Years after the groundbreaking IMPACT study, researchers have discovered that children who received peanut oral immunotherapy exhibit distinct allergen-specific antibody profiles compared to those who were given a placebo. The findings, presented at the 2025 American Academy of Allergy, Asthma, & Immunology (AAAAI) annual meeting, suggest that early intervention with this therapy can lead to lasting immunological changes that correlate with clinical outcomes. The follow-up research involved analyzing plasma antibody concentrations for various antibodies in participants five to seven years post-treatment.

Sustained Immune Response After Early Intervention

Children treated with peanut oral immunotherapy maintained significantly lower levels of peanut-specific IgE and Ara h 2 specific IgE compared to those who received a placebo. This indicates a long-lasting impact on the immune system, suggesting that early exposure to peanuts through controlled therapy may help mitigate allergic reactions over time. Additionally, these children showed higher ratios of protective IgG4 to IgE, signaling a shift towards immune tolerance.

The detailed analysis revealed that children who underwent peanut oral immunotherapy had markedly different antibody profiles even years after the initial treatment. Specifically, their median concentrations of peanut-specific IgE were notably lower (3.6 kUA/L vs 18.7 kUA/L), as were their Ara h 2 specific IgE levels (1.0 kUA/L vs 7.0 kUA/L). Furthermore, they exhibited greater ratios of peanut IgG4 to IgE and Arah2 IgG4 to IgE, indicating a favorable immune response. These results underscore the potential for early intervention to induce long-term immunological benefits, particularly in young children.

Impact on Remission and Ongoing Tolerance

Children who achieved remission following peanut oral immunotherapy displayed the lowest levels of peanut-specific IgE and Arah2 IgE, along with the highest IgG4 to IgE ratios. This suggests that achieving remission is associated with a stronger shift toward immune tolerance, which could offer significant protection against future allergic reactions. Conversely, non-responders maintained high levels of peanut-specific IgE, indicating persistent allergy.

The study also examined the effects of ongoing peanut consumption on antibody levels. Children who continued eating peanuts had higher levels of protective IgG4 and lower levels of IgE, suggesting that sustained exposure may play a crucial role in maintaining tolerance. These findings highlight the importance of both early intervention and continued exposure in managing peanut allergies. Overall, the research provides compelling evidence that peanut oral immunotherapy not only offers immediate benefits but also has the potential to provide long-lasting protection against peanut allergies.