Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults

Efficacy of subcutaneous immunotherapy for patients with asthma and allergic rhinitis in Korea: effect on eosinophilic inflammation

Background

Atopic asthma (AA) and allergic rhinitis (AR) are often seen as comorbidities and specific immunotherapy (SIT) is considered evidence-based treatment for them both.

Objective

The purpose of this study was to evaluate the efficacy of multiallergen subcutaneous SIT (SCIT) in reducing nasal and sputum eosinophilia, symptom scores, and impaired lung function in Korean pediatric patients with AR and AA.

Methods

Children aged 6-15 years with a documented history of bronchial asthma and seasonal/perennial AR were recruited then randomly selected to 1 of 2 groups: "immunotherapy group" (inhaled corticosteroids [ICS] and short-acting beta₂-agonist [SABA] + subcutaneous injection of standardized extracts of up to 4 allergens [n = 53]) or "drug only group" (ICS and SABA only [n = 19]). All data were collected retrospectively.

Results

Comparing the 2 treatment groups, the immunotherapy group showed a significantly (p = 0.006) greater reduction in nasal eosinophilia over the 3-year treatment period. Only the immunotherapy group exhibited a significant reduction in sputum eosinophilia over the 3-year treatment period (p = 0.003). Fifty-one point one percent of patients in the immunotherapy group showed significant improvement in the methacholine challenge test negative conversion rate compared to only 17.65% in the drug only group (p = 0.0168). There were significantly greater improvements in symptom scores in the immunotherapy group compared to the drug only group. For all allergens tested, only house dust mite reactivity changed significantly over the treatment period and only in the immunotherapy group (Dermatophagoides pteronyssinus [p < 0.0001] and Dermatophagoides farina [p = 0.035]).

Conclusion

SCIT was associated with greater improvements in lung function and bronchial hyperresponsiveness and reductions in nasal and sputum eosinophilia and allergen reactivity. Changes in symptom scores were also much greater in patients receiving SCIT when compared to those who did not receive it. Korean children with AA and AR respond well to long-term multiallergen SCIT.

Advances with glucocorticoids in the treatment of asthma: state of the art

INTRODUCTION

Asthma is one of the most frequent chronic diseases all over the world. Glucocorticoids (GCs), both inhaled (ICSs) and oral (OCSs), are the most effective treatment in asthma because they control symptoms and prevent exacerbations.

AREAS COVERED

The present article reviews the new therapeutic indications of GCs for the treatment of asthma and focuses on new molecules and safety issues.

EXPERT OPINION

Most patients with asthma benefit from corticosteroid-based treatments. Side effects are mainly due to prolonged use of oral GCs, while they are minor with inhaled GCs. Interesting insights come from the new ICSs, which are characterized by lower oral bioavailability and higher lipophilicity and are more effective with less side effects. Recent trials have shown the efficacy of early use of ICSs in mild asthma. Furthermore, the possibility to prescribe targeted therapies using specific biomarkers in steroid-sensitive asthma can reduce doses and duration of treatment, while biological agents should be reserved for non-responding patients. All this evidence confirm the need to continue on the path toward precision medicine, in which the treatments are based on clinical and molecular traits.

Asthma and Corticosteroid Responses in Childhood and Adult Asthma

Corticosteroids are the most effective treatment for asthma; inhaled corticosteroids (ICSs) are the first-line treatment for children and adults with persistent symptoms. ICSs are associated with significant improvements in lung function. The anti-inflammatory effects of corticosteroids are mediated by both genomic and nongenomic factors. Variation in the response to corticosteroids has been observed. Patient characteristics, biomarkers, and genetic features may be used to predict response to ICSs. The existence of multiple mechanisms underlying glucocorticoid insensitivity raises the possibility that this might indeed reflect different diseases with a common phenotype.

Montelukast Reduces Serum Levels of Eosinophil-Derived Neurotoxin in Preschool Asthma

PURPOSE

Several markers for eosinophilic inflammation have been proposed to predict response to asthma treatment. However, definitive criteria for treatment decisions have not yet been established. We investigate a potentially useful relatively non-invasive biomarker, eosinophil-derived neurotoxin (EDN), to predict favorable responses to budesonide or montelukast, common treatment for children with asthma.

METHODS

Young children (1 to 6 years old) were enrolled in this randomized, parallel, 2-group, open-label trial. Criteria for eligibility included: 1) being symptomatic during the run-in period; and 2) having a serum EDN (sEDN) level ≥ 53 ng/mL, with positive specific immunoglobulin E to house dust mite. Eligible patients were randomly placed into 2 groups: the BIS group received budesonide inhalation suspension (BIS) 0.5 mg once daily; the MONT group received montelukast 4 mg once daily. Ineligible patients were invited to receive montelukast 4 mg once daily (OBS group). Treatment period was 12 weeks.

RESULTS

Asthma control days increased significantly in the BIS and MONT groups (P < 0.000) over the 12-week study period. There was no significant change in sEDN in the BIS group but there was a significant decrease in the MONT group (P < 0.000). Patients in the OBS group with high EDN levels (< 53 ng/mL) showed a significant decrease due to MONT treatment (P = 0.023). Rescue medication usage significantly decreased in the BIS and MONT groups (P < 0.000).

CONCLUSIONS

EDN is a useful relatively non-invasive biomarker for predicting responses to montelukast and budesonide treatment of preschool children with beta2-agonist responsive recurrent wheeze and multiple-trigger wheeze (Trial registry at UMIN Clinical Trials Registry, UMIN000008335).

The effect of omalizumab treatment on IgE and other immunoglobulin levels in patients with chronic spontaneous urticaria and its association with treatment response

Introduction

Suppression of free immunoglobulin E (IgE) levels and an increase in total IgE levels are observed during omalizumab treatment. However, whether omalizumab has any effect on other immunoglobulins is unknown.

Aim

To investigate the effect of omalizumab treatment on serum IgE and other immunoglobulins, and demonstrate any association with response to treatment in patients with chronic spontaneous urticaria (CSU).

Material and methods

The study included 41 patients diagnosed with CSU. Baseline and post-12-week-treatment total IgE, IgA, IgM, and IgG levels and blood eosinophil, neutrophil, lymphocyte and platelet levels were compared. Patients were grouped based on weekly urticaria activity score (UAS-7) responses and these parameters were compared.

Results

There was a significant increase in baseline and post-12-week-treatment total IgE levels, while there was no significant difference in other immunoglobulin levels. A significant reduction was found in neutrophil counts after the treatment, whereas there was no significant difference in eosinophil, lymphocyte and platelet levels. There was no difference in these parameters between groups with complete response and without complete response.

