The use of imaging techniques for assessing severe childhood asthma

Role of circulating microRNA-132 in allergic bronchopulmonary aspergillosis: A case-control study

Allergic bronchopulmonary aspergillosis (ABPA) is an allergic respiratory disease. In the current study, we aimed to evaluate the roles of miRNA-21 and miRNA132 as biomarkers in the diagnosis of ABPA. A total of 30 controls, 30 allergic asthmatic patients, 30 severe asthma with fungal sensitization (SAFS) patients, and 30 ABPA patients were included. Real-time polymerase chain reaction was used to quantify the level of miRNAs expression. The expression level of miRNA-21 was significantly higher in allergic asthmatic, SAFS, and ABPA patients in comparison with controls (p < 0.001). However, no significant difference was detected in the expression level of miRNA-21 among the different patient groups (p > 0.05). The ABPA patients had significantly higher levels of miRNA-132 expression compared to controls, allergic asthmatic patients, and SAFS patients (p < 0.001), but there was a non-significant difference between controls and allergic asthmatic patients (p = 0.09). At a cut-off of 1.52, the sensitivity of miRNA-132 expression was 93.3% and the specificity was 100% different ABPA from healthy controls. At a cut-off of 6.5, miRNA-132 expression was found to reliably differentiate between ABPA and SAFS, with a sensitivity of 86.7% and a specificity of 80%. In ABPA patients, miRNA-132 expression positively correlation with the levels of serum IL-5 (r = 0.91, p < 0.001). miRNA-132 has a role in ABPA detection and distinguishing ABPA from allergic asthma and SAFS. These preliminary data from case-control study need further studies to confirm its finding.

Asthma-Like Features and Anti-Asthmatic Drug Prescription in Children with Non-CF Bronchiectasis

Bronchiectasis and asthma may share some characteristics and some patients may have both conditions. The present study aimed to examine the rationale of prophylactic inhaled corticosteroids (ICS) prescription in children with bronchiectasis. Data of children with radiologically established bronchiectasis were retrospectively reviewed. Episodes of dyspnea and wheezing, spirometric indices, total serum IgE, blood eosinophil counts, sensitization to aeroallergens, and air-trapping on expiratory CT scans, were recorded. The study included 65 children 1.5–16 years old, with non-CF bronchiectasis. Episodes of dyspnea or wheezing were reported by 22 (33.8%) and 23 (35.4%), respectively. Skin prick tests to aeroallergens (SPTs) were positive in 15 (23.0%) patients. Mosaic pattern on CT scans was observed in 37 (56.9%) patients. Dyspnea, presence of mosaic pattern, positive reversibility test, and positive SPTs were significantly correlated with the prescription of ICS. The prescription of ICS in children with bronchiectasis is more likely when there are certain asthma-like characteristics. The difficulty to set the diagnosis of real asthma in cases of bronchiectasis may justify the decision of clinicians to start an empirical trial with ICS in certain cases.

Small Airway Disease in Pediatric Asthma: the Who, What, When, Where, Why, and How to Remediate. A Review and Commentary

Asthma affects all portions of the airways. Small airways, however, comprise a substantial component of the conducting lung air flow. In asthma, inflammatory processes can affect the whole respiratory tract, from central to peripheral/small airways. The emphasis in adult and pediatric respiratory disease clinics is to focus on large airway obstruction and reversibility. This information, although valuable, underemphasizes a large portion of the conduction airway of asthmatics. Standard descriptions of asthma management focus on a multiple medication approaches. We particularly focused on the management of asthma in the international guidelines for the Global Initiative for Asthma (GINA). Overall, however, minimal attention is placed on the small airway pool in asthma medical management. We took the opportunity to thoroughly review and present specific data from the adult asthma literature which supported the concept that small airway abnormalities may play a role in the pathogenesis and clinical expression of asthma. Based on the conclusions of the adult asthma literature, we here present a thorough review of the literature as it relates to small airway disease in children with asthma. We used, collectively, individual data sources of data to expand the information available from standard diagnostic techniques, especially spirometry, in the evaluation of small airway disease. As the pharmacological approaches to moderate to severe asthma are advancing rapidly into the realm of biologics, we sought to present potential pharmacological options for small airway dysfunction in pediatrics prior to biological modifier intervention.

