Enabling Adults With Severe Asthma to Exercise: A Qualitative Examination of the Challenges for Patients and Health Care Professionals

BACKGROUND

Adults living with severe asthma have lower physical activity levels, particularly high-intensity physical activity, compared with their healthy peers. Physical inactivity is associated with increased morbidity and mortality.

OBJECTIVE

To understand patient and health care professional attitudes toward exercise and physical activity to inform future strategies for the improvement of healthy lifestyle behaviors, including exercise.

METHODS

Participants recruited from a specialist difficult asthma service were interviewed individually, and health care professionals (HCPs) from primary care, secondary care, and a tertiary center were invited to attend focus groups. Interviews and focus groups were transcribed verbatim. We performed thematic analysis on interviews and focus groups separately, followed by an adapted framework analysis to analyze datasets together.

RESULTS

Twenty-nine people with severe asthma participated in a semi-structured interview. A total of 51 HCPs took part in eight focus groups across the East Midlands, United Kingdom. Final analysis resulted in three major themes: barriers to exercise and exercise counseling - in which patients and HCPs identified disease and non-disease factors affecting those living with severe asthma; attitudes toward HCP support for exercise - highlighting education needs for HCPs and preference for supervised exercise programs; and areas for system improvement in supporting patients and HCPs - challenges exist across health sectors that limit patient support are described.

CONCLUSIONS

Patients identified the important role of HCPs in supporting and advising on lifestyle change. Despite a preference for supervised exercise programs, both patient and HCP barriers existed. To meet patients' varied support needs, improved integration of services is required and HCP skills need extending.

Understanding the measurement properties of the incremental shuttle walk test in patients with severe asthma

BACKGROUND AND OBJECTIVE

We investigated the repeatability and validity of the incremental shuttle walk test (ISWT) distance compared to peak oxygen uptake (VO_2pk ) during maximal incremental cycle ergometer (ICE) and treadmill (ITM) tests in adults with severe asthma.

METHODS

Adults with severe asthma, Medical Research Council (MRC) dyspnoea ≥2, were recruited from specialists caring for patients with severe asthma. All participants performed three ISWT (familiarization and two subsequent tests on the same day), an ICE and an ITM in a randomized order, on separate days, to intolerance with expiratory gas analysis.

RESULTS

A total of 50 patients (32 females, mean (SD), age: 54 (13) years, forced expiratory volume in 1 s (FEV₁ ): 1.9 (0.8) L and body mass index (BMI): 32 (6) kg/m² ) completed all five tests. The mean (SD) ISWT distance for each test was 400 (156), 418 (142) and 438 (157) m (P = 0.001), respectively. There was a strong correlation between the ISWT distance with VO_2pk derived from ITM (r = 0.74, P < 0.001) and ICE (r = 0.75, P < 0.001).

CONCLUSION

There was a small increase in the mean ISWT distance on sequential testing. In clinical practice, the coefficient of repeatability and heteroscedasticity need to be considered when assessing whether a true change has occurred within an individual patient. The ISWT has validity compared to VO_2pk on both ICE and ITM, but they are not interchangeable.

A qualitative study of the perspectives of key stakeholders on the delivery of clinical academic training in the East Midlands

OBJECTIVE

Major changes in the design and delivery of clinical academic training in the United Kingdom have occurred yet there has been little exploration of the perceptions of integrated clinic academic trainees or educators. We obtained the views of a range of key stakeholders involved in clinical academic training in the East Midlands.

DESIGN

A qualitative study with inductive iterative thematic content analysis of findings from trainee surveys and facilitated focus groups.

SETTING

The East Midlands School of Clinical Academic Training.

PARTICIPANTS

Integrated Clinical Academic Trainees, clinical and academic educators involved in clinical academic training.

MAIN OUTCOME MEASURES

The experience, opinions and beliefs of key stakeholders about barriers and enablers in the delivery of clinical academic training.

RESULTS

We identified key themes many shared by both trainees and educators. These highlighted issues in the systems and process of the integrated academic pathways, career pathways, supervision and support, the assessment process and the balance between clinical and academic training.

CONCLUSIONS

Our findings help inform the future development of integrated academic training programmes.

Survival following pulmonary rehabilitation in patients with COPD: the effect of program completion and change in incremental shuttle walking test distance

Rationale

Pulmonary rehabilitation (PR) in patients with COPD has consistently been shown to produce benefits in exercise capacity, symptoms, and health status. The data surrounding survival following PR are less clear. Our aims were to compare the long-term survival in two cohorts of patients referred for PR; those who successfully completed PR, and a comparator group constructed from patients who either did not complete PR or did not start the program. Additionally, we compared survival between those people who were able to achieve a clinically meaningful improvement in exercise capacity (incremental shuttle walking test) following PR with those who were not.

Methods

A retrospective longitudinal analysis of clinical service outcomes was conducted to compare the long-term survival in "completers" and "non-completers" of rehabilitation at two hospitals within the University Hospitals of Leicester NHS Trust from January 1, 2000 to February 23, 2012. For "completers", we also analyzed survival in those meeting (and not meeting) the desired level of change in the incremental shuttle walking test (≥50 m vs <50 m).

Results

We present to you the largest dataset on this topic (n=1,515). Survival data were ascertained for 823 (54.3%) patients with COPD who had completed a course of PR and for 692 (45.7%) patients who dropped out. Survival time was significantly greater in "completers" compared to "non-completers" of PR (p<0.001). In addition, PR success (≥50 m change in walking distance) was also associated with improved survival (p<0.05).

Conclusion

The data show an association between completion of PR and survival. In addition, PR success (>50 m change in walking distance) was also associated with improved survival.

