Severe childhood asthma and allergy to furry animals: Refined assessment using molecular‐based allergy diagnostics

Abstract

Allergy to cats and dogs and polysensitization towards these animals are associated with severe childhood asthma. Molecular-based allergy diagnostics offers new opportunities for improved characterization and has been suggested to be particularly useful in patients with polysensitization and/or severe asthma. The aim was to use extract- and molecular-based allergy diagnostics to compare patterns of IgE sensitization towards aeroallergens in children with problematic severe and controlled asthma. Children with a positive ImmunoCAP towards any furry animal (cat, dog or horse) were recruited from a Nationwide Swedish study on severe childhood asthma. Severe (n=37, age 13years) and controlled (n=28, age 14years) asthmatics underwent assessment of allergic sensitization by ImmunoCap (kUA /l) and immunosolid-phase allergen chip (ISAC). In addition, Asthma Control Test, spirometry and a methacholine challenge were performed. Children with severe asthma had lower asthma control (p<0.001) and FEV1 (p=0.001) and more bronchial hyper-responsiveness (p=0.008) in spite of high doses of inhaled steroids (≥800μg budesonide). Children with severe asthma displayed higher levels of IgE antibodies towards cat (17 vs. 3.9, p=0.027), dog (3.8 vs. 1.2, p=0.012) and horse (7.4 vs. 0.7, p=0.014). Sensitization towards Can f 2 (22% vs. 0%, p=0.009) and Equ c 1 (51% vs. 25%, p=0.03) was more common in severe asthma. IgE levels towards Equ c 1 correlated with asthma control (r=-0.41, p=0.04). Children with severe allergic asthma had higher sIgE levels to cat, dog and horse. Molecular-based allergy diagnostics revealed a more complex molecular spreading of allergen components in children with the most severe disease.