Conclusions

Omalizumab treatment can also be used in patients with immunoglobulin deficiency. Due to the observed reduction in neutrophil counts after the treatment, patients must be closely followed for whole blood parameters.

Eosinophilia as a treatable trait in three patients with asthma and COPD

The combination of asthma and chronic obstructive pulmonary disease (COPD) in an individual can present significant challenges to achieving satisfactory outcomes. More recently, the concepts of precision medicine and treatable traits have arisen as promising tools to improve care for this group. In this series, we present three cases of patients with features of both asthma and COPD in addition to peripheral blood eosinophilia. The novel implementation of personalized management of the individual based on this treatable trait (eosinophilia) resulted in significant benefits. These benefits included improvement in symptoms, lung function, and a marked decline in critical care admissions and exacerbation rates.

Longitudinal outcomes of different asthma phenotypes in primary care, an observational study

While asthma presentation is heterogeneous, current asthma management guidelines in primary care are quite homogeneous. In this study we aim to cluster patients together into different phenotypes, that may aid the general practitioner in individualised asthma management. We analysed data from the ACCURATE trial, containing 611 adult asthmatics, 18-50 year-old, treated in primary care, with one year follow-up. Variables obtained at baseline (n = 14), were assessed by cluster analysis. Subsequently, established phenotypes were assessed separately on important asthma outcomes after one year follow-up: asthma control (Asthma Control Questionnaire (ACQ)), quality of life (Asthma Quality of Life Questionnaire (AQLQ)), exacerbation-rate and medication-usage. Five distinct phenotypes were identified. The first phenotype was predominantly defined by their early onset atopic form of asthma. The second phenotype mainly consisted of female patients with a late onset asthma. The third phenotype were patients with high reversibility rates after bronchodilator usage. The fourth phenotype were smokers and the final phenotype were frequent exacerbators. The exacerbators phenotype had the worst outcomes for asthma control and quality of life and experienced the highest exacerbation-rate, despite using the most medication. The early onset phenotype patients were relatively well controlled and their medication dosage was low.

ASTHMA

INDIVIDUALIZING TREATMENT BY PHENOTYPE: Asthma patients should be characterised according to their individual asthma type to ensure more targeted treatment. Even though asthma manifests itself in a wide variety of forms with differing degrees of severity, treatment of the disease often takes a broad, one-size-fits-all approach. To determine if asthma can indeed be split into distinct phenotypes, Rishi Khusial at the Leiden University Medical Center and co-workers across the Netherlands analysed data from 611 adult asthmatics treated in primary care, and followed them up after one year. The team identified five phenotypes in the primary care cohort, including one group with early onset asthma, another whose asthma responded well to bronchodilators, and a group classed as frequent exacerbators. Further analysis of long-term asthma outcomes showed clear differences between phenotypes, particularly in terms of asthma control and quality of life.

Predictive Biomarkers for Asthma Therapy

PURPOSE OF REVIEW

Asthma is a heterogeneous disease characterized by multiple phenotypes. Treatment of patients with severe disease can be challenging. Predictive biomarkers are measurable characteristics that reflect the underlying pathophysiology of asthma and can identify patients that are likely to respond to a given therapy. This review discusses current knowledge regarding predictive biomarkers in asthma.

RECENT FINDINGS

Recent trials evaluating biologic therapies targeting IgE, IL-5, IL-13, and IL-4 have utilized predictive biomarkers to identify patients who might benefit from treatment. Other work has suggested that using composite biomarkers may offer enhanced predictive capabilities in tailoring asthma therapy. Multiple biomarkers including sputum eosinophil count, blood eosinophil count, fractional concentration of nitric oxide in exhaled breath (FeNO), and serum periostin have been used to identify which patients will respond to targeted asthma medications. Further work is needed to integrate predictive biomarkers into clinical practice.

Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults

BACKGROUND

Asthma severity and control can be measured both subjectively and objectively. Sputum analysis for evaluation of percentage of sputum eosinophilia directly measures airway inflammation, and is one method of objectively monitoring asthma. Using sputum analysis to adjust or tailor asthma medications is potentially superior to traditional methods based on symptoms and spirometry.

OBJECTIVES

To evaluate the efficacy of tailoring asthma interventions based on sputum analysis in comparison to traditional methods (usually symptom-based with or without spirometry/peak flow) for asthma-related outcomes in children and adults.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trials' registries, and reference lists of articles. The last search was conducted in February 2017.

SELECTION CRITERIA

All randomised controlled comparisons of adjustment of asthma therapy based on sputum eosinophils compared to traditional methods (primarily clinical symptoms and spirometry/peak flow).

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. In this update, two reviewers selected relevant studies, independently assessed trial quality and extracted the data. We contacted authors for further information when relevant. We analysed data as 'treatment received' and performed sensitivity analyses.

MAIN RESULTS

Three new studies were added in this update, resulting in a total of six included studies (five in adults and one involving children/adolescents). These six studies were clinically and methodologically heterogeneous (use of medications, cut-off for percentage of sputum eosinophils and definition of asthma exacerbation). Of 374 participants randomised, 333 completed the trials. In the meta-analysis, there was a significant reduction in the occurrence of any exacerbations when treatment was based on sputum eosinophil counts, compared to that based on clinical symptoms with or without lung function; pooled odds ratio (OR) was 0.57 (95% confidence interval (CI) 0.38 to 0.86). The risk of having one or more exacerbations over 16 months was 82% in the control arm and 62% (95% CI 49% to 74%) in the sputum strategy arm, resulting in a number needed to treat to benefit (NNTB) of 6 (95% CI 4 to 13).There were also differences between the groups in the rate of exacerbation (any exacerbation per year) and severity of exacerbations defined by requirement for use of oral corticosteroids and hospitalisations: the risk of one or more hospitalisations over 16 months was 24% in controls compared to 8% (95% CI 3% to 21%) in the sputum arm. Data for clinical symptoms, quality of life and spirometry were not significantly different between groups. The mean dose of inhaled corticosteroids per day was also similar in both groups. However sputum induction was not always possible. The included studies did not record any adverse events.One study was not blinded and thus was considered to have a high risk of bias. However, when this study was removed in a sensitivity analysis, the difference between the groups for the primary outcome (exacerbations) remained statistically significant between groups. The GRADE quality of the evidence ranged from moderate (for the outcomes 'Occurrence of any exacerbation' and 'Hospitalisation' ) to low (for the outcome 'Mean dose of inhaled corticosteroids per person per day') due to the inconsistency in defining exacerbations and the small number of hospital admissions.

