The relationship between airway hyper-responsiveness, markers of inflammation and lung function depends on the duration of the asthmatic disease

Dust Exposure and Respiratory Health Among Workers in Primary Coffee Processing Factories in Tanzania and Ethiopia

Introduction: In primary coffee factories the coffee beans are cleaned and sorted. Studies from the 80- and 90-ties indicated respiratory health effects among the workers, but these results may not represent the present status. Our aim was to review recent studies on dust exposure and respiratory health among coffee factory workers in Tanzania and Ethiopia, two major coffee producing countries in Africa.

Methods: This study merged data from cross-sectional studies from 2010 to 2019 in 4 and 12 factories in Tanzania and Ethiopia, respectively. Personal samples of “total” dust and endotoxin were taken in the breathing zone. Chronic respiratory symptoms were assessed using the American Thoracic Society (ATS) questionnaire. Lung function was measured by a spirometer in accordance with ATS guidelines.

Results: Dust exposure among male production workers was higher in Ethiopia (GM 12 mg/m³; range 1.1–81) than in Tanzania (2.5; 0.24–36). Exposure to endotoxins was high (3,500; 42–75,083) compared to the Dutch OEL of 90 EU/m³. The male workers had higher prevalence of respiratory symptoms than controls. The highest symptom prevalence and odds ratio were found for cough (48.4%; OR = 11.3), while for breathlessness and wheezing the odds ratios were 3.2 and 2.4, respectively. There was a significant difference between the male coffee workers and controls in the adjusted FEV1 (0.26 l/s) and FVC (0.21 l) and in the prevalence of airflow limitation (FEV1/FVC < 0.7) (6.3 vs. 0.9%). Among the male coffee workers, there was a significant association between cumulative dust exposure and the lung function variables FEV1 and FVC, respectively.

Conclusions: The results suggest that coffee production workers are at risk of developing chronic respiratory symptoms and reduced lung function, and that the findings are related to high dust levels. Measures to reduce dust exposure should be targeted to factors identified as significant determinants of exposure.

Effectiveness and Safety Studies of Omalizumab in Children and Adolescents With Moderate-To-Severe Asthma

BACKGROUND

Omalizumab is currently approved for the treatment of moderate-to-severe allergic asthma in patients 6 years and older.

OBJECTIVE

To assess the effectiveness and safety of subcutaneous omalizumab as an add-on therapy option for moderate-severe allergic asthma in patients aged 6-20 years old.

METHODS

The studies published from July, 1970 to May, 2021 were searched from the electronic databases which followed keywords: ("anti-IgE" OR "anti-immunoglobulin E" OR "anti-IgE antibody" OR "omalizumab" OR "rhuMAb-E25" OR "Xolair") AND "asthma" AND ("child" OR "children" OR "adolescents" OR "youth" OR "teenager" OR "kids" OR "pediatric"). Thirteen studies were pooled to determine the effectiveness and safety of omalizumab. Efficacy endpoints were evaluated using a fixed-effects model or a random-effects model depending on heterogeneity. Safety endpoints were evaluated by odds ratio.

RESULTS

Thirteen studies were included. In this meta-analysis, our results showed that fractional exhaled nitric oxide and asthma control test scores were significantly improved with omalizumab treatment. Serum immunoglobulin E was also decreased in children with moderate-to-severe asthma after treatment with omalizumab. The analysis found that there was no significant difference between pre-and post-treatment in forced expiratory volume in one second/ forced vital capacity ratio, forced expiratory flow between 25 and 75% of vital capacity, or FEV1. Overall, more adverse events occurred with omalizumab compared to placebo. However, the degree was mild to moderate.

CONCLUSION

This meta-analysis indicates that omalizumab is safe and effective to treat children and adolescents with moderate-to-severe asthma.

An official JRS statement: The principles of fractional exhaled nitric oxide (FeNO) measurement and interpretation of the results in clinical practice

Nitric oxide (NO) is produced in the body and has been shown to have diverse actions in the abundance of research that has been performed on it since the 1970s, leading to Furchgott, Murad, and Ignarro receiving the Nobel Prize in Physiology or Medicine in 1998. NO is produced by nitric oxide synthase (NOS). NOS is broadly distributed, being found in the nerves, blood vessels, airway epithelium, and inflammatory cells. In asthma, inflammatory cytokines induce NOS activity in the airway epithelium and inflammatory cells, producing large amounts of NO. Measurement of fractional exhaled nitric oxide (FeNO) is a simple, safe, and quantitative method of assessing airway inflammation. The FeNO measurement method has been standardized and, in recent years, this noninvasive test has been broadly used to support the diagnosis of asthma, monitor airway inflammation, and detect asthma overlap in chronic obstructive pulmonary disease (COPD) patients. Since the normal upper limit of FeNO for healthy Japanese adults is 37 ppb, values of 35 ppb or more are likely to be interpreted as a signature of inflammatory condition presenting features with asthma, and this value is used in clinical practice. Research is also underway for clinical application of these measurements in other respiratory diseases such as COPD and interstitial lung disease. Currently, there remains some confusion regarding the significance of these measurements and the interpretation of the results. This statement is designed to provide a simple explanation including the principles of FeNO measurements, the measurement methods, and the interpretation of the measurement results.

Asthma management: A new phenotype-based approach using presence of eosinophilia and allergy

Asthma is a heterogeneous disease. The Czech Pneumology and Allergology Societies commissioned 10 experts to review the literature and create joint national guidelines for managing asthma, reflecting this heterogeneity. The aim was to develop an easy-to-use diagnostic strategy as a rational approach to the widening opportunities for the use of phenotype-targeted therapy. The guidelines were presented on websites for public comments by members of both the societies. The reviewers' comments contributed to creating the final version of the guidelines. The key hallmark of the diagnostic approach is the pragmatic concept, which assesses the presence of allergy and eosinophilia in each asthmatic patient. The guidelines define three clinically relevant asthma phenotypes: eosinophilic allergic asthma, eosinophilic nonallergic asthma and noneosinophilic nonallergic asthma. The resulting multifunctional classification describing the severity, level of control and phenotype is the starting point for a comprehensive treatment strategy. The level of control is constantly confronted with the intensity of the common stepwise pharmacotherapy, and the concurrently included phenotyping is essential for phenotype-specific therapy. The concept of the asthma approach with assessing the presence of eosinophilia and allergy provides a way for more precise diagnosis, which is a prerequisite for using widening options of personalized therapy.

Can exhaled nitric oxide be a surrogate marker of bronchial hyperresponsiveness to adenosine 5'-monophosphate in steroid-naive asthmatic children?

BACKGROUND

The interrelation between airway inflammation, bronchial hyperresponsiveness (BHR) and atopy remains controversial.

OBJECTIVE

The aim of this study was to document whether exhaled nitric oxide (eNO) may be used as a surrogate marker that predicts BHR to adenosine 5'-monophosphate (AMP) in steroid-naive school children with asthma.

METHODS

This study was a retrospective analysis of steroid-naive school age children with atopic and non-atopic asthma. All patients whose eNO levels had been measured and who had been challenged with both methacholine (MCH) and AMP were included. Receiver operation characteristic analysis was performed, in both the atopic and the non-atopic groups, to evaluate the ability of eNO to detect the BHR to AMP.

RESULTS

One hundred and sixteen patients, sixty-nine (59.5%) of whom had been atopic, were included in the analysis. In the atopic group, eNO values were significantly higher in patients with BHR to AMP compared to those without BHR to AMP (51.9 ± 16.9 p.p.b. vs. 33.7 ± 16.4 p.p.b.; P < 0.001), whereas in the non-atopic group, the differences were not statistically significant (29.7 ± 16.9 p.p.b. vs. 22.6 ± 8.1 p.p.b.; P = 0.152). In the atopic group, eNO levels (R(2) : 0.401; β: 0.092; 95% CI: 1.19-14.42; OR: 7.12; P = 0.008) were found to be the only independent factor for BHR to AMP, whereas none of the parameters predicted BHR to AMP in the non-atopic group. The best cut-off value of eNO that significantly predicts BHR to AMP was 33.3 p.p.b. in the atopic group (P < 0.001), whereas a significant cut-off value for eNO that predicts BHR to AMP was not determined in the non-atopic group (P = 0.142). An eNO ≤ 17.4 p.p.b. has 100% negative predictive values and 100% sensitivity and 60.47% PPV for prediction of BHR to AMP in the atopic group.

CONCLUSIONS

Exhaled NO may be used to predict BHR to AMP in atopic but not in non-atopic steroid-naïve asthmatic children.

Longitudinal measurement of airway inflammation over one year in children and adults with intermittent asthma

BACKGROUND

Asthma is an inflammatory disease of the airways, but in clinical practice inflammation is rarely monitored. The aim of this study was to assess the level of airway inflammation in steroid naïve adult and pediatric patients with intermittent asthma over one year.

