Development of chronic airway obstruction in patients with eosinophilic bronchitis: a prospective follow-up study

Hidden Comorbidities in Asthma: A Perspective for a Personalized Approach

Bronchial asthma is the most frequent inflammatory non-communicable condition affecting the airways worldwide. It is commonly associated with concomitant conditions, which substantially contribute to its burden, whether they involve the lung or other districts. The present review aims at providing an overview of the recent acquisitions in terms of asthma concomitant systemic conditions, besides the commonly known respiratory comorbidities. The most recent research has highlighted a number of pathobiological interactions between asthma and other organs in the view of a shared immunological background underling different diseases. A bi-univocal relationship between asthma and common conditions, including cardiovascular, metabolic or neurodegenerative diseases, as well as rare disorders such as sickle cell disease, α1-Antitrypsin deficiency and immunologic conditions with hyper-eosinophilia, should be considered and explored, in terms of diagnostic work-up and long-term assessment of asthma patients. The relevance of that acquisition is of utmost importance in the management of asthma patients and paves the way to a new approach in the light of a personalized medicine perspective, besides targeted therapies.

Narrative Review: how long should patients with cough variant asthma or non-asthmatic eosinophilic bronchitis be treated?

The causes of chronic cough can be categorized into eosinophilic and noneosinophilic disorders, and approximately 30% to 50% of people with chronic cough have eosinophilic airway inflammation, the presence of which can be confirmed by sputum eosinophilia or elevated exhaled nitric-oxide levels. Cough variant asthma (CVA) is a phenotype of asthma which lacks wheezing or dyspnea, and consistently one of the most common causes of chronic cough worldwide. CVA and non-asthmatic eosinophilic bronchitis (NAEB) shares common feature such as chronic dry cough, eosinophilic inflammation, and development of chronic airflow obstruction (CAO) and asthma in a subset of patients. The distinctive characteristic of these conditions is the presence of airway hyperresponsiveness in CVA but not in NAEB. Coughing is responsive to bronchodilators such as beta-agonists in CVA, but such feature has not been clarified in NAEB. Inhaled corticosteroids (ICSs) are the first-line treatment, and leukotriene receptor antagonists are also effective, in patients with both CVA and NAEB. This review will give an outline of clinical and physiological features, and prognosis and its determinants of CVA and EBNA. Further, the rationale and evidence, despite limited, for the need of long-term treatment will be discussed. The development of airway remodeling due to mechanical stress to the airways exerted by long-standing coughing will also be discussed.

Characterization of Occupational Eosinophilic Bronchitis in a Multicenter Cohort of Subjects with Work-Related Asthma Symptoms

BACKGROUND

Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports.

OBJECTIVE

We investigated the clinical and inflammatory characteristics of subjects with OEB identified in a cohort of subjects who completed a specific inhalation challenge (SIC) with occupational agents.

METHODS

In this retrospective multicenter study, OEB was defined by (1) a fall in FEV1 less than 15% during the SIC and the absence of nonspecific bronchial hyperresponsiveness both before and after the SIC and (2) a postchallenge increase of 3% or more in sputum eosinophils. The subjects who fulfilled these criteria were compared with 226 subjects with a negative SIC and 30 subjects with a positive SIC who failed to show baseline nonspecific bronchial hyperresponsiveness.

RESULTS

An isolated increase in postchallenge sputum eosinophils was documented in 33 of 259 subjects (13%) with a negative SIC. These subjects reported significantly more often an isolated cough at work compared with the negative and positive SIC controls. When compared with positive SIC controls, the subjects with OEB experienced less frequently work-related wheezing and reported a shorter duration of symptoms at work. The sensitivity of the post-SIC increase in fractional exhaled nitric oxide in identifying OEB among subjects with a negative SIC was low, ranging from 43% to 24% using cutoff values of 8 ppb to 17.5 ppb, whereas the specificity was high (90%-97%).

CONCLUSIONS

This study highlights the relevance of induced sputum analysis in the investigation of work-related asthma symptoms to identify isolated increases in sputum eosinophils that are consistent with a diagnosis of OEB.

Cough and Eosinophilia

Eosinophilic airway inflammation is observed in 30% to 50% of chronic cough sufferers. It is a common feature of asthma and upper airway cough syndrome, and it is required in the diagnosis of nonasthmatic eosinophilic bronchitis. Our understanding of the mechanisms underlying allergic and nonallergic eosinophilic inflammation have evolved tremendously in the last 2 decades, but the cause of this inflammation in any individual is often uncertain. Inhaled corticosteroids are the mainstay therapy for cough due to asthma or nonasthmatic eosinophilic bronchitis, and response is related to the presence of biomarkers of eosinophilic airway inflammation. In upper airway cough syndrome, nasal topical corticosteroids are beneficial in allergic rhinitis and chronic rhinosinusitis with polyposis. This review will describe the diagnosis, current and possible future treatments, and prognosis of chronic cough in adults with eosinophilic inflammation.

Perspectives on chronic cough in Korea

Chronic cough is a common condition, and generally affects about 3% of Korean adults with a significant influence on quality of life (QoL). Despite continued clinical and academic efforts, there are unmet needs for chronic cough prevention and management in Korea. Epidemiologically, there are two major challenges: an aging population and air pollution. Korea is one of the most rapidly aging countries, and the relative proportion of elderly to younger people is expected to double within the next two decades. Air pollution is a major concern, but there is very limited evidence on the effects of air pollutant on cough in Korean patients. Clinically, upper and lower airway diseases, such as rhinitis/rhinosinusitis and cough variant asthma/eosinophilic bronchitis, are reported to account for about 75% of chronic cough in Korean adults, which formed the basis in formulating clinical practice guidelines. However, further studies are warranted to resolve clinical uncertainty, particularly for the evaluation and treatment of upper airway conditions in chronic cough. The prevalence of gastroesophageal reflux disease (GERD) is increasing, thus its relevance to cough among Koreans may warrant re-evaluation. Infection-associated chronic cough, such as tuberculosis, is another continuing concern. The proportion of chronic refractory or unexplained cough is assumed to be 10–20% among patients visiting referral clinics for chronic cough. This review presents our perspectives on current epidemiological and clinical issues of chronic cough in Korea, and addresses major knowledge gaps and future research priorities.

Blood Eosinophil Count as a Predictor of Lung Function Decline in Healthy Individuals

BACKGROUND

Little is known about the effect of blood eosinophil count (BEC) on a decline in lung function in healthy individuals.

OBJECTIVE

Using a well-established health screening database, we assessed the associations between BEC and a decline in lung function, measured as the forced expiratory volume in 1 second (FEV₁).

METHODS

Serial BEC and FEV₁ data were analyzed using linear mixed models adjusted for gender, height, and smoking status. The association between BEC consistency and a decline in FEV₁ was evaluated in subpopulation analyses.

RESULTS

A total of 4634 individuals were enrolled. The mean number of health screenings was 7.49 over an average of 11.74 years of observation. A higher log2-transformed BEC was significantly associated with a greater decline in FEV₁ that was stronger in nonsmokers (P = 8.56 × 10^-8) than in smokers (P = 1.52 × 10^-3). In subpopulation analyses of 2018 individuals with consistent BECs, those with BECs consistently ≥100/μL (P = 4.58 × 10^-6), ≥200/μL (P = 3.53 × 10^-7), and ≥300/μL (P = 1.12 × 10^-3) had a significantly higher dose-dependent FEV₁ decline than those with BECs consistently <100/μL. A BEC threshold of 100/μL in nonsmokers and 200/μL in smokers may predict an accelerated decline in FEV₁.

