Aspergillus sensitization in bronchial asthma: A separate phenotype

Background: Bronchial asthma is one of the common chronic respiratory illnesses worldwide, with a global disease burden that affects approximately 300 million individuals. It affects 5-10% of the population in developed countries. India constitutes approximately one-tenth of the global disease burden, where an estimated 7 million children are affected by this illness. Airway hyperresponsiveness or bronchial hyperreactivity in asthma is an exaggerated response to numerous exogenous and endogenous stimuli. In India, the most important endogenous stimuli is considered to be fungal antigens from the genus, Aspergillus. Positive skin reactions to Aspergillus fumigatus among individuals with atopic asthma is 10 to 20%; however, a causal relationship is yet to be established. A separate entity, termed "severe asthma with fungal sensitivity," is often used to describe milder allergic reactions to fungal aeroallergens that has fungal sensitization as the starting point of pathogenesis than allergic bronchopulmonary aspergillosis. Methods: A total of 57 patients with bronchial asthma were prospectively enrolled and evaluated for Aspergillus sensitization and its impact on asthma control. Results: Symptoms were well controlled in a majority of patients (57.89%) and partly controlled in 14.04%. Uncontrolled symptoms were observed in only 28.07% of patients. The proportion of patients with uncontrolled symptoms was higher among patients who were sensitized (45.00%) compared with patients who were not sensitized (18.92%). The proportion of patients with well-controlled symptoms was higher in individuals who were not sensitized compared with individuals who were sensitized (62.16% versus 50.00%). Conclusion: The severity of asthma was associated with fungal sensitization, with sensitization to Aspergillus as a part of the pathogenesis. Aspergillus sensitization is significantly associated with bronchiectasis, even in the absence of clinical features.