The role of oral methotrexate as a steroid sparing agent in refractory eosinophilic asthma

The use of oral methotrexate for refractory eosinophilic asthma in a tertiary asthma referral centre, Glenfield Hospital, Leicester, was evaluated between January 2006 and December 2014. The patients (n = 61) were carefully phenotyped at baseline with markers of airway inflammation. In addition, a structured oral methotrexate proforma was utilized to evaluate response to therapy and adverse events. Oral steroid withdrawal was attempted 3 months after commencing treatment. Several outcomes were evaluated at 12 months, including both efficacy and adverse effects; 15% (n = 9/61) responded by achieving a decrease in daily oral corticosteroid dose (mean 8.43 (±8.76) mg), although we were unable to identify factors that predicted a treatment response. There were no other significant changes in any other clinical outcome measures. There was a high rate of adverse events (19/61 (31%)), primarily gastrointestinal/hepatitis. Our findings support the use of biological agents in preference to using oral methotrexate as a steroid sparing agent at the first instance. In the event of failure of these agents, oral methotrexate remains a therapeutic option, which can be considered in highly specialist severe asthma centres.

Asthma in adults (acute): magnesium sulfate treatment

INTRODUCTION

About 10% of adults have suffered an attack of asthma, and up to 5% of these have severe disease that responds poorly to treatment. Patients with severe disease have an increased risk of death, but patients with mild to moderate disease are also at risk of exacerbations. Most guidelines about the management of asthma follow stepwise protocols. This overview does not endorse or follow any particular protocol, but presents the evidence about a specific intervention, magnesium sulfate.

METHODS AND OUTCOMES

We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of magnesium sulfate for acute asthma? We searched: Medline, Embase, The Cochrane Library, and other important databases up to November 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview).

RESULTS

At this update, searching of electronic databases retrieved 50 studies. After deduplication and removal of conference abstracts, 24 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 10 studies and the further review of 14 full publications. Of the 14 full articles evaluated, one systematic review was updated and one systematic review was added at this update. We performed a GRADE evaluation for five PICO combinations.

CONCLUSIONS

In this systematic overview, we categorised the efficacy for two comparisons based on information about the effectiveness and safety of magnesium sulfate (iv) versus placebo and magnesium sulfate (nebulised) plus short-acting beta2 agonists (inhaled) versus short-acting beta2 agonists (inhaled) alone.

Effectiveness of voriconazole in the treatment of Aspergillus fumigatus-associated asthma (EVITA3 study)

BACKGROUND

IgE sensitization to Aspergillus fumigatus and a positive sputum fungal culture result are common in patients with refractory asthma. It is not clear whether these patients would benefit from antifungal treatment.

OBJECTIVES

We sought to determine whether a 3-month course of voriconazole improved asthma-related outcomes in patients with asthma who are IgE sensitized to A fumigatus.

METHODS

Asthmatic patients who were IgE sensitized to A fumigatus with a history of at least 2 severe exacerbations in the previous 12 months were treated for 3 months with 200 mg of voriconazole twice daily, followed by observation for 9 months, in a double-blind, placebo-controlled, randomized design. Primary outcomes were improvement in quality of life at the end of the treatment period and a reduction in the number of severe exacerbations over the 12 months of the study.

RESULTS

Sixty-five patients were randomized. Fifty-nine patients started treatment (32 receiving voriconazole and 27 receiving placebo) and were included in an intention-to-treat analysis. Fifty-six patients took the full 3 months of medication. Between the voriconazole and placebo groups, there were no significant differences in the number of severe exacerbations (1.16 vs 1.41 per patient per year, respectively; mean difference, 0.25; 95% CI, 0.19-0.31), quality of life (change in Asthma Quality of Life Questionnaire score, 0.68 vs 0.88; mean difference between groups, 0.2; 95% CI, -0.05 to -0.11), or any of our secondary outcome measures.

CONCLUSION

We were unable to show a beneficial effect of 3 months of treatment with voriconazole in patients with moderate-to-severe asthma who were IgE sensitized to A fumigatus on either the rate of severe exacerbations, quality of life, or other markers of asthma control.

Isolation of filamentous fungi from sputum in asthma is associated with reduced post-bronchodilator FEV1

Background

Fungal sensitization is common in severe asthma, but the clinical relevance of this and the relationship with airway colonization by fungi remain unclear. The range of fungi that may colonize the airways in asthma is unknown.

Objective

To provide a comprehensive analysis on the range of filamentous fungi isolated in sputum from people with asthma and report the relationship with their clinico-immunological features of their disease.

Methods

We recruited 126 subjects with a diagnosis of asthma, 94% with moderate-severe disease, and 18 healthy volunteers. At a single stable visit, subjects underwent spirometry; sputum fungal culture and a sputum cell differential count; skin prick testing to both common aeroallergens and an extended fungal panel; specific IgE to Aspergillus fumigatus. Fungi were identified by morphology and species identity was confirmed by sequencing. Four patients had allergic bronchopulmonary aspergillosis.

Results

Forty-eight percent of asthma subjects were IgE-sensitized to one fungal allergen and 22% to ≥ 2. Twenty-seven different taxa of filamentous fungi were isolated from 54% of their sputa, more than one species being detected in 17%. This compared with 3 (17%) healthy controls culturing any fungus (P < 0.01). Aspergillus species were most frequently cultured in isolation followed by Penicillium species. Post-bronchodilator FEV₁ (% predicted) in the subjects with asthma was 71(± 25) in those with a positive fungal culture vs. 83 (± 25) in those culture-negative, (P < 0.01).

Conclusion and Clinical Relevance

Numerous thermotolerant fungi other than A. fumigatus can be cultured from sputum of people with moderate-to-severe asthma; a positive culture is associated with an impaired post-bronchodilator FEV₁, which might be partly responsible for the development of fixed airflow obstruction in asthma. Sensitization to these fungi is also common.

The relationship between clinical outcomes and medication adherence in difficult-to-control asthma

Medication non-adherence and the clinical implications in difficult-to-control asthma were audited. Prescription issue data from 115 patients identified sub-optimal adherence (<80%) in 65% of patients on inhaled corticosteroids (ICS) or combined ICS/long-acting β2 agonist (LABA). In those using separate ICS and LABA, adherence to LABA (50%) was significantly better than to ICS (14.3%). Patients with sub-optimal ICS adherence had reduced FEV(1) and higher sputum eosinophil counts. Adherence ratio was an independent predictor of previous ventilation for acute severe asthma (p=0.008). The majority of patients with difficult-to-control asthma are non-adherent with their asthma medication. Non-adherence is correlated with poor clinical outcomes.