METHODS

54 children and 50 adults with intermittent asthma (GINA step 1) were included. On up to 6 visits lung function, airway hyperresponsiveness to methacholine (PC20FEV1), sputum eosinophils and exhaled nitric oxide (FeNO) were assessed.

RESULTS

36 pediatric and 34 adult patients were able to produce at least three adequate sputum samples over the study period and were included into the analysis.In 8 children (22%) the percentage of sputum eosinophils was always below 2.5%. A higher level of eosinophils (>2.5%) was found on at least one visit in 16 (44%) and always >2.5% in 12 children (33%). In the adult group the respective numbers were 14 patients (41%) with always low (<2.5%), 17 (50%) with at least once over 2.5% and three patients (9%) were always above the threshold of 2.5% sputum eosinophils.

CONCLUSION

These results demonstrate that a substantial number of children and adults with intermittent asthma under ß-agonist treatment only, have variable or persistently high levels of eosinophilic airway inflammation. Long-term studies are needed to observe the progression of asthma severity in such patient populations.

Advances in the diagnosis and management of asthma in older adults

Global estimates on aging predict an increased burden of asthma in the older population. Consequently, its recognition, diagnosis, and management in clinical practice require optimization. This review aims to provide an update for clinicians, highlighting advances in the understanding of the aging process and immunosenescence together with their applicability to asthma from a diagnostic and therapeutic perspective. Aging impacts airway responses and immune function, and influences efficacy of emerging phenotype-specific therapies when applied to the elderly patient. Differentiating eosinophilic and neutrophilic disease accounts for atopic illness and distinguishes long-standing from late-onset asthma. Therapeutic challenges in drug delivery, treatment adherence, and side-effect profiles persist in the older patient, while novel recording devices developed to aid detection of an adequate inhalation evaluate treatment effectiveness and compliance more accurately than previously attainable. Anticytokine therapies improve control of brittle asthma, while bronchial thermoplasty is an option in refractory cases. Multidimensional intervention strategies prove best in the management of asthma in the older adult, which remains a condition that is not rare but rarely diagnosed in this patient population.

[Asthma in the elderly]

Asthma is a common condition in the elderly although often confounded with chronic obstructive pulmonary disease (COPD) in this population. Asthma in the elderly seems to represent a specific phenotype characterized by more severe, but often less perceived, airway obstruction, a neutrophilic or mixed-type of airway inflammation and frequent comorbidities. Patients aged 65 years and over have an increased asthma-related morbidity and mortality compared to younger patients, probably due to difficulties in regard to diagnosis, assessment of the disease severity and treatment. Research is urgently needed to determine the optimal treatment of the aged patient. In this document we will review the state of knowledge on this topic and discuss the challenges of multidisciplinary asthma management in the elderly.

Aeroallergen and food IgE sensitization and local and systemic inflammation in asthma

BACKGROUND

We recently reported an independent association between IgE sensitization to food allergens and increased airway inflammation, assessed by fraction of exhaled nitric oxide (FeNO), in a population-based study (J Allergy Clin Immunol, 130, 2012, 397). Similar studies have not been performed in populations with asthma. The aim of the present study was to investigate the allergic sensitization profile in asthmatics and examine FeNO, airway responsiveness and blood eosinophilia in relation to type and degree of IgE sensitization.

METHOD

FeNO, airway responsiveness, blood eosinophil count (B-Eos) and IgE sensitization to food allergens and aeroallergens were determined in 408 subjects with asthma, aged 10-34 years.

RESULTS

Asthmatics had higher prevalence of IgE sensitization against all allergens than controls (P < 0.001). Mite, pollen, furry animal, mould and food sensitizations were each associated with increased FeNO, airway responsiveness and B-Eos in asthmatics. IgE sensitization to mould, furry animals and food allergens was independently related to FeNO (all P < 0.05) after adjustment for age, sex, height, smoking history and medication. IgE sensitization to mould (P < 0.001) and furry animals (P = 0.02) was related to airway responsiveness in a similar model. Finally, IgE sensitization to mould (P = 0.001), furry animals (P < 0.001) and food allergens (P < 0.001) was independently related to B-Eos.

CONCLUSION

Independent effects of IgE sensitization to aeroallergens (furry animals and mould) and food allergens were found on both local and systemic markers of inflammation in asthma. The finding regarding food IgE sensitization is novel, and a clinical implication might be that even food sensitization must be assessed to fully understand inflammation patterns in asthma.

Respiratory symptoms, exhaled nitric oxide, and lung function among workers in Tanzanian coffee factories

OBJECTIVE

To compare chronic respiratory symptoms, fractional exhaled nitric oxide (FENO), and lung function between Robusta and Arabica coffee workers and a control group.

METHODS

Chronic respiratory symptoms were assessed by a questionnaire (n = 138 coffee workers and n = 120 controls). The FENO was measured by NIOX MINO device (Aerocrine AB, Solna, Sweden). Lung function was examined by a portable spirometer.

RESULTS

Coffee workers had higher prevalence of chronic respiratory and asthma symptoms than controls. Robusta coffee workers were exposed to higher levels of endotoxin and had more asthma symptoms than Arabica coffee workers (38% vs. 18%). Coffee workers had reduced lung function associated with cumulative exposure to total dust and endotoxin.

CONCLUSION

Work in coffee factories is associated with small but significant lung function impairment. These changes were not associated with the level of FENO.

Using fractional exhaled nitric oxide (FeNO) to diagnose steroid-responsive disease and guide asthma management in routine care

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a surrogate marker of eosinophilic airway inflammation and good predictor of corticosteroid response.

AIM

To evaluate how FeNO is being used to guide primary care asthma management in the United Kingdom (UK) with a view to devising practical algorithms for the use of FeNO in the diagnosis of steroid-responsive disease and to guide on-going asthma management.

METHODS

Eligible patients (n = 678) were those in the Optimum Patient Care Research Database (OPCRD) aged 4-80 years who, at an index date, had their first FeNO assessment via NIOX MINO® or Flex®. Eligible practices were those using FeNO measurement in at least ten patients during the study period. Patients were characterized over a one-year baseline period immediately before the index date. Outcomes were evaluated in the year immediately following index date for two patient cohorts: (i) those in whom FeNO measurement was being used to identify steroid-responsive disease and (ii) those in whom FeNO monitoring was being used to guide on-going asthma management. Outcomes for cohort (i) were incidence of new ICS initiation at, or within the one-month following, their first FeNO measurement, and ICS dose during the outcome year. Outcomes for cohort (ii) were adherence, change in adherence (from baseline) and ICS dose.

OUTCOMES

In cohort (i) (n = 304) the higher the FeNO category, the higher the percentage of patients that initiated ICS at, or in the one month immediately following, their first FeNO measurement: 82%, 46% and 26% of patients with high, intermediate and low FeNO, respectively. In cohort (ii) (n = 374) high FeNO levels were associated with poorer baseline adherence (p = 0.005) but greater improvement in adherence in the outcome year (p = 0.017). Across both cohorts, patients with high FeNO levels were associated with significantly higher ICS dosing (p < 0.001).

CONCLUSIONS

In the UK, FeNO is being used in primary practice to guide ICS initiation and dosing decisions and to identify poor ICS adherence. Simple algorithms to guide clinicians in the practical use of FeNO could improved diagnostic accuracy and better tailored asthma regimens.

Exhaled nitric oxide as screening tool in subjects with suspected asthma without reversibility

BACKGROUND

As fractional exhaled nitric oxide (FeNO) has been evaluated only in certain settings for asthma diagnosis, we investigated whether FeNO values could predict positive methacholine challenge testing (expressed as PD20) in subjects with suspected asthma but without spirometric reversibility.

METHODS

Subjects with asthma-like symptoms and negative bronchodilation test were initially evaluated to undergo FeNO measurement and methacholine bronchial challenge. Diagnostic performance of FeNO to predict PD20 to methacholine <800 μg was examined by constructing receiver-operating characteristic curves.

RESULTS

A total of 112 subjects met the inclusion criteria. In all subjects, FeNO >32 ppb was associated with a sensitivity of 0.47 and a specificity of 0.85 for the identification of the PD20 <800 μg (AUC = 0.691, 95% CI = 0.6-0.775, p = 0.00002). In smokers, FeNO >11 ppb was associated with a sensitivity of 0.85 and a specificity of 0.5 for the identification of PD20 <800 μg (AUC = 0.625, 95% CI = 0.45-0.772, p = 0.18), while in atopics a FeNO level >26 ppb was associated with a sensitivity of 0.55 and a specificity of 0.85 (AUC = 0.677, 95% CI = 0.53-0.8, p = 0.02).

CONCLUSIONS

In subjects with symptoms compatible with asthma but without spirometric reversibility, specific cutoff levels for FeNO levels significantly predict the positive methacholine challenge, with significant confounding factors being atopy and current smoking.