An Official American Thoracic Society Research Statement: Current Challenges Facing Research and Therapeutic Advances in Airway Remodeling

BACKGROUND

Airway remodeling (AR) is a prominent feature of asthma and other obstructive lung diseases that is minimally affected by current treatments. The goals of this Official American Thoracic Society (ATS) Research Statement are to discuss the scientific, technological, economic, and regulatory issues that deter progress of AR research and development of therapeutics targeting AR and to propose approaches and solutions to these specific problems. This Statement is not intended to provide clinical practice recommendations on any disease in which AR is observed and/or plays a role.

METHODS

An international multidisciplinary group from within academia, industry, and the National Institutes of Health, with expertise in multimodal approaches to the study of airway structure and function, pulmonary research and clinical practice in obstructive lung disease, and drug discovery platforms was invited to participate in one internet-based and one face-to-face meeting to address the above-stated goals. Although the majority of the analysis related to AR was in asthma, AR in other diseases was also discussed and considered in the recommendations. A literature search of PubMed was performed to support conclusions. The search was not a systematic review of the evidence.

RESULTS

Multiple conceptual, logistical, economic, and regulatory deterrents were identified that limit the performance of AR research and impede accelerated, intensive development of AR-focused therapeutics. Complementary solutions that leverage expertise of academia and industry were proposed to address them.

CONCLUSIONS

To date, numerous factors related to the intrinsic difficulty in performing AR research, and economic forces that are disincentives for the pursuit of AR treatments, have thwarted the ability to understand AR pathology and mechanisms and to address it clinically. This ATS Research Statement identifies potential solutions for each of these factors and emphasizes the importance of educating the global research community as to the extent of the problem as a critical first step in developing effective strategies for: (1) increasing the extent and impact of AR research and (2) developing, testing, and ultimately improving drugs targeting AR.

Predicting asthma morbidity in children using proposed markers of Th2-type inflammation

BACKGROUND

Assessment of inflammation is becoming a common practice in the clinical work-up of children with persistent asthma. Biomarkers of Th2-mediated inflammation include blood eosinophils (B-Eos), exhaled nitric oxide (FeNO), total serum IgE (S-IgE), and serum periostin. The aim of this study was to investigate the associations between asthma morbidity and increased levels of these biomarkers in pediatric asthma.

METHODS

School-age children (n = 96) with various manifestations of persistent asthma were included in this nationwide Swedish study. The protocol included the asthma control test, Juniper's quality of life questionnaire (QoL), assessment of pulmonary function, bronchial hyperresponsiveness, height-adjusted FeNO, blood sampling for S-IgE, B-Eos, and periostin, and high-resolution computed tomography (HRCT) of the lungs.

RESULTS

Children with both high levels of height-adjusted FeNO and B-Eos were younger (p = 0.001), had more often severe asthma (p = 0.015), were more allergic (p < 0.001), had a reduced asthma control (p = 0.035), reduced QoL (p = 0.035), more exacerbations (p = 0.004), reduced FEV1/FVC (p = 0.001), and increased bronchial hyperresponsiveness (p < 0.001) as well as greater bronchial wall thickening on HRCT (p = 0.022) compared to those with low levels of both biomarkers. Grouping children according to high and low serum periostin levels did not relate to differences in clinical characteristics and biomarkers.

CONCLUSIONS

Assessment of both local and systemic Th2-mediated inflammation by the analysis of easily attainable biomarkers such as exhaled NO and blood eosinophils has a high predictive value for the identification of children with the highest asthma morbidity. Adjusting FeNO values according to the individual child's height increases the clinical usefulness of this biomarker.

Imaging Acute Airway Obstruction in Infants and Children

Acute airway obstruction is much more common in infants and children than in adults because of their unique anatomic and physiologic features. Even in young patients with partial airway occlusion, symptoms can be severe and potentially life-threatening. Factors that predispose children to airway compromise include the orientation of their larynx, the narrow caliber of their trachea, and their weak intercostal muscles. Because the clinical manifestations of acute airway obstruction are often nonspecific, clinicians often rely on the findings at imaging to establish a diagnosis. Several key anatomic features of the pediatric airway make it particularly susceptible to respiratory distress, and the imaging recommendations for children suspected of having acute airway obstruction are presented. Although cross-sectional imaging may be helpful, the diagnosis can often be established by using radiographs alone. Radiographs of the chest and upper airway should be routinely acquired; however, for the child who is in severe distress, a single lateral radiographic view may be all that is necessary. The purpose of this article is to provide an imaging approach to acquired causes of acute airway obstruction in children, including (a) abnormalities affecting the upper portion of the airway, such as croup, acute epiglottitis, retropharyngeal infection, and foreign bodies, and (b) abnormalities affecting the lower portion of the airway, such as asthma, bronchiolitis, and foreign bodies. It is essential that the radiologist recognize key imaging findings and understand the pathophysiologic features of acute airway obstruction because in most cases, when the cause is identified, the condition responds well to prompt management.