Does body mass index influence the outcomes of a Waking-based pulmonary rehabilitation programme in COPD?

Body mass index (BMI) is an important prognostic measure in chronic obstructive pulmonary disease (COPD). However, its effects on pulmonary rehabilitation (PR) are unknown. This study aimed to evaluate the effectiveness of a walking-based PR programme across the BMI range and the impact of BMI on exercise performance and health status. A total of 601 patients with COPD completed a PR programme. The effects of BMI on exercise capacity (incremental and endurance shuttle walk tests (ISWT and ESWT)) and health status (chronic respiratory questionnaire (CRQ)) before and after PR were evaluated. 16% of patients were underweight, with 53% overweight or obese. At baseline, the obese had worse ISWT (−54 m ± 14 m; p = 0.001) despite a higher predicted forced expiratory volume in 1 s (7.4m ± 1.6%; p < 0.001). Patients in all BMI categories made clinically important improvements in ISWT distance: BMI <21, 62 m; 21–25, 59 m; 25–30, 59 m; >30, 65 m ( p = < 0.001). All four domains of the CRQ increased above the level of clinical significance for all BMI categories (all p < 0.001). The majority of patients with COPD were overweight associated with a lower walking capacity. A walking-based PR programme was comparably effective across the BMI spectrum. Patients with COPD should be referred for standard PR, independent of BMI.

Acute exacerbations of chronic obstructive pulmonary disease: identification of biologic clusters and their biomarkers

RATIONALE

Exacerbations of chronic obstructive pulmonary disease (COPD) are heterogeneous with respect to inflammation and etiology.

OBJECTIVES

Investigate biomarker expression in COPD exacerbations to identify biologic clusters and determine biomarkers that recognize clinical COPD exacerbation phenotypes, namely those associated with bacteria, viruses, or eosinophilic airway inflammation.

METHODS

Patients with COPD were observed for 1 year at stable and exacerbation visits. Biomarkers were measured in sputum and serum. Viruses and selected bacteria were assessed in sputum by polymerase chain reaction and routine diagnostic bacterial culture. Biologic phenotypes were explored using unbiased cluster analysis and biomarkers that differentiated clinical exacerbation phenotypes were investigated.

MEASUREMENTS AND MAIN RESULTS

A total of 145 patients (101 men and 44 women) entered the study. A total of 182 exacerbations were captured from 86 patients. Four distinct biologic exacerbation clusters were identified. These were bacterial-, viral-, or eosinophilic-predominant, and a fourth associated with limited changes in the inflammatory profile termed “pauciinflammatory.” Of all exacerbations, 55%, 29%, and 28% were associated with bacteria, virus, or a sputum eosinophilia. The biomarkers that best identified these clinical phenotypes were sputum IL-1β, 0.89 (area under receiver operating characteristic curve) (95% confidence interval [CI], 0.83–0.95); serum CXCL10, 0.83 (95% CI, 0.70–0.96); and percentage peripheral eosinophils, 0.85 (95% CI, 0.78–0.93), respectively.

CONCLUSIONS

The heterogeneity of the biologic response of COPD exacerbations can be defined. Sputum IL-1β, serum CXCL10, and peripheral eosinophils are biomarkers of bacteria-, virus-, or eosinophil-associated exacerbations of COPD. Whether phenotype-specific biomarkers can be applied to direct therapy warrants further investigation.

Development of the i-BODE: validation of the incremental shuttle walking test within the BODE index

BACKGROUND

The BODE index has been shown to predict mortality in COPD. The index includes the 6 min walking test as the measure of exercise capacity. The incremental shuttle walking test (ISWT) is an alternative measure of exercise capacity which can be used to prescribe exercise and has been found to correlate well with peak VO2. The objective of the study was to evaluate the incorporation of the ISWT within the BODE index (named the i-BODE) to predict mortality in COPD.

METHODS

Data was analysed from 633 patients with COPD attending pulmonary rehabilitation over an 11 year period, and mortality determined a minimum of one year on from initial assessment. An i-BODE score was calculated using ISWT(m) then Cox regression analysis evaluated the capacity of the index to predict risk of death.

RESULTS

BMI, ISWT (m), MRC dyspnoea score, pack years and age were all significantly associated with mortality. Cox regression revealed the i-BODE index was an independent and significant predictor of mortality (hazard ratio 1.27 (CI 1.17-1.35), p < 0.001) and Kaplan Meier survival analysis showed each quartile increase in severity in i-BODE score was significantly associated with increased mortality (p < 0.001 by log rank test).

CONCLUSION

We have found the i-BODE index to be an independent predictor of mortality in COPD, even when other strong predictors such as age and pack years are adjusted for. We conclude that the ISWT can be successfully substituted for the 6MWT as an alternative measure of exercise capacity within the BODE index.

IgE sensitization to Aspergillus fumigatus is associated with reduced lung function in asthma

RATIONALE

The importance of Aspergillus fumigatus sensitization and colonization of the airways in patients with asthma is unclear.

OBJECTIVES

To define the relationship between the clinical and laboratory features of A. fumigatus-associated asthma.

METHODS

We studied 79 patients with asthma (89% classed as GINA 4 or 5) classified into 3 groups according to A. fumigatus sensitization: (1) IgE-sensitized (immediate cutaneous reactivity > 3 mm and/or IgE > 0.35 kU/L); (2) IgG-only-sensitized (IgG > 40 mg/L); and (3) nonsensitized. These were compared with 14 healthy control subjects. Sputum culture was focused toward detection of A. fumigatus and compared with clinical assessment data.