CONCLUSIONS

BEC is associated with a decline in FEV₁, and a consistently high BEC is an independent risk factor for an accelerated decline in FEV₁. These results suggest the use of the BEC to identify healthy individuals at high risk for developing chronic lung disease, which in turn may enable a tailored preventive strategy.

Duration of treatment with inhaled corticosteroids in nonasthmatic eosinophilic bronchitis: a randomized open label trial

BACKGROUND

Nonasthmatic eosinophilic bronchitis (NAEB) responds well to inhaled corticosteroids (ICS), while recurrence is common after discontinuing treatment. There are no data available to show whether treatment duration of ICS in patients with NAEB is related to recurrence. We aim to evaluate the effect of different duration of treatment with ICS on relapse of NAEB.

METHODS

A total of 101 patients with NAEB were recruited to the open label, randomized, parallel-group trial. Patients were randomized to receive 1-month, 2-month, or 4-month treatment with inhaled budesonide (200 μg, twice daily). Sputum induction, cough visual analogue scale (VAS), and cough symptom score (CSS) were conducted at baseline and after completion of treatment. The patients were followed up for 1 year after treatment. The primary outcome was the relapse rate of NAEB in 1 year.

RESULTS

ICS significantly decreased cough VAS, CSS, and sputum eosinophilia among these groups. There were no statistically significant between-group differences in cough VAS, CSS scores, and sputum eosinophil counts at the end of treatment, and no significant between-group differences in those changes from baseline to post-treatment. Significantly, more participants in the 1-month treatment group experienced a recurring episode of NAEB than those in the 3-month treatment group (41.9% versus 12.0%, p = 0.0137) at 1-year follow-up. The 2-month treatment group showed a lower tendency, with a relapse rate of 20.0% (p = 0.0644).

CONCLUSIONS

Our results suggest that inhaled corticosteroids should be administrated for at least 2 months to reduce the relapse of NAEB.

CLINICAL TRIAL REGISTRATION

The study was registered on ClinicalTrials.gov (NCT02002715). The reviews of this paper are available via the supplemental material section.

Managing Chronic Cough Due to Asthma and NAEB in Adults and Adolescents: CHEST Guideline and Expert Panel Report

BACKGROUND

Asthma and non-asthmatic eosinophilic bronchitis (NAEB) are among the commonest causes of chronic cough in adults. We sought to determine the role of non-invasive measurements of airway inflammation, including induced sputum and fractional exhaled nitric oxide, in the evaluation of cough associated with asthma, and what the best treatment is for cough due to asthma or NAEB.

METHODS

We undertook three systematic reviews of randomized controlled trials and observational trials of adults and adolescents > 12 years of age with a chronic cough due to asthma or NAEB. Eligible studies were identified in MEDLINE, CENTRAL, and SCOPUS and assessed for relevance and quality. Guidelines were developed and voted upon using CHEST guideline methodology.

RESULTS

Of the citations reviewed, 3/1,175, 53/656, and 6/134 were identified as being eligible for inclusion in the three systematic reviews, respectively. In contrast to established guidelines for asthma therapies in general and the inclusion in some guidelines for a role of biomarkers of airway inflammation to guide treatment in severe disease, the evidence of specific benefit related to the use of non-invasive biomarkers in patients with chronic cough due to asthma was weak. The best therapeutic option for cough in asthma or NAEB is inhaled corticosteroids followed by leukotriene receptor antagonism.

CONCLUSIONS

This guideline offers recommendations on the role of non-invasive measurements of airway inflammation and treatment for cough due to asthma or NAEB based on the available literature, and identifies gaps in knowledge and areas for future research.

Relationship of Microbial Profile With Airway Immune Response in Eosinophilic or Neutrophilic Inflammation of Asthmatics

PURPOSE

Different characteristics of airway microbiome in asthmatics may lead to differential immune responses, which in turn cause eosinophilic or neutrophilic airway inflammation. However, the relationships among these factors have yet to be fully elucidated.

METHODS

Microbes in induced sputum samples were subjected to sequence analysis of 16S rRNA. Airway inflammatory phenotypes were defined as neutrophils (>60%) and eosinophils (>3%), and inflammation endotypes were defined by levels of T helper (Th) 1 (interferon-γ), Th2 (interleukin [IL]-5 and IL-13), Th-17 (IL-17), and innate Th2 (IL-25, IL-33, and thymic stromal lymphopoietin) cytokines, inflammasomes (IL-1β), epithelial activation markers (granulocyte-macrophage colony-stimulating factor and IL-8), and Inflammation (IL-6 and tumor necrosis factor-α) cytokines in sputum supernatants was assessed by enzyme-linked immunosorbent assay.

RESULTS

The numbers of operational taxonomic units were significantly higher in the mixed (n = 21) and neutrophilic (n = 23) inflammation groups than in the paucigranulocytic inflammation group (n = 19; p < 0.05). At the species level, Granulicatella adiacens, Streptococcus parasanguinis, Streptococcus pneumoniae, Veillonella rogosae, Haemophilus parainfluenzae, and Neisseria perflava levels were significantly higher in the eosinophilic inflammation group (n = 20), whereas JYGU_s levels were significantly higher in the neutrophilic inflammation group compared to the other subtypes (p < 0.05). Additionally, IL-5 and IL-13 concentrations were correlated with the percentage of eosinophils (p < 0.05) and IL-13 levels were positively correlated with the read counts of Porphyromonas pasteri and V. rogosae (p < 0.05). IL-1β concentrations were correlated with the percentage of neutrophils (p < 0.05). had a tendency to be positively correlated with the read count of JYGU_s (p = 0.095), and was negatively correlated with that of S. pneumoniae (p < 0.05).

CONCLUSIONS

Difference of microbial patterns in airways may induce distinctive endotypes of asthma, which is responsible for the neutrophilic or eosinophilic inflammation in asthma.

Activation of Transient Receptor Potential Melastatin Family Member 8 (TRPM8) Receptors Induces Proinflammatory Cytokine Expressions in Bronchial Epithelial Cells

Purpose

Cold air is a major environmental factor that exacerbates asthma. Transient receptor potential melastatin family member 8 (TRPM8) is a cold-sensing channel expressed in the airway epithelium. However, its role in airway inflammation remains unknown. We investigated the role of TRPM8 in innate immune responses in bronchial epithelial cells and asthmatic subjects.

Methods

The TRPM8 mRNA and protein expression on BEAS2B human bronchial epithelial cells was examined by real-time polymerase chain reaction (PCR), immunofluorescence staining and western blotting. Additionally, interleukin (IL)-4, IL-6, IL-8, IL-13, IL-25 and thymic stromal lymphopoietin (TSLP) levels before and after menthol, dexamethasone and N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl) piperazine-1-carboxamide (BCTC) treatments were measured via real-time PCR. TRPM8 protein levels in the supernatants of induced sputum from asthmatic subjects and normal control subjects were measured using enzyme-linked immunosorbent assay, and mRNA levels in sputum cell lysates were measured using real-time PCR.

Results

Treatment with up to 2 mM menthol dose-dependently increased TRPM8 mRNA and protein in BEAS2B cells compared to untreated cells (P < 0.001) and concomitantly increased IL-25 and TSLP mRNA (P < 0.05), but not IL-33 mRNA. BCTC (10 μM) significantly abolished menthol-induced up-regulation of TRPM8 mRNA and protein and IL-25 and TSLP mRNA (P < 0.01). TRPM8 protein levels were higher in the supernatants of induced sputum from asthmatic subjects (n = 107) than in those from healthy controls (n = 19) (P < 0.001), and IL-25, TSLP and IL-33 mRNA levels were concomitantly increased (P < 0.001). Additionally, TRPM8 mRNA levels correlated strongly with those of IL-25 and TSLP (P < 0.001), and TRPM8 protein levels were significantly higher in bronchodilator-responsive asthmatic subjects than in nonresponders.