Subjective cold hyper-responsiveness grade reflects age- and duration-related increase of nonspecific nasal hyperreactivity

OBJECTIVE

We evaluated the effect of patients' age and duration of allergic rhinitis on nonspecific nasal hyper-reactivity (NHR) using cold dry air (CDA) provocation.

METHODS

In 156 patients of various ages with allergic rhinitis and different symptom duration, we evaluated the change of symptoms, the subjective cold hyper-responsiveness (SCH) grade, the change of acoustic parameters such as total nasal volume (TNV) and minimal cross-sectional area (MCA), and the amount of rhinorrhea before and after CDA provocation.

RESULTS

Patients in different age or duration groups did not show significant differences in the change of each nasal symptom. SCH grade 2 or 3 was more frequently observed in patients older than 30 years (p=0.018). There was a significant correlation between the age of the patients and the SCH grade (R=0.184, p=0.022). Patients with >10 years of duration reported higher SCH grade (p=0.022). There was a significant correlation between the duration of disease and SCH grade (R=0.284, p<0.001). However, there were no significant differences in the change of TNV and MCA, and the amount of rhinorrhea after CDA provocation between different age and duration groups.

CONCLUSION

SCH grade reflects the age- and duration-related increase of NHR. Further studies to elucidate the pathophysiologic mechanisms are needed in the future.

Is FENO50 useful diagnostic tool in suspected asthma?

BACKGROUND

Asthma diagnosis is based on the presence of symptoms and the demonstration of airflow variability. Airway inflammation measured by fractional exhaled nitric oxide, measured at a flow rate of 50 ml/s (FE(NO50)) remains a controversial diagnostic tool.

AIM

To assess the ability of FE(NO50) to identify bronchial hyperresponsiveness (BHR) to methacholine (provocative concentration of methacholine causing a 20% fall in FEV(1); PC20M ≤ 16 mg/ml) and to establish whether or not symptoms relate to FE(NO50) and PC20M in patients with no demonstrated reversibility to β(2) -agonist.

METHODS

We conducted a prospective study on 174 steroid naive patients with respiratory symptoms, forced expiratory volume in 1 s (FEV(1) ) ≥ 70% predicted and no demonstrated reversibility to β(2) -agonist. Patients answered to a standardised symptom questionnaire and underwent FE(NO50) and methacholine challenge. Receiver-operating characteristic (ROC) curve and logistic regression analysis assessed the relationship between PC20M and FE(NO50) , taking into account covariates (smoking, atopy, age, gender and FEV(1)).

RESULTS

A total of 82 patients had a PC20M ≤ 16 mg/ml and had significantly higher FE(NO50) (19 ppb vs. 15 ppb; p < 0.05). By constructing ROC curve, we found that FE(NO50) cut-off value of 34 ppb was able to identify not only BHR with high specificity (95%) and positive predictive value (88%) but low sensitivity (35%) and negative predictive value (62%). When combining all variables into the logistic model, FE(NO50) (p = 0.0011) and FEV(1) (p < 0.0001) were independent predictors of BHR whereas age, gender, smoking and atopy had no influence. The presence of diurnal and nocturnal wheezing was associated with raised FE(NO50) (p < 0.001 and p < 0.05, respectively).

CONCLUSION

The value of FE(NO50) > 34 ppb has high predictive value of PC20M < 16 in patients with suspected asthma in whom bronchodilating test failed to demonstrate reversibility or was not indicated. However, FE(NO50) ≤ 34 ppb does not rule out BHR and should prompt the clinician to ask for a methacholine challenge.

An official ATS clinical practice guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications

BACKGROUND

Measurement of fractional nitric oxide (NO) concentration in exhaled breath (Fe(NO)) is a quantitative, noninvasive, simple, and safe method of measuring airway inflammation that provides a complementary tool to other ways of assessing airways disease, including asthma. While Fe(NO) measurement has been standardized, there is currently no reference guideline for practicing health care providers to guide them in the appropriate use and interpretation of Fe(NO) in clinical practice.

PURPOSE

To develop evidence-based guidelines for the interpretation of Fe(NO) measurements that incorporate evidence that has accumulated over the past decade.

METHODS

We created a multidisciplinary committee with expertise in the clinical care, clinical science, or basic science of airway disease and/or NO. The committee identified important clinical questions, synthesized the evidence, and formulated recommendations. Recommendations were developed using pragmatic systematic reviews of the literature and the GRADE approach.

RESULTS

The evidence related to the use of Fe(NO) measurements is reviewed and clinical practice recommendations are provided.

CONCLUSIONS

In the setting of chronic inflammatory airway disease including asthma, conventional tests such as FEV(1) reversibility or provocation tests are only indirectly associated with airway inflammation. Fe(NO) offers added advantages for patient care including, but not limited to (1) detecting of eosinophilic airway inflammation, (2) determining the likelihood of corticosteroid responsiveness, (3) monitoring of airway inflammation to determine the potential need for corticosteroid, and (4) unmasking of otherwise unsuspected nonadherence to corticosteroid therapy.

Predictors of airway hyperresponsiveness differ between old and young patients with asthma

BACKGROUND

Age-related increases in morbidity and mortality due to asthma may be due to changes in pathophysiology as patients with asthma get older. There is limited knowledge about the effects of age on the predictors of airway hyperresponsiveness (AHR), a key feature of asthma. The aim of this study was to determine if the pathophysiologic predictors of AHR, including inflammation, ventilation heterogeneity, and airway closure, differed between young and old patients with asthma.

METHODS

Sixty-one young (18-46 years) and 43 old (50-80 years) patients with asthma had lung function, lung volumes, fraction of exhaled nitric oxide, ventilation heterogeneity, and airway responsiveness to methacholine measured. Airway response to methacholine was measured by the dose-response slope, as the percent fall in FEV(1) per micromole of methacholine. Indices of ventilation heterogeneity were calculated for convection-dependent and diffusion-dependent airways.

RESULTS

In young patients with asthma, the independent predictors of AHR were convection-dependent ventilation heterogeneity, exhaled nitric oxide, and % predicted FEV(1)/FVC (model r(2) = 0.51, P < .0001). In old patients with asthma, the independent predictors of airway responsiveness were % predicted residual volume, diffusion-dependent ventilation heterogeneity, and % predicted FEV(1) (model r(2) = 0.57, P < .0001).

CONCLUSIONS

In old patients with asthma, AHR is predicted by gas trapping and ventilation heterogeneity in peripheral, diffusion-dependent airways. In the young, it is predicted by ventilation heterogeneity in less peripheral conducting airways and by inflammation. These findings suggest that there are differences in the pathophysiologic determinants of AHR between young and old patients with asthma.

FeNO as a Marker of Airways Inflammation: The Possible Implications in Childhood Asthma Management

The aim of this study was to verify FeNO usefulness, as a marker of bronchial inflammation, in the assessment of therapeutic management of childhood asthma. We performed a prospective 1-year randomized clinical trial evaluating two groups of 32 children with allergic asthma: "GINA group", in which therapy was assessed only by GINA guidelines and "FeNO group", who followed a therapeutic program assessed also on FeNO measurements. Asthma Severity score (ASs), Asthma Exacerbation Frequency (AEf), and Asthma Therapy score (ATs) were evaluated at the start of the study (T1), 6 months (T2), and 1 year after (T3). ASs and AEf significantly decreased only in the FeNO group at times T2 and T3 (p[T1-T2] = 0.0001, and p[T1-T3] = 0.01; p[T1-T2] = 0.0001; and p[T1-T3] < 0.0001, resp.). After six months of follow-up, we found a significant increase of patients under inhaled corticosteroid and/or antileukotrienes in the GINA group compared to the FeNO group (P = .02). Our data show that FeNO measurements, might be a very useful additional parameter for management of asthma, which is able to avoid unnecessary inhaled corticosteroid and antileukotrienes therapies, however, mantaining a treatment sufficient to obtain a meaningful improvement of asthma.

Bronchial hyperresponsiveness to histamine correlates with airway remodelling in adults with asthma

BACKGROUND

Chronic eosinophilic inflammation may promote bronchial hyperresponsiveness (BHR), which involves reversible reduction of airflow and airway remodelling such as a thickening of the reticular basement membrane (RBM) and hypertrophy and hyperplasia of airway smooth muscle (ASM). BHR to histamine (Hist) and acetylcholine (ACh) cannot differentiate airway inflammation and remodelling.

OBJECTIVE

To examine the correlations between eosinophilic inflammation or airway remodelling and BHR to Hist or ACh in adults with severe asthma.

METHODS

We examined eosinophils in the sputum of 50 adult patients with severe asthma before inhaled corticosteroid (ICS) treatment. Airway responses to ACh and Hist were measured on separate days after the first hospital visit and before bronchofiberscopy. Bronchial specimens were obtained by bronchofibrescopy for evaluation of RBM and ASM thickening after systemic corticosteroid treatment.