MEASUREMENTS AND MAIN RESULTS

A. fumigatus was cultured from 63% of IgE-sensitized patients with asthma (n = 40), 39% of IgG-only-sensitized patients with asthma (n = 13), 31% of nonsensitized patients with asthma (n = 26) and 7% of healthy control subjects (n = 14). Patients sensitized to A. fumigatus compared with nonsensitized patients with asthma had lower lung function (postbronchodilator FEV₁ % predicted, mean [SEM]: 68 [±5]% versus 88 [±5]%; P < 0.05), more bronchiectasis (68% versus 35%; P < 0.05), and more sputum neutrophils (median [interquartile range]: 80.9 [50.1-94.1]% versus 49.5 [21.2-71.4]%; P < 0.01). In a multilinear regression model, A. fumigatus-IgE sensitization and sputum neutrophil differential cell count were important predictors of lung function (P = 0.016), supported by culture of A. fumigatus (P = 0.046) and eosinophil differential cell count (P = 0.024).

CONCLUSIONS

A. fumigatus detection in sputum is associated with A. fumigatus-IgE sensitization, neutrophilic airway inflammation, and reduced lung function. This supports the concept that development of fixed airflow obstruction in asthma is consequent upon the damaging effects of airway colonization with A. fumigatus.

Quantitative analysis of high-resolution computed tomography scans in severe asthma subphenotypes

Background

Severe asthma is a heterogeneous condition. Airway remodelling is a feature of severe asthma and can be determined by the assessment of high-resolution computed tomography (HRCT) scans. The aim of this study was to assess whether airway remodelling is restricted to specific subphenotypes of severe asthma.

Methods

A retrospective analysis was performed of HRCT scans from subjects who had attended a single-centre severe asthma clinic between 2003 and 2008. The right upper lobe apical segmental bronchus (RB1) dimensions were measured and the clinical and sputum inflammatory characteristics associated with RB1 geometry were assessed by univariate and multivariate regression analyses. Longitudinal sputum data were available and were described as area under the time curve (AUC). Comparisons were made in RB1 geometry across subjects in four subphenotypes determined by cluster analysis, smokers and non-smokers, and subjects with and without persistent airflow obstruction.

Results

Ninety-nine subjects with severe asthma and 16 healthy controls were recruited. In the subjects with severe asthma the RB1 percentage wall area (%WA) was increased (p=0.009) and lumen area (LA)/body surface area (BSA) was decreased (p=0.008) compared with controls but was not different across the four subphenotypes. Airway geometry was not different between smokers and non-smokers and RB1 %WA was increased in those with persistent airflow obstruction. RB1 %WA in severe asthma was best associated with airflow limitation and persistent neutrophilic airway inflammation (model R²=0.27, p=0.001).

Conclusions

Airway remodelling of proximal airways occurs in severe asthma and is associated with impaired lung function and neutrophilic airway inflammation.

Tumour necrosis factor-alpha expression in tumour islets confers a survival advantage in non-small cell lung cancer

BACKGROUND

The role of TNFalpha in cancer is complex with both pro-tumourigenic and anti-tumourigenic roles proposed. We hypothesised that anatomical microlocalisation is critical for its function.

METHODS

This study used immunohistochemistry to investigate the expression of TNFalpha in the tumour islets and stroma with respect to survival in 133 patients with surgically resected NSCLC.

RESULTS

TNFalpha expression was increased in the tumour islets of patients with above median survival (AMS) compared to those with below median survival (BMS)(p = 0.006), but similar in the stroma of both groups. Increasing tumour islet TNFalpha density was a favorable independent prognostic indicator (p = 0.048) while stromal TNFalpha density was an independent predictor of reduced survival (p = 0.007). Patients with high TNFalpha expression (upper tertile) had a significantly higher 5-year survival compared to patients in the lower tertile (43% versus 22%, p = 0.01). In patients with AMS, 100% of TNFalpha+ cells were macrophages and mast cells, compared to only 28% in the islets and 50% in the stroma of BMS patients (p < 0.001).

CONCLUSIONS

The expression of TNFalpha in the tumour islets of patients with NSCLC is associated with improved survival suggesting a role in the host anti-tumour immunological response. The expression of TNFalpha by macrophages and mast cells is critical for this relationship.

FURTHER STUDIES OF THE INFECTIOUS UNIT OF VACCINIA

A study has been made of the comparative virulence of several strains of vaccine virus for a number of hosts, and wide variation in animal susceptibility has been demonstrated. The results obtained in experiments with a chick-embryo-adapted strain are interpreted as indicating that the particles of virus are of essentially uniform virulence. Results of statistical analyses are presented which indicate that as the virulence of a strain of virus increases the number of elementary bodies per infectious unit approaches 1, and at that limit the chance of infection is governed primarily by the presence or absence of virus in the inoculum. With lower virulence the chance of a lesion following inoculation of virus is still described by the binomial theorem, but the actual distribution is primarily of susceptible cells not of viral particles. It is postulated that with regard to the proportion of cells available for parasitism, differences exist between different animals of a species, and that this distribution is of a normal character.

MORPHOLOGICAL STRUCTURE OF THE VIRUS OF VACCINIA

The pictorial data obtained by means of the electron microscope indicate a remarkable regularity in the morphology of the elementary body of vaccinia. The virus particles apparently have internal structure and some sort of limiting membrane.

INHIBITION BY CERTAIN POLYSACCHARIDES OF HEMAGGLUTINATION AND OF MULTIPLICATION OF INFLUENZA VIRUS

The complex carbohydrates apple pectin, citrus pectin, flaxseed mucilage, blood group A substance, gum acacia, and gum myrrh as well as an extract of RBC, when examined in a pattern test, were shown to inhibit the agglutination of chicken RBC by influenza A virus. A number of other simple and complex carbohydrates showed no inhibitory effect. The hemagglutination-inhibiting action of apple pectin was examined in some detail and evidence was adduced to show that it affected both virus and red cell. Apple pectin was also found to inhibit the multiplication of influenza A virus in embryonated eggs.

