Oral immunotherapy - a promising new treatment for food allergy?

Following my last post about plasma donation in British Columbia, I received positive responses from my research colleagues at the Centre of Innovative Medicine. We decided to donate this time at Globule Héma Québec. Joining me were the dedicated individuals from the oral immunotherapy (OIT) team: Liane Beaudette RN, Duncan Lejtenyi (research coordinator), and Mackenzie Lawson (clinical research coordinator).

 

I was introduced to this OIT team through Dr. Natacha Tardio and Dr. Moshe Ben-Shoshan when I was a third-year resident. The goal was to actively change the lives of individuals affected by food allergies through research. As the years unfolded, my connection with the OIT team went from a professional collaboration towards a research tribe with mutual support and a shared purpose. 

 

Food allergy has significant quality of life implications, with many patients carrying psychosocial burdens ranging from bullying, isolation, and disruption of personal and family lives. Patients may have trouble differentiating between an allergic reaction and anxiety attack because symptoms may appear similar. These include a rapid heart rate, difficulty breathing, or stomach pain. For people of different ethnic backgrounds, there may be a cultural layer as well.  

 

As a Chinese Canadian, I found that food allergies have generally been met with a level of understanding and awareness that reflects the progress made in recognizing and accommodating food allergies. However, when I visited Hong Kong, I discovered just how abundant peanuts are found in everyday dishes. For example, peanuts may hide under a serving of char siu (叉烧), be wrapped inside dumplings (潮州粉果), boiled in soups, mixed into the sauce served with rice noodle rolls (腸粉), or lurk inside French toast (西多士). Who knew?

 

Of course, the traditional guidance is to avoid as much as possible, and if an anaphylactic reaction occurs, then to use an epinephrine autoinjector and consider calling emergency medical services. But is there a way to somehow decrease the risk of reaction if accidentally exposed, or even to incorporate the food into the regular diet?

 

In the landscape of food allergies, oral immunotherapy (OIT) is becoming a more promising treatment particularly for children navigating the challenges of severe allergic reactions. OIT involves a gradual and systematic process, wherein incremental amounts of the allergen are introduced over extended periods, aiming to retrain the immune system. The goal of OIT is desensitization – a state where individuals gain a newfound freedom in their relationship with the allergen. While OIT does not offer a cure, it stands as a metaphorical seat belt, providing a level of protection akin to safeguarding against accidents.

 

While this transformative treatment offers hope for individuals with food allergies, its rigorous nature requires a profound commitment from patients and their families. For those willing to undertake the journey, the potential rewards are significant. The methodology is even more stringent in a research setting. The entry criteria include a positive history of food allergy, positive skin tests and specific immunoglobulin E responses to the culprit food, and a food challenge. The triple-blinded oral food challenge requires the principal investigator, patient, and administering nurse to remain unaware of the allergen or placebo being given.

 

The oral food challenge involves a two-day process in an ICU setting, where patients are exposed to increasing amounts of the allergen or placebo within a masking food such as pudding or applesauce. In the event of a reaction, epinephrine is given swiftly and then tryptase levels are drawn to confirm an anaphylactic reaction. 

 

Once enrolled in the study, participants commit to regular up dosing sessions, occurring every 2-4 weeks. These sessions are incremental steps towards reaching a maintenance dose. The subsequent 12-month period involves maintaining this dose, allowing the body to adapt and build tolerance. Afterwards, participants undergo an exit challenge with the culprit food to assess the progress achieved and the new allergic threshold.

 

Although OIT is not for the faint of heart, I have personally seen lives changed by this therapy. Even though it is tedious and sometimes anxiety-provoking, the continued sense of purpose is perhaps why the dedicated team members such as Duncan, Liane, Mackenzie, and the principal investigators, come to work every day to make a difference in the lives of people affected by food allergies. 

Special thanks to:

• Liane Beaudette, Duncan Lejtenyi & Mackenzie Lawson for their support and blood/plasma donation

• Adriana Alves @drialvesoficial for photos of her son in OIT

References:

Oral immunotherapy (OIT) in practice [Internet]. FoodAllergy.org. Available from: https://www.foodallergy.org/resources/oral-immunotherapy-oit-practice

‌Warren C, Dyer A, Lombard L, Dunn-Galvin A, Gupta R. The Psychosocial Burden of Food Allergy Among Adults: A US Population-Based Study. J Allergy Clin Immunol Pract. 2021 Jun;9(6):2452-2460.e3. doi: 10.1016/j.jaip.2021.02.039. Epub 2021 Mar 4. PMID: 33677077; PMCID: PMC9190169.

Bird JA, Leonard S, Groetch M, Assa'ad A, Cianferoni A, Clark A, Crain M, Fausnight T, Fleischer D, Green T, Greenhawt M, Herbert L, Lanser BJ, Mikhail I, Mustafa S, Noone S, Parrish C, Varshney P, Vlieg-Boerstra B, Young MC, Sicherer S, Nowak-Wegrzyn A. Conducting an Oral Food Challenge: An Update to the 2009 Adverse Reactions to Foods Committee Work Group Report. J Allergy Clin Immunol Pract. 2020 Jan;8(1):75-90.e17. doi: 10.1016/j.jaip.2019.09.029. PMID: 31950914.

https://acaai.org/allergies/management-treatment/living-with-allergies/food-allergy-avoidance/

Food Allergy Avoidance. ACAAI Public Website. https://acaai.org/allergies/management-treatment/living-with-allergies/food-allergy-avoidance/

The current state of oral immunotherapy (OIT) for the treatment of food allergy [Internet]. Available from: https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/the-current-state-of-oral-immunotherapy

Wasserman RL, Jones DH, Windom HH. Oral immunotherapy for food allergy: The FAST perspective. Ann Allergy Asthma Immunol. 2018 Sep;121(3):272-275. doi: 10.1016/j.anai.2018.06.011. Epub 2018 Jun 19. PMID: 29928983.