AUTHORS' CONCLUSIONS

In this updated review, tailoring asthma interventions based on sputum eosinophils is beneficial in reducing the frequency of asthma exacerbations in adults with asthma. Adults with frequent exacerbations and severe asthma may derive the greatest benefit from this additional monitoring test, although we were unable to confirm this through subgroup analysis. There is insufficient data available to assess tailoring asthma medications based on sputum eosinophilia in children.Further robust RCTs need to be undertaken and these should include participants with different underlying asthma severities and endotypes.

Obesity's effect on asthma extends to diagnostic criteria

BACKGROUND

The use of inflammatory biomarkers to delineate the type of lung inflammation present in asthmatic subjects is increasingly common. However, the effect of obesity on these markers is unknown.

OBJECTIVES

We aimed to determine the effect of obesity on conventional markers of inflammation in asthmatic subjects.

METHODS

We performed secondary analysis of data from 652 subjects previously enrolled in 2 Asthma Clinical Research Network trials. We performed linear correlations between biomarkers and logistic regression analysis to determine the predictive value of IgE levels, blood eosinophil counts, and fraction of exhaled nitric oxide values in relationship to sputum eosinophil counts (>2%), as well as to determine whether cut points existed that would maximize the sensitivity and specificity for predicting sputum eosinophilia in the 3 weight groups.

RESULTS

Overall, statistically significant but relatively weak correlations were observed among all 4 markers of inflammation. Within obese subjects, the only significant correlation found was between IgE levels and blood eosinophil counts (r = 0.33, P < .001); furthermore, all other correlations between inflammatory markers were approximately 0, including correlations with sputum eosinophil counts. In addition, the predictive value of each biomarker alone or in combination was poor in obese subjects. In fact, in obese subjects none of the biomarkers of inflammation significantly predicted the presence of high sputum eosinophil counts. Obese asthmatic subjects have lower cut points for IgE levels (268 IU), fraction of exhaled nitric oxide values (14.5 ppb), and blood eosinophil counts (96 cells/μL) than all other groups.

CONCLUSIONS

In obese asthmatic subjects conventional biomarkers of inflammation are poorly predictive of eosinophilic airway inflammation. As such, biomarkers currently used to delineate eosinophilic inflammation in asthmatic subjects should be approached with caution in these subjects.

Eosinophil Count Is a Common Factor for Complex Metabolic and Pulmonary Traits and Diseases: The LifeLines Cohort Study

There is ongoing debate on the association between eosinophil count and diseases, as previous studies were inconsistent. We studied the relationship of eosinophil count with 22 complex metabolic, cardiac, and pulmonary traits and diseases. From the population-based LifeLines Cohort Study (N = 167,729), 13,301 individuals were included. We focused on relationship of eosinophil count with three classes of metabolic (7 traits, 2 diseases), cardiac (6 traits, 2 diseases), and pulmonary (2 traits, 2 diseases) outcomes. Regression analyses were applied in overall, women and men, while adjusted for age, sex, BMI and smoking. A p-value of <0.00076 was considered statistically significant. 58.2% of population were women (mean±SD 51.3±11.1 years old). In overall, one-SD higher of ln-eosinophil count was associated with a 0.04 (±SE ±0.002;p = 6.0×10⁻⁶) SD higher levels in ln-BMI, 0.06 (±0.007;p = 3.1×10⁻¹²) SD in ln-TG, 0.04 (±0.003;p = 7.0×10⁻⁶) SD in TC, 0.04 (±0.004;p = 6.3×10⁻⁷) SD in LDL, 0.04 (±0.006;p = 6.0×10⁻⁶) SD in HbA1c; and with a 0.05 (±0.004;p = 1.7×10⁻⁸) SD lower levels in HDL, 0.05 (±0.007;p = 3.4×10⁻²³) SD in FEV1, and 0.09 (±0.001;p = 6.6×10⁻²⁸) SD in FEV1/FVC. A higher ln-eosinophil count was associated with 1.18 (95%CI 1.09–1.28;p = 2.0×10⁻⁵) odds ratio of obesity, 1.29 (1.19–1.39;p = 1.1×10⁻¹⁰) of metabolic syndrome, 1.40 (1.25–1.56;p = 2.7×10⁻⁹) of COPD and 1.81 (1.61–2.03;p = 1.0×10⁻²³) of asthma. Similar results were found in women. We found no association between ln-eosinophil count either with blood pressure indices in overall, women and men; or with BMI, LDL, HbA1c and obesity in men. In a large population based cohort, we confirmed eosinophil count as a potential factor implicated in metabolic and pulmonary outcomes.

Nasal and pharyngeal eosinophil peroxidase levels in adults with poorly controlled asthma correlate with sputum eosinophilia

The objective of the study was to compare nasal, pharyngeal, and sputum eosinophil peroxidase (EPX) levels with induced sputum eosinophil percentage in 10 adults with poorly controlled asthma and 10 normal controls. EPX was measured using an ELISA and normalized for grams of protein for nasal and pharynx specimens and for mL-gram of protein for sputum. Sputum EPX levels were statistically different between asthma and control subjects (P = 0.024). EPX levels measured in the nasal and pharyngeal swab samples derived from the same patients were also different between asthma and control subjects, each displaying a high degree of significance (P = 0.002). Spearman's correlation coefficients for nasal EPX and pharyngeal EPX levels compared to induced sputum eosinophil percentage were 0.81 (P = 0.0007) and 0.78 (P = 0.0017), respectively. Thus, there is a strong association in a given patient between both nasal and pharyngeal EPX levels and the eosinophil percentage of induced sputum.

Predicting frequent asthma exacerbations using blood eosinophil count and other patient data routinely available in clinical practice

PURPOSE

Acute, severe asthma exacerbations can be difficult to predict and thus prevent. Patients who have frequent exacerbations are of particular concern. Practical exacerbation predictors are needed for these patients in the primary-care setting.

PATIENTS AND METHODS

Medical records of 130,547 asthma patients aged 12-80 years from the UK Optimum Patient Care Research Database and Clinical Practice Research Datalink, 1990-2013, were examined for 1 year before (baseline) and 1 year after (outcome) their most recent blood eosinophil count. Baseline variables predictive (P<0.05) of exacerbation in the outcome year were compared between patients who had two or more exacerbations and those who had no exacerbation or only one exacerbation, using uni- and multivariable logistic regression models. Exacerbation was defined as asthma-related hospital attendance/admission (emergency or inpatient) or acute oral corticosteroid (OCS) course.