Lung epithelial stem cells and their niches: Fgf10 takes center stage

Throughout life adult animals crucially depend on stem cell populations to maintain and repair their tissues to ensure life-long organ function. Stem cells are characterized by their capacity to extensively self-renew and give rise to one or more differentiated cell types. These powerful stem cell properties are key to meet the changing demand for tissue replacement during normal lung homeostasis and regeneration after lung injury. Great strides have been made over the last few years to identify and characterize lung epithelial stem cells as well as their lineage relationships. Unfortunately, knowledge on what regulates the behavior and fate specification of lung epithelial stem cells is still limited, but involves communication with their microenvironment or niche, a local tissue environment that hosts and influences the behaviors or characteristics of stem cells and that comprises other cell types and extracellular matrix. As such, an intimate and dynamic epithelial-mesenchymal cross-talk, which is also essential during lung development, is required for normal homeostasis and to mount an appropriate regenerative response after lung injury. Fibroblast growth factor 10 (Fgf10) signaling in particular seems to be a well-conserved signaling pathway governing epithelial-mesenchymal interactions during lung development as well as between different adult lung epithelial stem cells and their niches. On the other hand, disruption of these reciprocal interactions leads to a dysfunctional epithelial stem cell-niche unit, which may culminate in chronic lung diseases such as chronic obstructive pulmonary disease (COPD), chronic asthma and idiopathic pulmonary fibrosis (IPF).

Management of severe asthma in childhood--state of the art and novel perspectives

The majority of children with asthma have mild or moderate disease and can obtain adequate control of symptoms through avoidance of triggering factors and/or with the help of medications. There is still a group of children with severe asthma in whom symptom control is poor depending either on identifiable aggravating factors or on true therapy resistance. These children have a poor quality of life and are limited by the severity of their disease. There is a need for a staged approach to the assessment and treatment of this small but vulnerable and resource-consuming group. The current review will provide an overview of a possible standardized approach to characterize this heterogeneous group of severely sick children including some newly developed ways of assessing asthma severity and potentialities of new asthma therapies. Furthermore, the umbrella term 'problematic severe asthma' is described. The term encompasses children whose severe asthma is due to identifiable exacerbating factors, as well as children who are resistant to any conventional therapeutic approach. Characteristics of these two groups of children are described, as are possible biomarkers and current and emerging diagnostic tools for allergy evaluation. Some recent advances and future possibilities for treatment of severe asthma are also presented in this review.

Wheezing in preschool children

Wheezing is a common condition in pediatric practice, it can be defined as a musical sound, high-pitched and continuous, emitting from the chest during breath exhalation. Although almost 50% of children experiences wheeze in the first 6 years of life, only 40% of them will report continued wheezing symptoms after childhood. The classification of wheeze in preschool children is more difficult compared to school aged children. It is based on the onset and duration of symptoms and divided children in three categories: transient early wheezing, non-atopic wheezing and atopic wheezing/asthma. History and physical examination, skin prick test, exhaled nitric oxide, lung function test are the parameter to evaluate children with wheezing. The aim of management of wheezing is to finalize the control of symptoms, reduce exacerbations and improve the quality of life. All guidelines underline the complexity in making a diagnosis of asthma under five years and the need to identify phenotypes that may help paediatricians in the therapeutic choices.

The chitinase-like protein YKL-40: a possible biomarker of inflammation and airway remodeling in severe pediatric asthma

BACKGROUND

Problematic severe childhood asthma includes a subgroup of patients who are resistant to therapy. The specific mechanisms involved are unknown, and novel biomarkers are required to facilitate treatment and diagnosis of therapy-resistant asthma. The chitinase-like protein YKL-40 has been related to asthma and airway remodeling.

OBJECTIVES

To compare serum YKL-40 levels in children with severe, therapy-resistant asthma (n = 34), children with controlled persistent asthma (n = 39), and healthy controls (n = 27), and to investigate correlations with biomarkers of inflammation and airway remodeling.

