Cypress pollen allergy is responsible for two distinct phenotypes of allergic rhinitis different from other pollinosis.

Summary: Different phenotypes of allergic rhinitis have been identified based on the seasonality of the allergen involved. Within pollinosis, importance has to be paid to the responsible pollen species. Guidelines for clinical management are mostly based on studies performed in patients with grass pollen allergy. Only few data is available on tree pollen allergy and more specifically on cypress pollen allergy. We focused on the clinical and biological features of cypress pollen allergy to determine whether it is associated with a specific phenotype of allergic rhinitis or not. Our results suggest that cypress pollen can be responsible for two distinct phenotypes of rhinitis, both different from other pollinosis. In the most common phenotype, cypress pollen was not responsible for bronchial hyperresponsiveness or systemic inflammation. Close attention has to be paid to the allergen involved in allergic rhinitis. Different phenotypes leading to different pharmacological strategies may apply.

Comparison of anti-interleukin-5 therapies in patients with severe asthma: global and indirect meta-analyses of randomized placebo-controlled trials.

Inconsistent results have been reported regarding IL-5 blockade treatment in asthma. There were no direct between-treatment comparisons. Only differences between each drug and placebo were studied. We identified all RCTs with anti-IL5 treatments for patients with asthma over the 1990-September 2015 period. RCTs were searched on Medline, Cochrane and Embase. At least 50 patients were enrolled in each study. Outcomes considered were exacerbation rate reduction, FEV1 changes, ACQ-5 improvement, adverse events and serious adverse events. A global meta-analysis was first conducted followed by an indirect comparison of each IL-5-targeting drug: benralizumab, reslizumab and mepolizumab. Further eosinophilic subgroup analysis and sensitivity analysis were also conducted in case of heterogeneity. Ten trials involving 3421 patients were eligible for meta-analysis. IL-5 blockade significantly reduced annual exacerbation rates vs. placebo by 40% [29-50] (P < 0.01, I2 = 0.61). ACQ-5 was significantly improved vs. placebo but below the recognized MCID level (-0.31 [-0.41, -0.21], P < 0.01, I2 = 0.11). FEV1 changes from baseline were improved vs. placebo by 0.09 L [0.05-0.12] (P < 0.01, I2 = 0.28). The subgroup analysis identified a slight additional improvement in mean treatment effects in eosinophilic (> 300 mm3 /L) patients with severe asthma. Similar patterns and rates of adverse events and severe adverse events were reported with the three drugs. The data interpretations were not affected by the sensitivity analysis. IL-5 blockade appears to be a relevant treatment strategy to improve severe asthma management, particularly for eosinophilic patients. No clear superiority appeared between the drugs when appropriate doses were compared.

Asthma-COPD overlap syndrome (ACOS) vs 'pure' COPD: a distinct phenotype?

BACKGROUND: Some studies suggest that asthma-COPD overlap syndrome (ACOS) is associated with worse outcomes than chronic obstructive pulmonary disease (COPD). The goal of this study was to further explore the clinical characteristics and survival of patients with ACOS identified in a real-life cohort of patients with COPD. METHODS: Data from the French COPD cohort 'INITIATIVES BronchoPneumopathie Chronique Obstructive' (n = 998 patients) were analyzed to assess the frequency of ACOS defined as a physician diagnosis of asthma before the age of 40 years and to analyze its impact. Univariate analyses were performed to assess the relationship between ACOS and sociodemographic characteristics, risk factors (smoking, occupational exposure, atopic diseases), symptoms (chronic bronchitis, dyspnea-modified Medical Research Council scale and baseline dyspnea index), quality of life (QoL), mood disorders, exacerbations, comorbidities, lung function, prescribed treatment, and survival. RESULTS: ACOS was diagnosed in 129 patients (13%). In multivariate analyses, ACOS was associated negatively with cumulative smoking (odds ratio [OR]: 0.992; 95% CI 0.984-1.000 per pack-year) and positively with obesity: OR: 1.97 [1.22-3.16], history of atopic disease (hay fever: OR: 5.50 [3.42-9.00] and atopic dermatitis: OR 3.76 [2.14-6.61]), and drug use (LABA + ICS: 1.86 [1.27-2.74], antileukotrienes 4.83 [1.63-14.34], theophylline: 2.46 [1.23-4.91], and oral corticosteroids: [2.99;.1.26-7.08]). No independent association was found with dyspnea, QoL, exacerbations, and mortality. CONCLUSIONS: Compared to 'pure' COPD patients, patients with ACOS exhibit lower cumulative smoking, suffer more from obesity and atopic diseases, and use more asthma treatments. Disease severity (dyspnea, QoL, exacerbations, comorbidities) and prognosis (mortality) are not different from 'pure' COPD patients.

