UA's Arizona Respiratory Center Receives $2.5 Million Grant for Asthma Study Testing the Hygiene Hypothesis

The hygiene hypothesis suggests that microbial exposures may reduce susceptibility to asthma.

UA's Arizona Respiratory Center Receives $2.5 Million Grant for Asthma Study Testing the Hygiene Hypothesis

The hygiene hypothesis has received a lot of attention in recent years. It suggests that microbial exposures early in life may drive immune system development in a way that reduces susceptibility to asthma and other allergic diseases. While the increase in asthma in the industrial, non-farming populations seems to supports the hygiene hypothesis, recent data suggest that the relationship between microbial products and asthma and allergies is more complex than originally thought.
New information about innate immune pathways has offered a potential explanation for observations that are in apparent contradiction with the hygiene hypothesis. To better understand how genetic variation may influence response to microbial exposure, the National Institutes of Allergy, Immunology and Infectious Diseases (NIADI) has awarded the Arizona Respiratory Center a $2.5 million grant for the Microbial Innate Immunity in Asthma Pathogenesis Study (MIIAPS).

This five-year study will build on the successful Infant Immune Study at the Arizona Respiratory Center, which focuses on immune system markers for asthma risk. More than 450 newborns and their parents have been enrolled in this study. Data have been collected on this population to evaluate changes in immune response in the first year of life, and provide a foundation for continued follow-up of children to an age when asthma may be more definitively determined.

The MIIAPS Study adapts the hygiene hypothesis to new information that provide a basis for suggesting that different microbial exposures may have substantially different effects on developing immune systems early in life. This research focuses on the relationship between specific microbial exposures and variations within the innate immunity genes.

Asthma is the most frequent chronic condition in childhood in the United States. "These investigations of both genetic and environmental factors that influence immune system maturation may provide the basis for understanding the mechanisms underlying asthma susceptibility and resistance," says Marilyn Halonen, PhD, principal investigator of this study at the Arizona Respiratory Center and UA professor of pharmacology. Knowledge from this study may reveal insights into the primary prevention of this extremely common and serious disease, the prevalence of which is increasing.


The Arizona Respiratory Center was designated the first Center of Excellence at the UA College of Medicine in 1971. Today, the internationally known Center combines the highest caliber of research, clinical care and teaching. The Center is recognized as one of the top institutions for respiratory care.