RESULTS

Eosinophil scores in the sputum before ICS treatment were correlated with BHR to ACh but not to Hist. Asthma duration was inversely correlated with % forced expiratory volume in 1 s, %V(50), %V(25), BHR to Hist, and ASM thickness, but not BHR to ACh or RBM. A multivariate logistic regression model showed that Long duration of asthma affected ASM thickness more than it affected %V(50). ASM thickness was inversely correlated with BHR to Hist but not to ACh.

CONCLUSION

In adult patients with severe asthma, BHR to ACh is related to the degree of eosinophilic airway inflammation, whereas BHR to Hist indicates airway remodeling, particularly ASM hypertrophy.

Measuring systemic inflammatory regulation in older adults: evidence and utility

Aging is frequently accompanied by a proinflammatory state with adverse health consequences. This state is commonly assessed by markers in serum, either in isolation or ad hoc combination. We sought, alternatively, to develop scores summarizing multiple markers in accordance with biology on inflammatory regulation and evaluate their value added for discriminating functional outcomes in older adults. Data came from InCHIANTI (Invecchiare in Chianti; Aging in the Chianti Area) study participants age 65 years and older. Serum concentrations of seven inflammatory biomediators were subjected to latent variable analysis implementing a biological model of counterbalancing up- and down-regulation processes. Resulting process constructs were approximated by principal component scores; these, and individual markers, were evaluated as predictors of mobility impairment and frailty status in regression analyses, adjusting for key confounders. The biomediators' interrelationships were well predicted by the hypothesized biology. The up-regulation score was independently associated with worsened mobility functioning and frailty risk. For mobility, the association was stronger than, persisted independently of, and accounted for association with each biomediator. The down regulation score was associated with frailty outcomes. We conclude that systemic inflammation is relevant to the process that leads to functional loss in older persons and can be validly measured through biologically informed summary of inflammatory markers.

Effect of age on relationship between exhaled nitric oxide and airway hyperresponsiveness in asthmatic children

BACKGROUND

Numerous studies have examined the relationship between the fractional concentration of exhaled nitric oxide (Feno) and airway hyperresponsiveness (AHR). Our objective was to determine the effects of age on the relationship between Feno and AHR in asthmatic children.

METHODS

AHR was examined in 267 asthmatic patients (age range, 5 to 20 years). A challenge test was performed using acetylcholine chloride (Ach). We determined the provocative concentration of Ach producing a 20% decrease in FEV(1) from baseline (PC(20)). Feno was examined using the recommended online method before the Ach challenge test.

RESULTS

In children < 12 years of age (range, 5 to 11 years), decreasing AHR (PC(20)) was significantly related to higher Feno (r = -0.43; beta = -0.28; p < 0.001). In adolescents >or= 12 years of age (range, 12 to 20 years), decreasing PC(20) was associated with peripheral airway obstruction (FEV(1): r = 0.32; beta = 5.5; p = 0.002; forced expiratory flow at 50% of the FVC: r = 0.24; beta=8.4; p = 0.006; and forced expiratory flow at 25% of FVC: r = 0.28; beta=11.4; p = 0.002). AHR and Feno were weakly related (r = -0.18; beta = -0.14; p = 0.02).

CONCLUSIONS

In children with asthma, AHR is associated with airway inflammation. AHR in children with asthma may consist of variable components mainly reflecting airway inflammation. In contrast, in adolescents with asthma, AHR is associated with airway structural changes and weakly with airway inflammation. AHR in adolescents with asthma may consist of chronic components mainly reflecting airway remodeling.

Factors affecting bronchial hyperreactivity in asthmatic children

Bronchial hyperresponsiveness (BHR), the exaggerated airway narrowing in response to nonspesific stimuli, is a common characteristic of asthma. One hundred thirty-five children who were diagnosed asthma in the outpatient clinic of Gazi University Hospital, Pediatric Allergy and Asthma Department between January 2007 and January 2008 were retrospectively analysed from the asthma database of the division. BHR was not found to be different according to sex. Younger the age of the patient, more severe was BHR (p = 0.096, r = 0.164). Younger the age at onset of the symptoms, the more severe was the BHR (p < 0.001, r = 0.307). Patients who had an asthmatic first degree relative and who were exposed to passive smoking at home, had more severe BHR (p = 0.006 and p = 0.032, respectively). There were more hospitalizations among the asthmatic children with moderate-severe BHR (p = 0.027) however no correlation was found between chronic asthma severity and the degree of BHR). In this study we found that age, age at onset of symptoms, having a parent with asthma, exposure to tobacco smoke and baseline lung function are related to BHR measured at referral. Serum levels of Ig E or skin prick test positivity were not found to have any effect on BHR severity. Considering BHR severity, we could not reveal any relation between atopic and nonatopic children. However among atopic subjects, the ones with indoor allergen sensitization had more severe BHR.

Identifying the components of asthma health status in children with mild to moderate asthma

BACKGROUND

Weak and inconsistent correlations between measurements of asthma health status suggest that the disease is composed of nonoverlapping components.

OBJECTIVE

Factor analysis was used to explore the relationships between measures of asthma morbidity and to identify heterogeneous components of asthma health status in children 5 to 12 years old. Results were compared across time (baseline and 48-month visit) and treatment arms.

METHODS

Analyses were conducted in 7 different study windows in a database from a large clinical trial of children with mild to moderate asthma (n = 1041). Measurements of lung function, symptoms, and health care utilization from daily diary cards, serum IgE levels, total eosinophil count, skin test positivity, and airway hyperresponsiveness were included. Data on fractional exhaled nitric oxide and sputum eosinophil cationic protein were included in a subgroup of patients.

RESULTS

In each of the study windows, factor analysis identified 5 factors that explained between 50% and 60% of the common variance. Factors identified included (1) inflammatory markers, (2) symptoms/medication use, (3) asthma exacerbations, and measures of lung function, which subdivided into (4) FEV(1) and forced vital capacity, and (5) bronchodilator response and the FEV(1)/forced vital capacity ratio. Exploratory analyses suggest that fractional exhaled nitric oxide account for the atopy/inflammatory marker factor, and sputum measurements account for a sixth, separate factor.

CONCLUSION

The consistent identification of a 5-factor structure across time and treatment arms suggests that each of these factors provides independent information in the assessment of asthma.

Exhaled nitric oxide: independent effects of atopy, smoking, respiratory tract infection, gender and height

Measurement of exhaled nitric oxide is widely used in respiratory research and clinical practice, especially in patients with asthma. However, interpretation is often difficult, due to common interfering factors, and little is known about interactions between factors. We assessed the influences and interactions of factors such as smoking, respiratory tract infections and respiratory allergy concerning exhaled nitric oxide values, with the aim to derive a scheme for adjustment. We studied 897 subjects (514 females, 383 males; mean age+/-standard deviation 34.5+/-13.0 years) with and without respiratory allergy (allergic rhinitis and/or asthma), smoking and respiratory tract infection. Logarithmic nitric oxide levels were described by an additive model comprising respiratory allergy, smoking, respiratory tract infection, gender and height (p0.001 each), without significant interaction terms. Geometric mean was 17.5ppb in a healthy female non smoker of height 170cm, whereby respiratory allergy corresponded to a change by factor 1.50, smoking 0.63, infection 1.24, male gender 1.17, and each 10cm increase (decrease) in height to 1.11 (0.90). Factors were virtually identical when excluding asthma and using the category allergic rhinitis instead of respiratory allergy (n=863). Within each category formed by combinations of these different predictors, the range of residual variation was approximately constant. We conclude that the factors influencing exhaled nitric oxide, which we analyzed, act independently of each other. Thus, circumstances such as smoking and respiratory tract infection do not appear to affect the usefulness of exhaled nitric oxide, provided that appropriate factors for adjustment are applied.

Factor analysis in the Genetics of Asthma International Network family study identifies five major quantitative asthma phenotypes

BACKGROUND

Asthma is a clinically heterogeneous disease caused by a complex interaction between genetic susceptibility and diverse environmental factors. In common with other complex diseases the lack of a standardized scheme to evaluate the phenotypic variability poses challenges in identifying the contribution of genes and environments to disease expression.

OBJECTIVE

To determine the minimum number of sets of features required to characterize subjects with asthma which will be useful in identifying important genetic and environmental contributors. Methods Probands aged 7-35 years with physician diagnosed asthma and symptomatic siblings were identified in 1022 nuclear families from 11 centres in six countries forming the Genetics of Asthma International Network. Factor analysis was used to identify distinct phenotypes from questionnaire, clinical, and laboratory data, including baseline pulmonary function, allergen skin prick test (SPT).

RESULTS

Five distinct factors were identified:(1) baseline pulmonary function measures [forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC)], (2) specific allergen sensitization by SPT, (3) self-reported allergies, (4) symptoms characteristic of rhinitis and (5) symptoms characteristic of asthma. Replication in symptomatic siblings was consistent with shared genetic and/or environmental effects, and was robust across age groups, gender, and centres. Cronbach's alpha ranged from 0.719 to 0.983 suggesting acceptable internal scale consistencies. Derived scales were correlated with serum IgE, methacholine PC(20), age and asthma severity (interrupted sleep). IgE correlated with all three atopy-related factors, the strongest with the SPT factor whereas severity only correlated with baseline lung function, and with symptoms characteristic of rhinitis and of asthma.

