Patients and ethical considerations
Patients (n=289) were recruited between 2017 and 2021 from paediatric or adult pulmonology and allergology departments in the Toulouse Teaching Hospital. All patients were attending for a suspicion of allergy to one or several foods. In all patients, food allergy diagnosis was established based on open oral food challenge (OFC) and/or anamnesis and the demonstration of sensitization to culprit foods. Blood samples were taken as part of routine allergy diagnosis or follow-up, in agreement with current EAACI and WAO guidelines (18, 19). The present study concerned only previously generated clinical and laboratory data and additional experiments with excess serum, and was thus was categorized as a type 3b non–interventional research, Art. L1121-1 CSP under the French law. The study was approved by Research Ethics Committee (Comité de Protection des Personnes ) Sud-Ouest et Outre-Mer II, for samples collected in Toulouse Teaching Hospital (sample collection declaration DC20162804). Sera from eight patients exhibiting MUXF3-positive sIgE without a history of food allergy, distinct from the 289 patients described above, were also selected.