COMPLEMENT FIXATION WITH THE NEUROTROPIC VIRUSES

Antigens capable of fixing complement specifically with the appropriate antibodies have been prepared from brain tissue of hamsters and mice infected with the viruses of St. Louis, Japanese, Western, and Eastern encephalitis, and with the West Nile virus. The antigens were freed of the material which reacts with normal serum by means of centrifugation at relatively high speed. In addition, the infectivity of the preparation was destroyed by irradiation with ultraviolet light. Cross reactions were demonstrated by means of the complement-fixation technique with materials from animals infected with the viruses of Eastern and Western equine encephalitis. No relationship was detectable by this procedure between St. Louis, Japanese, and West Nile viruses. These findings emphasize the need for further investigation and correlation of the immunological reactions of the groups of neurotropic viruses, since the equine agents are apparently unrelated when studied by neutralization and cross-immunity tests while these methods provide evidence of the presence of common antigenic structures in the St. Louis, Japanese, and West Nile agents.

Chemokine receptor expression in tumour islets and stroma in non-small cell lung cancer

BACKGROUND

We have previously demonstrated that tumour islet infiltration by macrophages is associated with extended survival (ES) in NSCLC. We therefore hypothesised that patients with improved survival would have high tumour islet expression of chemokine receptors known to be associated with favourable prognosis in cancer. This study investigated chemokine receptor expression in the tumour islets and stroma in NSCLC.

METHODS

We used immunohistochemistry to identify cells expressing CXCR1, CXCR2, CXCR3, CXCR4, CXCR5 and CCR1 in the tumour islets and stroma in 20 patients with surgically resected NSCLC. Correlations were made with macrophage and mast cell expression.

RESULTS

There was increased expression of CXCR2, CXCR3, and CCR1 in the tumour islets of ES compared with poor survival (PS) patients (p = 0.007, 0.01, and 0.002, respectively). There was an association between 5 year survival and tumour islet CXCR2, CXCR3 and CCR1 density (p = 0.02, 0.003 and <0.001, respectively) as well as stromal CXCR3 density (p = 0.003). There was a positive correlation between macrophage density and CXCR3 expression (rs = 0.520, p = 0.02) and between mast cell density and CXCR3 expression (rs = 0.499, p = 0.03) in the tumour islets.

CONCLUSION

Above median expression of CXCR2, CXCR3 and CCR1 in the tumour islets is associated with increased survival in NSCLC, and expression of CXCR3 correlates with increased macrophage and mast cell infiltration in the tumour islets.

Qualitative analysis of high-resolution CT scans in severe asthma

BACKGROUND

High-resolution CT (HRCT) scanning is part of the management of severe asthma, but its application varies between centers. We sought to describe the HRCT scan abnormalities of a large severe asthma cohort and to determine the utility of clinical features to direct the use of HRCT scanning in this group of patients.

METHODS

Subjects attending our Difficult Asthma Clinic (DAC) between February 2000 and November 2006 (n = 463) were extensively re-characterized and 185 underwent HRCT scan. The HRCT scans were analyzed qualitatively and the interobserver variability was assessed. Using logistic regression we defined clinical parameters that were associated with bronchiectasis (BE) and bronchial wall thickening (BWT) alone or in combination.

RESULTS

HRCT scan abnormalities were present in 80% of subjects and often coexisted with BWT (62%), BE (40%), and emphysema (8%). The interobserver agreement for BE (kappa = 0.76) and BWT (kappa = 0.63) was substantial. DAC patients who underwent HRCT scanning compared with those who did not were older, had longer disease duration, had poorer lung function, were receiving higher doses of corticosteroids, and had increased neutrophilic airway inflammation. The sensitivity and specificity of detecting BE clinically were 74% and 45%, respectively. FEV(1)/FVC ratio emerged as an important predictor for both BE and BWT but had poor discriminatory utility for subjects who did not have airway structural changes (FEV(1)/FVC ratio, >or= 75%; sensitivity, 67%; specificity, 65%).

CONCLUSION

HRCT scan abnormalities are common in patients with severe asthma. Nonradiologic assessments fail to reliably predict important bronchial wall changes; therefore, CT scan acquisition may be required in all patients with severe asthma.

Mepolizumab and exacerbations of refractory eosinophilic asthma

BACKGROUND

Exacerbations of asthma are associated with substantial morbidity and mortality and with considerable use of health care resources. Preventing exacerbations remains an important goal of therapy. There is evidence that eosinophilic inflammation of the airway is associated with the risk of exacerbations.

METHODS

We conducted a randomized, double-blind, placebo-controlled, parallel-group study of 61 subjects who had refractory eosinophilic asthma and a history of recurrent severe exacerbations. Subjects received infusions of either mepolizumab, an anti-interleukin-5 monoclonal antibody (29 subjects), or placebo (32) at monthly intervals for 1 year. The primary outcome measure was the number of severe exacerbations per subject during the 50-week treatment phase. Secondary outcomes included a change in asthma symptoms, scores on the Asthma Quality of Life Questionnaire (AQLQ, in which scores range from 1 to 7, with lower values indicating more severe impairment and a change of 0.5 unit considered to be clinically important), forced expiratory volume in 1 second (FEV(1)) after use of a bronchodilator, airway hyperresponsiveness, and eosinophil counts in the blood and sputum.

RESULTS

Mepolizumab was associated with significantly fewer severe exacerbations than placebo over the course of 50 weeks (2.0 vs. 3.4 mean exacerbations per subject; relative risk, 0.57; 95% confidence interval [CI], 0.32 to 0.92; P=0.02) and with a significant improvement in the score on the AQLQ (mean increase from baseline, 0.55 vs. 0.19; mean difference between groups, 0.35; 95% CI, 0.08 to 0.62; P=0.02). Mepolizumab significantly lowered eosinophil counts in the blood (P<0.001) and sputum (P=0.002). There were no significant differences between the groups with respect to symptoms, FEV(1) after bronchodilator use, or airway hyperresponsiveness. The only serious adverse events reported were hospitalizations for acute severe asthma.

CONCLUSIONS

Mepolizumab therapy reduces exacerbations and improves AQLQ scores in patients with refractory eosinophilic asthma. The results of our study suggest that eosinophils have a role as important effector cells in the pathogenesis of severe exacerbations of asthma in this patient population. (Current Controlled Trials number, ISRCTN75169762.)