RESULTS

Blood eosinophil count >400/µL (versus ≤400/µL) increased the likelihood of two or more exacerbations >1.4-fold (odds ratio [OR]: 1.48 (95% confidence interval [CI]: 1.39, 1.58); P<0.001). Variables that significantly increased the odds by up to 1.4-fold included increasing age (per year), female gender (versus male), being overweight or obese (versus normal body mass index), being a smoker (versus nonsmoker), having anxiety/depression, diabetes, eczema, gastroesophageal reflux disease, or rhinitis, and prescription for acetaminophen or nonsteroidal anti-inflammatory drugs. Compared with treatment at British Thoracic Society step 2 (daily controller ± reliever), treatment at step 0 (none) or 1 (as-needed reliever) increased the odds by 1.2- and 1.6-fold, respectively, and treatment at step 3, 4, or 5 increased the odds by 1.3-, 1.9-, or 3.1-fold, respectively (all P<0.05). Acute OCS use was the single best predictor of two or more exacerbations. Even one course increased the odds by more than threefold (OR: 3.75 [95% CI: 3.50, 4.01]; P<0.001), and three or more courses increased the odds by >25-fold (OR: 25.7 [95% CI: 23.9, 27.6]; P<0.001).

CONCLUSION

Blood eosinophil count and several other variables routinely available in patient records may be used to predict frequent asthma exacerbations.

Assessing the risks and benefits of step-down asthma care: a case-based approach

Guidelines have called for pharmacologic stepped care to improve asthma treatment. Therapeutic options which have been approved provide physicians and their patients alternatives for stepping up asthma treatment to achieve control. However, few studies have been performed to identify and characterize procedures for optimal stepping-down treatment in patients with asthma. The resulting uncertainty as well as a lack of prioritization for asthma reassessment once control has been maintained has led to a lack of well-defined procedures for stepping down asthma treatment. However, recent studies provide guidance regarding the risks of stepping down asthma medications. This review uses case-based examples to demonstrate how health care providers may engage patients in discussions regarding guideline recommendations to promote individualized asthma care.

Changes in blood eosinophilia during omalizumab therapy as a predictor of asthma exacerbation

INTRODUCTION

Omalizumab is a monoclonal anti-immunoglobulin E antibody developed for the treatment of severe allergic asthma. The number of exacerbations used as a parameter of omalizumab therapy efficacy may be insufficient in many cases due to a relatively short time to first evaluation (16 weeks). Therefore, it is advisable to look for parameters of more prognostic value while continuing omalizumab therapy.

AIM

To evaluate usefulness of analysis of changes of blood eosinophilia after 16 weeks of omalizumab therapy as a predictor of asthma exacerbations.

MATERIAL AND METHODS

The study was conducted on a group of 13 patients with severe persistent allergic asthma treated with omalizumab. Blood eosinophil counts were measured before and after 16 weeks of anti-IgE therapy. On the basis of percentage of eosinophilia decrease (> 50% or < 50% of the initial value), patients were divided into two groups. Analysis of the asthma exacerbation rate during 12 months and time to first exacerbation was performed.

RESULTS

In the group with a high decrease in blood eosinophil counts (group 1) we showed a statistically significantly lower asthma exacerbation rate in 12 months compared with the group with a low decrease in blood eosinophil counts (group 2) (p = 0.02). We also observed the tendency to longer time to first asthma exacerbation in group 1 compared to group 2 (p = 0.06).

CONCLUSIONS

Our results showed that a decrease in blood eosinophilia during omalizumab therapy can be a predictor of asthma exacerbation. Evaluation of changes in blood eosinophil count should be taken into the consideration while estimating response to anti-IgE therapy in patients with severe allergic asthma.

Interventions for managing asthma in pregnancy

BACKGROUND

Asthma is the most common respiratory disorder complicating pregnancy, and is associated with a range of adverse maternal and perinatal outcomes. There is strong evidence however, that the adequate control of asthma can improve health outcomes for mothers and their babies. Despite known risks of poorly controlled asthma during pregnancy, a large proportion of women have sub-optimal asthma control, due to concerns surrounding risks of pharmacological agents, and uncertainties regarding the effectiveness and safety of different management strategies.

OBJECTIVES

To assess the effects of interventions (pharmacologic and non-pharmacologic) for managing women's asthma in pregnancy on maternal and fetal/infant outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 June 2014) and the Cochrane Airways Group's Trials Register (4 June 2014).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing any intervention used to manage asthma in pregnancy, with placebo, no intervention, or an alternative intervention. We included pharmacological and non-pharmacological interventions (including combined interventions). Cluster-randomised trials were eligible for inclusion (but none were identified). Cross-over trials were not eligible for inclusion.We included multi-armed trials along with two-armed trials. We also included studies published as abstracts only.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial eligibility and quality and extracted data. Data were checked for accuracy.

MAIN RESULTS

We included eight trials in this review, involving 1181 women and their babies. Overall we judged two trials to be at low risk of bias, two to be of unclear risk of bias, and four to be at moderate risk of bias.Five trials assessed pharmacological agents, including inhaled corticosteroids (beclomethasone or budesonide), inhaled magnesium sulphate, intravenous theophylline, and inhaled beclomethasone verus oral theophylline. Three trials assessed non-pharmacological interventions, including a fractional exhaled nitric oxide (FENO)-based algorithm versus a clinical guideline-based algorithm to adjust inhaled corticosteroid therapy, a pharmacist-led multi-disciplinary approach to management versus standard care, and progressive muscle relaxation (PMR) versus sham training.The eight included trials were assessed under seven separate comparisons. Pharmacological interventionsPrimary outcomes: one trial suggested that inhaled magnesium sulphate in addition to usual treatment could reduce exacerbation frequency in acute asthma (mean difference (MD) -2.80; 95% confidence interval (CI) -3.21 to -2.39; 60 women). One trial assessing the addition of intravenous theophylline to standard care in acute asthma did not report on exacerbations (65 women). No clear difference was shown in the risk of exacerbations with the use of inhaled beclomethasone in addition to usual treatment for maintenance therapy in one trial (risk ratio (RR) 0.36; 95% CI 0.13 to 1.05; 60 women); a second trial also showed no difference, however data were not clearly reported to allow inclusion in a meta-analysis. No difference was shown when inhaled beclomethasone was compared with oral theophylline for maintenance therapy (RR 0.88; 95% CI 0.59 to 1.33; one trial, 385 women). None of these trials reported on neonatal intensive care admissions.

