Abstract
Abstract
Background
Walnut OIT has been observed to induce cross‐desensitization to hazelnut, but predictors of this response remain unclear. We sought to identify molecular predictors of hazelnut cross‐desensitization following walnut OIT, to help guide treatment decisions in these co‐allergic patients.
Methods
Patients with confirmed IgE‐mediated walnut and hazelnut allergy underwent walnut OIT. Patients achieving full walnut desensitization to 4 g of walnut protein were re‐challenged to 4‐grams hazelnut protein after 6 months. Baseline sera were obtained and competitive ELISA inhibition assays performed to evaluate serum IgE cross‐recognition of total walnut, total hazelnut and hazelnut component‐specific IgE. Results were compared between patients fully (4‐grams protein) or clinically (≥30‐fold ED increase or mild reaction at full dose) cross‐desensitized to hazelnut and those who remained hazelnut allergic following walnut OIT.
Results
Overall, 12/22 (54.5%) patients were fully cross‐desensitized and 14/22 (63.6%) patients were clinically cross‐desensitized to hazelnut following walnut OIT. Among the latter, walnut inhibited total hazelnut‐specific IgE binding by a median of 95%, compared to 55% in those who remained hazelnut allergic (
p
p
= .003) and Cor a 16 (
p
= .023) in the cross‐desensitized group following walnut OIT, but not in the persistent hazelnut allergic group. A ≥70% inhibition threshold accurately predicted cross‐desensitization in 93% of cases (
p
Conclusion
Walnut OIT can induce clinical cross‐desensitization to hazelnut in >60% of co‐allergic individuals. Competitive ELISA inhibition is a promising predictive tool, with potential to guide targeted and efficient OIT strategies in walnut‐hazelnut co‐allergic patients.
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