26 April 2019
A new paper published in The Lancet has examined the evidence around providing oral immunotherapy for people with peanut allergy. This systematic review states that for patients who were followed for a year, current oral immunotherapy treatment may results in an increase in anaphylaxis and other allergic reactions compared with allergen avoidance or placebo. In response, the British Society for Immunology has released the following statement.
Dr Louisa James, British Society for Immunology spokesperson and Lecturer in Immunology at Queen Mary University of London, said:
“Allergic reactions can occur because the patient’s immune system produce IgE antibodies against peanut proteins, these antibodies can trigger allergic reactions when they come into contact with peanut. The aim of oral immunotherapy is to override this IgE-driven reaction by changing the way the immune system responds to peanut. The allergic reactions that occur during oral immunotherapy tend to happen during the early stages of treatment which reflects the fact that it takes several weeks or months of continuous exposure to peanut to overcome this IgE response.
"Peanut allergy affects around 1 in 50 children and has been steadily increasing in incidence over recent decades. Life threatening reactions are extremely rare but the likelihood and severity of allergic reactions to peanut are unpredictable, negatively affecting the everyday lives of patients and their carers.
“Over recent years several different research groups have carried out clinical trials to test whether oral immunotherapy could reduce or even remove the risk of allergic reactions to peanut. Peanut oral immunotherapy involves eating precise doses of peanut (usually as peanut flour) every day in increasing doses up to a ‘maintenance’ dose which typically contains the equivalent of around 4 peanuts.
“This study analysed the combined results of 12 separate randomised controlled trials of peanut oral immunotherapy in young children. Combining the results of several independent studies allows more confident evaluation of the results than looking at each study individually. The analysis found that patients treated with oral immunotherapy were less likely to react to peanut at the end of the study but were more likely to experience allergic reactions during the treatment. Both the risk and the frequency of severe reactions was increased in patients receiving oral immunotherapy and their occurrences were unpredictable.
“The long-term effects of oral immunotherapy for peanut allergy are yet to be fully evaluated and it is unclear if the benefits of current approaches translate into a cure. Different approaches are being developed which aim to improve the safety of oral immunotherapy but these will require testing in randomised controlled trials. As highlighted by this study, tests that can accurately predict the likelihood and severity of allergic reactions to peanut are imperative.
The full paper that this statement is in response to can be found at: Chu et al. 2019 Oral immunotherapy for peanut allergy (PACE): a systematic review and meta-analysis of efficacy and safety. The Lancet DOI: 10.1016/ S0140-6736(19)30420-9