METHODS

The study protocol included questionnaires, measurement of exhaled nitric oxide in exhaled air, blood sampling for inflammatory biomarkers, and high-resolution computed tomography of the lungs to identify bronchial wall thickening (therapy-resistant only). Serum YKL-40 levels were measured by ELISA, and all asthmatic children were genotyped for a CHI3L1 promoter single nucleotide polymorphism (rs4950928).

RESULTS

Serum YKL-40 levels were significantly higher in children with therapy-resistant asthma than in healthy children (19.2 ng/mL vs 13.8 ng/mL, P = .03). Among children with severe, therapy-resistant asthma, YKL-40 levels correlated with fraction of exhaled nitric oxide in exhaled air (r = 0.48, P = .004), blood neutrophils (r = 0.63, P < .001), and bronchial wall thickening on high-resolution computed tomography (r = 0.45, P = .01). Following adjustment for CHI3L1 genotype, significantly greater levels of YKL-40 were found in children with therapy-resistant asthma than in children with controlled asthma.

CONCLUSIONS

YKL-40 levels are increased in children with severe, therapy-resistant asthma compared to healthy children, and also compared to children with controlled asthma following correction for genotype.

Asthma: a simple concept but in reality a complex disease

BACKGROUND

Asthma is a disorder of the conducting airways that contract too easily and too much to cause variable airflow obstruction with symptoms of wheeze, cough, chest tightness and shortness of breath. Based on this knowledge, initial treatments were directed to dilating the contracted airways with anticholinergic and adrenergic drugs. The recognition that allergic-type inflammation underlay the hyperresponsive airways in asthma led to the introduction of anti-inflammatory drugs such as sodium cromoglicate and corticosteroids. Over the 2 decades that followed, these drugs have been progressively improved by increasing their therapeutic index and duration of action.

METHODS

A review of the recent literature indicates that since the 1980s, the explosive increase in knowledge of the cell and mediator mechanisms of asthma has only led to modest improvements in therapy including the introduction of leukotriene modifiers and a blocking monoclonal antibody against IgE. Indeed, biologics targeting allergic cytokines and effector cells have on the whole proven disappointing despite initial promise being shown in animal models.

RESULTS

Part of the difficulty lies in the oversimplified concept that asthma is only driven by allergic processes when in reality there are many environmental causes and triggers and the view that it is a homogeneous disorder only varying in severity.

CONCLUSIONS

The more recent views that asthma is a complex disorder made up of different subtypes with differing causes, treatment responses and natural histories creates a new opportunity for stratified medicine in which therapies acting upstream selectively target specific disease subtypes identified by specific diagnostic biomarkers.

Computational analysis of thoracic multidetector row HRCT for segmentation and quantification of small airway air trapping and emphysema in obstructive pulmonary disease

RATIONALE AND OBJECTIVES

Obstructive pulmonary disease phenotypes are related to variable combinations of emphysema and small-airway disease, the latter manifested as air trapping (AT) on imaging. The investigators propose a method to extract AT information quantitatively from thoracic multi-detector row high-resolution computed tomography (HRCT), validated by pulmonary function testing (PFT) correlation.

MATERIALS AND METHODS

Seventeen patients with obstructive pulmonary disease who underwent HRCT and PFT within a 3-day interval were retrospectively identified. Thin-section volumetric HRCT in inspiration and expiration was registered and analyzed using custom-made software. Nonaerated regions of lung were segmented through exclusion of voxels > -50 Hounsfield units (HU); emphysematous areas were segmented as voxels < -950 HU on inspiratory images. Small-airway AT volume (ATV) was segmented as regions of lung voxels whose attenuation values increased by less than a specified change threshold (set from 5 to 300 HU in 25-HU increments) between inspiration and expiration. Inspiratory and expiratory total segmented lung volumes, emphysema volume (EV), and ATV for each threshold were subsequently calculated and correlated with PFT parameters.

RESULTS

A strong positive correlation was obtained between total segmented lung volume in inspiration and total lung capacity (r = 0.83). A strong negative correlation (r = -0.80) was obtained between EV and the ratio between forced expiratory volume in 1 second and forced vital capacity. Stronger negative correlation with forced expiratory volume in 1 second/forced vital capacity (r = -0.85) was demonstrated when ATV (threshold, 50 HU) was added to EV, indicating improved quantification of total AT to predict obstructive disease severity. A moderately strong positive correlation between ATV and residual volume was observed, with a maximum r value of 0.72 (threshold, 25 HU), greater than that between EV and residual volume (r = 0.58). The benefit of ATV quantification was greater in a subgroup of patients with negligible emphysema compared to patients with moderate to severe emphysema.