Longitudinal stability of asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study.

BACKGROUND: Asthma is a biologically heterogeneous disease and development of novel therapeutics requires understanding of pathophysiologic phenotypes. There is uncertainty regarding the stability of clinical characteristics and biomarkers in asthma over time. This report presents the longitudinal stability over 12 months of clinical characteristics and clinically accessible biomarkers from ADEPT. METHODS: Mild, moderate, and severe asthma subjects were assessed at 5 visits over 12 months. Assessments included patient questionnaires, spirometry, bronchodilator reversibility, fractional exhaled nitric oxide (FENO), and biomarkers measured in induced sputum. RESULTS: Mild (n = 52), moderate (n = 55), and severe (n = 51) asthma cohorts were enrolled from North America and Western Europe. For all clinical characteristics and biomarkers, group mean data showed no significant change from visit to visit. However, individual data showed considerable variability. FEV1/FVC ratio showed excellent reproducibility while pre-bronchodilator FEV1 and FVC were only moderately reproducible. Of note bronchodilator FEV1 reversibility showed low reproducibility, with the nonreversible phenotype much more reproducible than the reversible phenotype. The 7-item asthma control questionnaire (ACQ7) demonstrated moderate reproducibility for the combined asthma cohorts, but the uncontrolled asthma phenotype (ACQ7 > 1.5) was inconstant in mild and moderate asthma but stable in severe asthma. FENO demonstrated good reproducibility, with the FENO-low phenotype (FENO < 35 ppb) more stable than the FENO-high phenotype (FENO ≥ 35 ppb). Induced sputum inflammatory phenotypes showed marked variability across the 3 sputum samples taken over 6 months. CONCLUSIONS: The ADEPT cohort showed group stability, individual stability in some parameters e.g. low FEV1/FVC ratio, and low FENO, but marked individual variability in other clinical characteristics and biomarkers e.g. type-2 biomarkers over 12 months. This variability is possibly related to seasonal variations in climate and allergen exposure, medication changes and acute exacerbations. The implications for patient selection strategies based on clinical biomarkers may be considerable.

Prevalence and reversibility of lung hyperinflation in adult asthmatics with poorly controlled disease or significant dyspnea.

BACKGROUND: In asthma, inflammation affects both the proximal and distal airways and may induce significant hyperinflation (HI). This study sought to evaluate the prevalence of HI in asthmatic patients with poorly controlled disease and/or dyspnea. METHODS: Poor asthma control was defined by an Asthma Control Test (ACT) score <20 (n = 287), and dyspnea was defined as a modified Medical Research Council score ≥1 (n = 18). HI was defined as either a residual volume/total lung capacity (RV/TLC) above the upper limit of normal (RV-HI) or a functional residual capacity (FRC) >120% predicted (FRC-HI). HI reversibility after administration of salbutamol (400 µg) was defined as a decrease in RV >20% or a reduction in FRC >10%. Changes in dyspnea and chest tightness were evaluated on a visual analogue scale. RESULTS: Both RV-HI and FRC-HI were observed in 48% of the 305 patients (mean ± SD age: 49 ± 17; FEV1 : 75 ± 18% predicted) included in the study. The prevalence of HI was higher in patients with a FEV1 <60% predicted (93% for RV-HI and 71% for FRC-HI, vs 21% and 41% in patients with a FEV1 > 80%). In patients with HI, the ACT score was lower and chest tightness higher. HI reversibility was obtained in 38% of the asthmatics with FRC-HI and 29% of the asthmatics with RV-HI, whereas FEV1 reversibility was obtained in half of these patients. CONCLUSIONS: HI is highly prevalent in poorly controlled asthmatics suggesting small airway dysfunction and may represent an additional criteria for evaluating responsiveness to bronchodilators.

Asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) longitudinal profiling study.