SECONDARY OUTCOMES

inhaled magnesium sulphate in acute asthma was shown to improve lung function measures (one trial, 60 women); intravenous theophylline in acute asthma was not associated with benefits (one trial, 65 women). No clear differences were seen with the addition of inhaled corticosteroids to routine treatment in three trials (374 women). While inhaled beclomethasone, compared with oral theophylline, significantly reduced treatment discontinuation due to adverse effects in one trial (384 women), no other differences were observed, except for higher treatment adherence with theophylline. Four of the five trials did not report on adverse effects. Non-pharmacological interventionsPrimary outcomes: in one trial, the use of a FENO-based algorithm was shown to significantly reduce asthma exacerbations (RR 0.61; 95% CI 0.41 to 0.90; 220 women); and a trend towards fewer neonatal hospitalisations was observed (RR 0.46; 95% CI 0.21 to 1.02; 214 infants). No exacerbations occurred in one trial assessing pharmacist-led management; this approach did not reduce neonatal intensive care admissions (RR 1.50; 95% CI 0.27 to 8.32; 58 infants). One trial (64 women) assessing PMR did not report on exacerbations or neonatal intensive care admissions.

SECONDARY OUTCOMES

the use of a FENO-based algorithm to adjust therapy led to some improvements in quality of life scores, as well as more frequent use of inhaled corticosteroids and long-acting β-agonists, and less frequent use of short-acting β-agonists (one trial, 220 women). The FENO-based algorithm was associated with fewer infants with recurrent episodes of bronchiolitis in their first year of life, and a trend towards fewer episodes of croup for infants. Pharmacist-led management improved asthma control scores at six months (one trial, 60 women); PMR improved lung function and quality of life measures (one trial, 64 women). No other differences between comparisons were observed.

AUTHORS' CONCLUSIONS

Based on eight included trials, of moderate quality overall, no firm conclusions about optimal interventions for managing asthma in pregnancy can be made. Five trials assessing pharmacological interventions did not provide clear evidence of benefits or harms to support or refute current practice. While inhaled magnesium sulphate for acute asthma was shown to reduce exacerbations, this was in one small trial of unclear quality, and thus this finding should be interpreted with caution. Three trials assessing non-pharmacological interventions provided some support for the use of such strategies, however were not powered to detect differences in important maternal and infant outcomes. While a FENO-based algorithm reduced exacerbations, the effects on perinatal outcomes were less certain, and thus widespread implementation is not yet appropriate. Similarly, though positive effects on asthma control were shown with PMR and pharmacist-led management, the evidence to date is insufficient to draw definitive conclusions.In view of the limited evidence base, further randomised trials are required to determine the most effective and safe interventions for asthma in pregnancy. Future trials must be sufficiently powered, and well-designed, to allow differences in important outcomes for mothers and babies to be detected. The impact on health services requires evaluation. Any further trials assessing pharmacological interventions should assess novel agents or those used in current practice. Encouragingly, at least five trials have been identified as planned or underway.

Biomarkers in airway diseases

The inherent limitations of spirometry and clinical history have prompted clinicians and scientists to search for surrogate markers of airway diseases. Although few biomarkers have been widely accepted into the clinical armamentarium, the authors explore three sources of biomarkers that have shown promise as indicators of disease severity and treatment response. In asthma, exhaled nitric oxide measurements can predict steroid responsiveness and sputum eosinophil counts have been used to titrate anti-inflammatory therapies. In chronic obstructive pulmonary disease, inflammatory plasma biomarkers, such as fibrinogen, club cell secretory protein-16 and surfactant protein D, can denote greater severity and predict the risk of exacerbations. While the multitude of disease phenotypes in respiratory medicine make biomarker development especially challenging, these three may soon play key roles in the diagnosis and management of airway diseases.

Managing older patients with coexistent asthma and chronic obstructive pulmonary disease: diagnostic and therapeutic challenges

Asthma and chronic obstructive pulmonary disease (COPD) are common obstructive airway diseases, especially among older people. These conditions are associated with a significant and increasing disease burden. The diagnosis and management of asthma and COPD in older populations are complex, and consequently clinicians are faced with many therapeutic and diagnostic challenges. Both aging and obstructive airway diseases are associated with complex co-morbidities and these coexisting illnesses confound management. Moreover, the age-related physiological changes that occur in the lungs may lead to airflow limitation, and this may be difficult to distinguish from an active disease state. In practice, management of asthma and COPD is informed by disease-specific clinical practice guidelines; however, most older people with these conditions are excluded from clinical trials that are designed to inform practice, creating major evidence gaps. Furthermore, seldom do clinical practice guidelines consider the complexities of management in older populations. The problems experienced by older people are complex and multifactorial and our approach to management must reflect these challenges. Opportunities exist to improve the management and outcomes for older people with obstructive airway disease and there is an urgent need for clinical trials to test management approaches in this population; current research must consider the challenges and evidence gaps that exist.

Identification and validation of nebulized aerosol devices for sputum induction

BACKGROUND

Induced sputum cell counts are a noninvasive and reliable method for evaluating the presence, type and degree of airway inflammation in patients with asthma. Currently, standard nebulizer devices used for sputum induction in multiple patients are labelled as single-patient devices by the manufacturer, which conflicts with infection prevention and control requirements. As such, these devices cannot feasibly be used in a clinical sputum induction program. Therefore, there is a need to identify alternative nebulizer devices that are either disposable or labelled for multipatient use.

OBJECTIVE

To apply validated rigorous, scientific testing methods to identify and validate commercially available nebulizer devices appropriate for use in a clinical sputum induction program.

METHODS

Measurement of nebulized aerosol output and size for the selected nebulizer designs followed robust International Organization for Standardization methods. Sputum induction using two of these nebulizers was successfully performed on 10 healthy adult subjects. The cytotechnologist performing sputum cell counts was blinded to the type of nebulizer used.

RESULTS

The studied nebulizers had variable aerosol outputs. The AeroNeb Solo (Aerogen, Ireland), Omron NE-U17 (Omron, Japan) and EASYneb II (Flaem Nuova, Italy) systems were found to have similar measurements of aerosol size. There was no significant difference in induced sputum cell results between the AeroNeb Solo and EASYneb II devices.

