Scientists figure out how to switch off peanut allergy

The peanut allergy is one of the eight most common types of food allergies, and the common use of peanuts in a wide range of foods makes it particularly dangerous. But now scientists have a solution: trick your immune system.

Technically speaking, it's not peanuts themselves that are dangerous to people with the allergy - it's actually the immune system's extreme reaction to peanuts, which is known as anaphylaxis. It's not an extremely common phenomenon, as the National Institutes of Health estimate 15,000 to 30,000 anaphylaxis episodes in the United States each year, and just 100 to 200 deaths. But there's no treatment available for these allergies, and severe reactions can include sudden constriction of the airways, a drop in blood pressure, shock, and eventually loss of consciousness or even death.

Now researchers at Northwestern University may have found a solution. The key is finding a way to short-circuit the immune system's response to peanut proteins. To do that, researchers Paul Bryce and Stephen Miller attached peanut proteins to blood cells, which are then reintroduced to the body. The T cells in the immune system recognize the familiar blood cells and start building up a tolerance to the peanut proteins, effectively removing the immune response that creates the peanut allergy. This method has been used before in helping to treat autoimmune disease, and now the researchers have been able to extend it to working with food allergies.

Bryce explains:

"We think we've found a way to safely and rapidly turn off the allergic response to food allergies. T cells come in different 'flavors.' This method turns off the dangerous Th2 T cell that causes the allergy and expands the good, calming regulatory T cells. We are supposed to be able to eat peanuts. We've restored this tolerance to the immune system."

The researchers have tested the treatment on a mouse model that replicates the potentially lethal peanut allergy. They placed the peanut proteins on leukocytes, which are white blood cells, and then put these cells back into the mice. After just two treatments, the mice were able to eat peanuts without any allergic reaction. In a second experiment, they were also able to treat an allergy to egg that causes lung inflammation in mice. Bryce is optimistic that multiple proteins could be attached to the blood cells, allows multiple food allergies to be treated all at once.

He adds:

"Their immune system saw the peanut protein as perfectly normal because it was already presented on the white blood cells. Without the treatment, these animals would have gone into anaphylactic shock. This is an exciting new way in which we can regulate specific allergic diseases and may eventually be used in a clinical setting for patients."

Via the Journal of Immunology. Image by random_alias on Flickr.