CONCLUSIONS

Small-airway AT segmentation in conjunction with emphysema segmentation through computer-assisted methodologies may provide better correlations with key PFT parameters, suggesting that the quantification of emphysema-related and small airway-related components of AT from thoracic HRCT has great potential to elucidate phenotypic differences in patients with chronic obstructive pulmonary disease.

Validation of computational fluid dynamics in CT-based airway models with SPECT/CT

PURPOSE

To compare the results obtained by using numerical flow simulations with the results of combined single photon emission computed tomography (SPECT) and computed tomography (CT) and to demonstrate the importance of correct boundary conditions for the numerical methods to account for the large amount of interpatient variability in airway geometry.

MATERIALS AND METHODS

This study was approved by all relevant institutional review boards. All patients gave their signed informed consent. In this study, six patients with mild asthma (three men; three women; overall mean age, 46 years ± 17 [standard deviation]) underwent CT at functional residual capacity and total lung capacity, as well as SPECT/CT. CT data were used for segmentation and computational fluid dynamics (CFD) simulations. A comparison was made between airflow distribution, as derived with (a) SPECT/CT through tracer concentration analysis, (b) CT through lobar expansion measurement, and (c) CFD through flow computer simulation. Also, the heterogeneity of the ventilation was examined.

RESULTS

Good agreement was found between SPECT/CT, CT, and CFD in terms of airflow distribution and hot spot detection. The average difference for the internal airflow distribution was less than 3% for CFD and CT versus SPECT/CT. Heterogeneity in ventilation patterns could be detected with SPECT/CT and CFD.

CONCLUSION

This results of this study show that patient-specific computer simulations with appropriate boundary conditions yield information that is similar to that obtained with functional imaging tools, such as SPECT/CT.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100322/-/DC1.

Management of severe asthma in children

Children who are referred to specialist care with asthma that does not respond to treatment (problematic severe asthma) are a heterogeneous group, with substantial morbidity. The evidence base for management is sparse, and is mostly based on data from studies in children with mild and moderate asthma and on extrapolation of data from studies in adults with severe asthma. In many children with severe asthma, the diagnosis is wrong or adherence to treatment is poor. The first step is a detailed diagnostic assessment to exclude an alternative diagnosis ("not asthma at all"), followed by a multidisciplinary approach to exclude comorbidities ("asthma plus") and to assess whether the child has difficult asthma (improves when the basic management needs, such as adherence and inhaler technique, are corrected) or true, therapy-resistant asthma (still symptomatic even when the basic management needs are resolved). In particular, environmental causes of secondary steroid resistance should be identified. An individualised treatment plan should be devised depending on the clinical and pathophysiological characterisation. Licensed therapeutic approaches include high-dose inhaled steroids, the Symbicort maintenance and reliever (SMART) regimen (with budesonide and formoterol fumarate), and anti-IgE therapy. Unlicensed treatments include methotrexate, azathioprine, ciclosporin, and subcutaneous terbutaline infusions. Paediatric data are needed on cytokine-specific monoclonal antibody therapies and bronchial thermoplasty. However, despite the interest in innovative approaches, getting the basics right in children with apparently severe asthma will remain the foundation of management for the foreseeable future.

[Asthma: a disease of the whole bronchial tree]

Inflammation and remodelling are constant features of asthma. They are present throughout the whole bronchial tree, even in the small airways (less than 2 mm). The inflammatory cell infiltrate and structural changes are, in most cases, identical. However, in severe asthma, nocturnal asthma and fatal asthma, the cellular infiltrate in the distal airways is more intense and the number of activated cells is increased. In fatal asthma there are major alterations in the distal airways involving the smooth muscle and the bronchial epithelium, and mucus hypersecretion leading to distal airway plugging. Thus the histopathological changes in the distal airways contribute to the most severe stages of asthma and should be targeted by treatment. Currently the non-invasive tools that reflect inflammation are unable to assess these changes in the distal airways.

