Food Desensitization and SLIT
Food desensitization by SLIT is supposed to reduce the degree of sensitivity. Can we introduce SLIT for food in our routine practice? If permitted what is the suggested dose of MD/M?
By Dr. Liz Veramendi-Espinoza:
At present, there is no Food and Drug Administration (FDA)-approved Sublingual Immunotherapy (SLIT) to treat food allergies. In January 2020, FDA approved Oral Immunotherapy (OIT) Palforzia [Peanut (Arachis hypogaea) Allergen Powder-dnfp] to mitigate allergic reactions that may occur with accidental exposure to peanuts. The effectiveness of Palforzia was supported by a randomized, double-blind, placebo-controlled study which showed that 67.2% of Palforzia recipients tolerated a 600 mg dose of peanut protein in the challenge, compared to 4.0% of placebo recipients. The most commonly reported adverse events (AEs) were abdominal pain, vomiting, nausea, itching (including in the mouth and ears), cough, runny nose, hives, shortness of breath, and anaphylaxis (1).
Regarding SLIT, its safety profile is better than OIT, but with lower efficacy for some patients, and serum biomarkers are not available to predict which patients will benefit most from which therapy. Although rates of successful desensitization or sustained unresponsiveness are high for SLIT and especially OIT, the effects are commonly lost after treatment cessation. Consequently, it is essential to consider alternative approaches, such as adjuvants, that would augment the response and protect the individual from potential AEs (2).
SLIT protocols consist of starting doses at the microgram level and increasing to milligrams of a typical maintenance daily dose of less than 10 mg protein for up to 3 to 5 years. SLIT decreases the life-threatening risk of unintentional food exposure while maintaining a favorable safety profile with mostly transient oropharyngeal itching in less than 5% of peanut SLIT doses. Many published SLIT protocols use commercially available skin test extracts. However, it has been proposed to make SLIT by OIT solutions to improve access to consistent, economical, and customizable food desensitization (3).
At the beginning of COVID-19, several Allergy and Immunology organizations suggested deferral initiation of Food Allergen Immunotherapy, mainly focused on OIT, to decrease expose patients to hospital that subsequently may negatively affect adherence. However, as the length of this pandemic may be prolonged, recent recommendations suggest that clinicians may continue initiate and updosing. This is further supported by SLIT and low-dose OIT studies that demonstrated acceptable safety and reduction in accidental reactions, even at low doses. The final OIT dose is likely not the most important determinant of success, but rather that each dose contributes to building tolerance, irrespective of the time taken to reach the predetermined target (4,5).
1. FDA approves first drug for treatment of peanut allergy for children [Internet]. FDA. FDA; 2020 [accesed september, 27th 2021]. Available at: https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-treatment-peanut-allergy-children
2. Nicolaides RE, Parrish CP, Bird JA. Food Allergy Immunotherapy with Adjuvants. Immunol Allergy Clin North Am. 2020;40(1):149–73.
3. Gendo K, Orden T, Tevrizian A, Jacobs J, Mozelsio N, Gilbert K, et al. Food Sublingual Immunotherapy Using Consistent, Cheaper and Customizable Oral Immunotherapy Solutions. J Asthma Allergy. 2021;14:467–70.
4. Answers to Your Questions about Administering Immunotherapy | AAAAI Education Center [Internet]. 2021 [accesed september, 27th 2021]. Available at: https://education.aaaai.org/resources-for-a-i-clinicians/immunotherapy-qa_COVID-19
5. Mack DP, Chan ES, Shaker M, Abrams EM, Wang J, Fleischer DM, et al. Novel Approaches to Food Allergy Management During COVID-19 Inspire Long-Term Change. J Allergy Clin Immunol Pract. 2020;8(9):2851–7.
Liz Veramendi-Espinoza, MD
Allergy and Clinical Immunology