A team of St Vincent’s researchers, led by Prof Andrew Carr and Dr Winnie Tong, have commenced an Australia-first trial to help people living with peanut anaphylaxis, and are recruiting peanut allergic people over the age of 16 to take part.
Peanut allergy affects 1 in 100 Australian adults and caused 20% of adult deaths related to food anaphylaxis. It can also cause a significant amount of anxiety for sufferers, particularly when it comes to eating and socialising.
Currently there is no cure, and the process of strict avoidance, supplemented by carrying an adrenaline auto-injector (e.g. Epipen) to treat anaphylaxis caused by accidental exposure is not ideal.
One tool available to clinicians to treat some allergies is immunotherapy. Allergen immunotherapy (also known as “desensitisation”) involves exposing an individual to gradually increasing amounts of the substance to which they are allergic in order to induce immune tolerance, which allows reactions to become less severe or to disappear completely.
Food immunotherapy is very new, and most research has focused on peanut allergy in children. This research has demonstrated improved tolerance of peanut, less severe reactions to peanut, and improved quality of life and anxiety levels. Adults have not seen the same benefits to date, and the limited data that does exist for adults shows it is less efficacious, and participants have more side effects.
Allergies to peanut and other foreign proteins are driven by a protein in the blood called immunoglobulin E (lgE). When an allergic person is exposed to their allergen, the IgE in their blood sticks to mast cells which release chemicals such as histamine. This is then responsible for the symptoms of itch, hives, swelling, asthma and low blood pressure seen with life-threatening allergic reactions.
Omalizumab is a medication that sticks to IgE, and so prevents the mast cells from releasing the chemicals that cause allergic reactions. Omalizumab is currently approved for the treatment of some patients with allergic asthma and chronic hives.
In children, combining omalizumab with peanut immunotherapy has resulted in both more rapid and more effective desensitisation.
In this trial, researchers are using omalizumab in combination with peanut oral immunotherapy in adults, to gauge whether peanut immunotherapy will be safer, quicker and more tolerable, overcoming some of those issues seen in previous studies.
The aim is to bring participants to a point where accidental exposures to small amounts of peanut will result in less severe reactions or no reactions at all. This does not intend to be a cure for peanut allergy, but to improve safety and quality of life for those living with peanut anaphylaxis into adulthood.
For details and to register for the trial, click here.
Dr Winnie Tong