Researchers that previously studied the safety and efficacy of peanut oral immunotherapy (OIT) in preschoolers have since turned their attention to tree nuts. Their subsequent study was published earlier this year in The Journal of Allergy and Clinical Immunology: In Practice.
OIT refers to the medically supervised therapy of feeding an allergic individual an increasing amount of a food allergen with the goal of increasing the threshold that triggers a reaction.
As part of a Canada-wide quality improvement project, tree nut OIT (cashew/pistachio, walnut/pecan, hazelnut, almond, and macadamia nut) was performed in preschoolers who met one of two specific criteria:
- They had a skin prick test wheal diameter greater than or equal to 3 mm or a specific IgE level greater than or equal to 0.35 kU/L and a convincing objective IgE-mediated reaction
- no ingestion history and a specific IgE level greater than or equal to 5 kU/L.
During the therapy, dose escalations were performed every 2 to 4 weeks until a maintenance dose of 300 mg of TN protein was reached. Adverse effects during therapy were recorded using the World Allergy Organization Subcutaneous Immunotherapy Reaction Grading System, where 1 represents the mildest reaction and 5 is fatal).
Of the 92 patients who participated in the therapy from 2018 to 2021, 79 (85.9%) underwent single-food tree nut OIT and 13 (14.1%) underwent multifood tree nut OIT to 2 (10.8%) or 3 (3.3%) tree nuts.
Of the cohort, 89 (96.7%) patients reached maintenance, and 4 (4.3%) dropped out. Sixty-five (70.7%) patients experienced relatively minor reactions during buildup: 35 (38.0%) grade 1 reactions, 30 (32.6%) grade 2 reactions, no grade 3 or 4 reactions, and 2 (2.17%) received epinephrine.
The researchers concluded that tree nut OIT for preschoolers was safe and tolerable, with results comparable to their previously reported peanut OIT findings.
- Real-World Safety Analysis of Preschool Tree Nut Oral Immunotherapy — JACI: In Practice
- Oral Immunotherapy Defined — AAAAI