DISCUSSION

There is a need for rigorous, scientific evaluation of nebulizer devices for clinical applications, including sputum induction, for measurement of cell counts.

CONCLUSION

The present study was the most comprehensive analysis of different nebulizer devices for sputum induction to measure cell counts, and provides a framework for appropriate evaluation of nebulizer devices for induced sputum testing.

Clinical utility of asthma biomarkers: from bench to bedside

Asthma is a chronic disease characterized by airway inflammation, bronchial hyperresponsiveness, and recurrent episodes of reversible airway obstruction. The disease is very heterogeneous in onset, course, and response to treatment, and seems to encompass a broad collection of heterogeneous disease subtypes with different underlying pathophysiological mechanisms. There is a strong need for easily interpreted clinical biomarkers to assess the nature and severity of the disease. Currently available biomarkers for clinical practice - for example markers in bronchial lavage, bronchial biopsies, sputum, or fraction of exhaled nitric oxide (FeNO) - are limited due to invasiveness or lack of specificity. The assessment of markers in peripheral blood might be a good alternative to study airway inflammation more specifically, compared to FeNO, and in a less invasive manner, compared to bronchoalveolar lavage, biopsies, or sputum induction. In addition, promising novel biomarkers are discovered in the field of breath metabolomics (eg, volatile organic compounds) and (pharmaco)genomics. Biomarker research in asthma is increasingly shifting from the assessment of the value of single biomarkers to multidimensional approaches in which the clinical value of a combination of various markers is studied. This could eventually lead to the development of a clinically applicable algorithm composed of various markers and clinical features to phenotype asthma and improve diagnosis and asthma management.

Usefulness of induced sputum eosinophil count to assess severity and treatment outcome in asthma patients

Context:

Currently treatment decisions in asthma are governed by clinical assessment and spirometry. Sputum eosinophil, being a marker of airway inflammation, can serve as a tool for assessing severity and response to treatment in asthma patients.

Aims:

To establish correlation between change in sputum eosinophil count and forced expiratory volume in one second (FEV₁)% predicted value of asthma patients in response to treatment. In this study, we also predicted prognosis and treatment outcome of asthma patients from baseline sputum eosinophil count.

Settings and Design:

A longitudinal study was conducted to determine the treatment outcome among newly diagnosed asthma patients who were classified into A (n = 80) and B (n = 80) groups on the basis of initial sputum eosinophil count (A ≥ 3% and B < 3%).

Materials and Methods:

After starting treatment according to Global Initiative for Asthma Guideline, both A and B groups were evaluated every 15 days interval for the 1^st month and monthly thereafter for a total duration of 12 months. In each follow-up visit detailed history, induced sputum eosinophil count and spirometry were done to evaluate severity and treatment outcome.

Results:

FEV₁% predicted of group A asthma patients gradually increased and sputum eosinophil count gradually decreased on treatment. Longer time was required to achieve satisfactory improvement (FEV₁% predicted) in asthma patients with sputum eosinophil count ≥3%. There was statistically significant negative correlation between FEV₁% predicted and sputum eosinophil count (%) in of group A patients in each follow-up visit, with most significant negative correlation found in 8^th visit (r = −0.9237 and P = < 0.001). Change in mean FEV₁% (predicted) from baseline showed strong positive correlation (r = 0.976) with change in reduction of mean sputum eosinophil count at each follow-up visits in group A patients.

Conclusions:

Sputum eosinophil count, being an excellent biomarker of airway inflammation, can serve as a useful marker to assess disease severity, treatment outcome, and prognosis in asthma patients.

Multidimensional assessment and tailored interventions for COPD: respiratory utopia or common sense?

Introduction

The rising disease burden from chronic obstructive pulmonary disease (COPD) requires new approaches.

Method

We suggest an approach based around three elements: inflammometry and multidimensional assessment to identify therapeutic targets and case management to design and implement an individualised treatment programme based on these assessments.

Discussion

This tailored approach to treatment would maximise efficacy, limit cost and permit a better risk–benefit ratio of treatment. The advantages include the ability to add up the benefits of individual therapies leading to a cumulative therapeutic benefit that is greater than each individual therapy alone. We can now design a multifaceted inflammometry intervention for airway diseases based on targeting eosinophilic inflammation, non-eosinophilic pathways and systemic inflammation. COPD is a complex and challenging disease. The use of inflammometry and multidimensional assessment is necessary to identify relevant treatment targets and maximise the scope of therapy while limiting unnecessary use of drugs. An individualised programme of management can be designed and coordinated by using a case manager. This new approach may provide tangible benefits to people with COPD.

Elevated peripheral eosinophils are associated with new-onset and persistent wheeze and airflow obstruction in world trade center-exposed individuals

BACKGROUND

Exposure to World Trade Center (WTC) dust and fumes is associated with the onset of asthma-like respiratory symptoms in rescue and recovery workers and exposed community members. Eosinophilic inflammation with increased lung and peripheral eosinophils has been described in subpopulations with asthma. We hypothesized that persistent asthma-like symptoms in WTC-exposed individuals would be associated with systemic inflammation characterized by peripheral eosinophils.

METHODS

The WTC Environmental Health Center (WTC EHC) is a treatment program for local residents, local workers, and cleanup workers with presumed WTC-related symptoms. Patients undergo a standardized evaluation including questionnaires and complete blood count. Between September 2005 and March 2009, 2462 individuals enrolled in the program and were available for analysis. Individuals with preexisting respiratory symptoms or lung disease diagnoses prior to September 2001 and current or significant tobacco use were excluded,

RESULTS

One thousand five hundred and seventeen individuals met the inclusion criteria. Patients had a mean age of 47 years, were mostly female (51%), and had a diverse race/ethnicity. Respiratory symptoms that developed after WTC dust/fume exposure and remained persistent included dyspnea on exertion (68%), cough (57%), chest tightness (47%), and wheeze (33%). A larger percentage of patients with wheeze had elevated peripheral eosinophils compared with those without wheeze (21% vs. 13%, p < .0001). Individuals with elevated peripheral eosinophils were more likely to have airflow obstruction on spirometry (16% vs. 7%, p = .0003).

CONCLUSION

Peripheral eosinophils were associated with wheeze and airflow obstruction in a diverse WTC-exposed population. These data suggest that eosinophils may participate in lung inflammation in this population with symptoms consistent with WTC-related asthma.

