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Probiotic, peanut oral immunotherapy provides long-lasting clinical benefit

Combined probiotic and peanut oral immunotherapy delivered long-lasting clinical benefit and long-term repression of the allergic immune response to peanut, according to findings recently published in The Lancet: Child & Adolescent Health.

“The quality of life of children with food allergies is worse than that of children with diabetes. Accidental exposure to food allergens is common, with an annual incidence of 12% to 15% in children with peanut allergy,” Kuang-Chih Hsiao, MBChB DipPaed FRACP, of the department of pediatrics, Murdoch Childrens Research Institute in Melbourne, Australia, and colleagues wrote. “[However] no data for long-term outcomes after peanut oral immunotherapy have been published. In this study, we aimed to examine whether the previously reported clinical and immunological benefits of [probiotic and peanut oral immunotherapy (PPOIT)] were maintained 4 years after treatment.”

Researchers provided 48 participants that completed a PPOIT trial 4 years earlier with a questionnaire that assessed peanut intake and adverse reactions. These participants were also asked to take part in a double-blind placebo-controlled peanut challenge to evaluate 8-week sustained unresponsiveness, measurement of peanut sIgE and sIgG4 concentrations, and to undergo peanut skin prick tests.

Hsiao and colleagues found that four PPOIT-treated participants and six placebo participants described allergic reactions to peanut after intentional or accidental intake since ceasing treatment, but none had anaphylaxis. Also, the PPOIT group were significantly more likely than the placebo group to have continued eating peanut (16 of 24 vs. 1 of 24; absolute difference, 63%; P = .001.)

In addition, seven of 12 participants from the PPOIT group obtained 8-week sustained unresponsiveness compared with one of 15 participants from the placebo group (absolute difference, 52%, P = .012). Participants in the PPOIT group had age-adjusted and sex-adjusted and significantly higher peanut sIgG4 and sIgE ratios compared to placebo participants (geometric mean 67.3 vs. 5.2) and PPOIT participants had smaller wheals in peanut skin prick test (mean 8.1 mm vs. 13.3 mm; absolute difference –5.2 mm).

“Our [study] is the first report, to our knowledge, of long-term outcomes several years after cessation of peanut oral immunotherapy and the first study to incorporate challenge-proven sustained unresponsiveness as an outcome measure,” Hsaio and colleagues wrote.

“... The findings of this study are a step towards identification of an effective treatment to address the food allergy problem in developed countries.

In a related commentary, Matthew J. Greenhawt¸ MD, of the department of pediatrics at the University of Colorado, wrote, “the therapeutic effect shown is remarkable and redefines the notion of sustained unresponsiveness,” but also cautioned that the findings cannot be seen as conclusive.

" ... Additional research is essential to understand caregiver preferences, better align therapeutic goals, and refine cost-effectiveness models,” he wrote. “Despite achieving an important milestone, this study included small patient numbers, did not retain all participants in long-term follow-up, and did not include entry peanut challenge to show participants’ baseline threshold ... or comparison of oral immunotherapy with PPOIT to delineate the effect that is attributable to the probiotic.”

Greenhawt added that a multicenter trial currently underway is looking into these potential shortcomings. – by Janel Miller

Disclosure: Please see the study for a full list of relevant disclosures.