PURPOSE OF THE STUDY.
The goal of this study was to evaluate the safety of egg oral immunotherapy (OIT) and to predict who may have significant reactions or complications during the therapy.
This study was a nonrandomized controlled, parallel-group intervention trial with an active study population of 50 consecutively enrolled children aged 5 to 18 years. The study children underwent egg OIT after confirming immunoglobulin (Ig)E-mediated egg allergy by using a double-blind, placebo-controlled egg food challenge (DBPCFC). The control group included 32 children who also had a positive DBPCFC but continued avoidance during a median observation period of 18 months.
Subjects were started on an induction phase that lasted 16 weeks, including a 2-day in-hospital intensive rush phase. Once they reached the maintenance phase, children consumed 1 raw egg or their maximal tolerated dose twice weekly for 12 months. All dose-related reactions over a median period of 18 months on OIT (range: 12–28 months) were registered. Children were retrospectively divided into 3 subgroups: (1) children who stopped reacting to OIT doses over time (resolved reactions [RR]); (2) children with ongoing dose-related reactions over the entire period on OIT (persistent reactions); and (3) children who discontinued OIT within the induction phase due to frequent reactions not improved by protocol re-adaptation and medication (early discontinuation).
At the end of the induction phase, 40 (80%) children had achieved complete desensitization to egg. In the control group, only 5 (14%) of 32 developed natural tolerance over time (P < .001). During the study period, 45 (90%) of the children had dose-related reactions of varying magnitude, and the rate of reactions was 7.6%. Epinephrine was needed in 26% of the children. The 3 subgroups corresponded to 3 different safety phenotypes: (1) 24 children (48%, RR) experienced infrequent and mainly mild reactions that resolved over time (none required epinephrine); (2) 17 children (34%, persistent reactions) experienced more frequent and severe ongoing reactions over time; and (3) 9 children (18%, early discontinuation) had frequent, moderate reactions, and discontinued OIT due to their reactions. In those children who discontinued OIT, high serum-specific IgE levels to egg white, ovomucoid, and ovalbumin were found. They reacted to smaller amounts of egg on initial DBPCFC and had more severe asthma. In contrast, lower egg-specific IgE levels and less severe reactions at food challenge were associated with the subgroup RR. One baseline parameter measured, serum-specific ovomucoid IgE, helped predict the likelihood of tolerating OIT. Levels <8.85 killiunit/L indicated 77% probability of belonging to the RR group, whereas levels above it indicated 95% probability of early discontinuation or ongoing reactions over time.
The results of this study showed that egg OIT could induce desensitization in a large number of subjects with egg allergy. Egg OIT involves substantial risks, but baseline parameters, particularly ovomucoid serum-specific IgE, may help identify which children are better candidates for this therapy.
This study tries to determine which children are not good candidates for this therapy. This study had higher reaction rates than previous studies, presumably related to participant selection criteria. The results reinforce the need for appropriate patient selection for OIT and place a significant emphasis on safety, highlighting that the safety and efficacy of OIT are still not well established. Serum-specific ovomucoid IgE level may be helpful in determining which children are not good candidates for such therapy.
- Copyright © 2014 by the American Academy of Pediatrics