Conclusions

TRPM8 may be involved in the airway epithelial cell innate immune response and a molecular target for the treatment of asthma.

Clinical Outcome of Eosinophilic Airway Inflammation in Chronic Airway Diseases Including Nonasthmatic Eosinophilic Bronchitis

We enrolled patients with confirmed sputum eosinophilia who had visited our tertiary referral hospital between 2012 and 2015. We evaluated the incidence and predictors of exacerbations in patients with nonasthmatic eosinophilic bronchitis (NAEB), and investigated predictors of improvement in eosinophilic inflammation in chronic airway diseases with or without persistent airflow limitation. In total, 398 patients with sputum eosinophilia were enrolled. Of these, 152 (38.2%) had NAEB. The incidence rate of exacerbations requiring treatment with antibiotics, systemic corticosteroids, or hospital admission was 0.13 per patient-year (95% CI, 0.06-0.19) in NAEB. Inhaled corticosteroid (ICS) did not affect the risk of exacerbations, even in an analysis of propensity score. One hundred seventy-six patients had chronic airway diseases; in 37 of these (21.0%), sputum eosinophilia had improved at the 1-year follow-up. Patients who had persistent airflow limitation were less likely to show an improvement in eosinophilic inflammation (aOR, 0.26; 95% CI, 0.09-0.77) when they were treated with ICSs for less than 75% of the follow-up days. Exacerbations requiring systemic corticosteroids, antibiotics, or hospitalization did occur, although infrequently, in NAEB patients. Among patients with chronic airway diseases, those with persistent airflow limitation were less likely to show an improvement in eosinophilic airway inflammation.

Non-astmatic Eosinophilic Bronchitis

Non-asthmatic eosinophilic bronchitis (NAEB) is eosinophilic inflammation of the respiratory tract, without any bronchospasm. In this article, we want to draw attention to the NAEB. It should also be considered in differential diagnosis of chronic cough. Eosinophilia is present in all induced or spontaneous sputum samples of NAEB patients. NAEB patients and asthmatic patients have similar airway inflammation. Remarkably, NAEB mainly occurs in the lower airways. Unlike asthma, mast cells in NAEB are active in the bronchial epithelium. Diagnosis is based on the clinical, radiological, and spirometric measurements of other causes of chronic cough (Post-nasal discharge syndrome, asthma, gastroesophageal reflux etc.) and the assessment of inflammation in the lower respiratory tract. Airway inflammation can be assessed by sputum induction. The main treatment is anti-inflammatory therapy with inhaled corticosteroids and taking protective measures if inflammation is due to occupational exposure or allergen inhalation. If NAEB is untreated, it may be transient, episodic, or persistent; rarely, long-term oral steroid treatment may be required in patients. There is a requirement for studies that investigate the role of non-invasive markers of chronic inflammation associated with NAEB and the effectiveness of other treatments.

Role of S100A9 in the development of neutrophilic inflammation in asthmatics and in a murine model

S100A9 is an endogenous danger signal that promotes and exacerbates the neutrophilic inflammatory response. To investigate the role of S100A9 in neutrophilic asthma, S100A9 levels were measured in sputum from 101 steroid-naïve asthmatics using an ELISA kit and the levels were significantly correlated with percentages of neutrophils in sputum. Intranasal administration of recombinant S100A9 markedly increased neutrophil numbers at 8h and 24h later with concomitant elevation of IL-1β, IL-17, and IFN-γ levels. Treatment with an anti-S100A9 antibody restored the increased numbers of neutrophils and the increased airway resistance in OVA/CFA mice toward the levels of sham-treated mice. Concomitantly, the S100A9 and neutrophil elastase double positive cells were markedly reduced with attenuation of IL-1β, IL-17, and IFN-γ levels by the treatment with the anti-S100A9 antibody. Our data support a role of S100A9 to initiate and amplify the neutrophilic inflammation in asthma, possibly via inducing IL-1β, IL-17 and IFN-γ.

Prevalence of Respiratory Viral Infections in Korean Adult Asthmatics With Acute Exacerbations: Comparison With Those With Stable State

PURPOSE

Viral infections are involved in ~50% of exacerbations among Caucasian adult asthmatics. However, there have been few reports on the causative virus of exacerbations in Korean adult asthmatics. Thus, we compared frequencies and types of viruses between lower respiratory tract illnesses (LRTIs) with exacerbations (exacerbated LRTIs) and those without exacerbations (stable LRTIs) to evaluate contribution of respiratory viruses to exacerbations.

METHODS

Viral RNA was extracted from sputum using the Viral Gene-spin™ Kit. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect adenovirus (ADV), metapneumovirus (MPV), parainfluenza virus (PIV) 1/2/3, influenza virus (IFV) A, IFV B, respiratory syncytial virus (RSV) A/B, and rhinovirus (RV) A.

RESULTS

Among the 259 patients, 210 underwent a single sputum examination, and the remaining 49 underwent 2 to 4 sputum examinations. Virus was detected in 68 of the 259 exacerbated episodes and in 11 of the 64 stable episodes. Among the exacerbated episodes, RV was the most frequently detected virus, followed by influenza A, parainfluenza, RSV A/B, and ADV. Among the 11 stable episodes, RV was most frequently detected. Detection rates of these viruses did not differ between the 2 groups (P>0.05). Thirty-five patients underwent the virus examination at 2 episodes of exacerbation, while 14 patients underwent at each time of exacerbated and stable episodes. Virus detection rate at the second examination was significantly higher in cases with 2 exacerbation episodes than in those with initial exacerbation and sequential stable episodes (P=0.003). A seasonal pattern was noted in the detection rates of RV (September to December), IFV (January to April), PIV (May to September), and RSV A/B (September to April).

CONCLUSIONS

Respiratory viruses were identified in approximately 20% of LRTI irrespective of the presence of asthma exacerbation. RV and IFV A/B were most frequently detected. A group of patients experienced frequent viral infections followed by asthma exacerbations.

Will nonasthmatic eosinophilic bronchitis develop into chronic airway obstruction?: a prospective, observational study

OBJECTIVE

The long-term prognosis of nonasthmatic eosinophilic bronchitis (NAEB) is still unclear. The aim of this study was to observe the frequency of relapse among patients with NAEB and the likelihood of NAEB developing into chronic airflow obstruction over time.

METHODS

Patients with NAEB were followed for at least 1 year between 2003 and 2013. During this period, we evaluated clinical symptoms, sputum eosinophil count, spirometry, and bronchial hyperresponsiveness. A linear mixed model was adopted to determine the relationship between time and lung function.

RESULTS

A total of 234 patients with NAEB were identified, of whom 141 were followed for > 1 year (median, 4.1 years). Up to 59.6% of patients had a relapse after treatment. Both allergic rhinitis (OR, 4.37; 95% CI, 1.049-18.203; P = .043) and sputum eosinophilia after 4 weeks of treatment with inhaled corticosteroids (OR, 9.493; 95% CI, 2.381-37.850; P = .001) were risk factors for relapse. Among the 141 patients, mild asthma developed in eight (5.7%). During the follow-up period, no progressive decline in FVC, FEV1, and FEV1/FVC were observed (P > .05). Although the proportion of small airway dysfunction (maximum midexpiratory flow [MMEF] < 65%) significantly increased at the last visit in all groups (all P < .05), only the relapse group showed an MMEF decline at the end of follow-up (P < .05) in the linear mixed model.

