Researchers may have uncovered a new type of cell that could unlock some of the mysteries of severe food allergies and perhaps lead to new treatments.
The discovery was made by scientists at Cincinnati Children’s Hospital Medical Center.
They published their findings today in the journal Immunity.
In their report, the researchers said they have identified a cell that produces large amounts of an inflammatory immune protein that amplifies anaphylactic shock when foods such as peanuts and shellfish are eaten.
“Without these cells, you will not get severe food allergies,” said Yui-Hsi Wang, Ph.D., a researcher in the division of allergy and immunology at the Cincinnati medical center, in a statement.
Finding the Trigger Cells in Mice
In their research, Wang and his team fed an egg-white protein to trigger allergic reactions in several strains of lab-bred mice.
They noticed some of the mice developed large amounts of mucosal mast cells called MMC9. These cells produce significant amounts of the immune protein, interleukin 9 (IL-9), which is believed responsible for the severe reaction in some food allergies.
The researchers said the mice that produced intestinal MMC9 cells had serious allergic reactions. The mice that did not produce any MMC9 cells had only minor allergic responses.
To confirm their results, the researchers injected an antibody into the mice that had severe reactions. The antibody eliminated the MMC9 cells and the food allergy reactions dissipated.
When the cells were reintroduced into those mice, the food allergy reactions returned.
The researchers then examined small biopsy samples from the intestines of food allergy patients. They found significant genetic impressions of the IL-9 protein in those samples. The researchers are now trying to find the human equivalent of the MMC9 cells they found in the mice.
“Certain people must have this type of cell in their G.I. [gastrointestinal] tract,” Wang told Healthline.
How This Information Could Help
Food allergies affect 4 to 6 percent of children and 4 percent of adults, according to the Centers for Disease Control and Prevention.
Eight types of food account for 90 percent of all reactions, according to the American College of Allergy, Asthma and Immunology (ACAAI).
They are eggs, milk, peanuts, tree nuts, fish, shellfish, wheat, and soy. In children, the most common culprits are milk, eggs, and peanuts, according to the ACAAI website.
Wang noted that 40 percent of children have some food sensitivity, but only 8 percent of that group develops severe food allergies that lead to anaphylactic shock.
He said his team suspects that some people are genetically wired to have higher food sensitivity, but they aren’t certain yet why some people have such violent reactions.
Wang said his team’s research could help pinpoint exact causes for this ailment.
He also hopes that identification of specific cell types could lead to biomarkers that could be used for blood tests to diagnosis food allergies.
A Treatment in the Future?
Right now, the best treatment for food allergies is to avoiding eating the foods that cause the reactions.
This is sometimes easier said than done, especially when people eat in restaurants or when children eat at schools.
Some allergists will prescribe an epinephrine auto-injector for patients with severe allergic reactions to food. In November 2013, President Obama signed a law that encourages states to require schools to have the auto-injectors on hand.
Wang said he hopes his research can lead to a treatment so people wouldn’t have to avoid certain foods or use an auto-injector in an emergency to stabilize a reaction.
However, Wang said such a treatment is most likely a number of years away.
“We’d like to identify some compounds that could inhibit this activity,” Wang said. “That is a dream for the future.”