Published Online: December 18, 2014
Peanut allergy has become an increasingly common problem for children in the western world. Current management recommendations include avoidance of foods containing peanuts and having emergency medication on hand in the event of accidental exposure. Recent clinical trials have shown that both oral (OIT) and sublingual (SLIT) immunotherapy can desensitize allergic patients, and that a subset may even have prolonged protection after the treatment is stopped. Now, in a study published in The Journal of Allergy and Clinical Immunology (JACI), Narisety and colleagues present the results of the first clinical trial to directly compare these two treatment methods with regard to their effectiveness, risks, and laboratory outcomes.
For this study, children with peanut allergy were randomly assigned into two groups, one treated with active SLIT/placebo OIT, and the other with active OIT/placebo SLIT. Both groups increased doses over time and continued treatment for one year, after which the study was unblinded with the potential to adjust treatment. To measure the effectiveness of treatment, the study participants underwent peanut food challenges (ingesting small amounts of peanut) before the start of therapy and at least twice later in the study. Those who reached the highest dose during the last food challenge were taken off treatment for 4 weeks and re-challenged.
The results of the study showed that both treatment groups increased their peanut challenge threshold. However, significantly greater effects were seen in the OIT treated group. Adverse reactions were common but generally mild, and occurred far more frequently with active OIT, including more moderate reactions, more doses requiring treatment, and most importantly, a higher drop-out rate due to adverse reactions. Four of the 21 subjects who started the study had sustained unresponsiveness at study completion, all of whom had received active OIT in at least the unblinded phase of the study. Additional detailed mechanistic studies were also conducted which are reported in the accompanying article by Gorelik and colleagues in the same journal issue.
In summary, in this study OIT appeared far more effective than SLIT for the treatment of peanut allergy, but was also associated with significantly more adverse reactions and early study withdrawal. Sustained unresponsiveness after 4 weeks of avoidance was seen in only a small minority of subjects. Additional research is needed to develop treatment protocols that will maximize both effectiveness and tolerability.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.