Caroline J. Lodge, PhD

Credit: University of Melbourne

Oral immunotherapy (OIT) for hen’s egg, peanut, and milk can be effective in desensitization and even for remission in some cases, according to new findings, though a higher risk of allergic reactions was noted.¹

The findings were the result of a study examining immunotherapy to food allergens, given that the most promising type of immunotherapy to-date is oral immunotherapy.²

The study’s investigators sought to synthesize current evidence from randomized controlled trials (RCTs) on the safety and efficacy of oral immunotherapy for desensitization and for remission.

Consequently, this research was conducted and it was authored by Caroline J. Lodge, PhD, from the University of Melbourne’s Allergy and Lung Health Unit at the Melbourne School of Population and Global Health in Australia.

“It is critical to limit to best quality RCTs to obtain accurate information concerning efficacy and safety to provide the most unbiased estimates of the risks and benefits of using these treatments,” Lodge and colleagues wrote. “We aimed to review the current best evidence from RCTs for the effectiveness of peanut, egg, and cow's milk OIT on desensitization and remission and adverse allergic events.”

Background and Findings

The study’s investigators conducted a comprehensive search of EMBASE, PubMed, and Cochrane databases for peer-reviewed publications. The team focused on randomized controlled trials published in English, specifically investigating the effectiveness of oral immunotherapy for egg, peanut, or milk allergies.

The investigators’ included studies examined the outcomes of desensitization (DS) and sustained unresponsiveness (SU), with the participants undergoing oral food challenges (OFC) prior to and following the intervention. Adverse reactions were also considered.

After removing duplicates, two authors independently screened and assessed the suitability of the remaining studies. Data extraction was performed independently by 2 authors, covering immunotherapy specifics, trial details, and adverse effects.

The extracted information included study characteristics, outcomes from treatments, and the proportion of those achieving DS/SU. The study's definitions for DS and SU were provided, along with the criteria for adverse reactions.

The investigators assessed desensitization and sustained unresponsiveness as outcomes, along with adverse reactions. Their study utilized a rigorous screening and data extraction process to assess the included publications.

Eight randomized controlled trials were conducted by the research team, involving a total of 1414 participants, with varying numbers ranging from 29 - 555 participants. These studies took place in the UK, Germany, USA, multi-country sites (Europe and US), and Australia.

The age of the participants ranged from 3.1 - 12.4 years on average. The age inclusion criteria used in the research differed among the studies, with 4 of the studies including participants up to 16 or 17 years and 2 studies including those up to 21 years.

Notably, 5 studies provided detailed information on why some screened participants did not become included, and out of the 1495 people screened in these studies, 205 (14%) were excluded because they showed tolerance to peanuts during the initial double-blind placebo-controlled food challenge.

Overall, desensitization showed efficacy for all allergens, including peanut, hen's egg, and cow's milk. The risk ratios (RR) for desensitization were found to be 11.32, 4.67, and 13.98 for peanut, hen's egg, and cow's milk, respectively.

Sublingual immunotherapy (SU) also showed evidence of efficacy for peanut and hen's egg, with RR values of 7.74 and 6.91, respectively. However, the team noted that interventions resulted in increased allergic events. The risk of adrenaline use also increased for peanut, hen's egg, and cow's milk, with RR values of 2.96, 1.71, and 8.45, respectively.

“Participants included in these RCTs are not representative of the entire food allergy population and care must be taken applying these findings to other populations where both efficacy and adverse effects may differ,” they wrote. “Decisions around undertaking OIT need to be informed by consideration of individual circumstances.”

References

1. ^{Lodge CJ, Waidyatillake N, Peters RL, Netting M, Dai X, Burgess J, Hornung CJ, Perrett KP, Tang MLK, Koplin JJ, Dharmage SC. Efficacy and safety of oral immunotherapy for peanut, cow's milk, and hen's egg allergy: A systematic review of randomized controlled trials. Clin Transl Allergy. 2023 Jul 1;13(7):e12268. doi: 10.1002/clt2.12268. PMCID: PMC10314278.}
2. ^{Burks AW, Sampson HA, Plaut M, Lack G, Akdis CA. Treatment for food allergy. J Allergy Clin Immunol. 2018;141(1):1‐9. 10.1016/j.jaci.2017.11.004.}