BACKGROUND: Asthma is a heterogeneous disease and development of novel therapeutics requires an understanding of pathophysiologic phenotypes. The purpose of the ADEPT study was to correlate clinical features and biomarkers with molecular characteristics, by profiling asthma (NCT01274507). This report presents for the first time the study design, and characteristics of the recruited subjects. METHODS: Patients with a range of asthma severity and healthy non-atopic controls were enrolled. The asthmatic subjects were followed for 12 months. Assessments included history, patient questionnaires, spirometry, airway hyper-responsiveness to methacholine, fractional exhaled nitric oxide (FENO), and biomarkers measured in induced sputum, blood, and bronchoscopy samples. All subjects underwent sputum induction and 30 subjects/cohort had bronchoscopy. RESULTS: Mild (n = 52), moderate (n = 55), severe (n = 51) asthma cohorts and 30 healthy controls were enrolled from North America and Western Europe. Airflow obstruction, bronchodilator response and airways hyperresponsiveness increased with asthma severity, and severe asthma subjects had reduced forced vital capacity. Asthma control questionnaire-7 (ACQ7) scores worsened with asthma severity. In the asthmatics, mean values for all clinical and biomarker characteristics were stable over 12 months although individual variability was evident. FENO and blood eosinophils did not differ by asthma severity. Induced sputum eosinophils but not neutrophils were lower in mild compared to the moderate and severe asthma cohorts. CONCLUSIONS: The ADEPT study successfully enrolled asthmatics across a spectrum of severity and non-atopic controls. Clinical characteristics were related to asthma severity and in general asthma characteristics e.g. lung function, were stable over 12 months. Use of the ADEPT data should prove useful in defining biological phenotypes to facilitate personalized therapeutic approaches.

Frequent exacerbators--a distinct phenotype of severe asthma.

BACKGROUND: Exacerbations represent a major source of morbidity and mortality in asthma and are a prominent feature of poorly controlled, difficult-to-treat disease. OBJECTIVE: The goal of our study was to provide a detailed characterization of the frequent exacerbator phenotype and to identify risk factors associated with frequent and seasonal exacerbations. METHODS: Ninety-three severe asthmatics (SA) and 76 mild-to-moderate patients (MA) were screened and prospectively followed up for 1 year (NCT00555607). Medical history, baseline clinical data and biomarkers were used to assess risk factors for frequent exacerbations. RESULTS: During the study, 104 exacerbations were recorded in the SA group and 18 in the MA. Frequent exacerbators were characterized by use of higher doses of inhaled (1700 vs. 800 µg) and oral (6.7 vs. 1.7 mg) glucocorticosteroids, worse asthma control (ACQ score 2.3 vs. 1.4), lower quality of life (SGRQ score 48.5 vs. 33.3), higher sputum eosinophils (25.7% vs. 8.2%) and a more rapid decline in FEV1 /FVC ratio (-0.07 vs. -0.01 ΔFEV1 /FVC, frequent vs. non-frequent, respectively, P < 0.05). Exhaled NO > 45 p.p.b. and a history of smoking were associated with an increased risk of frequent exacerbations (odds ratios: 4.32 and 2.90 respectively). CONCLUSION AND CLINICAL RELEVANCE: We were able to distinguish and characterize a subphenotype of asthma subjects--frequent exacerbators--who are significantly more prone to exacerbations. Patients with FeNO > 45 p.p.b. and a history of smoking are at increased risk of frequent exacerbations and require careful monitoring in clinical practice.

Myeloid dendritic cells are primed in allergic asthma for thymic stromal lymphopoietin-mediated induction of Th2 and Th9 responses.

BACKGROUND: Type 1 myeloid dendritic cells (mDCs) contribute to inception of allergic asthma (AA) and are regulated by epithelial-derived cytokines. OBJECTIVES: To evaluate whether mDCs from AA patients are primed for thymic stromal lymphopoietin (TSLP)-driven responses. METHODS: mDCs from 18 AA patients and 15 controls were purified using immunomagnetic sorting. Cells were pulsed with TSLP or Dermatophagoides pteronyssinus (Der p) allergen, before FACS phenotyping and co-culture with allogeneic CD4+ T cells. Bronchial biopsies from 15 AA patients and four controls were immunostained for CD1c and TSLP receptor (TSLPR). RESULTS: Allergic asthma patients had a higher proportion of TSLPR+ mDCs, in blood and bronchial mucosa. When compared to mDCs from controls, both TSLP- and Der p-pulsed blood mDCs from AA patients induced increased polarization of CD4+ T cells into Th2 cells (IL-5, IL-13, and GATA3+), while only TSLP-mDCs promoted Th9 cells (IL-9 and PU.1+ /IRF4+). In addition, OX40L was induced upon TSLP stimulation and was required for the induction of Th2, but not Th9, cells. In contrast, development of Th9 cells in this model depended on TGF-ß1. CONCLUSIONS: Our data indicate overlapping but partially distinct effects of TSLP and Der p allergen pathways, showing that DCs are primed in human asthma for TSLP-driven induction of both Th2 and Th9 cells. This novel TSLP/mDC/Th9 axis operates through a distinct, OX40L-independent pathway. These data further highlight the TSLP pathway as a relevant target in human asthma.

