Interferon: Asthma’s Holy Grail?

Could there be a cure for asthma on the horizon? Depends on whom you ask and what they know. I’ve sat on both sides of the answer, but now investigators at the University of Texas Southwestern Medical Center seem to be onto something highly intriguing.

They’ve determined that interferon -- a protein used in the treatment of multiple sclerosis, hepatitis C and a variety of cancers -- blocks the production of Th2, cells known to cause inflammation leading to asthma and atopic dermatitis.

Normally, Th2 cells help protect against infections by secreting chemicals that bring on inflammation. However, Th2 cells tend to get carried away in some people -- causing them to over-react when exposed to otherwise harmless substances such as animal dander, pollens and pollutants. Like tapping the first in a long chain of dominoes -- once Th2 cells become reactive, a whole set of inflammatory chain reactions take place, causing common allergic diseases such as asthma and atopic dermatitis.

“This finding is incredibly important because humans are being treated with interferon for a variety of diseases, yet no one has tried treating asthma patients with interferon,” said J. David Farrar, MD, assistant professor of immunology and molecular biology at UT Southwestern and senior author of the study. “The current therapies for asthma are inhalers and steroids, both of which offer only temporary relief.”

Dr. Farrar says that in isolated human immune cells, interferon targets and blocks Th2 cells before and after they form. In effect, interferon removes the key domino from the lineup.
But at what doses, and which patients are candidates for therapy, and when will a therapy be ready for use in what ages of patients and… ? So many questions, so little time! That’s why we’re writing about this topic in the Winter 2010 issue of Allergy & Asthma Today. Do you have questions you’d like to ask Dr. Farrar about this study? Send them to editor@aanma.org.

The study was funded by the National Institutes of Health (NIH) and Exxon Mobil.