CONCLUSION

In children and adolescents with established asthma, five distinct sets of correlated patient characteristics appear to represent important aspects of the disease. Factor scores as quantitative traits may be better phenotypes in epidemiological and genetic analyses than those categories derived from the presence or absence of combinations of +ve SPTs and/or elevated IgE.

Retrospective characterization of airway reversibility in patients with asthma responsive to bronchodilators

BACKGROUND

National and international asthma guidelines recommend the use of reversibility to assist in the diagnosis of asthma.

SCOPE

This retrospective pooled analysis assessed the reversibility characteristics of a large cohort of patients (n = 30 816) selected from 106 clinical trials conducted by GlaxoSmithKline in which bronchodilator reversibility (> or = 12%) was required for participation in the trials.

FINDINGS

Patients (n = 1434) with a baseline forced expiratory volume in 1 second (FEV1) between 40% and < 50% at screening had a mean reversibility of 42% and those (n = 550) with a baseline FEV1 between 90% and < 100% had a mean reversibility of 18%. In general, the lower the patient's baseline lung function, the higher the reversibility. Further, in a subset of studies (n = 7; 1477 patients) that provided reversibility data at study baseline and endpoint, the mean reversibility for patients receiving placebo or fluticasone propionate (FP) was 26%. At study completion, nearly 30% fewer patients receiving placebo were shown to be reversible and approximately half of the patients receiving fluticasone propionate were no longer reversible.

CONCLUSION

This analysis shows that airway reversibility is affected by asthma severity as measured cross-sectionally by spirometry, pharmacotherapeutic interventions, including placebo, and time. Additional studies are needed to confirm this finding in broader populations as studies in this analysis were limited to those conducted in the US by GlaxoSmithKline.

Outcome and severity of adult onset asthma--report from the obstructive lung disease in northern Sweden studies (OLIN)

BACKGROUND

Studies of longitudinal changes in severity and the long-term outcome of asthma in epidemiological settings are uncommon.

AIM

To assess the outcome of incident asthma in a cohort of subjects who developed asthma after the age of 20 years.

METHODS

This is a prospective study of the outcome of 309 subjects with incident asthma being included in a case-referent study based on all adults aged 20-60 years living in three municipalities/towns in Northern Sweden. The subjects fulfilled the criteria for incident asthma defined as onset of symptoms common in asthma within 12 months prior to the study and a verified bronchial variability. In 2003, 250 (81%) of the subjects with asthma were re-examined with structured interview, lung-function test and methacholine test.

RESULTS

At follow-up, 237 (95%) subjects still had an active asthma, i.e. they had symptoms or used asthma medicines. Among those with active asthma, 65% were using inhaled cortico-steroids. Severity grading (GINA 2000) showed that 21% had mild intermittent asthma, 30% mild persistent, 44% moderate persistent, and 5% severe asthma, contrasting to 75% with moderate or severe asthma at entry. Higher age, higher BMI and low lung function were associated with greater asthma severity. Twelve subjects (5%) were in remission. Predictors for remission were non-sensitisation and a normal lung function. Age, sex, BMI, and smoking habits were not significantly different between those in remission and those not.

CONCLUSIONS

Remission of adult onset asthma was low. Severity of asthma changed considerably over time, however, the overall change was towards a milder disease probably as a result of treatment.

Effect of inhaled steroid therapy on exhaled nitric oxide and bronchial responsiveness in children with asthma

Inhaled steroid therapy is reported to reduce the level of exhaled nitric oxide (eNO), but the effects of inhaled corticosteroids (ICS) on bronchial hyperresponsiveness (BHR) have been controversial. The aim of this study was to determine the effects of ICS on the relationship between eNO and BHR. Twenty-six children with asthma were recruited, including 14 children who were receiving ICS (ICS group) and 12 who were not (ICS-naive group). The fractional exhaled nitric oxide concentration (FE(NO)) was examined by the recommended online method. To evaluate BHR, an acetylcholine challenge test was performed. In the ICS-naive group, FE(NO) was significantly correlated with PC20 (p < 0.05, r = -0.70), but not in the ICS group. In conclusion, FE(NO) was significantly correlated with BHR in the ICS-naive group, but this relationship was not present in the ICS group. Our results suggest that the use of ICS should be taken into consideration when evaluating the relation between BHR and airway inflammation.

Effects of ciclamilast, a new PDE 4 PDE4 inhibitor, on airway hyperresponsiveness, PDE4D expression and airway inflammation in a murine model of asthma

PDE4 (phosphodiesterase-4) plays a critical role in pathogenesis of allergic asthma and chronic obstructive pulmonary disease (COPD). PDE4 inhibitors are presently under clinical development for the treatment of asthma and/or COPD. Ciclamilast, a new PDE4 inhibitor, is a piclamilast (RP 73401) structural analogue, but has a more potent inhibitory effect on PDE4 and inflammation in the airway tissues and less side effects than that of piclamilast. In this study, we elucidate primarily on the roles of compound on PDE4 enzyme in physiological and pathological processes in a mouse model of asthma. The sensitized/challenged mice were reexposed to ovalbumin and airway response to inhaled methacholine was monitored. Orally administration of ciclamilast, in a dose-dependent manner, significantly inhibited changes in lung resistance and lung dynamic compliance, as well as upregulation of cAMP-PDE activity, increase of PDE4D mRNA expression, but not PDE4B from lung tissue in the murine model. In addition, the compound dose-dependently reduced mRNA expression of eotaxin, tumor necrosis factor (TNF)-alpha and interleukin (IL)-4, but slightly increased mRNA expression of interferon (IFN)-gamma from lung tissue. Further, levels of eotaxin, TNF-alpha and IL-4, and eosinophil and neutrophil accumulation in bronchoalveolar lavage fluid were also significantly reduced. Pathological examination, goblet cell hyperplasia and inflammatory cells infiltration in lung tissue were suppressed by treatment with ciclamilast. A significant correlation was observed between the increases in PDE4D mRNA expression and airway hyperresponsiveness. These studies confirm that inhibitory effect of ciclamilast on airway hyperresponsiveness includes its inhibiting PDE4D mRNA expression, down-modulating PDE4 activity, anti-inflammation and anti-mucus hypersecretion, and ciclamilast may have therapeutic potential for the treatment of asthma.

Inhibition of phosphodiesterase activity, airway inflammation and hyperresponsiveness by PDE4 inhibitor and glucocorticoid in a murine model of allergic asthma

Phosphodiesterase 4 (PDE4) isozyme plays important roles in inflammatory and immunomodulatory cells. In this study, piclamilast, a selective PDE4 inhibitor, was used to investigate the role of PDE4 in respiratory function and inflammation in a murine asthma model. Sensitized mice were challenged with aerosolized ovalbumin for 7 days, piclamilast (1, 3 and 10 mg/kg) and dexamethasone (2 mg/kg) were orally administered once daily during the period of challenge. Twenty-four hours after the last challenge, airway hyperresponsiveness to methacholine was determined by whole-body plethysmography, airway inflammation and mucus secretion by histomorphometry, pulmonary cAMP-PDE activity by HPLC, cytokine levels in bronchoalveolar lavage fluid and their mRNA expression in lung by ELISA and RT-PCR, respectively. In control mice, significant induction of cAMP-PDE activity was parallel to the increases of hyperresponsiveness, inflammatory cells, cytokine levels, mRNA expression as well as goblet cell hyperplasia. However, piclamilast dose-dependently and significantly improved airway resistance and dynamic compliance, and the maximal effect was similar to that of dexamethasone. Piclamilast treatment dose-dependently and significantly prevented the increase in inflammatory cell number and goblet cell hyperplasia, as well as production of cytokines, including eotaxin, TNFalpha and IL-4. Piclamilast exerted a weaker inhibitory effect than dexamethasone on eosinophils and neutrophils, had no effect on lymphocyte accumulation. Moreover, piclamilast inhibited up-regulation of cAMP-PDE activity and cytokine mRNA expression; the maximal inhibition of cAMP-PDE was greater than that exerted by dexamethasone, and was similar to dexamethasone on cytokine mRNA expression. This study suggests that inhibition of PDE4 by piclamilast robustly improves the pulmonary function, airway inflammation and goblet cell hyperplasia in murine allergenic asthma.

Asthma in older adults: observations from the epidemiology and natural history of asthma: outcomes and treatment regimens (TENOR) study

BACKGROUND

The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) was a 3-year, multicenter, observational study of 4,756 patients 6 years or older with severe or difficult-to-treat asthma by physician evaluation. More than 280 pulmonologist and allergist sites across the United States participated.