Stability of phenotypes defined by physiological variables and biomarkers in adults with asthma.

BACKGROUND: Although asthma is characterized by variable airways obstruction, most studies of asthma phenotypes are cross-sectional. The stability of phenotypes defined either by biomarkers or by physiological variables was assessed by repeated measures over 1 year in the Pan-European BIOAIR cohort of adult asthmatics. METHODS: A total of 169 patients, 93 with severe asthma (SA) and 76 with mild-to-moderate asthma (MA), were examined at six or more visits during 1 year. Asthma phenotype clusters were defined by physiological variables (lung function, reversibility and age of onset of the disease) or by biomarkers (eosinophils and neutrophils in induced sputum). RESULTS: After 1 year of follow-up, the allocation to clusters was changed in 23.6% of all asthma patients when defined by physiological phenotypes and, remarkably, in 42.3% of the patients when stratified according to sputum cellularity (P = 0.034). In the SA cohort, 30% and 48.6% of the patients changed allocation according to physiological and biomarker clustering, respectively. Variability of phenotypes was not influenced by change in oral or inhaled corticosteroid dose, nor by the number of exacerbations. Lower stability of single and repeated measure was found for all evaluated biomarkers (eosinophils, neutrophils and FeNO) in contrast to good stability of physiological variables (FEV1 ), quality of life and asthma control. CONCLUSION: Phenotypes determined by biomarkers are less stable than those defined by physiological variables, especially in severe asthmatics. The data also imply that definition of asthma phenotypes is improved by repeated measures to account for fluctuations in lung function, biomarkers and asthma control.

[Modeling T2 high severe asthma using human induced pluripotent stem cells (hiPSC)]. / Modélisation de l'asthme sévère par la technologie des cellules humaines souches pluripotentes induites (hiPSC).

Severe asthma patients with persistent airflow obstruction are characterized by functional obstruction due to mucus plugs containing mucins, fibrin, and eosinophil derived Charcot- Leyden crystals. The molecular mechanisms underlying this endotype are not clearly understood. Developing new models is crucial to respiratory research insofar as critical differences exist between human and rodent airway epithelium. We (and other teams) have shown that it is possible to reconstitute in vitro a complex and functional airway epithelium displaying all the features described in vivo from human-induced pluripotent stem cells (hiPSC). Our aim is to establish a human in vitro model of severe asthma that will recapitulate airway epithelium remodeling and mucus plugs.

Role of comorbid conditions in asthma hospitalizations in the south of France.

BACKGROUND: Reasons for asthma hospitalizations are dynamic and complex. Comorbid conditions are important contributors to most chronic diseases today. We aim to characterize and describe risk factors associated with hospitalizations due to asthma in the Languedoc-Roussillon region (France) in 2009. METHODS: Programme de Médicalisation des Systèmes d'Information (PMSI) data records from 2009 were sorted using selected International Classification of Diseases (ICD10) codes eliciting three groups of asthma hospitalizations according to acute severity. All available data including demographics, comorbid conditions, past hospitalizations either related or unrelated to asthma, seasonality and distance to medical facilities were used to compare the subjects within the three groups. RESULTS: One thousand two hundred and eighty-nine hospitalizations due to asthma exacerbation were found, concerning 1122 patients. We observed significant differences within the groups, using univariate analysis, concerning duration of hospitalizations (mean ± SD, 4.9 ± 5.9 days vs 6.4 ± 6.8 vs 15.8 ± 16.8, P < 0.001), deaths (percentage, 0.03% vs 1.50% vs 9.20%, P < 0.001) and numbers of comorbid conditions (0.80 ± 0.95 vs 0.75 ± 0.97 vs 1.74 ± 1.36, P < 0.001). Recurrent admissions for asthma during the period 2006-2008 were significantly more frequent in the more severe group (1.93 ± 3.91 vs 2.56 ± 4.47 vs 2.81 ± 3.97, P = 0.006). In the multivariate model, age and number of comorbid conditions were independently associated with severe hospitalizations and deaths. CONCLUSIONS: Asthma hospitalizations can be appropriately assessed using PMSI coding databases. In this study, age and the presence of comorbid conditions are the major risk factors for asthma hospitalizations and deaths.

