PURPOSE OF THE STUDY.
The ideal dose for safe and effective oral immunotherapy (OIT) is unknown. The goal of this study was to investigate the efficacy and safety of low-dose OIT with approximately 1/32 of the volume of a whole egg.
Thirty-three children (aged ≥5 years) with egg allergies confirmed by oral food challenge (OFC) against 1/32 of a heated whole egg (194 mg of egg protein) were enrolled. Twenty-one children were enrolled in the OIT group and 12 in the control group.
Children in the OIT group were admitted to the hospital for 5 days of buildup, and then at home, this group was encouraged to consume 62 to 194 mg of egg protein in scrambled form once a day. The amount of egg eaten, severity of provoked symptoms, and treatments administered were recorded in a diary. Egg consumption was completely absent in the control group. Twelve months later, the daily intake of egg ceased for 2 weeks, and an open OFC was performed on up to one-half of a whole egg. There were no significant differences between the groups in terms of subject background.
The proportion of subjects showing sustained unresponsiveness to 1/32 of a whole egg was 71.4% (15 of 21) in the OIT group and 0% (0 of 12) in the control group (P <.001). Subjects exhibiting sustained unresponsiveness to one-half of a whole egg were 33.3% (7 of 21) and 0% (0 of 12) in the OIT and control groups, respectively (P = .032). Compared with baseline levels, egg white– and ovomucoid-specific allergic markers were significantly different in the OIT group but not the control group. Adverse allergic reactions were infrequent, and most symptoms were classified as Grade 1 (mild). There were no Grade 3 (severe) symptoms reported. No subjects withdrew from the study, no epinephrine was used, and no emergency department visits occurred.
This study demonstrates that low-dose egg OIT may be safe and effective in a high-risk egg-allergic population, inducing both immunologic changes and sustained unresponsiveness to low doses and higher doses of egg. In addition, most adverse reactions were mild, no severe symptoms were reported, no epinephrine was used, and there were no emergency department visits.
One of the major concerns with traditional OIT to foods is the amount, frequency, and severity of adverse allergic reactions, often causing significant subject withdrawal from these studies. This study demonstrates that using a lower dose of OIT is potentially safer. It also demonstrated effectiveness at inducing sustained unresponsiveness to both a low dose and a higher dose of egg protein. There are several limitations to the study, the first being this was a nonrandomized, open-labeled trial with a small sample size. Also, sustained unresponsiveness was only measured 2 weeks after stopping therapy, whereas most traditional studies use 4 or 6 weeks. Nevertheless, this could prompt future randomized controlled trials examining the safety and effectiveness of low-dose OIT.
- Copyright © 2017 by the American Academy of Pediatrics