Tolerance Results and Immune Mechanisms in Cow´s Milk and/or Hen´s Egg Allergic Children Following Natural Evolution or Oral Immunotherapy

Inclusion criteria

NAT-cohort:

• Cow´s Milk and/or Hen´s Egg allergic patients 4 to 10 years old
• sIgE levels to milk OR egg extracts between 0.35 to 35kUA/L
• Positive entry Open food challenge with milk/egg with oFASS5 classification ≥2 with a maximum cumulative dose of up to 4193.7 mg of milk protein or 3110.8 mg of egg white protein
• Having a mild to moderate food allergy severity per the Definition of Food Allergy Severity (DEFASE) score (<13 points)
• Having signed the informed consent

OIT-cohort:

• Patients in the compITO study (NCT06976775) who are undergoing OIT and have achieved full desensitization to the food by month 7 of the study (end of study)
• Patients in the compITO study who are undergoing OIT and have achieved partial desensitization (tolerating a dose lower than the total dose, and a minimum of 3 doses above the entry challenge threshold) to the food by month 7 of the study (end of study)
• Having signed the informed consent

Exclusion criteria

NAT-cohort:

• Positive reaction in the entry open oral food challenge with a baseline Eliciting Dose (ED) 20 below the target ED20 for food. For milk, 23.1 mg (35.7 mg cumulative) of protein, or for egg, 19.5 mg (29.4 mg cumulative) of protein.
• Patient desire or medical indication to initiate OIT at any time within 29 months of study entry.
• No allergic reaction greater than oFASS5 grade 1 in the baseline challenge for the maximum cumulative programmed doses of 4193.7 mg of milk protein, or 3110.8 mg of egg white protein.
• Immunological diseases, immunomodulatory/blocking therapies.
• Severe atopic dermatitis according to the SCORing Atopic Dermatitis (SCORAD) classification
• Severe allergy, according to a DEFASE score ≥13
• Spirometry values with moderate-to-severe airflow obstruction (FEV1 <70%)
• Poorly controlled asthma according to clinical criteria
• Previous OIT for another food
• Within the first 3 months of treatment with Subcutaneous Aeroallergen Immunotherapy
• Within the first week of treatment with Sublingual Aeroallergen Immunotherapy
• Presence or suspicion of Eosinophilic Esophagitis
• Non-IgE-mediated allergy to milk or egg
• Pregnancy
• Significant medical comorbidities (renal, hepatic, or cardiac insufficiency, active infectious diseases, previous or concurrent cancers)
• Inability to provide informed consent
• Communication or cognitive barriers that prevent adherence to the protocol

OIT-cohort:

• Patients enrolled in the compITO study who have failed or withdrawn from the study for any reason.
• Patients with uncontrolled Atopic Dermatitis or Asthma at the time of enrolment, or who have developed Eosinophilic Esophagitis.
• Patients with confirmed pregnancy at the time of enrolment.
• Patients who have developed significant medical comorbidities (renal, hepatic, or cardiac insufficiency, active infectious diseases, previous or concurrent cancers) at the time of enrolment.
• Inability to provide informed consent.
• Communication or cognitive barriers that prevent adherence to the protocol.