Galectin-10, a potential biomarker of eosinophilic airway inflammation

Measurement of eosinophilic airway inflammation can assist in the diagnosis of allergic asthma and in the management of exacerbations, however its clinical implementation remains difficult. Galectin-10 has been associated with eosinophilic inflammation and has the potential to be used as a surrogate biomarker. This study aimed to assess the relationship between galectin-10 in sputum with sputum eosinophil counts, the current gold standard of eosinophil inflammation in the lung. Thirty-eight sputum samples were processed for both eosinophil counts by cytospins and semi-quantitative measurements of galectin-10 by western blots. A strong association was observed between galectin-10 levels in sputum and sputum eosinophil measurements, and they accurately determined sputum eosinophilia. The results support the potential for galectin-10 to be used as a surrogate biomarker of eosinophilic airway inflammation.

Canadian Thoracic Society 2012 guideline update: diagnosis and management of asthma in preschoolers, children and adults

BACKGROUND

In 2010, the Canadian Thoracic Society (CTS) published a Consensus Summary for the diagnosis and management of asthma in children six years of age and older, and adults, including an updated Asthma Management Continuum. The CTS Asthma Clinical Assembly subsequently began a formal clinical practice guideline update process, focusing, in this first iteration, on topics of controversy and⁄or gaps in the previous guidelines.

METHODS

Four clinical questions were identified as a focus for the updated guideline: the role of noninvasive measurements of airway inflammation for the adjustment of anti-inflammatory therapy; the initiation of adjunct therapy to inhaled corticosteroids (ICS) for uncontrolled asthma; the role of a single inhaler of an ICS⁄long-acting beta(2)-agonist combination as a reliever, and as a reliever and a controller; and the escalation of controller medication for acute loss of asthma control as part of a self-management action plan. The expert panel followed an adaptation process to identify and appraise existing guidelines on the specified topics. In addition, literature searches were performed to identify relevant systematic reviews and randomized controlled trials. The panel formally assessed and graded the evidence, and made 34 recommendations.

RESULTS

The updated guideline recommendations outline a role for inclusion of assessment of sputum eosinophils, in addition to standard measures of asthma control, to guide adjustment of controller therapy in adults with moderate to severe asthma. Appraisal of the evidence regarding which adjunct controller therapy to add to ICS and at what ICS dose to begin adjunct therapy in children and adults with poor asthma control supported the 2010 CTS Consensus Summary recommendations. New recommendations for the adjustment of controller medication within written action plans are provided. Finally, priority areas for future research were identified.

CONCLUSIONS

The present clinical practice guideline is the first update of the CTS Asthma Guidelines following the Canadian Respiratory Guidelines Committee's new guideline development process. Tools and strategies to support guideline implementation will be developed and the CTS will continue to regularly provide updates reflecting new evidence.

Measures of asthma control

PURPOSE OF REVIEW

Over the past decade, the concept of asthma control as distinct from asthma severity has been clearly defined. Well controlled asthma is the goal of therapy in all asthma patients. This review is a comprehensive description of the tools currently available for a methodical assessment of different aspects of asthma control in clinical practice and research.

RECENT FINDINGS

Several questionnaires for assessing asthma control have been extensively validated in adults. In children, validation data are less extensive. Considerable overlap exists between asthma control measures and measures of asthma-specific quality of life. Asthma-specific quality-of-life questionnaires have been used as primary outcome measures in major clinical trials evaluating asthma therapy. Biomarkers that reflect eosinophilic inflammation of the airways are used as intermediate outcome measures to reflect the biological basis of asthma control. There is some controversy, however, over which biomarkers are best incorporated into therapeutic algorithms that attempt to achieve maximal asthma control while minimizing treatment intensity.

SUMMARY

In designing clinical studies to evaluate different asthma therapies, researchers will find this review to be a useful resource in terms of choosing the appropriate tool for assessing asthma control. This is also a valuable resource for a methodical assessment of response to asthma therapy in routine clinical care.

New approaches to managing asthma: a US perspective

Despite remarkable advances in diagnosis and long-term management, asthma remains a serious public health concern. Newly updated expert guidelines emphasize the intra- and inter-individual variability of asthma and highlight the importance of periodic assessment of asthma control. These guidelines update recommendations for step-wise asthma treatment, address the burgeoning field of asthma diagnostics, and stress the importance of a patient and health care professional partnership, including written action plans and self monitoring. The field of asthma therapeutics is expanding rapidly, with promising new treatment options available or in development that may address some of the existing barriers to successful asthma management. These approaches simplify treatment, use combinations of agents in one delivery device that have complementary actions, or target specific pathways involved in asthma patho-physiology. Considerable activity is taking place in asthma pharmacogenetics. This review provides an overview of these new approaches to managing asthma, including their present status and future potential.

An integrative review of systematic reviews related to the management of breathlessness in respiratory illnesses

BACKGROUND

Breathlessness is a debilitating and distressing symptom in a wide variety of diseases and still a difficult symptom to manage. An integrative review of systematic reviews of non-pharmacological and pharmacological interventions for breathlessness in non-malignant disease was undertaken to identify the current state of clinical understanding of the management of breathlessness and highlight promising interventions that merit further investigation.

METHODS

Systematic reviews were identified via electronic databases between July 2007 and September 2009. Reviews were included within the study if they reported research on adult participants using either a measure of breathlessness or some other measure of respiratory symptoms.

RESULTS

In total 219 systematic reviews were identified and 153 included within the final review, of these 59 addressed non-pharmacological interventions and 94 addressed pharmacological interventions. The reviews covered in excess of 2000 trials. The majority of systematic reviews were conducted on interventions for asthma and COPD, and mainly focussed upon a small number of pharmacological interventions such as corticosteroids and bronchodilators, including beta-agonists. In contrast, other conditions involving breathlessness have received little or no attention and studies continue to focus upon pharmacological approaches. Moreover, although there are a number of non-pharmacological studies that have shown some promise, particularly for COPD, their conclusions are limited by a lack of good quality evidence from RCTs, small sample sizes and limited replication.

CONCLUSIONS

More research should focus in the future on the management of breathlessness in respiratory diseases other than asthma and COPD. In addition, pharmacological treatments do not completely manage breathlessness and have an added burden of side effects. It is therefore important to focus more research on promising non-pharmacological interventions.

Section 3. A discussion of flexible dosing and patient-centered therapy: highlights of the asthma summit 2009: beyond the guidelines

Despite positive clinical experience and the published clinical benefits of monotherapy with low-or medium-dose inhaled corticosteroids or combination therapy with ICS + long-acting beta-agonist to treat asthma, many patients remain suboptimally controlled. Alternative approaches are needed, and 3 options that have had some success are: 1) using the patient's level of inflammation by established biomarkers to set treatment; 2) self-management incorporating flexible dosing; and 3) using a single inhaler for rescue and maintenance therapy. Which strategy for which patient depends ultimately on the individual patient's disease burden, life-style, comorbidities, preferences, and his or her ability to self-manage the disease, including assessing symptoms and adhering with therapy.