CONCLUSIONS

More than 50% of patients with NAEB have repeated episodes associated with persistent sputum eosinophilia after treatment and allergic rhinitis. In the current cohort, chronic airway obstruction does not develop despite small airway dysfunction increases over time.

Efficacy of add-on montelukast in nonasthmatic eosinophilic bronchitis: the additive effect on airway inflammation, cough and life quality

Background:

The efficacy of montelukast (MONT), a cysteinyl leukotriene receptor antagonist, in nonasthmatic eosinophilic bronchitis (NAEB), especially its influence on cough associated life quality is still indefinite. We evaluated the efficacy of MONT combined with budesonide (BUD) as compared to BUD monotherapy in improving life quality, suppressing airway eosinophilia and cough remission in NAEB.

Methods:

A prospective, open-labeled, multicenter, randomized controlled trial was conducted. Patients with NAEB (aged 18-75 years) were randomized to inhaled BUD (200 μg, bid) or BUD plus oral MONT (10 μg, qn) for 4 weeks. Leicester cough questionnaire (LCQ) life quality scores, cough visual analog scale (CVAS) scores, eosinophil differential ratio (Eos), and eosinophil cationic protein (ECP) in induced sputum were monitored and compared.

Results:

The control and MONT groups contained 33 and 32 patients, respectively, with similar baseline characteristics. Significant with-in group improvement in CVAS, LCQ scores, Eos, and ECP was observed in both groups during treatment. After 2-week treatment, add-on treatment of MONT was significantly more effective than BUD monotherapy for CVAS decrease and LCQ scores improvement (both P < 0.05). Similar results were seen at 4-week assessment (both P < 0.05). 4-week add-on therapy of MONT also resulted in a higher percentage of patients with normal sputum Eos (<2.5%) and greater decrease of ECP (both P < 0.05).

Conclusions:

MONT combined with BUD was demonstrated cooperative effects in improvement of life quality, suppression of eosinophilic inflammation, and cough remission in patients with NAEB.

Eosinophilic Pneumonia

Eosinophilic pneumonia may manifest as chronic or transient infiltrates with mild symptoms, chronic idiopathic eosinophilic pneumonia, or the frequently severe acute eosinophilic pneumonia that may be secondary to a variety of causes (drug intake, new onset of tobacco smoking, infection) and that may necessitate mechanical ventilation. When present, blood eosinophilia greater than 1 × 10⁹ eosinophils/L (and preferably greater than 1.5 × 10⁹/L) is of considerable help for suggesting the diagnosis, however it may be absent, as in the early phase of idiopathic acute eosinophilic pneumonia or when patients are already taking corticosteroids. On bronchoalveolar lavage, high eosinophilia (>25 %, and preferably >40 % of differential cell count) is considered diagnostic of eosinophilic pneumonia in a compatible setting, obviating the need of video-assisted thoracic surgical lung biopsy, which is now performed only on very rare occasions with inconsistency between clinical, biological, and imaging features. Inquiry as to drug intake must be meticulous (www.pneumotox.com) and any suspected drug should be withdrawn. Laboratory investigations for parasitic causes must take into account the travel history or residence and the epidemiology of parasites. In patients with associated extrathoracic manifestations, the diagnosis of eosinophilic granulomatosis with polyangiitis or of the hypereosinophilic syndromes should be raised. Presence of airflow obstruction can be found in hypereosinophilic asthma, allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, or in the recently identified syndrome of hyperosinophilic obliterative bronchiolitis. Corticosteroids remain the cornerstone of symptomatic treatment for eosinophilic pneumonias, with a generally dramatic response. Relapses are common when tapering the doses or after stopping treatment especially in idiopathic chronic eosinophilic pneumonia. Cyclophosphamide is necessary only in patients with eosinophilic granulomatosis with polyangiitis and poor-prognostic factors. Imatinib is very effective in the treatment of the myeloproliferative variant of hypereosinophilic syndromes. Anti-interleukin-5 monoclonal antibodies are promising in the spectrum of eosinophilic disorders.

Chronic cough - assessment of treatment efficacy based on two questionnaires

INTRODUCTION

Efficacy of chronic cough treatment is ambiguous. The aim of the study was to analyze chronic cough alleviation after specific treatment and the relationship between cough etiology and treatment efficacy.

MATERIAL AND METHODS

A stepwise diagnostic approach was used to diagnose cough etiology in non-smoking adults with chronic cough. In all patients specific treatment was applied. Two different questionnaires - a visual analog scale and a 5-degree scale - were used to assess cough severity before and after 4-6 months of treatment.

RESULTS

A significant correlation between pre-treatment and post-treatment results of both questionnaires was found (Spearman coefficient 0.43, p = 0.0003 and 0.73, p < 0.0001, respectively). Baseline questionnaire analysis revealed no differences in cough severity between patients with different cough causes or multiple cough causes. Although specific treatment resulted in a significant decrease of cough severity in the entire group, only partial improvement was noted. According to the visual analogue scale, a decrease of cough severity by at least 50% was achieved only in 54.4% of patients (37/68). Similarly, satisfactory improvement was noted in only 54.4% (37/68) of patients when using the 5-point scale. There were three sub-groups of patients, in whom no relevant decrease of cough severity was observed despite treatment: patients with 1. three coexisting cough causes, 2. non-asthmatic eosinophilic bronchitis, and 3. chronic idiopathic cough.

CONCLUSIONS

Cough severity does not depend on its etiology. Efficacy of chronic cough treatment in non-smoking patients is only moderate.

Serum angiopoietin is associated with lung function in patients with asthma: a retrospective cohort study

Background

Angiopoietin-1 (Ang-1) is an essential mediator of angiogenesis that establishes vascular integrity, and angiopoietin-2 (Ang-2) acts as its natural inhibitor. We considered that angiopoietin might be important in bronchial asthma.

Methods

In total, 35 patients with asthma and 20 healthy subjects were studied.

Results

The serum Ang-1 levels were significantly elevated in patients with asthma compared to control subjects (293.9 ± 13.8 pg/mL vs. 248.3 ± 16.2 pg/mL, respectively, p = 0.04). The serum Ang-2 levels were not different between the two groups. The areas under the curve (AUC) for serum angiopoietins revealed that the serum level of Ang-1 (0.68) was more sensitive and specific than the serum Ang-2 level (0.55) for differentiating between patients with asthma and control subjects. The serum Ang-1/Ang-2 ratio was correlated with the FEV1/FVC ratio (r = -0.312, p = 0.02), while serum Ang-2 was correlated with body mass index.

Conclusions

Our results indicate that the serum Ang-1 levels were higher in asthma patients compared with healthy subjects. As the Ang-1/Ang-2 ratio was related to lung function, the data suggest that serum angiopoietin is associated with lung function in patients with asthma.

Evaluation of atopy in patients with COPD

OBJECTIVE

To determine the prevalence of atopy and to evaluate clinical, laboratory, and radiological profiles in patients with COPD.

METHODS

This was a cross-sectional study involving outpatients with stable COPD (defined by the clinical history and a post-bronchodilator FEV1/FVC < 70% of the predicted value). The patients completed a questionnaire regarding clinical characteristics and atopy, after which they underwent nasal lavage cytology, skin prick testing, chest X-rays, arterial blood gas analyses, and determination of total serum IgE.

