How Autoclaving Alters Peanut Allergenicity, OIT Potential, With Casey Cohen, PhD

A new study showed that autoclaving peanuts breaks down major allergens, significantly lowering IgE binding, skin test reactivity, and allergic reactions. This does not mean clinicians should advise patients with a peanut allergy to consume autoclaved peanuts, but the findings suggest they may provide a safer substrate for oral immunotherapy (OIT).1

“We're never going to change the way the entire world will cook their peanuts. That's not realistic. But even if we could do that, there's no guarantee that everyone who is allergic to peanuts can tolerate any autoclaved peanuts,” Casey Cohen, PhD, of McGill University, told HCPLive. “What we're seeing is it seems like most people who are allergic would tolerate it, but we can't ever prove that… [We are] more interesting part at this point is to see if we can use this as a better substrate for OIT, because…using raw or roasted peanuts for OIT… [is] not perfect. It's far from it.”

In the first half of HCPLive’s interview with Cohen, he discussed how autoclaving distinguishes from traditional peanut processing methods in terms of allergenicity.2 He also provided insights into notable findings on the reductions in IgE binding and improved oral tolerability.

The analysis showed that autoclaving extensively fragments major peanut allergens, including Ara h 1 and Ara h 2, and completely degrades Ara h 8.1 Investigators observed a 74% reduction in peanut-specific IgE binding in sera from highly allergic patients compared with raw peanuts.

Skin prick testing revealed autoclaved peanut extract produced significantly smaller wheal sizes than standard commercial extract (median 5 mm vs 10 mm; P <.001). Patients with the greatest wheal size reductions tended to have lower IgE levels to peanut and allergen components.

During the oral food challenge (OFC), all 10 participants tolerated the maximum cumulative dose of autoclaved peanut (444 mg), equivalent to ≥ 1 whole peanut, with only mild to moderate symptoms. Patients receiving blanched peanuts could only tolerate 9 mg on average and often required epinephrine.

In the latter half of the interview, Cohen discussed why autoclaving reshapes peanut allergenicity and how those mechanistic insights may matter clinically. He explained that the team worked backward from the clinical signal.

After observing markedly reduced peanut-specific IgE binding and smaller skin test responses with autoclaved peanuts, the key question became what molecular changes were driving these effects. Mass spectrometry–based proteomic analysis provided that link. By focusing on peptide fragments below a defined molecular weight threshold, the investigators demonstrated that autoclaving does not simply “destroy” peanut proteins. Instead, it fragments them extensively, producing a diverse pool of smaller peptides derived from major allergens that are largely absent in raw or roasted preparations.

This fragmentation appears central to reduced allergenicity. The immune system is exposed to peanut proteins in a fundamentally different form—shorter peptides and altered epitopes—rather than intact, highly stable allergens such as Ara h 2. Cohen emphasized that this molecular mediation helps explain why reduced IgE binding, smaller skin prick test responses, and improved OFC outcomes track together. Clinically, it suggests that allergenicity is not solely about the presence or absence of peanut protein, but about its structural presentation to the immune system.

For clinicians, Cohen emphasized that these data do not justify consuming autoclaved peanuts outside a controlled setting. Even if most allergic individuals appear to tolerate autoclaved peanuts, safety will still require supervised food challenges. The immediate relevance lies in immunotherapy development rather than dietary guidance.

Compared with FDA-approved Palforzia, an OIT peanut allergen powder linked to frequent adverse effects, variable efficacy, and high discontinuation rates, autoclaved peanuts may offer theoretical advantages due to minimal side effects. Whether this translates into effective desensitization remains unproven and represents the next critical step.

Cohen proposed a randomized OIT trial directly comparing autoclaved peanut-based therapy with conventional roasted peanut OIT. He emphasized that autoclaving preserves substantial protein content while creating novel fragments, which the team believes could be key to inducing safer, more effective immune tolerance rather than merely reducing allergen exposure.

“Maybe one would think, ‘okay, autoclaving might just be destroying everything that's in there, all the proteins. No wonder they don't get any reaction.’ But we actually prove that that's not the case,” Cohen said. “We…show there is still clearly a substantial amount of protein left in the peanut protein and specific allergens. [The] fact that there is still some protein intact, and of course, all the fragments, meaning different forms of those same proteins, we think those have the biggest potential for OIT.”

Cohen has no reported disclosures.

References

1. Cohen CG, Toscano-Rivero D, Ahmed EA, et al. Autoclaved Peanuts Exhibit Reduced Immunoglobulin E Binding and Improved Oral Tolerability. Allergy. Published online January 6, 2026. doi:10.1111/all.70208

2. Derman C. Autoclaved Peanuts Reduce IgE Binding, Improve Tolerability, With Casey Cohen, PhD. HCPLive. Published on January 23, 2026. Accessed on January 23, 2026.