Peanut consumption through 5 years of age provides lasting tolerance into adolescence

Peanut consumption through 5 years of age provides lasting tolerance into adolescence | Image Credit: © Tanawut - © Tanawut - stock.adobe.com.

A recently published follow-up trial evaluating early peanut introduction for allergy prevention revealed that peanut consumption starting in infancy through 5 years of age provided lasting peanut tolerance into adolescence, irrespective of subsequent peanut consumption.¹

In the original trial, published in The New England Journal of Medicine in February 2015, investigators evaluated strategies of peanut consumption and avoidance to determine which strategy is most effective in preventing development of peanut allergy.²

The original study, "Promoting Tolerance to Peanut in High-Risk Children" (LEAP) (NCT00329784), included 640 infants with severe eczema, egg allergy, or both to consume or avoid peanuts until 60 months of age. Participants were aged at least 4 months but younger than 11 months at randomization.²

Participants were assigned to separate study cohorts based on preexisting sensitivity to peanut extract (determined via skin-prick test). The proportion of participants with peanut allergy at 60 months of age was the primary outcome.²

In the original study, 530 infants were placed in the intention-to-treat group. Among this group who initially had negative results on the skin-prick test, the prevalence of peanut allergy at 60 months of age was 13.7% in the peanut avoidance group compared to 1.9% in the consumption group (P < 0.001). Prevalence of peanut allergy among 98 participants in the intention-to-treat group who had positive test results was 35.3% in the avoidance group and 10.6% in the consumption group.²

"Increases in levels of peanut-specific IgG4 antibody occurred predominantly in the consumption group; a greater percentage of participants in the avoidance group had elevated titers of peanut-specific IgE antibody," wrote the study investigators. "A larger wheal on the skin-prick test and a lower ratio of peanut-specific IgG4:IgE were associated with peanut allergy."²

According to the follow-up trial publication in The New England Journal of Medicine Evidence, published May 28, 2024, an extension of the original trial demonstrated the prevention effect persisted after 1 year of peanut avoidance. The follow up study, "Follow up of LEAP Participants and Their Families" (NCT03546413), examined durability of peanut tolerance at 144 months of age after years of ad libitum peanut consumption.^1,3

The investigative team enrolled 508 of the original 640 participants in the follow up trial, with the primary endpoint being the rate of peanut allergy at 144 months of age. At this age, “peanut allergy remained significantly more prevalent in participants in the original peanut avoidance group than in the original peanut consumption group,” wrote the study authors (45.4% vs 4.4% [P < 0.001]).¹

Between 72 and 144 months of age, individuals in both groups reported avoiding peanuts for “prolonged periods of time.” Those in the peanut consumption group had levels of Ara h2-specific immunoglobulin E (peanut allergen associated with anaphylaxis) of 0.03 ± 3.42 kU/l and levels of peanut-specific immunoglobulin G4 of 535.5 ± 4.98 μg/l. Those in the peanut avoidance group had levels of Ara h2-specific immunoglobulin E of 0.06 ± 11.21 kU/l and levels of peanut-specific immunoglobulin G4 of 209.3 ± 3.84 μg/l.¹

Based on the original and follow up studies of peanut avoidance and consumption, the investigative team concluded, “Peanut consumption, starting in infancy and continuing to age 5 years, provided lasting tolerance to peanut into adolescence irrespective of subsequent peanut consumption, demonstrating that long-term prevention and tolerance can be achieved in food allergy.”¹

References:

1. Du Toit G, Huffaker MF, Radulovic S, et al. Follow-up to adolescence after early peanut introduction for allergy prevention. NEJM Evidence. 2024;3(6). doi:10.1056/EVIDoa2300311

2. Du Toit G, Roberts G, Sayre PH, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015;372(9):803-813. doi:10.1056/NEJMoa1414850

3. Follow up of LEAP Participants and Their Families. ClinicalTrials.gov. Updated March 29, 2024. Accessed May 29, 20224. https://clinicaltrials.gov/study/NCT03546413