RESULTS

Of the 149 subjects studied, 53 (35.6%), 49 (32.8%), and 88 (59.1%) presented with nasal eosinophilia, a positive skin prick test result, and symptoms of allergic rhinitis, respectively. Correspondence analysis confirmed these findings, showing two distinct patterns of disease expression: atopy in patients with COPD that was less severe; and no evidence of atopy in those with COPD that was more severe (reduced FEV1 and hyperinflation). There was a statistically significant association between nasal eosinophilia and a positive bronchodilator response.

CONCLUSIONS

Using simple and reproducible methods, we were able to show that there is a high frequency of atopy in patients with COPD. Monitoring inflammation in the upper airways can be a useful tool for evaluating respiratory diseases in the elderly and in those with concomitant asthma and COPD, a clinical entity not yet fully understood.

Re-challenge with ovalbumin failed to induce bronchial asthma in mice with eosinophilic bronchitis

OBJECTIVE

To investigate whether eosinophilic bronchitis without airway hyperresponsiveness will develop bronchial asthma in allergic mice.

METHODS

Mice were sensitized with OVA on days 0, 7, and 14, challenged on days 21 to 23 (1(st) OVA challenge), and re-challenged on days 46 to 48 (2(nd) OVA challenge), intranasally with 10 (the EB group) and 200 (the AS group) μg OVA. Lung resistance (RL) was assessed 24 h after each challenge and on day 45 followed by analysis of leukocyte distribution in the bronchoalveolar lavage (BAL) fluid and histological examination.

RESULTS

Twenty-four hours after the 1(st) OVA challenge, aerosolized methacholine caused a dose-dependent increase in RL in all groups. At doses ≥1.56 mg/mL, RL in the AS group was significantly higher than that of the NS-1 group (P<0.01 or 0.05) and at doses ≥12.5 mg/mL, RL was markedly higher in the AS group than that of the EB group (P<0.01). The percentage of eosinophils in both the EB group and the AS group was markedly higher than that of the control group. Twenty-four hours after the 2(nd) OVA challenge, at doses ≤12.5 mg/mL, there was no significant difference in RL among all groups (P>0.05). At doses ≥12.5 mg/mL, RL in the AS group was significantly higher than that of the control group and EB group (P<0.01 or 0.05). The percentage of eosinophils in the AS group was noticeably higher than that of the EB group(P<0.05). Furthermore, there was apparent infiltration by inflammatory cells, predominantly eosinophils, into the sub-epithelial region of the bronchus and the bronchioles and around the vessels in the EB and AS group.

CONCLUSION

Re-challenge with low doses of ovalbumin did not increase airway reactivity and failed to induce bronchial asthma in mice with ovalbumin-induced EB.

Rhinitis patients with sputum eosinophilia show decreased lung function in the absence of airway hyperresponsiveness

Purpose

Sputum eosinophilia is observed frequently in patients with rhinitis. Sputum eosinophilia in patients with non-asthmatic allergic rhinitis has been suggested to be related to nonspecific airway hyperresponsiveness (AHR). However, the clinical significance of sputum eosinophilia in patients with non-asthmatic rhinitis without AHR has not been determined. We conducted a retrospective study examining the influence of sputum eosinophilia in patients with non-asthmatic rhinitis without AHR on pulmonary function and expression of fibrosis-related mediators.

Methods

Eighty-nine patients with moderate-to-severe perennial rhinitis without AHR were included. All underwent lung function tests (forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC]), skin tests to inhalant allergens, methacholine bronchial challenge tests, and hypertonic saline-induced sputum to determine eosinophil counts. Sputum mRNA levels for transforming growth factor-β (TGF-β), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were also examined. Patients were divided into two groups according to the presence of sputum eosinophilia (≥3%, eosinophilia-positive [EP] and <3%, eosinophilia-negative [EN] groups).

Results

FEV1 was significantly lower (P=0.04) and FEV1/FVC tended to be lower (P=0.1) in the EP group than in the EN group. In sputum analyses, the MMP-9 mRNA level (P=0.005) and the ratio of MMP-9 to TIMP-1 expression (P=0.01) were significantly higher in the EP group than in the EN group. There was no significant difference in TGF-β mRNA expression between the two groups.

Conclusions

Sputum eosinophilia in patients with moderate-to-severe perennial rhinitis without AHR influenced FEV1 and the expression pattern of fibrosis-related mediators.

Impact of atopy on asthma and allergic rhinitis in the cohort for reality and evolution of adult asthma in Korea

PURPOSE

Atopy is an important cause of asthma. Few data on the prevalence of atopy or comparisons with clinical characteristics of asthma in Korean patients have been published. We evaluated the effects of atopy on clinical profiles and airway inflammation in Korean asthmatics.

METHODS

We retrospectively enrolled 1,492 asthmatics from the Cohort for Reality and Evolution of Adult Asthma in Korea (COREA) cohort who had undergone skin prick tests for aeroallergens. The patients' clinical characteristics, lung function, PC20, and sputum and blood inflammatory cell counts were compared based on the presence or absence of atopy. Atopy was defined as one or more positive reactions (A/H ratio >1) on a skin prick test.

RESULTS

Among 11 aeroallergens, house dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus) were the most prevalent cause of a positive skin prick test. As compared with non-atopic asthmatics, atopic asthmatics showed early onset of the disease. Atopic patients with asthma had a higher FEV1, FVC, and FEV1/FVC as compared with non-atopic patients with asthma. In addition, asthmatics without atopy had more uncontrolled asthma (P=0.001) and severe rhinitis (P<0.05) as compared with atopic asthmatics. Smoking, as measured in pack years, was higher in the non-atopic asthmatics than in the atopic asthmatics. The erythrocyte sedimentation rate was higher in non-atopic asthmatics than in the atopic asthmatics and patients with non-atopic asthma had a higher sputum neutrophil count than did those with atopic asthma.

CONCLUSIONS

Our data indicate that atopic asthmatics had an early onset of disease and high IgE levels, while the non-atopic asthmatics had decreased lung function and a high sputum neutrophil count, suggesting that a different approach is needed to treat atopic asthma.

Add-on montelukast vs double-dose budesonide in nonasthmatic eosinophilic bronchitis: a pilot study

BACKGROUND

Budesonide at 800 μg/d is generally suggested for treatment of nonasthmatic eosinophilic bronchitis (NAEB). In asthma, adjunctive therapy with montelukast has been shown to confer addictive anti-inflammatory effects to inhaled corticosteroid (ICS). However, whether such effects could be extrapolated to NAEB is not known.

OBJECTIVES

To study the efficacy and tolerability of add-on therapy with montelukast as compared to double-dose ICS in suppressing airway eosinophilia and decreasing cough severity in NAEB.

METHODS

In a randomized controlled trial, 26 nonsmoking, steroid-naïve NAEB patients presenting with chronic cough were treated with 800 μg/d budesonide or 400 μg/d budesonide plus montelukast 10 mg/d for 4 weeks. Cough visual analogue scale (CVAS) and eosinophil differential ratio in induced sputum (Eos) were monitored at baseline, Week 1, 2 and 4. Adverse events during treatment were recorded.

RESULTS

The two groups were comparable in age, gender distribution, cough duration, FEV(1)% predicted, FEV(1)/FEV ratio, baseline CVAS and geometric mean of Eos. Both regimens significantly reduced Eos and CVAS throughout the treatment course, with abrogation of sputum eosinophilia at end of therapy. There was no significant difference between the two groups in reduction of Eos and CVAS at all time points. Both regimens were well tolerated.

