As the researchers note, an estimated 3% to 6% of the population of the US has a food allergy—and recent studies have shown that the percentage is increasing. Because of that, researchers seek to better understand allergies and to stop them. In this new effort, the researchers were focused on the underlying cause of peanut allergies.To gain a better understanding of the factors that lead to a peanut allergy, the researchers collected samples of B-lineage plasma cells (which produce IgE) from the esophagus, duodenum and stomach from 19 peanut allergy suffers, each of whom were about to take part in a clinical trial set to test the effectiveness of prescribed doses of peanut proteins for allergy treatment. The cells were then sequenced.

In studying their data, the researchers found an abnormal amount of IgE in the guts of the peanut allergy sufferers, and that many of them had similar peanut-reactive IgE genome sequences. They also found evidence showing that many of the plasma cells had undergone class switch recombination (CSR), in which a cell stops producing one type of antibody and starts producing another—in this case, IgE.

In addition to adding another piece to the puzzle of food allergies, the results suggest it might be possible to treat patients with peanut allergies with therapies that target the prevention of CSR. The results also suggest similar studies might aid in the development of therapies for other food allergies, as well.