The role of transforming growth factor-ß1 in airway inflammation of childhood asthma.

TGF-beta-targeting structural and inflammatory cells has been implicated in the mechanisms leading to the inflammatory and restructuring processes in asthma, suggesting an impact of TGF-beta1 signaling on the development and persistency of this disease. We investigated the potential early involvement of TGF-beta1 activity in the immunological and molecular mechanisms underlying progression of inflammation in childhood asthma. We evaluated the levels of TGF-beta1 in induced sputum supernatants (ISSs) and the expression of small mother cell against decapentaplegic (Smad) 2 and Smad7 proteins in induced sputum cells (ISCs) from children with intermittent asthma (IA), moderate asthma (MA) and control subjects (C). Furthermore, we investigated the regulatory role of TGF-beta1 activity on eosinophil and neutrophil adhesion to epithelial cells using adhesion assay, and on the granulocyte expression of adhesion molecule CD11b/CD18 Macrophage-1 antigen (MAC-1), by flow cytometry. We found that the levels of TGF-beta1 are increased in ISSs of IA and MA in comparison to C, concomitantly to the activation of intracellular signaling TGFbeta/Smads pathway in ISCs. In MA, TGF-beta1 levels correlated with the number of sputum eosinophils and neutrophils. Furthermore, we showed the ability of sputum TGF-beta1 to promote eosinophil and neutrophil adhesion to epithelial cells, and to increase the expression of MAC-1 on the granulocyte surface. This study shows the activation of TGFbeta/Smad signaling pathway in the airways of children with IA and, despite the regular ICS treatment, in children with MA, and provides evidence for the contribution of TGF-beta1 in the regulation of granulocyte activation and trafficking.

Adherence in severe asthma.

Adherence in asthma is an important cause for concern. Although nearly 50% of asthma patients are considered poorly adherent to therapeutic advices, adherence is still difficult to assess, understand and improve despite major medical consequences. In this review, we revisited the literature of the last 10 years related to adherence in severe asthma. The concepts have changed and "compliance" is usually replaced by "adherence". Assessment of adherence is addressing ethical issues, but provides important insight into difficult-to-treat asthma. Different tools have been used but none is routinely recommended. Health-related outcomes (poor control, exacerbations, hospitalizations, lung function decline), which are clearly associated with severe asthma, are often worsened by non-adherence with consequences also on patient related outcomes (quality of life). The potential behaviour associated with non-adherence and all other related factors including easy-to-recognize psychological traits can help for patient's future management. Therapeutic educational interventions have been recognized with a scientifically proven efficiency even though evolution and improvements are needed. A multidisciplinary approach is required in severe asthma. Therapeutic adherence for a given patient is always a prerequisite to any other aspects when addressing severe asthma phenotypes. Severe asthma should be considered only in those who still experienced poor asthma outcomes despite optimal adherence. At a glance, poor adherence and severe asthma should be considered antinomic. Better understanding of the causes and customised management are potential future directions.

Safety and efficacy of a CXCR2 antagonist in patients with severe asthma and sputum neutrophils: a randomized, placebo-controlled clinical trial.

BACKGROUND: Increased numbers of neutrophils are reported in the airways of patients with severe asthma. It is not clear if they contribute to the lack of control and severity. There are currently no strategies to investigate this by decreasing neutrophil numbers in the airways. OBJECTIVE: To investigate the safety and efficacy of SCH527123, a selective CXCR2 receptor antagonist, in patients with severe asthma and increased number of neutrophils in sputum. METHODS: In a randomized, double-blind, parallel study, patients with severe asthma and sputum total cell count < 10 × 10(6) /g and neutrophils > 40% were randomized to SCH527123, 30 mg daily PO (n = 22) or placebo (n = 12) for 4 weeks. Primary end-points were safety and change in sputum and blood neutrophil counts. Secondary end-points were change in asthma control questionnaire (ACQ) score, minor and major exacerbations, spirometry and sputum neutrophil activation markers. RESULTS: The SCH 527123 caused a mean reduction of 36.3% in sputum neutrophil percentage compared to a 6.7% increase in the placebo arm (P = 0.03). The mean absolute neutrophil count in blood was reduced by 14% at the end of 4 weeks, but recovered by the 5th week. There were no differences in the overall rates of adverse events among the groups. There were fewer mild exacerbations (1.3 vs. 2.25, P = 0.05) and a trend towards improvement in the ACQ score (mean difference between groups of 0.42 points, P = 0.053). No statistically significant changes were observed in forced expiratory volume in 1 s (FEV (1)), sputum myeloperoxidase, IL8 or elastase. CONCLUSIONS: The SCH527123 is safe and reduces sputum neutrophils in patients with severe asthma. CLINICAL RELEVANCE: This new treatment provides an opportunity to investigate the role of neutrophils in severe asthma with potential clinical benefits. Larger studies of longer duration are needed to evaluate the impact on other outcomes of asthma including exacerbations.

