Environmental exposures have been recognized as critical in the initiation and exacerbation of asthma, particularly in children, among whom asthma is the most common chronic disease. In June 2014, the National Institute of Allergy and Infectious Diseases (NIAID), National Institute of Environmental Health Sciences (NIEHS), National Heart, Lung, and Blood Institute (NHLBI), and Merck Childhood Asthma Network (MCAN) sponsored a joint workshop entitled "The Indoor Environment and Childhood Asthma: Implications for Home Environmental Intervention in Asthma Prevention and Management." U.S. and international experts with backgrounds in allergy/allergens, immunology, asthma, environmental health, environmental exposures and pollutants, epidemiology, public health, and bioinformatics were assembled to discuss the current state of the science with respect to the indoor environment and its effects on the development and morbidity of childhood asthma.
A primary focus of the workshop was critical review of trials and research relevant to the prevention or control of asthma through environmental intervention; sessions were divided in five working groups:
- New Insights into indoor exposure assessment
- New insights into indoor exposure properties and dose-response associations with allergy/asthma outcomes
- Fundamental concepts and methods/Implications for environmental interventions: New insights into exposure reduction techniques
- Progress and limitations of home environmental control of allergens: Primary prevention trials
- Indoor environmental interventions for asthma management
The participants identified critical limitations and gaps in the scientific methodologies and knowledge, and proposed the following areas for future research.
Research Priorities Working Group 1:
- Analytical/Technological Improvements
- Personal monitoring devices
- Expansion of arrays to include endotoxin, flagellin, markers of innate immunity, biomarkers
- Development of efficacious (and unbiased) sample collection, extraction and processing techniques for environmental microbiome samples
- Enhanced data collection in population studies, e.g. birth cohorts
- Environmental monitoring in immunotherapy and drug development studies to understand the impact of environmental exposures on the efficacy of immunotherapy and other drugs
- Data driven environmental modification strategies
- Improved metagenomic and bioinformatic techniques to define microbes taxonomically and functionally (including fungi), with the goal of isolating taxonomic or functional groups of microbes with potentially therapeutic or adverse effects.
Research Priorities Working Group 2:
- How do the biochemical characteristics of allergens, such as protease or lipid binding activity, contribute to the allergic response?
- What is the precise role of specific allergic adjuvants and protective microbial substances and do these adjuvants and protective substances work in concert?
- What are combined, or integrated, effects of concomitant exposure to bacterial products, pollutants, and allergens on immune responses and asthma in cross-sectional or prospective observational cohort studies? How do findings regarding combined effects inform development of trials or therapeutic approaches to asthma prevention or treatment?
- How can nasal brushings or other non-invasive biospecimens be utilized to understand mechanisms of action of allergens and co-exposures like bacteria or smoking on pulmonary responses?
Research Priorities Working Group 3:
- Novel technologies with particle or gas filtration should be tried in multiple settings, including home and school environments, first to test their efficiency in reducing exposure and then to assess their adjunct role in treating asthma.
- Trials should include assessment of whether response to air filtration varies by asthma severity or allergic status of asthmatic children
- Research focused on mold exposure reduction strategies is needed to allow the development of more targeted (and presumably effective) interventions which are appropriate for different types of climatic regions and housing stock.
- Interventions should be tested that can be applied to low-income mobile populations with limited resources.
- Given the cost of structural housing interventions, opportunities to design and conduct double-blind studies which test their effectiveness in improving health may be limited. High-quality observational studies that systematically study the ‘treatment’ effect of these changes for individuals with diagnosed asthma should be conducted.
Research Priorities Working Group 4:
- To investigate patterns of human microbiome associated with allergic diseases, and the influence of the indoor environment on that microbiome.
- To investigate the biological mechanisms that underlie the interaction between genetic susceptibility and aeroallergen and/or microbial exposure in initiating asthma
- To explore the relationship between environmental exposures and epigenetic changes and the relevance to risk of asthma development
- To investigate differential effects of type, dose and route of allergen exposure in the development asthma
- To perform randomized controlled trials of (i) dietary interventions, and (ii) stress reduction measures, in primary prevention of asthma in ethnically diverse populations
- To investigate the optimal age for intervention for prevention of asthma
- For each of the major potentially modifiable factors,
- To identify the subpopulations that would benefit from the intervention, and, perhaps, the subpopulations that might be at adverse risk, or not benefit.
- To define interventions that would be of benefit to most children (e.g., smoking cessation)
Research Priorities Working Group 5:
- Further defining the role of environmental interventions in asthma management
- Determining the most cost- and clinically- effective approaches to environmental interventions
- Determining how to effectively implement environmental interventions in healthcare, public health policy, and clinical practice.
- Diane Gold MD., Harvard University
- Elizabeth Matsui M.D., John Hopkins University
- Avrum Spira M.D., Boston University
- Joanne Sordillo Sc.D., Harvard University
- Martin Chapman Ph.D., Indoor Biotechnologies
- Dennis Ownby M.D., Augusta University
- Petros Koutrakis Ph.D., Harvard University
- Gary Adamkiewicz Ph.D., Harvard University
- Victoria Persky M.D., University of Illinois at Chicago
- Wanda Phipatanakul M.D., Harvard University
- Brian Leaderer Ph.D., Yale University
- Syed Hasan Arshad M.D., University of Southampton, UK
- Ulrike Gehring Ph.D., Utrecht University, NL
- Clare Ramsey M.D., University of Manitoba
- Christine Johnson M.P.H., Henry Ford Health System
- Augusto Litonjua M.D., Harvard University
- Juan Celedon M.D., Ph.D., University of Pittsburgh
- Shakira Suglia Sc.D., Columbia University
- Matt Perzanowski Ph.D., Columbia University
- James Gern M.D., University of Wisconsin
- George O’Connor M.D., Boston University
- Suzanne Kennedy Ph.D., Rho Federal Systems Division
- Herman Mitchell Ph.D., Rho Federal Systems Division
NIH and other Government Staff
- Geoffrey Mueller Ph.D., NIEHS
- Paivi Salo Ph.D., NIEHS
- Donald Cook Ph.D., NIEHS
- Ginger Chew Sc.D., CDC
- Patricia Noel Ph.D., NHLBI
- Alkis Togias M.D., NIAID
- Julie Schwaninger M.S., NIAID
- Darryl Zeldin M.D., NIEHS