D3.205 - Two-year Outcomes of Multiple Low-Dose Oral Immunotherapies for combination of Tree Nuts or Peanut for Severe Allergy Patients

Reports on multiple low-dose oral immunotherapies (LDOIT) for combination of tree nuts (TN) or peanuts (Pn) are limited. We aimed to evaluate the efficacy and safety of the LDOIT in severe multiple TN/Pn allergy patients.

This study included patients who initiated multiple LDOIT for multiple TN/Pn between January 2017 and January 2024. Inclusion criteria were positive reactions to oral food challenges (OFC) with ≤0.5 g of each allergen. The target maintenance dose was 0.5 g of each allergen (approx. 40–130 mg protein). All patients were asked to take loratadine at 3 days before LDOIT initiation. After 3–6 days of hospitalization for setting safe consumption doses, patients were allowed to increase the ingestion dose up to 0.5 g/day at home. Short-term unresponsiveness (STU) was assessed by OFC with 0.5 g or 3.0 g after 2 weeks of avoidance at 1- and 2-year follow-ups.

25 participants (median age 8.5 years; 52% male) were enrolled. A total of 53 TN/ Pn allergies were targeted: Wn (n=21), Pn (n=15), Cs (n=12), Hz (n=2), Ma (n=2), and Am (n=1). Participants underwent LDOIT for 2 (n=23), 3 (n=1), and 4 (n=1) allergens. Baseline median allergen-specific IgE levels to crude extracts and components were Wn: 15.7 kUA/L, Jug r 1: 9.15 kUA/L; Pn: 20.0 kUA/L, and Ara h 2: 21.0 kUA/L, Cs: 9.26 kUA/L, and Ana o 3: 13.4 kUA/L, respectively. At 1 year, desensitization rates to 0.5 g were: Wn 62%, Pn 67%, Cs 67%, Hz 50%, Ma 100%, Am 0%; and STU rates to 0.5 g were: Wn 57%, Pn 53%, Cs 67%, Hz 50%, Ma 100%, Am 0%, respectively. At 2 years, STU rates to 0.5 g were: Wn 62%, Pn 60%, Cs 50%, Hz 50%, Ma 100%, Am 0%; whereas STU rates to 3 g were: Wn 38%, Pn 27%, Cs 50%, Hz 0%, Ma 100%, Am 0%. Specific IgE levels for targeted allergens initially increased at 1 month but subsequently declined. No OIT-related reactions required intramuscular adrenaline, although one patient used adrenaline once following accidental ingestion of OIT target allergen.

Multiple LDOIT for the combination of TN/ Pn effectively induces desensitization and STU to 0.5 g, and furthermore STU to 3.0 g was achieved in some patients. This protocol offers a safe and efficient option for patients with multiple severe TN/Pn allergies who are not likely to grow, providing multiple allergen protections against accidental ingestion.