Proceedings of the Canadian Society of Allergy and Clinical Immunology Annual Scientific Meeting 2019

2020 Allergy, Asthma & Clinical Immunology  
Correspondence: Marie Chantal Arseneault Allergy Asthma Clin Immunol 2020, 16(Suppl 1):#1 Background: Allergic rhinoconjunctivitis is commonly caused by allergens from the birch homologous group, which includes birch, oak, hazel, alder and hornbeam, all characterised by having Bet v 1 homologous allergens that extensively cross-react. The current study characterized the ability of the SQ tree SLIT-tablet (containing birch extract) to induce immunological responses that cross-react with all
more » ... react with all species in the birch homologous group. Methods: Blood samples were collected from adults who had moderate to severe rhinoconjunctivitis induced by birch pollen who were treated with the SQ tree SLIT-tablet for 24 weeks ( Identifier NCT02481856). Serum IgE (pre-treatment) and IgG4 (posttreatment) specific for birch, oak, hazel, alder, beech, chestnut and hornbeam were measured by standard ImmunoCAP. Correlation analyses and inhibition assays were performed to evaluate immunological cross-reactivity. The study was approved by the Ontario IRB, approval number 12069. Results: The analyses demonstrated a high level of correlation between IgE reactivity (pre-treatment) between birch and alder, hazel, hornbeam and oak. The strongest correlation in IgE titers was observed between birch and alder (r = 0.98), and the weakest between birch and oak (r = 0.83). A strong correlation between IgE titers was also observed for beech, but not for chestnut. The analyses also demonstrated a high level of correlation between IgG4 reactivity (treatment-induced) towards birch and alder, hazel, hornbeam, beech and oak, with the strongest correlation between birch and alder (r = 0.95), and the weakest between birch and oak (r = 0.78). Inhibition experiments revealed that in the majority of patients, alder-, hazel-and oakspecific IgE and IgG4 reactivity was inhibited > 80% by birch allergen extract. Conclusion: The data demonstrate a high level of cross-reactivity between birch-specific IgE and IgG4, and allergens from the birch homologous group, which suggests that the significant clinical effect determined previously for both birch and oak exposure may extend to the entire birch homologous group. #2 Dupilumab improved asthma control and health-related quality of life in patients with oral corticosteroid-dependent, severe asthma during the LIBERTY ASTHMA VENTURE study
doi:10.1186/s13223-020-00445-x fatcat:oywq2plkdrdfzkasscnt67f2fa