Efficacy and safety of etanercept in moderate-to-severe asthma: a randomised, controlled trial.

Increased tumour necrosis factor-α levels have been observed in bronchial biopsies and induced sputum from subjects with severe asthma. We investigated etanercept (ETN) as a therapeutic option for treating moderate-to-severe persistent asthma. In this 12-week, randomised, double-blind, placebo-controlled, phase 2 trial, subjects (n=132) with moderate-to-severe persistent asthma received subcutaneous injections of 25 mg ETN or placebo twice weekly, and were evaluated at baseline, and at weeks 2, 4, 8 and 12. The primary end-point was the change from baseline to week 12 in pre-bronchodilator forced expiratory volume in 1 s (FEV1)% predicted. Secondary end-points included morning peak expiratory flow, FEV1% pred, Asthma Control Questionnaire (5-item version), asthma exacerbations, provocative concentration of methacholine causing a 20% decrease in FEV1, and the Asthma Quality of Life Questionnaire. No significant differences were observed between ETN and placebo for any of the efficacy end-points. ETN treatment was well tolerated, with no unexpected safety findings observed during the study. Clinical efficacy of ETN was not shown in subjects with moderate-to-severe persistent asthma over 12 weeks. However, ETN treatment was a well-tolerated therapy. Studies in specific subsets of patients with asthma with longer-term follow-up may be needed to fully evaluate the clinical efficacy of ETN in this population.

Viruses and bacteria in acute asthma exacerbations--a GA² LEN-DARE systematic review.

A major part of the burden of asthma is caused by acute exacerbations. Exacerbations have been strongly and consistently associated with respiratory infections. Respiratory viruses and bacteria are therefore possible treatment targets. To have a reasonable estimate of the burden of disease induced by such infectious agents on asthmatic patients, it is necessary to understand their nature and be able to identify them in clinical samples by employing accurate and sensitive methodologies. This systematic review summarizes current knowledge and developments in infection epidemiology of acute asthma in children and adults, describing the known impact for each individual agent and highlighting knowledge gaps. Among infectious agents, human rhinoviruses are the most prevalent in regard to asthma exacerbations. The newly identified type-C rhinoviruses may prove to be particularly relevant. Respiratory syncytial virus and metapneumovirus are important in infants, while influenza viruses seem to induce severe exacerbations mostly in adults. Other agents are relatively less or not clearly associated. Mycoplasma and Chlamydophila pneumoniae seem to be involved more with asthma persistence rather than with disease exacerbations. Recent data suggest that common bacteria may also be involved, but this should be confirmed. Although current information is considerable, improvements in detection methodologies, as well as the wide variation in respect to location, time and populations, underline the need for additional studies that should also take into account interacting factors.

5(S),15(S)-dihydroxyeicosatetraenoic acid and lipoxin generation in human polymorphonuclear cells: dual specificity of 5-lipoxygenase towards endogenous and exogenous precursors.