CONCLUSIONS

This preliminary study demonstrated that add-on montelukast might be an effective and well tolerated alternative to the generally suggested dose of ICS in treating steroid-naive NAEB, with suppression of eosinophilic inflammation, reduction of cough severity and sparing of ICS doses. (NCT01121016).

Anatomy and neuro-pathophysiology of the cough reflex arc

Coughing is an important defensive reflex that occurs through the stimulation of a complex reflex arc. It accounts for a significant number of consultations both at the level of general practitioner and of respiratory specialists. In this review we first analyze the cough reflex under normal conditions; then we analyze the anatomy and the neuro-pathophysiology of the cough reflex arc. The aim of this review is to provide the anatomic and pathophysiologic elements of evaluation of the complex and multiple etiologies of cough.

Definitions and classification of work-related asthma

The workplace can trigger or induce asthma and cause the onset of different types of work-related asthma (WRA). Based on current knowledge of clinical features, pathophysiologic mechanisms, and evidence supporting a causal relationship, the following conditions should be distinguished in the spectrum of WRA: (1) immunologic occupational asthma (OA), (2) nonimmunologic OA, (3) work-exacerbated asthma, and (4) variant syndromes, including eosinophilic bronchitis, potroom asthma, and asthmalike disorders caused by organic dusts. The rationale, issues, and controversies relating to this approach are critically reviewed to stimulate the development of a consensus on operational definitions of the various phenotypes of WRA.

Cough and Asthma

Cough is the most common complaint for which patients seek medical attention. Cough variant asthma (CVA) is a form of asthma, which presents solely with cough. CVA is one of the most common causes of chronic cough. More importantly, 30 to 40% of adult patients with CVA, unless adequately treated, may progress to classic asthma. CVA shares a number of pathophysiological features with classic asthma such as atopy, airway hyper-responsiveness, eosinophilic airway inflammation and various features of airway remodeling. Inhaled corticosteroids remain the most important form of treatment of CVA as they improve cough and reduce the risk of progression to classic asthma most likely through their prevention of airway remodeling and chronic airflow obstruction.

Structural changes in the airways: cause or effect of chronic cough?

Patients with a chronic cough have asthma or "asthma-related" diagnoses such as cough variant asthma or non-asthmatic eosinophilic bronchitis usually responsive to inhaled corticosteroid therapy, or non-asthma-related diagnoses including "idiopathic" or "unexplained" cases. Both of these conditions involve airway inflammation. More recently, structural changes or remodeling of the lower airways, which have been considered characteristic of classic asthma with wheezing, have also been demonstrated in patients with chronic cough, irrespective of its cause. In this article, the presence, pathogenesis, and possible consequences of such structural changes in patients with chronic cough are reviewed. Although whether chronic cough leads to structural changes or structural changes is a cause of chronic cough is difficult to determine, the concomitance of both mechanisms may lead to a positive feedback mechanism or a vicious cycle of cough persistence.

Eosinophilic bronchitis, eosinophilia associated genetic variants, and notch signaling in asthma

While much has indeed been learned about the biology and role of eosinophils, the paradigm of eosinophils has the pros and cons in development of asthma. To answer the questions in the black box, this review firstly discusses the biological and morphological differences between asthma and eosinophilic bronchitis (EB). EB is an interesting clinical manifestation of eosinophilic airway disease that does not involve airway hyperresponsiveness (AHR), demonstrating that airway eosinophilia alone is insufficient to merit a diagnosis of asthma. Secondly, I will describe and discuss the effect(s) of single-nucleotide polymorphisms (SNPs) in the genes CCR3, IL-5 RECEPTOR ALPHA (IL5RA), and IL1RL1, and finally the in vitro and in vivo effects of Notch inhibition on both eosinophil differentiation and experimental asthma. Eosinophilic airway inflammation is not as important in the pathogenesis and maintenance of asthma as had previously been thought. However, the role of eosinophils in other asthma subphenotypes, including refractory or severely remodeled asthma, needs to be evaluated further. High-throughput methodologies such as genomics will facilitate the discovery of new markers of inflammation; these, in turn, will aid in the evaluation of the role of eosinophils in asthma and its various subphenotypes.

Upper-airway cough syndrome with latent eosinophilic bronchitis

Upper-airway cough syndrome often coexists with other diseases that elicit chronic cough. However, the concomitant conditions are not always relevant to chronic cough, which complicates the cause diagnosis of chronic cough. The objective of this study was to explore the diagnosis and clinical implication of upper-airway cough syndrome with latent eosinophilic bronchitis. Eleven patients with upper-airway cough syndrome and latent eosinophilic bronchitis were retrospectively analyzed for their clinical manifestations, changes of eosinophilia in induced sputum, and cough threshold with capsaicin defined as capsaicin concentration that elicits two or more coughs (C2) and five or more coughs (C5) between pretreatment and post-treatment. All patients reported a history of allergic rhinitis, showed persistent dry cough or small amounts of viscid sputum with a time course of 2-60 months (median = 7 months), and presented with symptoms and signs of rhinitis, normal lung function, and airway responsiveness. Initial eosinophil percentage in induced sputum was 3.5-8.0%. Cough disappeared after 2-5 (3 +/- 1) weeks of only oral antihistamine. With successful treatment, cough threshold C2 increased from 1.73 +/- 1.45 to 4.43 +/- 4.50 micromol/L (t = 2.64, P = 0.025) and C5 increased from 2.79 +/- 2.16 to 10.10 +/- 8.22 micromol/L (t = 3.10, P = 0.011). However, there was no significant change of eosinophil percentage in induced sputum (4.8 +/- 1.5% vs. 4.4 +/- 1.4%, t = 0.84, P = 0.427). Upper-airway cough syndrome with latent eosinophilic bronchitis is a unique condition. The recognition of the entity may avoid unnecessary use of corticosteroids.

Targeted treatment in COPD: a multi-system approach for a multi-system disease

Chronic obstructive pulmonary disease is a varied condition when examined from a number of different perspectives including factors which influence disease development, pathological process and clinical features. There may be a complex interaction between the degree by which each of these processes influences the development of COPD and the subsequent clinical phenotype with which the patient presents. The varied host response and subsequent clinical phenotype has generated much interest in recent years. It is possible that failure of treatment to impact on mortality and reverse the disease process is because of the heterogeneous nature of the condition. Identification and targeted treatment of clinical and pathological phenotypes within the broad spectrum of COPD may therefore improve outcome. This article will review previous work which has attempted to phenotype COPD and identify if specific treatment for these phenotypes has been shown to be of benefit. It will examine the work on pathological processes and clinical manifestations, both pulmonary and systemic, and will focus on pharmacological therapies.

Diagnosis and management of premature ventricular complexes-associated chronic cough

BACKGROUND

Chronic cough frequently remains unexplained. Although various cardiac arrhythmias have already been reported as a cause of chronic cough, this phenomenon has not been evaluated prospectively. Therefore, we studied the incidence and management of cough associated with premature ventricular complexes (PVCs) in a population of patients with this condition.

METHODS

Patients without organic heart disease who had been referred for the management of symptomatic PVC were evaluated prospectively. PVC-associated cough was recognized if cough episodes occurred just after spontaneous or induced PVC or observed in an ECG or a multichannel recording system that included ECG. A differential diagnosis of cough was performed according to the guidelines on cough. Afterward, antiarrhythmic therapy was instituted to eliminate PVC and cough.