OBJECTIVE

To compare health care utilization (HCU), medication use, asthma control, and quality of life (QoL) in older (> or =65 years; n = 566) and younger (18-64 years; n = 2,912) adult patients in TENOR.

METHODS

Patients had to be under a physician's care for at least 1 year and have high medication use or HCU in the past year. Heavy smokers (> or =30 pack-years) and patients with cystic fibrosis were excluded.

RESULTS

Although older patients in TENOR had worse lung function as measured by decreased percent predicted forced expiratory volume in 1 second (FEV1) (P < .001), they had significantly lower HCU compared with younger patients. They also had higher use of inhaled corticosteroids and better QoL than younger patients. Older patients reported fewer problems controlling their asthma (P < .001) but reported worse communication with their physicians (P = .02).

CONCLUSIONS

Older patients in TENOR appeared to do better than younger patients, despite having worse lung function. Older patients in TENOR may have received more aggressive care than older asthmatic patients in other studies, based on a higher use of inhaled and oral corticosteroids. Whether differences in treatment or disease influenced other physiologic or inflammatory outcomes that contribute to the disconnect between HCU and FEV1 awaits further study.

Correlation of exhaled nitric oxide, spirometry and asthma symptoms

Asthma is the most common chronic disease of childhood. Asthma severity is monitored by spirometry. However, this does not directly measure airway inflammation. Exhaled nitric oxide (FeNO) is a proposed method to measure airway inflammation non-invasively. Previous studies have shown that FeNO correlates with endobronchial biopsies and symptoms in patients with asthma. We monitored daily asthma symptoms compared to monthly spirometry and FeNO. Total monthly symptom scores correlated with both forced expiratory volume at 1 sec (FEV1) and FeNO. FeNO had a strong correlation than FEV1. FeNO and FEV1 were not correlated. We propose that FeNO should be used as an additional monitoring tool for asthma.

Modulation of citric acid-induced cough following lipopolysaccharide-mediated neutrophilia in the guinea pig

This investigation examined a possible correlation between lipopolysaccharide (LPS)-induced pulmonary neutrophilia and cough. Conscious male guinea pigs were acutely exposed to aerosolized LPS and thereafter at various times challenged with citric acid aerosol (CA; 250mM) to induce cough followed by bronchoalveolar lavage (BAL) to quantitate inflammatory cell accumulation. LPS caused a hyporesponsive cough at 24h post-LPS with neutrophilia apparent from 2h post-LPS. By 96h post-LPS both cough and neutrophilia had returned towards normal. Dexamethasone (DEX, 2mgkg(-1)/day for 3 days prior) did not affect the cough hyporesponsiveness at 24h; however it attenuated LPS-induced BAL fluid neutrophilia. Since LPS can stimulate inducible nitric oxide synthase (iNOS) we hypothesized that the cough hyporesponsiveness may involve nitric oxide. To investigate this we treated animals with an aerosolized iNOS inhibitor 1400W (1mM) immediately prior to LPS. 1400W had no significant effect on either cough hyporesponsiveness or BAL fluid neutrophilia at 24h post-LPS. Despite differing effects on neutrophilia, these findings clearly indicate that neither DEX nor iNOS inhibition had any direct effect on LPS-induced cough hyporesponsiveness. The mechanism underlying the LPS-induced cough hyporesponsiveness does not appear to be directly linked to LPS-induced neutrophilic inflammation.

The -675 4G/5G plasminogen activator inhibitor-1 promoter polymorphism in house dust mite-sensitive allergic asthma patients

BACKGROUND

Plasminogen activator inhibitor (PAI)-1 plays an important role in inflammation and tissue remodeling. Recently, the -675 4G/5G PAI-1 polymorphism has been linked with asthma.

OBJECTIVE

This study was undertaken to evaluate associations of the -675 4G/5G PAI-1 polymorphism with functional and immunologic parameters of newly diagnosed house dust mite-sensitive allergic asthmatics (HDM-AAs).

METHODS

This study was performed in 127 HDM-AAs, who responded with at least 20% fall of forced expiratory volume during the first second (FEV(1)) to a bronchial challenge with Dermatophagoides pteronyssinus allergen and during the follow up observation fulfilled GINA criteria for mild-moderate asthma. About 89 healthy control nonatopic subjects (HCs) were used as controls.

RESULTS

The frequency of 4G allele was greater in HDM-AAs (0.69; 95% CI: 0.62-0.76) than in HCs (0.55; 95% CI: 0.48-0.62; P = 0.0034). The PAI-1 polymorphism was associated with an increased risk of HDM-AA; adjusted for sex and age odds ratio was 2.62; (95% CI: 1.16-5.92) for 4G/5G genotype and 3.48 (95% CI: 1.54-7.89) for 4G/4G genotype compared with 5G/5G genotype. Total serum immunoglobulin E (tsIgE) level in 4G/4G homozygotes (557 +/- 343 kU/l) was significantly greater than in 5G/5G homozygotes (241 +/- 288 kU/l; P < 0.001). Both nonspecific and allergen-specific bronchial reactivities were greater in 4G/4G homozygotes than in 5G/5G homozygotes. 4G/4G genotype was associated with significantly higher morning plasma PAI-1 concentration in HDM-AAs and HCs. Morning plasma PAI-1 concentration correlated significantly with log(PC20) (r = -0.39; P = 0.0001) and with log(tsIgE) (r = 0.247; P = 0.0117).

CONCLUSION

These results support the hypothesis linking the 4G/4G PAI-1 genotype with an increased risk of allergic asthma, bronchial hyperreactivity, and increased tsIgE levels.

Exhaled nitric oxide and exercise-induced bronchoconstriction in young male conscripts: association only in atopics

This study was conducted to evaluate how bronchial responsiveness to direct and indirect stimuli relate to nitric oxide producing airway inflammation, and whether the relationship differs between atopic and nonatopic patients with various degrees of bronchial hyperresponsiveness and airway inflammation in a group of otherwise homogenous young men. We studied 181 consecutive non-smoking steroid-naive young male conscripts referred to military hospital because of respiratory symptoms suggesting asthma. Skin prick tests, spirometry, measurement of exhaled nitric oxide (FENO), and standardized airway challenges with histamine and exercise were performed. 128 patients were atopic. FENO was significantly higher in the atopic group, median 21.2 ppb, compared to 10.2 ppb in the nonatopic group. Still, 36% of all nonatopic patients had elevated FENO. Bronchial responsiveness to histamine (HIB) was similar in the two groups, but exercise-induced bronchoconstriction (EIB) was stronger in atopics (P < 0.01). FENO associated significantly with atopy (P < 0.001), severity of EIB (P < 0.001) and HIB (P = 0.006) in multiple linear regression model. In separate regression models for atopic and nonatopic patients FENO associated with severity of EIB and HIB in atopic patients only. The results were similar when patients with confirmed diagnosis of asthma were analyzed separately. Our results indicate that FENO significantly associates with EIB and HIB in atopic, but not in nonatopic steroid-naïve patients with asthmatic symptoms. The finding suggests that in such atopic patients degree of airway hyperresponsiveness may reflect severity of airway inflammation. However, in nonatopic patients with similar symptoms other mechanisms of airway hyperresponsiveness may be more important.

Exhaled nitric oxide predicts airway hyper-responsiveness to hypertonic saline in children that wheeze

BACKGROUND

Exhaled nitric oxide (eNO) has shown good validity for the assessment of airway inflammation in asthmatic children. In large-scale epidemiological studies, this method would be preferred above airway challenge tests, because it is a quick and easy applicable tool.

OBJECTIVE

In this study, we aimed to assess the discriminatory capacity of eNO, and prechallenge FEV1 for airway hyper-responsiveness (AHR) in 8-13-year old schoolchildren.

MATERIALS AND METHODS

Parents completed the ISAAC questionnaire, and children were tested for atopy, AHR to hypertonic (4.5%) saline (HS), and eNO. Diagnostic value was assessed by the area under the receiver operating curves (ROC), and calculation of positive and negative predicted values at different cut-off points for eNO and prechallenge FEV1.

RESULTS

Areas under the ROC-curves of AHR were 0.65 for eNO and 0.62 for FEV1. Values increased to 0.71 and respectively 0.75 for a combined occurrence of AHR and current wheeze. Highest sensitivity and specificity were obtained at a cut-off value of 43 ppb for eNO and 103% predicted for FEV1. At these cut-off values, the positive predictive values for the presence of AHR in symptomatic children were respectively 83% (eNO) and 33% (FEV1), and negative predictive values in asymptomatic children were, respectively, 90 (eNO) and 80% (FEV1).

CONCLUSION

Exhaled nitric oxide is a valid screening tool for AHR to HS in children that present with current wheeze, and it outperforms FEV1 as a predictor of AHR.

