced neutrophil infiltration, maintenance of vascular integrity, and lowered chemokine production in the lungs of mice on HSD. Statin therapy also protected through reduced bacterial burden in the lungs. Despite these protective correlates, mortality in the simvastatin-receiving cohorts was equivalent to controls. Thus, oral simvastatin at physiologically relevant doses only modestly protects against pneumococcal pneumonia.