RESULTS

Of the 120 patients who were referred for the management of PVC, 10 had a chronic cough. After extensive workup for the cause of chronic cough, the cough was thought to be solely due to PVC in one patient, partially due to PVC plus another cause in five patients, and not due to PVC but to nonasthmatic eosinophilic bronchitis, gastroesophageal reflux disease, and chronic sinusitis in four patients. Patients with PVC-associated cough reported more severe perception of symptoms associated with arrhythmia than patients without cough (mean [+/- SD] visual analog scale score, 8.2 +/- 0.5 vs 5.7 +/- 1.6, respectively; p < 0.01). PVC-associated cough disappeared after antiarrhythmic treatment (radiofrequency ablation [n = 4], oral antiarrhythmic agent [n = 1]), or after spontaneous remission of PVC (n = 1).

CONCLUSIONS

PVC may be a cause of chronic cough. Interdisciplinary cooperation is warranted for the proper diagnosis and management of PVC-associated cough.

Eosinophilic airway disorders associated with chronic cough

Chronic cough is a major clinical problem. The causes of chronic cough can be categorized into eosinophilic and noneosinophilic disorders, the former being comprised of asthma, cough variant asthma (CVA), atopic cough (AC) and non-asthmatic eosinophilic bronchitis (NAEB). Cough is one of the major symptoms of asthma. Cough in asthma can be classified into three categories; 1) CVA: asthma presenting solely with coughing, 2) cough-predominant asthma: asthma predominantly presenting with coughing but also with dyspnea and/or wheezing, and 3) cough remaining after treatment with inhaled corticosteroid (ICS) and beta2-agonists in patients with classical asthma, despite control of other symptoms. There may be two subtypes in the last category; one is cough responsive to anti-mediator drugs such as leukotriene receptor antagonists and histamine H1 receptor antagonists, and the other is cough due to co-morbid conditions such as gastroesophageal reflux. CVA is one of the commonest causes of chronic isolated cough. It shares a number of pathophysiological features with classical asthma with wheezing such as atopy, airway hyperresponsiveness (AHR), eosinophilic airway inflammation and various features of airway remodeling. One third of adult patients may develop wheezing and progress to classical asthma. As established in classical asthma, ICS is considered the first-line treatment, which improves cough and may also reduce the risk of progression to classical asthma. AC proposed by Fujimura et al. presents with bronchodilator-resistant dry cough associated with an atopic constitution. It involves eosinophilic tracheobronchitis and cough hypersensitivity and responds to ICS treatment, while lacking in AHR and variable airflow obstruction. These features are shared by non-asthmatic eosinophilic bronchitis (NAEB). However, atopic cough does not involve bronchoalveolar eosinophilia, has no evidence of airway remodeling, and rarely progresses to classical asthma, unlike CVA and NAEB. Histamine H1 antagonists are effective in atopic cough, but their efficacy in NAEB is unknown. AHR of NAEB may improve with ICS within the normal range. Taken together, NAEB significantly overlaps with atopic cough, but might also include milder cases of CVA with very modest AHR. The similarity and difference of these related entities presenting with chronic cough and characterized by airway eosinophilia will be discussed.

Chronic cough – occupational considerations

Chronic cough is a common symptom in a wide range of respiratory conditions, and may also occur as a result of upper airway or gastro-esophageal problems. Whilst chronic cough of any cause may be exacerbated by work, in some cases it has a direct occupational cause, resulting from a harmful acute or chronic workplace exposure. Such occupational conditions may only be suspected by taking a detailed occupational history, and directly asking employed patients whether their cough improves away from work. Early and accurate diagnosis, linked with tailored drug therapy, modification of workplace exposures, and expert compensation advice is likely to offer the best outcome for this group of patients.

Eosinophilic bronchitis-like lesion as the cause of death in a Macaca mulatta: a first case report

BACKGROUND

Eosinophilic bronchitis is a recently described, relatively benign condition in humans that is characterized by a corticosteroid-responsive chronic cough and sputum eosinophilia without the abnormalities of airway function seen in asthma. The exact cause of this condition is currently unknown, however has been associated with various occupational exposures in humans. It has also been reported to progress to irreversible airway obstruction. This disease has been reported in dogs and horses, but not in non-human primates.

METHODS

Gross examination of an otherwise healthy 13-year-old, colony-born Macaca mulatta, which died of severe non-responsive respiratory distress revealed that the lungs were markedly inflated and moist.

RESULTS

Hematoxylin and eosin-stained sections from the lungs contained widespread accumulation of eosinophils, sloughed epithelial cells, and mucus centered around bronchioles and adjacent airways. There was no evidence of mast cell infiltration of peribronchiolar smooth muscle, goblet cell hyperplasia, or basement membrane thickening.

CONCLUSIONS

This ruled out recurrent episodes as would be expected in asthma, favoring the diagnosis of an eosinophilic bronchitis-like lesion. We report a first case of eosinophilic bronchitis-like features in a M. mulatta.

Airway hyperresponsiveness is dissociated from airway wall structural remodeling

BACKGROUND

Nonasthmatic eosinophilic bronchitis (EB) has emerged as a useful tool to study the structural and inflammatory mechanisms of airway hyperresponsiveness (AHR) in asthma. We have previously shown that vascular remodeling and reticular basement membrane (RBM) thickening are present in EB. However, it is not known whether other features of structural remodeling including increased airway smooth muscle (ASM) mass, matrix deposition, and glandular hyperplasia are also present in EB.

OBJECTIVES

We sought to determine whether structural remodeling occurs in EB and is associated with AHR and airflow limitation.

METHODS

Forty-two patients with asthma, 21 patients with EB, and 19 healthy volunteers were recruited. ASM area, RBM thickness, collagen 3 deposition, glandular area, mast cells, and granulocytes were assessed in bronchial biopsy samples.

RESULTS

Nonasthmatic eosinophilic bronchitis and asthma were associated with a significant increase in ASM mass and RBM thickness compared with healthy subjects. In contrast, we did not observe any significant differences in collagen 3 deposition in the lamina propria and ASM or the % area of glands in the lamina propria. Univariate analysis demonstrated that mast cell numbers in the ASM were the only feature of remodeling associated with AHR (beta = -0.51; P = .004). Stepwise linear regression revealed that a combination of mast cell numbers in the ASM (beta = -0.43) and disease duration (beta = -0.25; model-adjusted R(2) = 0.26; P = .027) best modeled AHR.

CONCLUSION

Mast cell localization to the ASM bundle, but not structural remodeling of the airway wall, is associated with AHR in asthma.

Eosinophilic bronchitis without asthma

BACKGROUND

Eosinophilic bronchitis without asthma causes chronic coughs without the physiologic features of asthma. The aim of this study was to review the clinical features, pathogenesis, diagnosis, treatment and prognosis of this condition.

METHODS

The current literature was reviewed using Pubmed for all studies published in the English language using the search term 'eosinophilic bronchitis'.

RESULTS

Eosinophilic bronchitis presents as normal spirometry, without evidence of airway hyperresponsiveness, and normal peak expiratory flow variability. When compared with asthma, mast cell recruitment to the superficial airways and mast cell activation appear to be a feature of eosinophilic bronchitis. In contrast, mast cell infiltration in the smooth muscle is significantly higher in asthma patients than in either eosinophilic bronchitis patients or healthy control subjects. In this condition, the absence of high IL-13 expression can contribute to the normal airway reactivity. The cough usually responds well to inhaled corticosteroids but dose and duration of treatment remain unclear. The condition can be transient, episodic or persistent unless treated, and occasionally, patients may require long-term treatment with oral corticosteroids.

CONCLUSIONS

The condition is an important cause of chronic coughs which are corticosteroid responsive. The study of eosinophilic bronchitis suggests that eosinophil-dependent mechanisms are generally not important in the pathogenesis of asthma.

