Asthma Awareness Month is a good time to highlight the broad NIEHS support for research on asthma causes, triggers, and interventions.
Through both in-house and grant-supported science, NIEHS is working to understand asthma biology, to discover factors that lead to asthma development, and to identify environmental conditions that may trigger asthma attacks in people who already have the disease, as well as remedial measures to prevent attacks. NIEHS-supported studies also provide a scientific foundation for decisions made by legislators and policymakers, when setting safety rules and pollution standards.
NIEHS Scientific Director Darryl Zeldin, M.D., an expert in lung research and head of the NIEHS Environmental Cardiopulmonary Disease Group, listed the most important questions for NIEHS asthma researchers.
- What specific genetic factors predispose individuals to developing asthma?
- Which environmental factors contribute most to asthma development?
- How do environmental factors interact with genetic factors to cause asthma?
Asthma is common and can be life-threatening if not controlled. In 2014, nearly 1 in 10 children aged 5 to 17 years, and 1 in 13 adults had asthma, according to national asthma statistics from the U.S. Centers for Disease Control and Prevention.
NIEHS, along with the National Heart, Lung, and Blood Institute and the National Institute of Allergy and Infectious Diseases, reaffirmed its commitment to research that improves health among asthmatics on World Asthma Day. A fact sheet from NIEHS offers more information on asthma and its environmental triggers, as well as steps to reduce exposures.
Childhood asthma gets special attention
“There is a lot of research on childhood asthma because childhood is a very susceptible time period, and contributing factors may be different for children and adults,” says Bonnie Joubert, Ph.D., who oversees asthma-related grants for the NIEHS Population Health Branch.
For example, a new study linked improvement in southern California air quality with better lung health among children, especially those with asthma (see sidebar).
Understanding the biology of asthma
Stephanie London, M.D, Dr.P.H., head of the NIEHS Genetics, Environment, and Respiratory Disease Group, has a longstanding interest in the biological mechanisms that contribute to asthma. Her research team is working with the Pregnancy and Childhood Epigenetics (PACE) consortium to study whether a specific change in gene expression, called methylation, may be related to childhood asthma. In another study, London and NIEHS colleagues recently found that exposure to air pollution can increase the risk of developing asthma in adult women.
NIEHS-funded researchers are also figuring out how to measure changes in the body using biomarkers that indicate exposure to pollutants or environmental conditions, according to Sri Nadadur, Ph.D., program administrator in the NIEHS Exposure, Response, and Technology Branch. “These biomarkers of exposure, or the body’s response to exposure, can be used to predict the onset or worsening of asthma,” he said.
Nadadur highlighted NIEHS-supported research on how exposure to diesel exhaust particles exacerbates, or worsens, asthma. The scientists, from the Cincinnati Children’s Hospital Medical Center, found an immune response in mice similar to that observed in children with allergic asthma triggered by traffic-related air pollution. They used this information to identify a measureable marker in blood, the protein interleukin-17A, which indicates exacerbation by diesel exhaust.
Asthma triggers and interventions
The NIEHS NHALES Study, which stands for Natural History of Asthma with Longitudinal Environmental Sampling, is researching how environmental factors affect people with moderate to severe asthma. It is currently recruiting participants. According to study director Stavros Garantziotis, M.D., the microbiome is of particular interest.
“The primary hypothesis is that the body’s bacteria may indicate asthma activity, or perhaps even cause asthma exacerbations,” said Garantziotis. “By collecting a number of biological and environmental specimens over time, we can learn a lot about what triggers asthma attacks.”
Other NIEHS researchers reported recently that higher levels of certain substances in house dust may trigger wheeze. These substances, called endotoxins, were higher in homes with children, pets, cockroach problems, indoor smoking, and carpeting, and in low-income homes.
The research led to helpful interventions for asthmatics. Parents who were given test kits to monitor home dust mite allergens, a common asthma trigger, achieved lower allergen levels in their homes than parents given education alone. According to the researchers, parents were more motivated to start and maintain allergen reduction strategies, like using special allergen-proof pillow covers, when they could see the results of their efforts with the test kit.
(Virginia Guidry, Ph.D., is a technical writer and public information specialist in the NIEHS Office of Communications and Public Liaison and a regular contributor to the Environmental Factor.)