peanut allergy

Peanut Allergy Unresponsiveness Sustained With Combination Therapy

Combined probiotic and peanut oral immunotherapy (PPOIT) is associated with long-term suppression of peanut allergy, according to a recent study.

The researchers’ randomized trial of PPOIT had shown positive results after 2 weeks, but longer-term effects were unknown.

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To better understand the long-term effects, the researchers evaluated 48 of 56 eligible participants enrolled in their PPOIT follow-up study. Participants had received either PPOIT or placebo during the trial. Mean time since treatment discontinuation was 4.2 years in both groups.

Allergy nurses administered a questionnaire to gauge peanut intake and adverse reactions to peanut in the 4 years following treatment cessation. To evaluate 8-week results, participants underwent peanut skin prick tests, measurement of peanut serum immunoglobulin E (sIgE) and serum immunoglobulin G4 (sIgG4) concentrations, and a peanut challenge.

Results indicated that participants who had received PPOIT were significantly more likely to have continued eating peanuts (16 of 24), compared with those who had received placebo (1 of 24). A total of 4 participants who had received PPOIT and 6 participants who had received placebo had reported allergic reactions to peanuts after intentional or accidental intake since treatment cessation. However, none had anaphylaxis.

The researchers also found that participants in the PPOIT group had smaller wheals in peanut skin prick test and had significantly higher peanut sIgG4:sIgE ratios compared with the placebo group. A total of 7 (58%) of 12 participants in the PPOIT group had achieved 8-week sustained unresponsiveness vs 1 (7%) of 15 participants in the placebo group.

“PPOIT provides long-lasting clinical benefit and persistent suppression of the allergic immune response to peanut,” the researchers concluded.

—Christina Vogt


Hsiao KC, Ponsonby AL, Axelrad C, Pitkin S, Tang MLK; PPOIT Study Team. Long-term clinical and immunological effects of probiotic and peanut oral immunotherapy after treatment cessation: 4-year follow-up of a randomised, double-blind, placebo-controlled trial [Published online August 15, 2017]. Lancet Child Adolesc Health. doi:10.1016/S2352-4642(17)30041-X.