Introduction It has been proposed that severe asthma patients with fungal sensitisation might endure worse clinical outcomes than non-sensitised patients. However, the extent of fungal sensitisation and its influence on the disease severity remain unconfirmed. This study explores the prevalence of severe asthma with fungal sensitisation (SAFS) and its clinical effect.
Methods Consecutive patients referred to a severe asthma centre has been put through systematic assessment protocol to establish their asthma diagnosis, severity, and clinical outcome measures that includes lung function, biomarkers, exacerbations and hospital admissions frequency. Total and specific serum immunoglobulin E (IgE) and skin prick testing to 27 allergens including 5 fungal allergens were undertaken.
Results A total of 263 patients with a mean age of 45.5 yrs (SD ± 14.6), 72% females, mean age at onset of asthma 21.52 years (range 0.0–69 years), mean pre FEV1% predicted 69.8 (SD ± 24.5) and FEV1/FVC ratio of 66.1 (SD ± 15.3) were considered for the analysis. Allergic characterisation demonstrated atopic status in 182/256 (71.1%), positive sensitisation to alternaria 27/256 (10.5%), aspergillus 57/256 (22.3%), candida 24/256 (9.4%), cladosporium 24/256 (9.4%), penicillium 16/256 (6.2%), meeting SAFS criteria 93/254 (36.4%), and allergic bronchopulmonary aspergillosis (ABPA) 18/247 (7.3%). The SAFS group had higher total IgE than non SAFS group: mean total IgE 974.5 ng/l vs 330.1. However, we observed no statistically different outcomes for the SAFS versus non SAFS groups, ACQ 3.17 vs 3.515, AQLQ 4.0 vs 3.52, FeNO 36.4 ppb vs 32.9, peripheral blood eosinophils (PBE) 385 cells/µl vs 361, annual hospital admissions 1.28 vs 0.97 and annual OCS burst therapy of 5.7 vs 5.9. In contrast the ABPA versus non ABPA cohort had higher PBE 585 cells/µl vs 364, total IgE 2882ng/L vs 326, lower% predFEV1 60.2L vs 71 L, and ever ITU admissions 0.9 vs 0.46.
Conclusion Fungal sensitisation is relatively common in severe asthma but it did not seem to influence overall clinical outcomes. ABPA is less common with worse outcomes.