Birch Associated Soy Allergy and Immuno-Therapy

INTERVENTION: Specific subcutaneous immunotherapy with extract containing either main Birch allergen Bet v 1 or placebo (randomisation 2:1), duration: 1 year, no follow up. CONDITION: Immediate type allergy to soy proteins in patients with birch pollinosis ; Respiratory ; Vasomotor and allergic rhinitis PRIMARY OUTCOME: Threshold dose of soy protein leading to first symptoms at DBPCFC (lowest observed adverse effect level ‐ LOAEL); two primary endpoints (without hierarchy) ‐ LOAELobj for clinically objective and LOAELsubj for subjective symptoms. Timepoints: baseline 9 months ‐ 1 week before intervention, control: 2 weeks ‐ 5 months after intervention. SECONDARY OUTCOME: 1. Skin prick test to soy. Timepoint: baseline 9 months ‐ 1 week before intervention, control: at end of intervention (week 50 ‐ 52 of intervention).; 2. Food allergy related quality of life. Timepoint: baseline 9 months ‐ 1 week before intervention, control: at end of intervention (week 50 ‐ 52 of intervention).; 3. Specific IgE and IgG4 against Bet v 1, Gly m 4, Cor a 1, Mal d 1, Pru Av 1, Cau c 1, Api g 1. Timepoint: baseline at start of invervention, control at week 12, 18, 30, 50 ‐ 52 of intervention.; 4. T‐cell reactivity to Bet v 1 and Gly m 4. Timepoint: baseline at start of intervention, control at week 18 and 50 ‐ 52. INCLUSION CRITERIA: 1. Male or female adult patients aged 18 ‐ 65 years inclusive, legally competent 2. Informed consent 3. History of spring pollinosis for at least 2 years 4. Sensitisation to birch pollen as demonstrated by positive SPT to birch (wheal greater than 3 mm) 5. Specific IgE for Bet v 1 and Gly m4 (both greater than ImmunoCAP class 1 6. Clinical relevance of Gly m4 sensitization as demonstrated by positive food challenge (DBPCFC) to soy proteins 7. For female patients: effective contraception and negative pregnancy test result