Local nitric oxide levels reflect the degree of allergic airway inflammation after segmental allergen challenge in asthmatics

Nitric oxide (NO) levels are increased in the exhaled air of asthmatics. As NO levels correlate with allergic airway inflammation, NO measurement has been suggested for disease monitoring. In patients with asthma, we previously demonstrated that intrabronchial treatment with a natural porcine surfactant enhanced airway inflammation after segmental allergen provocation. We studied whether local levels of NO reflect the degree of allergic airway inflammation following segmental allergen challenge with or without surfactant pretreatment. Segmental NO, as well as nitrite and nitrate in bronchoalveolar lavage (BAL) fluid, was measured before and after segmental challenge with either saline, saline plus allergen, or surfactant plus allergen in 16 patients with asthma and five healthy subjects. The data were compared with inflammatory BAL cells. Segmental NO levels were increased after instillation of saline (p < 0.05), or surfactant plus allergen in asthmatics (p < 0.05), and values were higher after surfactant plus allergen compared to saline challenge. Nitrate BAL levels were not altered after saline challenge but increased after allergen challenge (p < 0.05) and further raised by surfactant (p < 0.05), whereas nitrite levels were not altered by any treatment. Segmental NO and nitrate levels correlated with the degree of eosinophilic airway inflammation, and nitrate levels also correlated with neutrophil and lymphocyte numbers in BAL. In healthy subjects, NO, nitrite, and nitrate were unaffected. Thus, segmental NO and nitrate levels reflect the degree of allergic airway inflammation in patients with asthma. Measurement of both markers can be useful in studies using segmental allergen provocation, to assess local effects of potential immunomodulators.

Control of mild to moderate asthma over 1-year with the combination of salmeterol and fluticasone propionate

OBJECTIVE

The aim of this study was to assess asthma control using salmeterol plus fluticasone propionate (FP) in combination (SFC) versus salmeterol or FP as monotherapy in patients with mild to moderate asthma.

METHODS

In this randomised, double-blind, parallel-group study, 322 symptomatic patients were recruited, of which 282 were randomised to receive either salmeterol (50 microg), FP (250 microg), or SFC (50 microg/250 microg), via a single Diskus inhaler twice daily for 12 months. Outcome variables included the number of patients requiring an increase in study medication and the number experiencing 2 exacerbations during the 12-month treatment period. Airway hyper-responsiveness (AHR) and lung function tests were performed at clinic visits. Peak expiratory flow, rescue medication use, symptom scores and adverse events were recorded in diary cards.

RESULTS

Fewer patients required an increase in study medication with SFC (10.5%) than with either FP (34.8%) or salmeterol (61.1%) (P<0.001). Significantly fewer patients experienced 2 exacerbations with SFC (4.2%), compared with FP (17.4%; P<0.01) or salmeterol (40%; P<0.001). SFC improved AHR to a significantly greater extent than FP (methacholine PC20=1.8 mg/ml vs. 1.1 mg/ml; P<0.05) or salmeterol (methacholine PC20=1.8 mg/ml vs. 0.7 mg/ml; P<0.001).

CONCLUSIONS

The protection against exacerbations may be attributed to better control of inflammation, AHR and lung function parameters achieved with salmeterol and FP in combination, compared with either treatment alone.

Structural changes in the airways in asthma: observations and consequences

Structural changes reported in the airways of asthmatics include epithelial fragility, goblet cell hyperplasia, enlarged submucosal mucus glands, angiogenesis, increased matrix deposition in the airway wall, increased airway smooth muscle mass, wall thickening and abnormalities in elastin. Genetic influences, as well as fetal and early life exposures, may contribute to structural changes such as subepithelial fibrosis from an early age. Other structural alterations are related to duration of disease and/or long-term uncontrolled inflammation. The increase in smooth muscle mass in both large and small airways probably occurs via multiple mechanisms, and there are probably changes in the phenotype of smooth muscle cells, some showing enhanced synthetic capacity, others enhanced proliferation or contractility. Fixed airflow limitation is probably due to remodelling, whereas the importance of structural changes to the phenomenon of airways hyperresponsiveness may be dependent on the specific clinical phenotype of asthma evaluated. Reduced compliance of the airway wall secondary to enhanced matrix deposition may protect against airway narrowing. Conversely, in severe asthma, disruption of alveolar attachments and adventitial thickening may augment airway narrowing. The encroachment upon luminal area by submucosal thickening may be disadvantageous by increasing the risk of airway closure in the presence of the intraluminal cellular and mucus exudate associated with asthma exacerbations. Structural changes may increase airway narrowing by alteration of smooth muscle dynamics through limitation of the ability of the smooth muscle to periodically lengthen.

Clinical and atopic parameters and airway inflammatory markers in childhood asthma: a factor analysis

BACKGROUND

Recent studies have repeatedly shown weak correlations among lung function parameters, atopy, exhaled nitric oxide level (Feno), and airway inflammatory markers, suggesting that they are non-overlapping characteristics of asthma in adults. A study was undertaken to determine, using factor analysis, whether the above features represent separate dimensions of childhood asthma.

METHODS

Clinically stable asthmatic patients aged 7-18 years underwent spirometric testing, methacholine bronchial challenge, blood sampling for atopy markers and chemokine levels (macrophage derived chemokine (MDC), thymus and activation regulated chemokine (TARC), and eotaxin), Feno, and chemokines (MDC and eotaxin) and leukotriene B(4) measurements in exhaled breath condensate (EBC).

RESULTS

The mean (SD) forced expiratory volume in 1 second (FEV1) and Feno of 92 patients were 92.1 (15.9)% predicted and 87.3 (65.7) ppb, respectively. 59% of patients received inhaled corticosteroids. Factor analysis selected four different factors, explaining 55.5% of total variance. The Kaiser-Meyer-Olkin measure of sampling adequacy was 0.587. Plasma total and specific IgE levels, peripheral blood eosinophil percentage, and Feno loaded on factor 1; plasma TARC and MDC concentrations on factor 2; MDC, eotaxin and leukotriene B4 concentrations in EBC on factor 3; and plasma eotaxin concentration together with clinical indices including body mass index and disease severity score loaded on factor 4. Post hoc factor analyses revealed similar results when outliers were excluded.

CONCLUSIONS

The results suggest that atopy related indices and airway inflammation are separate dimensions in the assessment of childhood asthma, and inflammatory markers in peripheral blood and EBC are non-overlapping factors of asthma.

Fractional exhaled nitric oxide (FENO), lung function and airway hyperresponsiveness in naïve atopic asthmatic children

BACKGROUND

Measurement of fractional exhaled nitric oxide (FENO) is a noninvasive, simple, well-tolerated, and reproducible marker of airway inflammation. Asthmatic children with normal respiratory function could be affected by airway inflammation. The aim of this study was to assess the correlation between FENO and bronchial hyperesponsiveness (BHR) to methacholine, and between FENO and lung function in atopic children with intermittent asthma.

METHODS

Thirty-seven children (21 male), aged 7.2-14.4 years (median: 10.9 years), suffering from mild intermittent atopic asthma with a physician-diagnosed history of wheezing and/or chest tightness were studied. None had taken anti-asthmatic therapy for at least three months before the study. No child had symptoms of respiratory tract infection in the month before the study. All subjects underwent FENO measurement, pulmonary function testing and the methacholine provocation tests.

RESULTS

The mean percentages of FEV1 and FEF25-27 were 91.9+/-10.5 and 88.3+/-11.8, respectively. The mean FENO was 62.2+/-39.2 ppb and PC20 methacholine was 0.93 mg/ml+/-0.54. Significant correlations were identified between FENO and FEV1 (p<0.0059, r=0.468) and between FENO and FEF25-75 (p<0.0098, r=0.439). There was no correlation between FENO and logPC20 (p=0.14).

CONCLUSIONS

A single FENO measurement is probably of scarce prognostic and predictive value and it is not surprising to find discordance with BHR. We suggest that FENO measurement could represent a good marker of airway inflammation also in naïve atopic children with intermittent asthma. Repeated measurements over time are probably necessary to understand better the clinical implications of the data obtained in this study.

Dissociation of lung function and airway inflammation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is defined by progressive, irreversible airflow limitation and an inflammatory response of the lungs, usually to cigarette smoke. However, COPD is a heterogeneous disease in terms of clinical, physiologic, and pathologic presentation. We aimed to evaluate whether airflow limitation, airway responsiveness, and airway inflammation are separate entities underlying the pathophysiology of COPD by using factor analysis. A total of 114 patients (99 males/15 females, age 62 +/- 8 years, 42 pack-years smoking, no inhaled or oral steroids > 6 months) with irreversible airflow limitation (postbronchodilator FEV(1) 63 +/- 9% predicted, FEV(1)/inspiratory vital capacity [IVC] 48 +/- 9%) and symptoms of chronic bronchitis or dyspnea were studied in a cross-sectional design. Postbronchodilator FEV(1) and FEV(1)/IVC, reversibility to inhaled beta(2)-agonists, diffusing capacity, provocative concentration of methacholine required to produce a 20% drop in FEV(1), total serum IgE, exhaled nitric oxide, and induced sputum cell counts (% eosinophils, % neutrophils) were collected. Factor analysis yielded 4 separate factors that accounted for 63.6% of the total variance. Factor 1 was comprised of FEV(1), FEV(1)/IVC, and residual volume/total lung capacity. Factor 2 included reversibility, IgE, provocative concentration of methacholine required to produce a 20% drop in FEV(1,) and diffusing capacity. Factor 3 contained exhaled nitric oxide and factor 4 included sputum % neutrophils and % eosinophils. We conclude that airflow limitation, airway inflammation, and features commonly associated with asthma are separate and largely independent factors in the pathophysiology of COPD.