Macrophages within NSCLC tumour islets are predominantly of a cytotoxic M1 phenotype associated with extended survival

There is a marked survival advantage for patients with nonsmall cell lung cancer (NSCLC) expressing high numbers of macrophages in their tumour islets. The primary aim of the present study was to determine the immunological phenotype of NSCLC-associated macrophages. CD68(+) macrophages expressing markers of a cytotoxic M1 phenotype or a noncytotoxic M2 phenotype were identified in the islets and stroma of surgically resected tumours from 20 patients with extended survival (median 92.7 months) and 20 with poor survival (median 7.7 months), using immunohistochemistry. The islet density of both M1 and M2 macrophages was markedly increased in extended compared with poor survival patients. In the extended survival group, M1 islet density was significantly increased compared with M2 density, 70% of islet macrophages were positive for M1 markers versus 38% for M2, and the islet:stromal ratio of M1 macrophages was markedly increased compared with M2. The 5-yr survival for patients with above and below median expression of M1 macrophages in the islets was >75 and <5%, respectively. Macrophages infiltrating the tumour islets in nonsmall cell lung cancer were predominantly of the M1 phenotype in patients with extended survival. The survival advantage conferred by islet macrophage infiltration may be related to their cytotoxic antitumour activity.

Cluster analysis and clinical asthma phenotypes

RATIONALE

Heterogeneity in asthma expression is multidimensional, including variability in clinical, physiologic, and pathologic parameters. Classification requires consideration of these disparate domains in a unified model.

OBJECTIVES

To explore the application of a multivariate mathematical technique, k-means cluster analysis, for identifying distinct phenotypic groups.

METHODS

We performed k-means cluster analysis in three independent asthma populations. Clusters of a population managed in primary care (n = 184) with predominantly mild to moderate disease, were compared with a refractory asthma population managed in secondary care (n = 187). We then compared differences in asthma outcomes (exacerbation frequency and change in corticosteroid dose at 12 mo) between clusters in a third population of 68 subjects with predominantly refractory asthma, clustered at entry into a randomized trial comparing a strategy of minimizing eosinophilic inflammation (inflammation-guided strategy) with standard care.

MEASUREMENTS AND MAIN RESULTS

Two clusters (early-onset atopic and obese, noneosinophilic) were common to both asthma populations. Two clusters characterized by marked discordance between symptom expression and eosinophilic airway inflammation (early-onset symptom predominant and late-onset inflammation predominant) were specific to refractory asthma. Inflammation-guided management was superior for both discordant subgroups leading to a reduction in exacerbation frequency in the inflammation-predominant cluster (3.53 [SD, 1.18] vs. 0.38 [SD, 0.13] exacerbation/patient/yr, P = 0.002) and a dose reduction of inhaled corticosteroid in the symptom-predominant cluster (mean difference, 1,829 mug beclomethasone equivalent/d [95% confidence interval, 307-3,349 mug]; P = 0.02).

CONCLUSIONS

Cluster analysis offers a novel multidimensional approach for identifying asthma phenotypes that exhibit differences in clinical response to treatment algorithms.

Association between neutrophilic airway inflammation and airflow limitation in adults with asthma

BACKGROUND

There is debate about the mechanisms of persistent airflow limitation in patients with asthma. Chronic inflammation is assumed to be important, although there is limited and contradictory information about the relationship between airway inflammation and postbronchodilator FEV1.

METHODS

We have assessed the cross-sectional relationship between prebronchodilator and postbronchodilator FEV1 and measures of airway inflammation after allowing for the effects of potential confounding factors. Multivariate analysis was performed on data collected from 1,197 consecutive patients with asthma seen at the respiratory outpatient clinic at Glenfield Hospital between 1997 and 2004. Relationships between induced sputum total neutrophil and differential eosinophil cell counts, and prebronchodilator and postbronchodilator lung function were examined.

RESULTS

Sputum total neutrophil but not differential eosinophil count was associated with lower postbronchodilator FEV1. Both differential eosinophil and total neutrophil count were associated with lower prebronchodilator FEV1. These effects were independent after adjustment for age, smoking, ethnicity, asthma duration, and inhaled corticosteroid use. A 10-fold increase in neutrophil count was associated with a 92 mL reduction (95% confidence interval, 29 to 158; p = 0.007) in postbronchodilator FEV1.

CONCLUSIONS

In this large heterogeneous population of adults with asthma, we have shown that prebronchodilator FEV1 is associated with neutrophilic and eosinophilic airway inflammation, whereas sputum total neutrophil counts alone are associated with postbronchodilator FEV1. This supports the hypothesis that neutrophilic airway inflammation has a role in the progression of persistent airflow limitation in asthma and raises the possibility that this progression and the development of COPD share a common mechanism.

The use of exhaled nitric oxide to guide asthma management: a randomized controlled trial

RATIONALE

Current asthma guidelines recommend adjusting antiinflammatory treatment on the basis of the results of lung function tests and symptom assessment, neither of which are closely associated with airway inflammation.

OBJECTIVES

We tested the hypothesis that titrating corticosteroid dose using the concentration of exhaled nitric oxide in exhaled breath (Fe(NO)) results in fewer asthma exacerbations and more efficient use of corticosteroids, when compared with traditional management.

METHODS

One hundred eighteen participants with a primary care diagnosis of asthma were randomized to a single-blind trial of corticosteroid therapy based on either Fe(NO) measurements (n = 58) or British Thoracic Society guidelines (n = 60). Participants were assessed monthly for 4 months and then every 2 months for a further 8 months. The primary outcome was the number of severe asthma exacerbations. Analyses were by intention to treat.

MEASUREMENTS AND MAIN RESULTS

The estimated mean (SD) exacerbation frequency was 0.33 per patient per year (0.69) in the Fe(NO) group and 0.42 (0.79) in the control group (mean difference, -21%; 95% confidence interval [CI], -57 to 43%; p = 0.43). Overall the Fe(NO) group used 11% more inhaled corticosteroid (95% CI, -17 to 42%; p = 0.40), although the final daily dose of inhaled corticosteroid was lower in the Fe(NO) group (557 vs. 895 microg; mean difference, 338 microg; 95% CI, -640 to -37; p = 0.028).

