AUTHOR=Chen Hao , Zhang Xinyu , Zhu Li , An Nairui , Jiang Qing , Yang Yaqi , Ma Dongxia , Yang Lin , Zhu Rongfei 

TITLE=Clinical and immunological characteristics of Aspergillus fumigatus-sensitized asthma and allergic bronchopulmonary aspergillosis

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.939127

DOI=10.3389/fimmu.2022.939127

ISSN=1664-3224

ABSTRACT=<sec><title>Background</title><p><italic>Aspergillus fumigatus</italic> (<italic>A.f</italic>) is a common airborne allergen that contributes to allergic asthma. In some patients, <italic>A.f</italic> can colonize in the airway and lead to allergic bronchopulmonary aspergillosis (ABPA). However, our understanding of the pathogenesis of <italic>A.f</italic>-sensitized asthma and ABPA remains inadequate.</p></sec><sec><title>Objective</title><p>We aimed to investigate the clinical and immunological characteristics of <italic>A.f</italic>-sensitized asthma and ABPA.</p></sec><sec><title>Methods</title><p>A total of 64 ABPA and 57 A<italic>.f</italic>-sensitized asthma patients were enrolled in the study, and 33 non-<italic>A.f</italic>-sensitized asthma patients served as the control group. The clinical and immunological parameters included lung function, fractional exhaled nitric oxide (FeNO), induced sputum and blood cell analysis, specific IgE/IgG/IgA of A.f and its components, cytokines (IL-33, IL-25, and TSLP) and CD4<sup>+</sup>T cell subsets.</p></sec><sec><title>Results</title><p>The eosinophils in blood, induced sputum, and FeNO were significantly higher in ABPA patients compared to that in <italic>A.f</italic>-sensitized patients. The combination of FeNO and eosinophils (EO) parameters presented good diagnostic efficiency in differentiating <italic>A.f</italic> (+) asthma from ABPA, with a sensitivity of 80% and a specificity of 100%. Specific IgE, IgG, and IgA against <italic>A.f</italic> also increased in ABPA patients. However, serum IL-25, IL-33, and TSLP showed no significant differences between the two groups. Cell analysis showed an increase in IFN-γ<sup>+</sup>Th1 cells in the ABPA patients. FlowSOM analysis further confirmed that the frequency of CD3<sup>+</sup>CD4<sup>+</sup>PD-1<sup>+</sup>CD127<sup>+</sup>IFN-γ<sup>+</sup>T cells was higher in ABPA patients.</p></sec><sec><title>Conclusion</title><p>Our findings suggest the distinct humoral and cell immunological responses in <italic>A.f</italic>-sensitized asthma and ABPA patients. ABPA patients have more severe eosinophilic inflammation and enhanced Th1 responses compared with <italic>A.f</italic>-sensitized asthma patients.</p></sec>