NIH Studies Aim to Improve Health of US Asthmatics

Thomas Castles

Researchers investigate school environment and exposure to microbes, fungi.

The National Institutes of Health (NIH) is ringing in the month of May, a notoriously difficult period for asthma sufferers that has been identified as National Asthma and Allergy Awareness Month, by presenting solutions to improve the health of the nearly 25 million people in the US with asthma.

Three institutes lead asthma research at NIH: The National Institute of Environmental Health Sciences (NIEHS), the National Heart, Lung and Blood Institute (NHLBI), and the National Institute of Allergy and Infectious Diseases (NIAID). “These three institutes support different aspects of asthma research but are united in a commitment to reduce the burden of this debilitating disease,” according to the NIH.

Research funded by the three groups has demonstrated the importance of healthy school environments in mitigating asthma symptoms in children. A study of inner-city schools found that higher mouse allergen exposure at school was significantly associated with both increased asthma symptoms and lower lung function, independent of allergic sensitization and allergen exposure in the home.

This suggests that “the school environment is an important contributor to childhood asthma morbidity, and future school-based environmental interventions may benefit all children with asthma,” according to the study. Because of these findings, the NIH began preliminary tests on high-efficiency particulate air (HEPA) filters, which resulted in two indoor air quality improvements: a 40 percent reduction in fine dust particles, along with a 55 percent reduction in traffic-related black carbon levels. Both pollutants can irritate the lungs of people with asthma.

Research funded by NIEHS, NHLBI, and NIAID has also explored the complex role of the immune system in asthma. An August 2016 study published in the New England Journal of Medicine showed that exposure to the wide range of bacteria and microbes in dust on Amish farms that use animals rather than machines may protect children from asthma by stimulation and shaping of innate immune responses.

“Despite the similar genetic ancestries and lifestyles of Amish and Hutterite children, the prevalence of asthma and allergic sensitization was 4 to 6 times as low in the Amish, whereas median endotoxin levels in Amish house dust was 6.8 times as high,” according to the study. “The results of our studies…indicate that the Amish environment provides protection against asthma by engaging and shaping the innate immune response.”

The difference in triggering of the innate immune response may help explain why asthma is rare among the Amish but affects nearly 1 in 10 US children, who typically do not live in a rich microbial environment.

NIH studies have shown that while exposure to microbes can benefit the immune system and defend against asthma symptoms, children with high exposure to molds and fungi were more likely to have asthma at age 7. For children with allergies, the association was especially strong.

“Our data demonstrate that fungi are potent immunomodulators and have powerful effects on asthma independent of their potential to act as antigens,” the report read.

NIH-supported scientists will continue to work to prevent and treat asthma, the group said. “This month, we honor those children and adults who face the challenges of asthma every day, those who participate in clinical studies, and the researchers and health care professionals who help to address this condition.”

Read the full report here.