EXPERT ANALYSIS FROM THE 2016 AAAAI ANNUAL MEETING
LOS ANGELES (FRONTLINE MEDICAL NEWS) – A peanut allergy prevention strategy based upon regular consumption of peanut-containing foods from infancy to age 5 continued to provide protection even after peanut intake was halted for a full year from age 5 to 6, according to new results from an extension of the landmark LEAP trial, known as LEAP-On , presented at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.
The impetus for LEAP-On was the investigators’ concern that a period of peanut avoidance might cause loss of the protective state. But that didn’t occur.
“I think there is no doubt that we have prevented peanut allergy so far in these high-risk children. Next, the LEAP-Ad Lib study will tell us whether we’ve prevented it by age 10,” said Dr. Gideon Lack of King’s College London, who headed LEAP-On.
A second major randomized trial known as EAT (Enquiring About Tolerance) presented at the meeting provided further support for early dietary introduction of allergenic foods. EAT differed from LEAP (Learning Early About Peanut Allergy) and LEAP-On in that it ambitiously randomized infants to early introduction or avoidance of not one but six allergenic foods: peanut, cooked egg, cow’s milk, fish, sesame, and wheat. Also, while LEAP and LEAP-On involved roughly 600 infants known to be at very high risk for allergy, EAT was conducted in a general population of 1,303 infants who weren’t at increased risk, all of whom were exclusively breast-fed until the intervention beginning at age 3 months.
The presentation of the LEAP-On and EAT results at the AAAAI annual meeting was a major event marked by the National Institute of Allergy and Infectious Diseases by same-day release of new NIAID-sponsored draft recommendations for the diagnosis and management of food allergies.
In a press conference held at the AAAAI annual meeting to announce the start of a 45-day public comment period for the draft update of the 2010 guidelines, Dr. Daniel Rotrosen, director of NIAID’s division of allergy, immunology and transplantation, said the new guidelines were developed largely in response to the compelling LEAP findings. That trial demonstrated that sustained consumption of peanut starting in infancy resulted in an 81% lower rate of peanut allergy at age 5 years compared to a strategy of peanut avoidance (N Engl J Med. 2015;372:803-13).
The draft guidelines, now available on the NIAID website, represent a sharp departure from the former recommendation that physicians encourage exclusive breastfeeding for the first 6 months of life followed by cautious introduction of other foods. Whereas the former orthodoxy was that delayed introduction of allergenic foods protects against development of food allergy, the new evidence-based concept supported by the LEAP and EAT findings is that just the opposite is true: that is, introduction of such foods during the period of immunologic plasticity in infancy induces tolerance.
Thus, the draft guidelines recommend that infants at high risk for peanut allergy because they have severe eczema and/or egg allergy should have introduction of peanut-containing food at 4-6 months of age to reduce their risk of peanut allergy, preceded by evaluation using peanut-specific IgE or skin prick testing to make sure it’s safe. That age window coincides with well-child visits and vaccination schedules, Dr. Rotrosen noted.
These guidelines represent the consensus of 26 organizations that participated in their development. Among them are the American Academy of Pediatrics, the American Academy of Family Physicians, the American Academy of Dermatology, the American College of Gastroenterology, and AAAAI.
“I expect the new guidelines, when finalized, to be endorsed by the leadership of all the participating organizations,” Dr. Rotrosen said.
The new paradigm will require cultural change, said Dr. James R. Baker Jr., CEO and chief medical officer of Food Allergy Research and Education , a nonprofit organization that provided partial funding for LEAP and LEAP-On.
“I think for a long time we’ve vilified these foods. There’s nothing inherently wrong with their intake, and that’s a message we need to get across to parents and physicians so they can start thinking differently,” he said.
“The good news about these studies is that they show there’s no reason not to do this,” Dr. Baker added. “There’s no harm that comes from the early introduction.”
Dr. Lack, who led the EAT trial, noted that the study didn’t meet it’s primary endpoint of a significantly lower prevalence of food allergy to any of the six intervention foods at age 3 years in the intention-to-treat analysis. But adherence to the demanding EAT early-introduction protocol was a problem. Indeed, only 43% of participants adhered to the study protocol. In a per-protocol analysis restricted to the adherent group, however, early introduction was associated with a highly significant 67% reduction in the relative risk of food allergy at 3 years of age compared to controls. And for the two most prevalent food allergies – to peanut and egg – the relative risk reductions in the early-introduction group were 100% and 75%, respectively.
The EAT results suggest that an effective preventive dose of peanut in infants at least 3 months of age is roughly 2 g of peanut protein per week, equivalent to just under 2 tsp of peanut butter, according to Dr. Lack.
Simultaneously with presentation of the LEAP-On and EAT trials in Los Angeles, the studies were published online at NEJM.org (doi: 10.1056/NEJMoa1514210 for LEAP-ON and 10.1056/NEJMoa1514209 for EAT).
LEAP-On was supported primarily by NIAID. EAT was funded mainly by the UK Foods Standards Agency and the Medical Research Council. Dr. Lack reported receiving grants from those agencies as well as Food Allergy Research and Education.