Common causes and current guidelines

Chronic cough is a common and disabling symptom. Recent guidelines have attempted to provide direction in the clinical management of cough in both primary and secondary care. They have also provided a critical review of the available literature and identified gaps in current knowledge. Despite this they have been criticized for a reliance on a low quality evidence base. In this review, we summarize the current consensus on the clinical management of chronic cough and attempt to rationalize this based on recent evidence. We have also provided an overview of the likely pathophysiological mechanisms responsible for cough and highlighted areas, where knowledge deficits exist and suggest directions for future research. Such progress will be critical in the search for new and effective treatments for cough.

Canine Eosinophilic Bronchopneumopathy

Eosinophilic bronchopneumopathy (EBP) is a disease characterized by eosinophilic infiltration of the lung and bronchial mucosa, as demonstrated by examination of bronchoalveolar lavage fluid cytologic preparations or histologic examination of the bronchial mucosa. Although the precise cause of EBP is unknown, a hypersensitivity to aeroallergens is suspected. The diagnosis relies on typical history and clinical signs, demonstration of bronchopulmonary eosinophilia by cytology or histopathologic examination, and exclusion of known causes of lower airway eosinophilia. Most dogs display an excellent response to oral corticosteroid therapy; however, side effects of this treatment can be limiting. New therapeutic approaches are being studied, including the use of aerosol therapy, cyclosporine, or drugs interfering with T helper 2 immune response.

Vascular remodeling is a feature of asthma and nonasthmatic eosinophilic bronchitis

RATIONALE

Increased vascularity and expression of vascular endothelial growth factor (VEGF) are recognized features of the asthmatic airway. The association of vascular remodeling with airway hyperresponsiveness (AHR) is unclear.

OBJECTIVE

To assess vascular remodeling and sputum VEGF concentration in subjects with asthma, subjects with nonasthmatic eosinophilic bronchitis (EB), and healthy controls.

METHODS

In cohort 1, 19 patients with asthma (Global Initiative for Asthma [GINA] 1-2, n = 9; GINA 3-5, n = 10), 10 patients with EB, and 11 healthy matched controls were recruited. Expression of the endothelial marker EN4 was assessed in bronchial biopsy samples. Vessels were counted using the validated mean Chalkley count by a blind observer. For cohort 2, a second independent cohort of 31 patients with asthma (GINA 1-2, n = 11; GINA 3-5, n = 20), 14 patients with EB, and 15 matched controls was recruited. Induced sputum supernatant VEGF was measured by ELISA.

RESULTS

The mean chalkley count was significantly greater in GINA 3-5 asthma (5.2 [0.4]) and EB (4.8 [0.3]) compared with controls (3.5 [0.5]) and demonstrated a significant inverse correlation with the postbronchodilator FEV(1)% predicted in patients with asthma (R(2) = 0.28; P = .02). Sputum VEGF concentration was also increased in GINA 3-5 asthma (2365 [1361-4110] pg/g) and EB (4699 [2818-7834] pg/g) compared with controls (1094 [676-1774] pg/g) and was inversely related to postbronchodilator FEV(1)% predicted in asthma (R(2) = 0.2; P = .01).

CONCLUSION

Vascular remodeling is a feature of asthma, and EB and is inversely associated with the postbronchodilator FEV(1) in asthma, suggesting that vascular remodeling is associated with airflow obstruction but not AHR.

CLINICAL IMPLICATIONS

Vascular remodeling is dissociated from AHR in asthma and associated with airflow limitation.

Occupational eosinophilic bronchitis in a foundry worker exposed to isocyanate and a baker exposed to flour

Eosinophilic bronchitis without asthma may occur as a consequence of occupational exposure. The cases of a foundry worker and a baker who developed symptoms, respectively, due to exposure to isocyanate and flour, are reported. Cough was not associated with variable airflow obstruction or with airway hyper-responsiveness and was responsive to inhaled corticosteroids. The eosinophilia detectable in their sputum was causally related to the occupational exposure in the workplace. The examination of induced sputum should be used in addition to the objective monitoring of lung function for workers who have asthma-like symptoms in an occupational setting.

Characteristics of COPD phenotypes classified according to the findings of HRCT

The present study was performed to clarify the clinical characteristics of chronic obstructive pulmonary disease (COPD) patients classified into phenotypes according to the dominancy of emphysema and the presence of bronchial wall thickening evaluated by chest high-resolution computed tomography (HRCT). Eighty-five patients with stable COPD (FEV1 < or = 80%) were examined by chest HRCT. Emphysematous changes and bronchial wall thickening were evaluated visually, and COPD patients were classified into three phenotypes: absence of emphysema, with little emphysema with or without bronchial wall thickening (A phenotype), emphysema without bronchial wall thickening (E phenotype), and emphysema with bronchial wall thickening phenotype (M phenotype). Clinical characteristics were compared among the three phenotypes. The A phenotype group showed a higher prevalence of subjects who had never smoked and patients with wheezing, higher values of body mass index (BMI) and DLco, milder lung hyperinflation, and greater reversibility of airflow limitation responsive to inhaled beta2-agonist as compared with the other phenotypes. The degree of emphysema was significantly associated with Brinkman index, lower BMI, decrease in DLco, lower FEV1/FVC. The presence of bronchial wall thickening in A- and M- phenotype was significantly associated with reversibility responsive to treatment with inhaled corticosteroid and sputum eosinophilia. These findings suggest that the morphological phenotypes of COPD show several clinical characteristics and different responsiveness to treatment with bronchodilators and inhaled corticosteroids.

Real-time RT-PCR quantification of mRNA encoding cytokines, CC chemokines and CCR3 in bronchial biopsies from dogs with eosinophilic bronchopneumopathy

Idiopathic canine eosinophilic bronchopneumopathy (EBP) is a disease characterized by eosinophilic infiltration of the pulmonary interstitium and bronchial mucosa, a cause for which has not yet been discovered. A recent study, examining the relative proportion of various lymphocyte cell subsets within bronchoalveolar lavage fluid from dogs with EBP, has shown a selective increase in CD4(+) T-cells and a selective decrease in CD8(+) T-cells, suggesting that a similar Th2 immune response might occur in EBP. The aim of the present study was to determine the profile of cytokine, chemokine and CC chemokine receptor 3 (CCR3) messenger RNA (mRNA) expression in bronchial tissue from dogs with EBP. Real-time RT-PCR assays were used for the quantification of mRNA encoding for a panel of cytokines, CC chemokines and CCR3 in perendoscopic bronchial biopsies from eight dogs with EBP and seven age-matched control dogs. Messenger RNA transcribed from the housekeeping gene glyceraldehyde-3-phosphate dehydrogenase was used for normalisation of the threshold cycle in order to determine the relative copy numbers of the transcripts. No significant difference in the expression of any cytokine, MCP-1, -2, -4 and CCR3 was found between control and EBP dogs. The expression of transcript for MCP-3, eotaxin-2 and -3 was significantly greater in bronchial biopsies from dogs with EBP than in samples from control dogs while there was significantly less mRNA encoding RANTES in the mucosa of dogs with EBP. In conclusion, the cytokine mRNA expression profile in perendoscopic bronchial biopsies is similar in dogs with EBP and dogs without respiratory disease. Further studies on the quantification of mRNA encoding cytokines in isolated T lymphocytes from bronchoalveolar lavage fluid or bronchial biopsies are needed before any conclusion on the cytokine profile in canine EBP can be drawn. Eotaxin-2, -3 and MCP-3 appear to be implicated in the pathogenesis of the disease.