Esteban C. Gabazza

Efficacy of 23-valent pneumococcal vaccine in preventing pneumonia and improving survival in nursing home residents: double blind, randomised and placebo controlled trial

Objective To determine the efficacy of a 23-valent pneumococcal polysaccharide vaccine in people at high risk of pneumococcal pneumonia. Design Prospective, randomised, placebo controlled double blind study. Setting Nursing homes in Japan. Participants 1006 nursing home residents. Interventions Participants were randomly allocated to either 23-valent pneumococcal polysaccharide vaccine (n=502) or placebo (n=504). Main outcome measures The primary end points were the incidence of all cause pneumonia and pneumococcal pneumonia. Secondary end points were deaths from pneumococcal pneumonia, all cause pneumonia, and other causes. Results Pneumonia occurred in 63 (12.5%) participants in the vaccine group and 104 (20.6%) in the placebo group. Pneumococcal pneumonia was diagnosed in 14 (2.8%) participants in the vaccine group and 37 (7.3%) in the placebo group (P<0.001). All cause pneumonia and pneumococcal pneumonia were significantly more frequent in the placebo group than in the vaccine group: incidence per 1000 person years 55 v 91 (P<0.0006) and 12 v 32 (P<0.001), respectively. Death from pneumococcal pneumonia was significantly higher in the placebo group than in the vaccine group (35.1% (13/37) v 0% (0/14), P<0.01). The death rate from all cause pneumonia (vaccine group 20.6% (13/63) v placebo group 25.0% (26/104), P=0.5) and from other causes (vaccine group 17.7% (89/502) v placebo group (80/504) 15.9%, P=0.4) did not differ between the two study groups. Conclusion The 23-valent pneumococcal polysaccharide vaccine prevented pneumococcal pneumonia and reduced mortality from pneumococcal pneumonia in nursing home residents. Trial registration Japan Medical Association Center for Clinical Trials JMA-IIA00024.

What has been learnt from the thrombin-activatable fibrinolysis inhibitor-deficient mouse?

Summary.u2002 Thrombin‐activatable fibrinolysis inhibitor (TAFI) is a circulating zymogen that is activated physiologically by the thrombin/thrombomodulin complex to activated TAFI (TAFIa) which is a basic carboxypeptidase. Substrates include fibrin, leading to a reduction in rate of plasmin generation, and several proinflammatory mediators such as bradykinin, thrombin‐cleaved osteopontin and complement factor C5a. TAFI‐deficient mice have no phenotype without being challenged and TAFIa appears to play a limited role in physiological fibrinolysis in vivo. In several disease models, the TAFI‐deficient mice have different outcomes from the wild type (WT), but whether the difference is beneficial or an exacerbation of the disease depends on the model. The consequences of TAFI deficiency include increased plasmin as a result of enhanced incorporation of plasminogen and tissue plasminogen activator into the fibrin clot, but also loss of its ability to degrade other substrates, with the resultant up‐regulation of several proinflammatory mediators, including C5a. Criteria are recommended to demonstrate that a substrate is a physiological substrate of TAFIa.

Community-acquired pneumonia and nursing home-acquired pneumonia in the very elderly patients

The rapid increase in the elderly population is leading to a corresponding increase in the number of people requiring medical care. To date no comparative study between community-acquired pneumonia (CAP) and nursing home-acquired pneumonia (NHAP) has been reported in the very elderly non-intubated patients. The present study was undertaken to compare the clinical characteristics and microbial etiology between CAP and NHAP in elderly patients >/=85-years old. There were 54 patients with NHAP and 47 with CAP. Performance status was significantly worse in the NHAP than in the CAP group. Among all patients, the most frequent pathogens were Chlamydophilia pneumoniae followed by Streptococcus pneumoniae, Mycoplasma pneumoniae influenza virus and Staphylococcus aureus. The frequency of S. peumoniae was significantly higher in NHAP patients than in CAP patients after adjusting for age and sex. Physical activity, nutrition status and dehydration were significant prognostic factors of pneumonia among all patients. In-hospital mortality was significantly higher in NHAP than in CAP after adjusting for age and sex. This study demonstrated that the etiology and clinical outcome differ between CAP and NHAP patients in the very elderly non-intubated population.