5-Lipoxygenase activation of human blood polymorphonuclear cells (PMN) from asthmatic patients (asthmatics) was studied to investigate whether differences may exist with healthy subjects (controls). The respective cell capacities to produce lipoxins (LXs), leukotrienes, and 5(S), 15(S)-dihydroxyeicosatetraenoic acid [5(S),15(S)-diHETE] were compared under in vitro stimulation by ionophore A23187, with or without exogenous 15(S)-hydroxyeicosatetraenoic acid [15(S)-diHETE]. Eicosanoids were analyzed by elution with an isocratic reverse-phase high performance liquid chromatography system, and their profiles, detected by simultaneous monitoring at 302, 280, and 246 nm, were evaluated on the basis of chromatographic behavior: UV spectral characteristics and coelution with synthetic standards. In the presence of exogenous 15(S)-HETE, human PMN were able to produce LXs and 5(S),15(S)-diHETE, PMN from asthmatics were able to produce 5(S), 5(S),15(S)-diHETE, and LXs from endogenous sources, whereas in the same experimental conditions, no detectable amounts of these compounds were released by PMN from controls. The levels of 5(S),15(S)-diHETE, and LXs biosynthesized from endogenous arachidonic acid were highly correlated. Two different LX patterns were observed involving two possible metabolic pathways: (a) via the intermediate 5,6-epoxytetraene alone for LXs generation from exogenous 15(S)-HETE; and (b) via 5,6- and/or 14,15-epoxytetraenes leading to the formation of an enzyme-bound delocalized carbocation for LXs generation from endogenous arachidonate, respectively. The enhanced 5-lipoxygenase activation of blood PMN from asthmatics and the metabolism of exogenous 15(S)-HETE may reflect a priming induced by various mediators released from environmental cells, and could be considered as a model of transcellular signalization between PMN and endothelial cells.

Clinical COPD phenotypes: a novel approach using principal component and cluster analyses.

Classification of chronic obstructive pulmonary disease (COPD) is usually based on the severity of airflow limitation, which may not reflect phenotypic heterogeneity. Here, we sought to identify COPD phenotypes using multiple clinical variables. COPD subjects recruited in a French multicentre cohort were characterised using a standardised process. Principal component analysis (PCA) was performed using eight variables selected for their relevance to COPD: age, cumulative smoking, forced expiratory volume in 1 s (FEV(1)) (% predicted), body mass index, exacerbations, dyspnoea (modified Medical Research Council scale), health status (St George's Respiratory Questionnaire) and depressive symptoms (hospital anxiety and depression scale). Patient classification was performed using cluster analysis based on PCA-transformed data. 322 COPD subjects were analysed: 77% were male; median (interquartile range) age was 65.0 (58.0-73.0) yrs; FEV(1) was 48.9 (34.1-66.3)% pred; and 21, 135, 107 and 59 subjects were classified in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1, 2, 3 and 4, respectively. PCA showed that three independent components accounted for 61% of variance. PCA-based cluster analysis resulted in the classification of subjects into four clinical phenotypes that could not be identified using GOLD classification. Importantly, subjects with comparable airflow limitation (FEV(1)) belonged to different phenotypes and had marked differences in age, symptoms, comorbidities and predicted mortality. These analyses underscore the need for novel multidimensional COPD classification for improving patient care and quality of clinical trials.

Mast cell adhesion to bronchial smooth muscle in asthma specifically depends on CD51 and CD44 variant 6.

BACKGROUND: Mast cells infiltrate the bronchial smooth muscle (BSM) in asthmatic patients, but the mechanism of mast cell adhesion is still unknown. The adhesion molecules CD44 (i.e. hyaluronate receptor) and CD51 (i.e. vitronectin receptor) are widely expressed and bind to many extracellular matrix (ECM) proteins. The aims of the study are (i) to identify the role of ECM in mast cell adhesion to BSM and (ii) to examine the role of CD51 and CD44 in this adhesion. METHODS: Human lung mast cells, human mast cell line (HMC-1), and BSM cells from control donors or asthmatic patients were cultured in the presence/absence of various cytokines. Mast cell-BSM interaction was assessed using (3)H-thymidine-pulsed mast cells, confocal immunofluorescence, or electron microscopy. Adhesion molecules expression and collagen production on both cell types were evaluated by quantitative RT-PCR, western blot, and flow cytometry. RESULTS: Mast cell adhesion to BSM cells mostly involved type I collagen of the ECM. Such an adhesion was increased in normal BSM cells under inflammatory condition, whereas it was maximal in asthmatic BSM cells. Blockade of either CD51 or CD44 significantly decreased mast cell adhesion to BSM. At the molecular level, protein and the transcriptional expression of type I collagen, CD51 or CD44 remained unchanged in asthmatic BSM cells or in mast cells/BSM cells under inflammatory conditions, whereas that of CD44 variant isoform 6 (v6) was increased. CONCLUSIONS: Mast cell-BSM cell adhesion involved collagen, CD44, and CD51, particularly under inflammatory conditions. CD44v6 expression is increased in asthmatic BSM cells.