Interim findings from establishing the effectiveness, cost-effectiveness and safety of oral and sublingual immunotherapy for food allergy: A systematic review

Background:   The prevalence of food allergy in children has increased in recent decades. Oral and sublingual immunotherapy aims to desensitise people and induce immunological tolerance, enabling IgE-mediated food allergic patients to consume increased quantities of the food(s) in question. This is a promising new therapeutic approach and a careful critique and synthesis of the literature will be an important contribution towards establishing the safety, effectiveness and cost-effectiveness of this approach.

Objectives:  To identify and critically review the published and unpublished evidence for the effectiveness and safety of oral and sublingual immunotherapy in people with IgE-mediated food allergy.

Methods:  Systematic review and meta-analysis of all interventional studies i.e. randomised controlled trials (RCTs), quasi-RCTs and controlled clinical trials (CCTs) were identified from searching 11 electronic databases. The primary outcomes of interest are the recovery rate from food allergy as assessed by the ability to consume increased amount of the offending food allergen whilst on treatment (i.e. desensitisation) and success rates for complete tolerance to the causative food. Secondary outcomes of interest include the frequency and severity  of local/systematic adverse events,  quality of life, health services use including emergency department contacts and hospital admissions, and data on cost-effectiveness both from the perspectives of patients/families and healthcare providers.

Interim findings:  Our searches identified 721 potentially relevant papers; after de-duplication, 626 potentially eligible papers were included for screening. 606 studies were excluded for not meeting review criteria and another 20 potentially appropriate abstracts reviewed, of which 11 satisfied our inclusion criteria. There were seven RCTs and four CCTs; nine of these trials relate to oral immunotherapy and the remaining two are concerned with assessing sublingual therapy. Analyses are underway and results will be presented at the conference.

Implications: This work will clarify the evidence base for the use of oral and sublingual immunotherapy in people with IgE-mediated food allergy and will inform national and international deliberations on service provision.