Tailored interventions based on exhaled nitric oxide versus clinical symptoms for asthma in children and adults

BACKGROUND

The measurement of severity and control of asthma in both children and adults can be based on subjective or objective measures. It has been advocated that fractional exhaled nitric oxide (FeNO) can be used to monitor airway inflammation as it correlates with some markers of asthma. Interventions for asthma therapies have been traditionally based on symptoms and/or spirometry.

OBJECTIVES

To evaluate the efficacy of tailoring asthma interventions based on exhaled nitric oxide in comparison to clinical symptoms (with or without spirometry/peak flow) for asthma related outcomes in children and adults.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles. The last search was completed in February 2009.

SELECTION CRITERIA

All randomised controlled comparisons of adjustment of asthma therapy based on exhaled nitric oxide compared to traditional methods (primarily clinical symptoms and spirometry/peak flow).

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. Relevant studies were independently selected in duplicate. Two authors independently assessed trial quality and extracted data. Authors were contacted for further information with response from one.

MAIN RESULTS

Two studies have been added for this update, which now includes six (2 adults and 4 children/adolescent) studies; these studies differed in a variety of ways including definition of asthma exacerbations, FeNO cut off levels, the way in which FeNO was used to adjust therapy and duration of study. Of 1053 participants randomised, 1010 completed the trials. In the meta-analysis, there was no significant difference between groups for the primary outcome of asthma exacerbations or for other outcomes (clinical symptoms, FeNO level and spirometry). In post-hoc analysis, a significant reduction in mean final daily dose inhaled corticosteroid per adult was found in the group where treatment was based on FeNO in comparison to clinical symptoms, (mean difference -450 mcg; 95% CI -677 to -223 mcg budesonide equivalent/day). However, the total amount of inhaled corticosteroid used in one of the adult studies was 11% greater in the FeNO arm. In contrast, in the paediatric studies, there was a significant increase in inhaled corticosteroid dose in the FeNO strategy arm (mean difference of 140 mcg; 95% CI 29 to 251, mcg budesonide equivalent/day).

AUTHORS' CONCLUSIONS

Tailoring the dose of inhaled corticosteroids based on exhaled nitric oxide in comparison to clinical symptoms was carried out in different ways in the six studies and found only modest benefit at best and potentially higher doses of inhaled corticosteroids in children. The role of utilising exhaled nitric oxide to tailor the dose of inhaled corticosteroids cannot be routinely recommended for clinical practice at this stage and remains uncertain.

Innate cells and T helper 2 cell immunity in airway inflammation

Activated mast cells, eosinophils, and basophils infiltrate the airways of asthmatics as a result of an overexuberant T helper 2 (Th2) cell immune response that drives the production of IgE, primes mast cells and basophils, and promotes tissue eosinophilia and mast cell hyperplasia. Recent evidence demonstrates that these innate effectors can be activated outside of this classical Th2 cell paradigm and that they have additional roles in promoting the development of innate and adaptive pulmonary inflammation. There is also an appreciation for the role of airway epithelial cells in orchestrating allergic pulmonary inflammation. Emerging data from basic research highlight the involvement of many unique pathways in the inflammation triggered by complex native allergens and microbes at the airway mucosal surface. Here, we review the role of effector cells and airway epithelial cells in augmenting and, at times, bypassing traditional Th2 cell-mediated allergic inflammation.

Metabolomic biomarkers in a model of asthma exacerbation: urine nuclear magnetic resonance

RATIONALE

Airway obstruction in patients with asthma is associated with airway dysfunction and inflammation. Objective measurements including sputum analysis can guide therapy, but this is often not possible in typical clinical settings. Metabolomics is the study of molecules generated by metabolic pathways. We hypothesize that airway dysfunction and inflammation in an animal model of asthma would produce unique patterns of urine metabolites measured by multivariate statistical analysis of high-resolution proton nuclear magnetic resonance ((1)H NMR) spectroscopy data.

OBJECTIVES

To develop a noninvasive means of monitoring asthma status by metabolomics and urine sampling.

METHODS

Five groups of guinea pigs were studied: control, control treated with dexamethasone, sensitized (ovalbumin, administered intraperitoneally), sensitized and challenged (ovalbumin, administered intraperitoneally, plus ovalbumin aerosol), and sensitized-challenged with dexamethasone. Airway hyperreactivity (AHR) to histamine (administered intravenously) and inflammation were measured. Multivariate statistical analysis of NMR spectra based on a library of known urine metabolites was performed by partial least-squares discriminant analysis. In addition, the raw NMR spectra exported as xy-trace data underwent linear discriminant analysis.

MEASUREMENTS AND MAIN RESULTS

Challenged guinea pigs developed AHR and increased inflammation compared with sensitized or control animals. Dexamethasone significantly improved AHR. Using concentration differences in metabolites, partial least-squares discriminant analysis could discriminate challenged animals with 90% accuracy. Using only three or four regions of the NMR spectra, linear discriminant analysis-based classification demonstrated 80-90% separation of the animal groups.

CONCLUSIONS

Urine metabolites correlate with airway dysfunction in an asthma model. Urine NMR analysis is a promising, noninvasive technique for monitoring asthma in humans.

Targeting eosinophils in asthma

Recruitment of eosinophils has long been recognized as a hallmark of the inflammatory response in asthma. However, the functions of this population of cells in host defense remain poorly understood. Eosinophils play an important part in the inflammatory response and have key regulatory roles in the afferent arm of the immune response. More recently, eosinophils have been demonstrated to participate in host defense against respiratory viruses. The specific contributions of eosinophils to the pathophysiology of asthma remain controversial. However, the balance of evidence indicates that they have a significant role in the disease, suggesting that they may be appropriate targets for therapy. Towards this end, a novel intervention of considerable potential interest is the use of an antibody directed against the beta common chain of the receptor for interleukin-3, interleukin-5 and granulocyte-macrophage colony-stimulating factor. However, eliminating eosinophils may not be a risk-free therapeutic strategy, as there is potentially an increased likelihood of respiratory viral infections. This may predispose to the development of acute exacerbations of asthma, an outcome that would have significant clinical implications.