Immunotherapy for peanut allergy provides protection but not a cure
Our researchers have found that a potential treatment for peanut allergy provides some protection but does not cure an allergic patient.
Peanut allergy has doubled over the last two decades and affects around 1 in 50 children in the UK. It is rarely outgrown and is the most common cause of food allergy deaths.
A study by King’s College London, recently published in The Journal of Allergy and Clinical Immunology, tested samples from patients who suffer from peanut allergy with peanut oral immunotherapy (POIT) as their treatment. Researchers found that it does not stop them being allergic and instead just suppresses the reaction.
POIT works by reducing a patient’s sensitivity to peanut so they can tolerate small amounts and therefore are less at risk of accidental reactions to peanut contamination of other foods. POIT works by making the immune system produce antibodies that reduce the allergic response to peanut. However, a recent review has found that patients taking POIT have more allergic reactions to peanut compared to allergic patients who simply avoid peanut.
Researchers tested samples from peanut-allergic patients who underwent POIT and found that although POIT does suppress allergic reactions when the protective antibodies were removed, the allergic cells are still as reactive as before treatment. These findings support the concept that POIT does not ‘cure’ the allergies.
Peanut oral immunotherapy can confer some protection to accidental exposure to peanuts as a result of the so-called ‘blocking antibodies’ … If we remove these ‘blocking antibodies' we could see that the cells are still as reactive as before, confirming that the patients were still allergic and need to keep going with the POIT regimen to maintain the protection.
– Lead author, Dr Alexandra Santos, King’s College London and Evelina London Children’s Hospital.
A test known as mast cell activation test (MAT) was used to confirm whether the patients are still allergic after POIT and need to continue taking peanut as per POIT regimen or are no longer allergic and can eat peanuts freely. The next steps in the research are to validate these findings in other cohorts of peanut-allergic patients treated with POIT and confirm that the MAT is useful to monitor a patient’s response to this treatment.
Dr Alexandra Santos commented:
Definitive treatments for peanut and other food allergies are highly needed. Currently, immunotherapy is the only treatment option we can offer peanut-allergic patients… To a greater or lesser extent, the different forms of peanut immunotherapy can make allergic patients less sensitive, which can protect them from accidental exposure, but patients remain allergic.
There is currently no cure for peanut allergy. Standard management of peanut allergy involves strict peanut avoidance, which has been shown to severely affect quality of life.
This research was mainly supported by the Medical Research Council (MRC) and by the National Institute for Health Research (NIHR) Guy’s and St Thomas’ Biomedical Research Centre (BRC).
Read the full article on the King’s College London website.
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