Peanut allergy oral immunotherapy therapy successful in new study of children in the UK
January 29, 2014 / Author: Morgan Jones / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh
(dailyRx News) For parents of children with peanut allergies, the thought of their child accidentally eating a peanut can cause big concerns. But what if children could become tolerant to small amounts of peanuts?
That’s the hope behind a new study that examined oral immunotherapy in children with peanut allergies.
This study found that after receiving increasing exposure to peanut protein over 26 weeks, over half of participants were able to tolerate the equivalent of around five peanuts a day.
“Talk to your children about their allergies.”
According to the study’s authors, led by Andrew Clark, MD, of the Department of Medicine at the University of Cambridge in the United Kingdom, peanut allergies are becoming increasingly common and are the most common cause of severe allergic reactions to food.
“Small studies suggest peanut oral immunotherapy (OIT) might be effective in the treatment of peanut allergy,” wrote Dr. Clark and colleagues. In immunotherapy, the patient is exposed to increasing amounts of an allergen over time, with the aim of improving the immune system’s tolerance to the substance.
The researchers identified 99 participants at a clinical research facility in Cambridge between January 2010 and March 2013. Participants were all peanut allergy patients between the ages of 7 and 16 (average age was 12.4 years) without a major chronic illness.
These participants were divided into two treatment groups.
During the first phase of the study, which lasted 26 weeks, one group received OIT in the form of daily doses of peanut protein flour mixed into food. Doses were gradually increased up to 800 milligrams (mg) per day.
The other participants, the control group, practiced peanut avoidance — the main method currently available for managing a peanut allergy.
Dr. Clark and colleagues wanted to see if participants were able to achieve “desensitization” to peanuts, which was defined here as having no reaction during a food test. The food test gave participants a total dose of 1,400 mg of peanut protein, an amount equal to around 10 peanuts.
The researchers also measured how many participants could withstand ingesting 800 mg of peanut protein (around about five peanuts) each day for up to 26 weeks.
After the first phase of the study, 62 percent of the OIT group (24 out of 39 patients) achieved desensitization during the 1,400 mg peanut food test, compared to 0 percent of the 46 participants in the control group. Of the OIT group, 84 percent were able to ingest 800 mg of peanut protein a day.
During the second phase of the study, the participants in the control group underwent the OIT treatment.
After receiving the treatment, 54 percent of the original control group tolerated the 1,400 mg peanut challenge and 91 percent were able to ingest 800 mg of peanut protein.
Dr. Clark and colleagues reported that most of the side effects seen were mild. Itching of the mouth was seen after 6.3 percent of all peanut protein doses, and was experienced by 81 participants.
Some gastrointestinal symptoms were also seen, with abdominal pain occurring after 2.59 percent of all doses in 54 patients and nausea after 2.21 percent of all doses in 31 patients. No serious side effects were seen.
In a news release, Dr. Clark explained what these results could potentially mean for families of children with peanut allergies.
“This treatment allowed children with all severities of peanut allergy to eat large quantities of peanuts, well above the levels found in contaminated snacks and meals, freeing them and their parents from the fear of a potentially life threatening allergic reaction,” said Dr. Clark. “The families involved in this study say that it has changed their lives dramatically.”
However, it is important to note that further research among wider populations of patients with peanut allergies is needed. The study’s authors stressed that OIT for peanut allergies should not be attempted in non-specialist settings.
In an interview with dailyRx News, John Oppenheimer, MD, Fellow of the American Academy of Allergy, Asthma & Immunology (AAAAI), highlighted that the only treatment option currently available for peanut allergies is avoidance of peanuts and epinephrine shots if accidental consumption of peanuts causes anaphylaxis, a severe allergic reaction affecting the whole body.
“Unfortunately, studies have demonstrated that a significant number of peanut allergic patients unknowingly ingest peanuts, despite attempted avoidance with resultant allergic reactions that can culminate in severe anaphylaxis and even death,” explained Dr. Oppenheimer. “It is of no surprise that peanut allergic patients can have significant impediment of quality of life as a result of this illness.”
Dr. Oppenheimer said that this and other recent studies bring “a glimmer of hope” to the situation, but further research is needed, and that the treatment used in this study was not without the potential for side effects.
Dr. Oppenheimer also pointed out that this treatment shows desensitization, but not complete tolerance to peanuts. “Although this appears a subtle difference, it is really a very important one,” said Dr. Oppenheimer.
In desensitization, the patients need to keep continued and uninterrupted exposure to small amounts of peanuts to continue to maintain their state of desensitization.
“In other words, present OIT regimens provide protection only with uninterrupted use; however, with discontinuation, the patient is often left as sensitive to the food as when they began the protocol,” said Dr. Oppenheimer. “Certainly further research is needed, but this study provides us optimism.”
This study was published January 28 in The Lancet.