CONCLUSIONS

An asthma treatment strategy based on the measurement of exhaled nitric oxide did not result in a large reduction in asthma exacerbations or in the total amount of inhaled corticosteroid therapy used over 12 mo, when compared with current asthma guidelines. Clinical trial registered with www.controlled-trials.com (ISRCTN08067387).

The reclassification of asthma based on subphenotypes

PURPOSE OF REVIEW

Despite asthma being widely regarded as a heterogeneous disease, a consensus for an accurate system of classification has not been agreed. Recent studies have suggested that the recognition of subphenotypes of asthma based on the pattern of airway inflammation may be particularly useful in increasing our understanding of the disease. The present review discusses the important literature in this field, placing current work in its historical context.

RECENT FINDINGS

The use of noninvasive markers of airway inflammation has suggested the presence of four distinct phenotypes: eosinophilic, neutrophilic, mixed inflammatory and paucigranulocytic asthma. Recent studies suggest that these subgroups may differ in their aetiology, immunopathology and response to treatment. Several studies have focused on refractory asthma as a distinct phenotype with evidence of a more distal pattern of airway inflammation and of upregulation of the tumour necrosis factor-alpha axis. Finally, novel treatment approaches targeted at specific patterns of airway inflammation are emerging, making an appreciation of subphenotypes particularly relevant.

SUMMARY

The present review will discuss limitations to current classification systems, identify key current studies based on identifying inflammatory subphenotypes and provide suggestions for a novel approach that may further improve our understanding in this area.

Eosinophilic airway inflammation and exacerbations of COPD: a randomised controlled trial

Evidence suggests that eosinophilic airway inflammation is important in the pathogenesis of severe chronic obstructive pulmonary disease (COPD) exacerbations. The present authors tested the hypothesis that a management strategy that aims to reduce sputum eosinophil counts is associated with a reduction in exacerbations of COPD. A total of 82 patients with COPD were randomised into two groups. One group was treated according to traditional guidelines (British Thoracic Society (BTS) group) and the other (sputum group) was treated with the additional aim of minimising eosinophilic airway inflammation, assessed using the induced sputum eosinophil count. The primary outcome was exacerbations, which were categorised as mild, moderate or severe. The frequency of severe exacerbations per patient per year was 0.5 and 0.2 in the BTS and sputum groups, respectively (mean reduction 62%). The majority of this benefit was confined to patients with eosinophilic airway inflammation. There was no difference in the frequency of mild and moderate exacerbations. The average daily dose of inhaled or oral corticosteroids during the trial did not differ between the groups. Out of 42 patients in the sputum group, 17 required regular oral corticosteroids to minimise eosinophilic airway inflammation. A management strategy that aims to minimise eosinophilic airway inflammation, as well as symptoms, is associated with a reduction in severe exacerbations of chronic obstructive pulmonary disease.

Multiple inflammatory hits and the pathogenesis of severe airway disease

Refractory or difficult-to-control asthma is associated with some clinical and pathological features normally associated with chronic obstructive pulmonary disease (COPD), raising the possibility that there are similarities in their pathogenesis. It is suggested that the coexistence of two or more inflammatory stimuli to the airway (multiple hits) is a key factor leading to the development of more severe airway disease. Airway inflammation in response to chronic inflammatory conditions elsewhere may be a particularly important additional inflammatory stimulus. The "multiple hit" hypothesis for the origins of severe airway disease has important implications for treatment and prevention, since identification and removal of additional inflammatory stimuli may delay progression of the underlying airway disease.

Evidence of a role of tumor necrosis factor alpha in refractory asthma

BACKGROUND

The development of tumor necrosis factor alpha (TNF-alpha) antagonists has made it feasible to investigate the role of this cytokine in refractory asthma.

METHODS

We measured markers of TNF-alpha activity on peripheral-blood monocytes in 10 patients with refractory asthma, 10 patients with mild-to-moderate asthma, and 10 control subjects. We also investigated the effects of treatment with the soluble TNF-alpha receptor etanercept (25 mg twice weekly) in the patients with refractory asthma in a placebo-controlled, double-blind, crossover pilot study.

RESULTS

As compared with patients with mild-to-moderate asthma and controls, patients with refractory asthma had increased expression of membrane-bound TNF-alpha, TNF-alpha receptor 1, and TNF-alpha-converting enzyme by peripheral-blood monocytes. In the clinical trial, as compared with placebo, 10 weeks of treatment with etanercept was associated with a significant increase in the concentration of methacholine required to provoke a 20 percent decrease in the forced expiratory volume in one second (FEV1) (mean difference in doubling concentration changes between etanercept and placebo, 3.5; 95 percent confidence interval, 0.07 to 7.0; P=0.05), an improvement in the asthma-related quality-of-life score (by 0.85 point; 95 percent confidence interval, 0.16 to 1.54 on a 7-point scale; P=0.02), and a 0.32-liter increase in post-bronchodilator FEV1 (95 percent confidence interval, 0.08 to 0.55; P=0.01).

CONCLUSIONS

Patients with refractory asthma have evidence of up-regulation of the TNF-alpha axis. (ClinicalTrials.gov number, NCT00276029.).

Comparison of asthma treatment given in addition to inhaled corticosteroids on airway inflammation and responsiveness

There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation.

The use of exhaled nitric oxide concentration to identify eosinophilic airway inflammation: an observational study in adults with asthma

BACKGROUND

Assessment of eosinophilic airway inflammation may be helpful in the management of asthma. Nitric oxide (NO) has potential advantages as a tool to monitor airway inflammation although little is known about the relationship between NO and eosinophilic airway inflammation and the factors which influence it.

METHODS

We set out to define the relationship between exhaled NO and the sputum eosinophil count, identify the exhaled NO concentration that best identified a sputum eosinophil count >3% and investigate the impact of several potential confounding factors in 566 consecutive patients with varying severity of asthma. Finally we examined the ability of exhaled NO concentrations measured at differing exhalation flows to identify the presence of a sputum eosinophilia.

