Overcoming peanut allergy requires maintenance for most
In small study, nearly all people who stopped eating the legumes daily later experienced allergic reaction
By Nathan Seppa
Peanut allergy is proving a tough nut to crack. Many people seem able to overcome the allergy by consuming tiny-but-increasing amounts of the legume daily for months or years. But the protection often evaporates if they fail to keep eating peanuts regularly, a new study shows. Twenty people with the allergy could eat a handful of peanuts after two years of bit-by-bit consumption, but 17 of them relapsed after avoiding peanuts for several months and then trying to eat some.
Blood tests of the volunteers suggest that those who fared best developed an army of immune stalwarts called regulatory T cells, or T-regs, which were oriented toward cooling immune reactions toward peanut protein. The researchers also report that this still-experimental introduction of peanuts into the diet, called oral immunotherapy, seems to induce biochemical changes in T-regs that might drive some of the newfound protection. The report appears in the February Journal of Allergy and Clinical Immunology.