Sensitization to <em>Aspergillus </em>species is associated with frequent exacerbations in severe asthma

Abstract

BackgroundSevere asthma is a largely heterogeneous disease with varying phenotypic profiles. The relationship between specific allergen sensitization and asthma severity, particularly in Asia, remains unclear. We aim to study the prevalence of specific allergen sensitization patterns and investigate their association with outcomes in a severe asthma cohort in an Asian setting.MethodsWe conducted a cross-sectional study of patients receiving step 4 or 5 Global Initiative for Asthma treatment. Univariate and multivariate analyses were performed to assess the association between sensitization to a specific identifiable allergen by skin prick test (SPT) and uncontrolled asthma (defined in our study as the use of ≥2 steroid bursts or hospitalization in the past year, a history of near-fatal asthma or evidence of airflow obstruction on spirometry).ResultsTwo hundred and six severe asthma patients (mean age 45±17 years, 99 [48.1%] male) were evaluated. Of them, 78.2% had a positive SPT to one or more allergens. The most common allergen to which patients were sensitized was house dust mites (Blomia tropicalis, Dermatophagoides pteronyssinus and Dermatophagoides farinae). Also, 11.7% were sensitized to Aspergillus species. On multivariate analysis, Aspergillus sensitization was associated with uncontrolled asthma (odds ratio 6.07, 95% confidence interval 1.80–20.51). In particular, Aspergillus sensitization was independently associated with the use of ≥2 steroid bursts in the past year (odds ratio 3.05, 95% confidence interval 1.04–8.95). No similar associations of uncontrolled asthma with sensitization to any other allergens were found.ConclusionHigh allergen, specifically Aspergillus sensitization was observed in the Asian population with severe asthma by SPT. Aspergillus sensitization was specifically associated with frequent exacerbations and a greater corticosteroid requirement. An improved understanding of the severe asthma with Aspergillus sensitization phenotype is warranted, which is likely a subgroup of severe asthma with fungal sensitization.

Immunological corollary of the pulmonary mycobiome in bronchiectasis: the CAMEB study

“…The only fungal genus in the top 10 with higher prevalence in Singapore/Kuala Lumpur was Aspergillus , although this was detected at all the sampled sites ( figure 3b ). Given our identification of Aspergillus as an exclusive bronchiectasis-associated fungal genus with high airway abundance and its established pathogenic role in other chronic respiratory diseases [ 10 , 12 , 13 , 15 ], we pursued it for further investigation.…”

“…Fungi, particularly Aspergillus spp., cause a range of pulmonary consequences, including allergic, chronic and/or invasive disease [ 11 , 12 ]. An overzealous host response to Aspergillus , for instance, is clinically important in severe asthma with fungal sensitisation, chronic obstructive pulmonary disease (COPD) and CF [ 13 – 15 ]. The role of fungi in bronchiectasis not due to CF is, however, less well defined.…”

Geographic variation in the aetiology, epidemiology and microbiology of bronchiectasis

“…3. Allergic bronchopulmonary aspergillosis (ABPA) is a recognised aetiological factor for the occurrence of bronchiectasis while sensitisation increases the incidence of bronchiectasis in asthmatics [116][117][118][119].…”

Fungal bio-aerosol in multiple micro-environments from eastern India: source, distribution, and health hazards

“…The Asian population with severe asthma has noted maximum allergenic reactivity in Aspergillus sp. through SPT [29,30]. The highest degree of sensitization (3 +) was also found for A. fumigatus (Online Appendix A, Table A.6).…”