RESULTS

We found a significant positive relationship between exhaled NO and sputum eosinophil count (R(2)=0.26, P<0.001) which was best described using a non-linear model. There were no clinically important confounding factors to this model. In non-smokers an exhaled NO concentration of >8.3 p.p.b. at 250 mL/s gave 71% sensitivity and 72% specificity for identifying a sputum eosinophil count of >3%.

CONCLUSIONS

This value of exhaled NO would seem to be the best for identifying significant eosinophilic airway inflammation. It is applicable to a wide range of non-smoking patients with asthma; exhalation flow does not alter the ability of exhaled NO concentration to detect a sputum eosinophilia.

Biomarkers predicting response to corticosteroid therapy in asthma

International guidelines on the management of asthma support the early introduction of corticosteroids to control symptoms and to improve lung function by reducing airway inflammation. However, not all individuals respond to corticosteroids to the same extent and it would be an advantage to be able to predict the response to corticosteroid treatment. Several biomarkers have been assessed following treatment with corticosteroids including measures of lung function, peripheral blood and sputum indices of inflammation, exhaled gases and breath condensates. The most widely examined measures in predicting a response to corticosteroids are airway hyperresponsiveness, exhaled nitric oxide (eNO) and induced sputum. Of these, sputum eosinophilia has been demonstrated to be the best predictor of a short-term response to corticosteroids. More importantly, directing treatment at normalizing the sputum eosinophil count can substantially reduce severe exacerbations. The widespread utilization of sputum induction is hampered because the procedure is relatively labor intensive. The measurement of eNO is simpler, but incorporating the assessment of NO in an asthma management strategy has not led to a reduction in exacerbation rates. The challenge now is to either simplify the measurement of a sputum eosinophilia or to identify another inflammatory marker with a similar efficacy as the sputum eosinophil count in predicting both the short- and long-term responses to corticosteroids.

Asthma exacerbations: prevention is better than cure

Poorly controlled asthma is currently treated by adding or removing asthma medication in a stepwise fashion to try and improve symptoms and maintain lung function. It is becoming apparent that asthma exacerbations are independent of asthma control and severity, and that the simple method of using rescue courses of corticosteroids to treat an asthma exacerbation can be bettered by aiming to prevent its occurrence. New tools that can predict and prevent exacerbations are now becoming available. This article discusses these tools and takes a more detailed look at new treatment regimes being used.

Macrophage and mast-cell invasion of tumor cell islets confers a marked survival advantage in non-small-cell lung cancer

PURPOSE

The role played by the innate immune system in determining survival from non-small-cell lung cancer (NSCLC) is unclear. The aim of this study was to investigate the prognostic significance of macrophage and mast-cell infiltration in NSCLC.

METHODS

We used immunohistochemistry to identify tryptase+ mast cells and CD68+ macrophages in the tumor stroma and tumor islets in 175 patients with surgically resected NSCLC.

RESULTS

5-year survival was 52.9% in patients with an islet macrophage density greater than the median versus 7.7% when less than the median (P < .0001). In the same groups, respectively, median survival was 2,244 versus 334 days (P < .0001). Patients with a high islet macrophage density but incomplete resection survived markedly longer than patients with a low islet macrophage density but complete resection.

CONCLUSION

The tumor islet CD68+ macrophage density is a powerful independent predictor of survival from surgically resected NSCLC. The biologic explanation for this and its implications for the use of adjunctive treatment requires further study.

Alveolar nitric oxide in adults with asthma: evidence of distal lung inflammation in refractory asthma

Recent studies have suggested that alveolar nitric oxide (NO) concentration is a noninvasive test of distal lung inflammation. The current study determined whether alveolar NO concentration can be measured in patients with asthma of varying severity, tested the hypothesis that there is an association between alveolar NO and bronchoalveolar lavage (BAL) eosinophil count and determined whether refractory asthma is characterised by a raised alveolar NO concentration. Finally, the present authors assessed the effect of 2 weeks of prednisolone (30 mg q.d.) on alveolar NO concentration. Alveolar NO concentration was both measurable and repeatable in patients with refractory asthma. A positive correlation was found between alveolar NO concentration and BAL eosinophil count but not with bronchial wash or sputum eosinophil count. Alveolar NO concentration was increased in patients with refractory asthma (7.1 ppb) compared with mild-to-moderate asthma (3.4 ppb) and normal controls (3.4 ppb) and reduced by treatment with prednisolone. In conclusion, these findings support the hypothesis that alveolar nitric oxide is a measure of distal airway inflammation and suggest that distal lung inflammation is present in refractory asthma.

Observational study of the natural history of eosinophilic bronchitis

BACKGROUND

Eosinophilic bronchitis is an important cause of chronic cough. Treatment with inhaled corticosteroids is associated with a short-term improvement in cough and reduced sputum eosinophil count but the long-term outcome is uncertain.

OBJECTIVE

To determine the long-term outcome in patients diagnosed with and treated for eosinophilic bronchitis.

METHODS

We have performed a longitudinal study of symptoms, eosinophilic airway inflammation, spirometry and airway hyper-responsiveness in all patients diagnosed with eosinophilic bronchitis over 7 years.

RESULTS

We identified 52 patients with eosinophilic bronchitis and longitudinal data of greater than 1 year (mean 3.1 years) was available in 32 patients, all of whom were treated with inhaled steroids. Three (9%) patients developed symptoms consistent with asthma and a methacholine PC20<8 mg/mL on one or more occasion. Five (16%) patients developed fixed airflow obstruction defined by a persistent post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity<70%. One (3%) patient had complete resolution of symptoms and eosinophilic airway inflammation off treatment. The remaining patients had ongoing eosinophilic airway inflammation and/or continuing symptoms. Multiple linear regression identified smoking, female gender and area under the curve of sputum eosinophil count over time as the most important predictors of decline in FEV1.

CONCLUSIONS

The most common outcome in eosinophilic bronchitis is continuing disease and complete resolution is rare. Asthma and fixed airflow obstruction developed in relatively few patients. The most important factors associated with a more rapid decline in FEV1 were female gender, smoking and prolonged eosinophilic airway inflammation.