From Medscape Medical News
March 5, 2010 (New Orleans, Louisiana) — Oral immunotherapy (OIT) can induce clinical desensitization in children allergic to eggs, decrease egg IgE levels, and decrease egg-specific basophils, according to a new study presented here at the American Academy of Allergy, Asthma and Immunology (AAAAI) 2010 Annual Meeting.
"This was the first multicenter, randomized trial to examine the safety and efficacy of [OIT] for egg allergy," investigational team member Stacie M. Jones, MD, professor and chief of pediatric allergies and immunology at the University of Arkansas for Medical Sciences and the Arkansas Children's Hospital Research Institute in Little Rock, told meeting attendees during a late-breaking research session.
Investigators from Duke, Johns Hopkins, Mount Sinai, and National Jewish Health were also involved in this study, which was part of the Consortium of Food Allergy Research (CoFAR), established by the National Institute of Allergy and Infectious Diseases.
"Some of the most exciting research in allergy today focuses on possible treatments for patients with severe food allergy," said team member Robert A. Wood, MD, chief of pediatrics, allergy, and immunology at Johns Hopkins University School of Medicine, Baltimore, Maryland, in a press release.
"This important study ... provides further evidence that a real treatment for food allergy will soon be possible."
"In fact, a few of the kids from this study are now eating scrambled eggs without any problems," he told Medscape Allergy and Clinical Immunology during a presession press conference. "So some are cured of their allergy, but we're not yet ready to say what percent of those on active therapy are getting there."
OIT Group Shows Greater Tolerance
The estimated cumulative prevalence of egg allergy is 2.6% by the age of 2.5 years, which can cause serious problems after exposure, reported Dr. Jones.
In this study, the investigators enrolled 55 egg-allergic children between the ages of 5 and 18 years and randomized them to receive either a daily dose of egg white solid OIT (n = 40; 62% male; mean age, 7.13 years) or a placebo (n = 15; 60% male; mean age, 7.07 years). All patients underwent initial escalation, build-up, and maintenance (at 2000 mg) for a total of 44 weeks, followed by an oral food challenge.
"This was done to determine how many of the children had become desensitized, indicated by the ability to ingest 5 grams of egg," reported Dr. Jones.
Results at the end of the study showed that 21 of the 40 children who received the OIT passed the oral food challenge, whereas none of those who received the placebo did.
In addition, 33 of those treated with OIT ingested more than 2750 mg of the egg white solid compared with only 1 person in the placebo group.
The egg OIT group also showed significant decreases in both egg IgE levels (mean, −12.66 vs −1.26; P = .02) and egg percutaneous skin tests (−6.5 vs 0.1 mm; P = .001) compared with the placebo group, as well as a significant reduction in basophil activations (P < .001).
"Symptoms reported during the dosing phases were mild to moderate, with no symptoms reported in 11,802 of the doses consumed by the OIT group compared with only 4014 symptom-free doses consumed by the placebo group," said Dr. Jones.
The predominant dosing reactions were oropharyngeal at 15.46% vs 0.22% for the egg OIT and placebo groups, respectively.
"In conclusion, 10% to 15% of patients will not tolerate OIT in this protocol, but we didn't go in thinking this would be right for everyone," said Dr. Jones. "But for those who did tolerate it, the procedure was effective and safe for home use under supervision."
However, she added that more research is needed before it can be considered for clinical practice.
"Until we figure out the right dose and the right interval and can figure out what's going on with the reactions, we're just not quite there yet," said CoFAR team leader Hugh Sampson, MD, from the Department of Pediatrics and director of the Jaffe Food Allergy Institute at Mount Sinai Medical Center, New York City.
He reported that the researchers plan to continue following up the study participants to monitor dosing reactions and long-term tolerance.
Encouraging Results With Cautions
"This is a really important issue, and I was glad to see the consortium come together to work on this study," said John Oppenheimer, MD, associate clinical professor of medicine at New Jersey Medical School in Newark and past vice-chair of AAAAI's Clinical Therapeutics Committee.
"As a clinician, patients come to me every day with this problem, because it is a really common food," added Dr. Oppenheimer, who was not involved with the research. "With this study, we're beginning to get hope that we can diminish their level of sensitivity and induce tolerance levels."
He said that he will be interested to see the long-term results and to find out what converts these patients from true sensitization to true tolerance. "How long do they need to remain on immunotherapy and does it need to be continued the rest of their lives? These are the questions that remain. Overall, I'm excited but still cautious as I await further data."
"These findings are encouraging," agreed AAAAI president Mark Ballow, MD, professor of pediatrics and chief of the Division of Allergy, Immunology, and Rheumatology at State University of New York in Buffalo.
"For those who achieved a degree of tolerance to a certain amount of egg challenge, this is great because it can subsequently take their fear away from accidental exposure."
"That said, it's not yet ready for prime time, which I know is something this group also feels," added Dr. Ballow. "Looking at it over a longer time can make sure there aren't any hidden adverse events that may appear, which is always a concern."
This study was funded by the National Institute of Allergy and Infectious Diseases. The study authors have disclosed no relevant financial relationships.
American Academy of Allergy, Asthma and Immunology (AAAAI) 2010 Annual Meeting: Abstract L6. Presented March 2, 2010.