Sublingual immunotherapy (SLIT) can reduce the allergic response to peanut in adolescents and adults, suggests a new study supported by the National Institutes of Health (NIH).
SLIT is a treatment approach in which, under medical supervision, people place a small amount of allergen under the tongue to decrease their sensitivity to the allergen. This is one of the first randomized, placebo-controlled studies to test the efficacy and safety of SLIT to treat peanut allergy and is one of several federally funded trials investigating immune-based approaches to preventing and treating food allergy. The results appear online in the January issue of the Journal of Allergy and Clinical Immunology
The study enrolled 40 people aged 12 to 37 years with peanut allergy who were on a peanut-free diet. After an initial food challenge to measure how much peanut powder they could eat without having an allergic reaction, participants received 44 weeks of daily therapy, followed by a second food challenge. Fourteen of the 20 participants (70 percent) given peanut SLIT were able to consume at least 10 times more peanut powder than they could at the beginning of the study, compared with only 3 of the 20 participants (15 percent) given placebo. After 68 weeks on peanut SLIT, on average, participants could consume significantly more peanut powder without having an allergic reaction. Study investigators also observed that SLIT caused only minor side effects, such as itching in the mouth, suggesting that daily therapy is safe.
Although more work is needed, the investigators hope that SLIT could one day help protect people with peanut allergy from experiencing severe allergic reactions in cases of accidental exposure. The researchers caution that people should not try peanut SLIT on their own because any form of immunotherapy carries a significant risk for allergic reactions. The therapy should be administered only under the guidance of trained clinicians.