The effects of an anti-CD11a mAb, efalizumab, on allergen-induced airway responses and airway inflammation in subjects with atopic asthma

BACKGROUND

Efalizumab is a humanized IgG(1) mAb against the lymphocyte function antigen-1 (LFA-1) alpha chain, CD11a. Blocking of LFA-1/intercellular adhesion molecule interactions could inhibit asthmatic inflammation by blocking adhesion and activation of LFA-1-positive leukocytes.

OBJECTIVE

A randomized, double-blinded, placebo-controlled, parallel group, multicenter study investigated the effects of efalizumab on allergen-induced airway responsiveness and airway inflammation.

METHODS

Thirty-five nonsmoking subjects with mild allergic asthma were randomized to receive efalizumab (n = 24) or placebo (n = 11) in 8 weekly subcutaneous doses (0.7 mg/kg conditioning dose followed by 7 weekly doses of 2.0 mg/kg). Allergen challenges were performed at screening and after 4 and 8 weeks of treatment. Samples of sputum (n = 18 subjects) and blood (n = 35 subjects) were collected the day before challenges, and sputum was collected again at 7 and 24 hours after each challenge. Nonparametric tests were used to compare allergen-induced differences between efalizumab and placebo groups.

RESULTS

Subjects receiving efalizumab developed headache (48%) and flu syndrome (28%) compared to subjects receiving placebo (0%). After 8 weeks of efalizumab, the maximum late percent fall in FEV(1) (late asthmatic response) was inhibited by 50%, but neither the late response nor the late area under the curve was statistically different than placebo (P =.098 and.062, respectively). Efalizumab had no effect on the maximum early percent fall in FEV(1) (early asthmatic response) or early area under the curve compared to placebo (P >.59). Efalizu-mab significantly reduced the postallergen increase in sputum EG2-positive cells and metachromatic cells (P <.05). No other comparisons were statistically different.

CONCLUSIONS

Blocking of LFA-1/intercellular adhesion module interactions by efalizumab inhibits the development of allergen-induced cellular inflammatory responses measured in induced sputum and might attenuate the late asthmatic response. Larger studies are needed to confirm this.

Nitric oxide in allergic airway inflammation

PURPOSE OF REVIEW

Exhaled nitric oxide has been proposed as a useful noninvasive marker of airway inflammation in asthma. Great efforts have been made to standardize the methodology for exhaled nitric oxide measurement in both children and adults. As a consequence there is now an opportunity to establish the precise relationship between exhaled nitric oxide, atopy and airway inflammation, and to investigate whether or not there is a role for the measurement of exhaled nitric oxide in the management of patients with asthma.

RECENT FINDINGS

A number of recent studies have investigated the relationship between exhaled nitric oxide and airway inflammation in asthma measured directly, using sputum induction, bronchoalveolar lavage and endobronchial biopsy. These measurements suggest that exhaled nitric oxide reflects eosinophilic airway inflammation in asthma, although there is no evidence for any relationship between exhaled nitric oxide and other airway inflammatory cells. Exhaled nitric oxide levels were found to be higher in atopic compared with nonatopic groups. These levels, however, are further elevated in atopic patients with asthma, suggesting that exhaled nitric oxide is not simply a marker of atopy. Although there is little evidence to support the routine use of measurement of exhaled nitric oxide in the management of patients with asthma, it may prove to be useful in assessing adherence to treatment with inhaled corticosteroids, or in the identification of patients in whom respiratory symptoms are associated with eosinophilic airway inflammation.

SUMMARY

There is good evidence that exhaled nitric oxide reflects eosinophilic airway inflammation in asthma. Well designed, long-term studies are needed to evaluate whether the addition of exhaled nitric oxide measurements to clinical and lung function assessment results in improved asthma control.

Inhalation therapy for bronchial asthma: strategies and targets

Bronchial asthma is associated with symptoms, reversible airflow obstruction, airway hyper-responsiveness and inflammation along large and small airways. Inhalation therapy with bronchodilators (relievers) and anti-inflammatory agents (controllers) forms the basis of treatment for most patients with asthma of different severities. Conventionally, therapeutic efficacy is assessed on the basis of improvements in symptoms and lung function. However, airway hyper-responsiveness as a primary outcome may change therapeutic strategies. There are problems associated with this concept which need to be addressed, such as the heterogeneity of airway inflammation in the asthmatic lung. The goals for inhalation therapy should be to determine the site of airway inflammation for each degree of asthma severity, to improve inhaler technology, ensuring that the drug can reach the site of inflammation, and to improve compliance. New inhalers need to do the following: contain appropriate therapeutic agents; have particle dimensions small enough to be deposited in distal airways; and minimize the effects of incorrect inhalation and low compliance.

Physiopathology of airway hyperresponsiveness

Airway hyperresponsiveness (AHR), the tendency of the airways to narrow too much and too easily in response to various stimuli, is a universal feature of asthma, although it is not exclusive to this disease. Airway responsiveness shows a unimodal distribution in the general population and might vary with time, increasing after exposure to allergens, industrial substances, or infectious agents in predisposed individuals, or decreasing for variable time periods after environmental or pharmacologic interventions. Airway inflammation and structural airway changes can lead to this heightened airway response, but the mechanisms by which they modify airway function are still unclear. They might be associated with increased contractile properties of the airways--from an increase in contractile elements, a change in smooth muscle mechanical properties, or a reduction of forces opposing bronchoconstriction, such as reduced airway-parenchymal interdependence. Other factors, such as neurohumoral influences and "geometric factors" (eg, airway caliber), can modulate the degree of AHR.

Changes in sputum counts and airway hyperresponsiveness after budesonide: monitoring anti-inflammatory response on the basis of surrogate markers of airway inflammation

BACKGROUND

Airway hyperresponsiveness (AHR) to pharmacologic stimuli and sputum eosinophils might be useful in the individual adjustment of long-term asthma management. However, it is not clear whether inhaled glucocorticosteroids (GCSs) provide greater protection against specific surrogate markers of airways inflammation than other means. In addition, detailed longitudinal assessment of changes in airway response with inhaled GCSs has never been carried out.

OBJECTIVES

We compared changes in AHR to inhaled methacholine and adenosine 5'-monophosphate (AMP) after budesonide treatment in a randomized, double-blind, placebo-controlled, crossover study of patients with mild-to-moderate asthma. Subsequently, we undertook a separate study to examine the time course of the changes in AHR in more detail and the changes in sputum cell counts in relation to budesonide treatment.

METHODS

In the phase 1 of the study, patients undertook bronchial provocation studies with increasing doubling concentrations of methacholine (0.06 to 16 mg/mL) and AMP (3.125 to 800 mg/mL) before and after budesonide 0.8 mg/daily for 3 weeks. The bronchial responses to the inhaled agonists were expressed as the provocative concentration causing a 20% decline in FEV(1) (PC(20)). In phase 2 of the study, patients attended the laboratory on 12 separate occasions to investigate changes in PC(20) methacholine, PC(20) AMP, and sputum cell counts before, during, and after withdrawal of therapy with inhaled budesonide 0.8 mg/daily for 6 weeks.

RESULTS

Budesonide treatment for 3 weeks significantly attenuated the constrictor response by 0.8 +/- 0.3 doubling doses for methacholine and by 2.6 +/- 0.5 doubling doses for AMP. These changes were significantly different from each other (P =.003). Significant variation in PC(20) methacholine (P <.05) value, PC(20) AMP (P <.001) value, percentage of sputum eosinophils (P <.001), and percentage of sputum epithelial cells (P <.001) were observed throughout the longitudinal assessment of changes in airway response to budesonide. Compared with the other surrogate markers, PC(20) AMP appears to be useful in promptly detecting early inflammatory changes of the asthmatic airways; a significant change of 1.6 +/- 0.3, 2.2 +/- 0.3, and 2.8 +/- 0.3 doubling doses of PC(20) AMP was observed at 1, 4, and 6 weeks, respectively, in the course of budesonide treatment.

CONCLUSIONS

The present findings underline the exquisite selectivity of diverse surrogate markers of airway inflammation in response to inhaled budesonide. When compared with that to the other markers, AHR to inhaled AMP is an early and sensitive indicator of the beneficial anti-inflammatory effects of topical GCSs.