Inhibition of Allergic Bronchial Asthma by Thrombomodulin Is Mediated by Dendritic Cells

RATIONALEnbronchial asthma is caused by inappropriate acquired immune responses to environmental allergens. It is a major health problem, with a prevalence that is rapidly increasing. Curative therapy is not currently available.nnnOBJECTIVESnto test the hypothesis that thrombomodulin (TM) inhibits allergic bronchial asthma by inducing tolerogenic dendritic cells (DCs).nnnMETHODSnthe protective effect of TM was evaluated using a murine asthma model. Asthma was induced in mice by exposure to chicken egg ovalbumin, and the effects of inhaled TM or TM-treated DCs were assessed by administering before ovalbumin exposure.nnnMEASUREMENTS AND MAIN RESULTSntreatment with TM protects against bronchial asthma measured as improved lung function and reduced IgE and cells in alveolar lavage fluid by inducing tolerogenic dendritic dells. These are characterized by high expression of surface TM (CD141/TM(+)) and low expression of maturation markers and possess reduced T-cell costimulatory activity. The CD141/TM(+) DCs migrate less toward chemokines, and after TM treatment there are fewer DCs in the draining lymph node and more in the lungs. The TM effect is independent of its role in coagulation. Rather, it is mediated via the TM lectin domain directly interacting with the DCs.nnnCONCLUSIONSnthe results of this study show that TM is a modulator of DC immunostimulatory properties and a novel candidate drug for the prevention of bronchial asthma in atopic patients.

Correlation between circulating fibrocytes, and activity and progression of interstitial lung diseases.

Background and objective:u2003 Interstitial lung diseases (ILD) are characterized by progressive interstitial pulmonary fibrosis and a decline in lung function. Fibrocytes are bone marrow‐derived mesenchymal progenitor cells that may play a role in the pathogenesis of pulmonary fibrosis. Circulating fibrocyte numbers have been correlated with the prognosis of patients with idiopathic pulmonary fibrosis. The aim of the present study was to evaluate the relationship between circulating fibrocytes, and parameters of disease activity and progression in several groups of patients with ILD.

Differential role of regulatory T cells in early and late stages of pulmonary fibrosis

Regulatory T cells (Tregs) are a specific subset of T lymphocytes that regulate the function of other subsets of lymphocytes. Contradictory results have been reported regarding the role of Tregs in lung fibrosis. We wished to clarify the role of Tregs in the early and late stages of bleomycin-induced lung fibrosis in mice by depleting them with anti-CD25+ antibody (PC61). Mice treated with PC61 in early stages had significantly decreased number of CD4+CD25+ T cells compared to mice treated with the isotype control. The number of inflammatory cells, the concentrations of collagen, TGFβ1, the content of collagen and hydroxyproline in lung tissue were significantly reduced in PC61-treated mice compared to mice treated with the isotype control group. Pathological examination of the lung also disclosed reduced fibrotic changes and decreased fibrosis score in the PC61 group compared to control group. By contrast, mice treated with PC61 in late stages of the disease showed more infiltration of inflammatory cells and higher fibrotic score and hydroxyproline content in the lungs than mice treated with the isotype control. Our results suggest that Tregs play a detrimental role in early stages but protective role in late stages of pulmonary fibrosis in mice.

Efficacy of a novel class of RNA interference therapeutic agents.

RNA interference (RNAi) is being widely used in functional gene research and is an important tool for drug discovery. However, canonical double-stranded short interfering RNAs are unstable and induce undesirable adverse effects, and thus there is no currently RNAi-based therapy in the clinic. We have developed a novel class of RNAi agents, and evaluated their effectiveness in vitro and in mouse models of acute lung injury (ALI) and pulmonary fibrosis. The novel class of RNAi agents (nkRNA®, PnkRNA™) were synthesized on solid phase as single-stranded RNAs that, following synthesis, self-anneal into a unique helical structure containing a central stem and two loops. They are resistant to degradation and suppress their target genes. nkRNA and PnkRNA directed against TGF-β1mRNA ameliorate outcomes and induce no off-target effects in three animal models of lung disease. The results of this study support the pathological relevance of TGF-β1 in lung diseases, and suggest the potential usefulness of these novel RNAi agents for therapeutic application.