[Airways inflammation evaluation. Upper and lower airways]

It is done a review of evaluation methods of the inflammation in upper airways and bronchi used for diagnosis, therapeutic approach and prognosis of pathologies like rhinosinusitis and asthma. It is also analysed methods that supply relevant information of inflammation in COPD. The chronic inflammation of the airways is associated to respiratory distress, obstruction in basal lung function tests and to bronchial and nasal hyperreactivity. Computerized tomography informs about lumen dimensions, bronchial walls thickness and pulmonary density. These changes are associated to inflammation and to remodelling of the airways. Localized inflammation in respiratory tract can be detected by modifications of systemic inflammatory markers. The direct evaluation of inflammatory airways changes are based on immune, histological and chemical analysis of lung tissue obtained by biopsies and by fluids recoil in basal conditions or after stimulation. The eosinophils are increased in biopsies and in nasal and bronchoalveolar lavage in asthma and rhinitis and can change with therapy. Proteins and mRNA expression of cellular activation mediators are also observed. The induced sputum identifies eosinophilic inflammation that is inversely associated with lung function parameters. In each respiratory cycle the air is enriched in organic volatile compounds produced by cellular breathing. FENO is the bio marker more deeply studied in asthma and its increase is well documented in this disorder. In the exhaled air condensed, reactive oxygen species, membrane mediators, cytokines, and chemokines are identified. If the non invasive evaluation of inflammation became reliable and reproducible it will be indispensable in monitoring the airways diseases.

Small airways disease in asthma

A mounting body of physiologic and pathologic evidence indicates that asthma involves the central and the more distal airways. In patients with asthma, the peripheral lung accounts for a significant portion of airway resistance and, similar to the large airways, the small airways have been shown to be hyperresponsive to nonspecific stimuli, such as methacholine. Cellular inflammation, consisting of an infiltrate rich with lymphocytes and eosinophils, is present in the small airways of patients with asthma and may be more intense than that observed in the large airways. Clinical assessment of the peripheral airways continues to be a challenge, and new techniques, such as quantitative analysis of chest CT images, have proven to be useful research tools. The recognition of small airways involvement in asthma has clinical relevance, as new formulations of inhaled corticosteroids with smaller particle aerosols may be more effective in addressing this component of asthma.

Low attenuation area is associated with airflow limitation and airway hyperresponsiveness

BACKGROUND

Asthma is a chronic inflammatory disorder of the airways characterized by airflow limitation and airway hyperresponsiveness. Lung density indices on quantitative computed tomography (QCT) are assumed to reflect the degree of air trapping originated from airflow limitation in airway diseases.

PURPOSE

The present study investigated the availability of lung density indices on QCT in clinical evaluation of asthma.

METHODS

Eleven asthmatic patients and 48 healthy control subjects were prospectively evaluated by QCT, pulmonary function testing, and a methacholine challenge test. High-resolution computed tomography scans were performed at full-inspiratory and full-expiratory phases, and percentage of lung field occupied by low attenuation area (LAA%) and mean lung density (MLD) at both inspiratory and expiratory phases were measured.

RESULTS

MLD values at inspiratory phase were significantly increased in asthmatic patients compared with those in healthy control subjects. Inspiratory LAA% values were significantly decreased in asthmatics compared with the values in control subjects. On expiratory scans, MLD values of asthmatics were significantly lower than the values of control subjects. Expiratory LAA% values of asthmatics were significantly higher than the values of control subjects. The LAA% in the expiratory phase showed significant negative correlation with forced expiratory volume in 1 second (FEV(1)), FEV(1)/forced vital capacity, and the provocative dose of methacholine causing a 20% decrease in FEV(1) in asthmatic patients.

CONCLUSION

These results suggest that lung density indices on QCT may be useful for clinical evaluation of asthmatic patients and increased LAA% in the expiratory phase is associated with airflow limitation and airway hyperresponsiveness in asthma.

Advances in pediatric asthma in 2007

This year's summary focuses on recent advances in pediatric asthma as reported in 2007 publications in the Journal. This past year, new National Asthma Education and Prevention Program asthma guidelines were released with a special emphasis on new information in pediatric asthma. Journal theme issues in 2007 included the revised National Asthma Education and Prevention Program asthma guidelines, the accomplishments of the National Institutes of Health asthma networks, and focused discussions on environmental allergens, neutrophils, eosinophils, T cells, and epithelial cells, all of which affect pediatric asthma. The new asthma guidelines emphasize several key terms including severity, control, impairment, risk, and responsiveness that are relevant for advancing the care of children with asthma. This review highlights journal articles that relate to these guideline topics.