Scientists may have found the cell that causes severe allergic reaction.

Peanut Allergy

Researchers at Cincinnati Children’s Hospital may have found out what causes some people with food allergies to have severe allergic reactions to foods while others only have mild symptoms. This could lead to new therapies and easier diagnosis for food allergies.

What causes Food Allergies?

Il-9 is a protein in the immune system that causes allergic reactions. When someone eats a food that they are allergic to, large amounts of IL-9 are produced. Until now, no one knew what was causing the IL-9 to be produced. Scientists at Cincinnati Children’s Hospital have found that it is being produced by a cell called a Mucosal Mast Cell (MMC9).

Severe allergic reactions also require IgE, another part of the immune system that causes allergic responses. Without IgE or MMC9, severe allergic responses and anaphylaxis could not occur.

IgE- associated food allergies are triggered by certain foods such as peanuts, tree nuts, shellfish, dairy, eggs and others. IgE causes an immune response that is completely out of proportion. Unless it is treated quickly, it can lead to a total body reaction in the circulatory system, the gastrointestinal system and the respiratory system causing difficulty breathing, hypothermia, diarrhoea and shock.

The best way to prevent anaphylaxis is to avoid the foods that cause it. There are no medications that can prevent anaphylaxis, only medications that can treat it once it’s begun.


This study used mice that were specifically bred to have food sensitivities. They found that when exposed to the food, some of the mice produced large amounts of MMC9 cells and others didn’t. The mice that did produce the MM9 cells all had severe allergic reactions regardless of their levels of IgE.

The scientists also looked at human biopsy samples from people with severe food allergies and found large quantities of Il-9, this means that these findings in mice are relevant to human food allergies development. The scientists are now looking for the human equivalent of this cell.

40% of children have some IgE- associated food sensitivity but only 8 percent of those 40 percent develop severe food allergies that can lead to anaphylaxis.

Using these new findings, scientists could develop a way of testing for severe allergies. This would make it easy to recognise who is at a higher risk for severe food allergies. It could also eventually lead to improved treatments by finding a way to deactivate these cells.



Image Source: Flickr/ U.S. Dept of Agriculture

Disclaimer: The information provided is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis or treatment. Allergy Lifestyle Limited (t/a) Allergy Lifestyle) uses reasonable endeavours to check the accuracy of information provided however no warranty is given that they are error-free.

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