Supplementary Material for: Using Component-Resolved Diagnosis to Characterize the Sensitization to Specific Cat and Dog Allergens in Patients with Allergic Respiratory Diseases in Catalonia, Spain

Introduction: Sensitization to cat and dog allergens is common in patients with allergic respiratory diseases. The study objective was to determine the prevalence of immunoglobulin E (IgE) sensitization to specific cat and dog allergens using component-resolved diagnosis (CRD) in patients with allergic respiratory diseases plus cat and/or dog sensitization. Methods: We included 87 patients aged 8–62 years, diagnosed with allergic asthma and/or rhinitis plus cat and/or dog sensitization, and attended at the allergy section of a tertiary hospital in Badalona (Catalonia, Spain). We used CRD to determine IgE sensitization to specific cat/dog allergens and skin prick tests (SPTs) to determine differences between diagnostic test results. Results: Patients were monosensitized to cats (20.7%) or dogs (3.4%) or sensitized to both (75.9%). The highest positive allergen rates were for Fel d 1 (91.7%) and Fel d 4 (41%) in patients sensitized to cat allergens and for Can f 5 (80%) and Can f 1 (70%) in those sensitized to dog allergens. CRD and SPT results differed somewhat: 16.1% and 27.6% of patients CRD positive for cat or dog sensitization, respectively, were SPT negative, and 6.9% SPT positive for dog sensitization were CRD negative. Few statistically significant relationships were found between any allergen components and any respiratory disease characteristic or contact with furry animals. Conclusions: CRD may be used to determine the prevalence of IgE sensitization to specific cat and dog allergens in patients with allergic respiratory diseases plus cat and/or dog sensitization. As SPT may not correctly identify all patients sensitized to cats and dogs, our results support the use of CRD.