Eosinophils Promote Epithelial to Mesenchymal Transition of Bronchial Epithelial Cells

Eosinophilic inflammation and remodeling of the airways including subepithelial fibrosis and myofibroblast hyperplasia are characteristic pathological findings of bronchial asthma. Epithelial to mesenchymal transition (EMT) plays a critical role in airway remodelling. In this study, we hypothesized that infiltrating eosinophils promote airway remodelling in bronchial asthma. To demonstrate this hypothesis we evaluated the effect of eosinophils on EMT by in vitro and in vivo studies. EMT was assessed in mice that received intra-tracheal instillation of mouse bone marrow derived eosinophils and in human bronchial epithelial cells co-cultured with eosinophils freshly purified from healthy individuals or with eosinophilic leukemia cell lines. Intra-tracheal instillation of eosinophils was associated with enhanced bronchial inflammation and fibrosis and increased lung concentration of growth factors. Mice instilled with eosinophils pre-treated with transforming growth factor(TGF)-β1 siRNA had decreased bronchial wall fibrosis compared to controls. EMT was induced in bronchial epithelial cells co-cultured with human eosinophils and it was associated with increased expression of TGF-β1 and Smad3 phosphorylation in the bronchial epithelial cells. Treatment with anti-TGF-β1 antibody blocked EMT in bronchial epithelial cells. Eosinophils induced EMT in bronchial epithelial cells, suggesting their contribution to the pathogenesis of airway remodelling.

Development and Preclinical Efficacy of Novel Transforming Growth Factor-β1 Short Interfering RNAs for Pulmonary Fibrosis

Idiopathic pulmonary fibrosis is a chronic devastating disease of unknown etiology. No therapy is currently available. A growing body of evidence supports the role of transforming growth factor (TGF)-β1 as the major player in the pathogenesis of the disease. However, attempts to control its expression and to improve the outcome of pulmonary fibrosis have been disappointing. We tested the hypothesis that TGF-β1 is the dominant factor in the acute and chronic phases of pulmonary fibrosis and developed short interfering (si)RNAs directed toward molecules implicated in the disease. This study developed novel sequences of siRNAs targeting the TGF-β1 gene and evaluated their therapeutic efficacy in two models of pulmonary fibrosis: a model induced by bleomycin and a novel model of the disease developed spontaneously in mice overexpressing the full length of human TGF-β1 in the lungs. Intrapulmonary delivery of aerosolized siRNAs of TGF-β1 with sequences common to humans and rodents significantly inhibited bleomycin-induced pulmonary fibrosis in the acute and chronic phases of the disease and in a dose-dependent manner. Aerosolized human-specific siRNA also efficiently inhibited pulmonary fibrosis, improved lung function, and prolonged survival in human TGF-β1 transgenic mice. Mice showed no off-target effects after intratracheal administration of siRNA. These results suggest the applicability of these novel siRNAs as tools for treating pulmonary fibrosis in humans.

Indacaterol improves daily physical activity in patients with chronic obstructive pulmonary disease

Background The current mainstay of therapy for chronic obstructive pulmonary disease (COPD) is long-acting bronchodilators. To date, the effect of indacaterol, a β2-agonist, on activities of daily living in COPD patients is not well understood. The aim of this study was to evaluate the efficacy of indacaterol with regard to activities of daily living in patients with COPD. Methods In this nonrandomized open-label study, 23 patients with COPD were instructed to carry an accelerometer for 4 weeks without indacaterol therapy and then for another period of 4 weeks while receiving indacaterol therapy. Results The number of steps, duration of moderate or greater physical activity, and energy expenditure were significantly increased after treatment with indacaterol compared with baseline data in all patients with COPD; the metabolic equivalent of task was also significantly enhanced after treatment with indacaterol. Conclusion This study provides early evidence that indacaterol improves daily physical activity in patients with COPD.