Sensitization to Dog Dander Allergen Can f 1 is Associated with Asthma Symptom Severity and Exacerbations in a Singapore–Malaysia Cohort

Yang Yie Sio,1 Tan Ching Ong,1 Yee-How Say,2 Kavita Reginald,3 Fook Tim Chew1 1Department of Biological Sciences, National University of Singapore, Singapore; 2Department of Biomedical Science, Faculty of Science, Universiti Tunku Abdul Rahman (UTAR) Kampar Campus, Kampar, Perak, Malaysia; 3Department of Biomedical Sciences, Sir Jeffrey Cheah Sunway Medical School, Faculty of Medical and Life Sciences, Sunway University, Petaling Jaya, Selangor, MalaysiaCorrespondence: Fook Tim Chew, Email dbscft@nus.edu.sgBackground: Sensitization to pet dander allergens has been increasing globally, however, its clinical relevance to allergic disease exacerbation remains underexplored.Objective: We aimed to determine the prevalence of serum-specific IgE (SSIgE) response to the major dog allergen Canis familiaris 1 (Can f 1), and to evaluate its association with asthma-related symptom severity and exacerbation in a Singapore/Malaysia population.Patients and Methods: A comprehensive serological profiling of specific IgE responses to 38 common inhalant and seafood allergen sources was performed in 736 young adults from the Singapore/Malaysia Cross-sequential Genetics and Epidemiology Study (SMCGES) sub-cohort. SSIgE levels were analyzed in relation to asthma diagnosis, symptom frequency, and exacerbation history.Results: Detectable Can f 1-specific IgE was present in 13.5% of participants, predominantly at low-grade Class 1– 2 levels (0.35– 3.49 IU/mL). Individuals with pre-existing sensitization to common inhalant and seafood allergen sources, including house dust mites (HDM), cat dander (Felis domesticus 1, Fel d 1), pollen, fungi, crustaceans, mollusks, and fish, showed a significantly higher rate of Can f 1-specific IgE response. Among asthmatic subjects, elevated Can f 1 SSIgE levels were significantly associated with recent (past 12 months) wheezing (p=0.005), daytime (p=0.019) and nighttime asthma attacks (p=0.033), and asthma exacerbations (p=0.001). These associations remained to be significant and consistent in trend among asthmatic patients sensitized to HDM allergen sources.Conclusion: Sensitization to Can f 1 is associated with increased asthma-related symptom burden and exacerbation risk, particularly in individuals with pre-existing atopy among young adults in Singapore and Malaysia. These findings highlight Can f 1-specific IgE as a potential molecular marker for identifying higher-risk asthma phenotypes in the tropical environment.Keywords: allergens, allergenicity, dogs, lipocalin, immunoglobulin E