The Basophil Surface Marker CD203c Identifies Aspergillus Sensitization in 2 Cystic Fibrosis

• Main Authors: Mirković, Bojana, Lavelle, Gillian M., Azim, Ahmed Abdul, Helma, Kristine, Gargoum, Fatma S., Molloy, Kevin, Gernez, Yael, Dunne, Katie, Renwick, Julie, Murphy, Philip, Moss, Richard B., Greene, Catherine M., Gunaratnam, Cedric, Chotirmall, Sanjay Haresh, McElvaney, Noel G.
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2016
• Subjects: Basophil activation test; CD203c; Cystic fibrosis; Aspergillus fumigatus; Body mass index; Flow cytometry; FEV1; Itraconazole, sensitization; Allergic bronchopulmonary aspergillosis
• Online Access: https://hdl.handle.net/10356/81769; http://hdl.handle.net/10220/39941
• Institution: Nanyang Technological University

Background: Colonization by Aspergillus fumigatus in patients with cystic fibrosis (CF) can cause A fumigatus sensitization and/or allergic bronchopulmonary aspergillosis (ABPA), which affects pulmonary function and clinical outcomes. Recent studies show that specific allergens upregulate the surface-expressed basophil marker CD203c in sensitized subjects, a response that can be readily measured by using flow cytometry. Objective: We sought to identify A fumigatus sensitization in patients with CF by using the basophil activation test (BAT). Methods: Patients with CF attending Beaumont Hospital were screened for study inclusion. BAT was used to identify A fumigatus sensitization. Serologic (total and A fumigatus–specific IgE), pulmonary function, and body mass index measurements were performed. Results: The BAT discriminates A fumigatus–sensitized from nonsensitized patients with CF. Persistent isolation of A fumigatus in sputum is a significant risk factor for A fumigatus sensitization. Levels of the A fumigatus–stimulated basophil activation marker CD203c inversely correlated with pulmonary function and body mass index in A fumigatus–sensitized but not nonsensitized patients with CF. Total and A fumigatus–specific IgE, but not IgG, levels are increased in A fumigatus–sensitized patients with CF and ABPA when compared with those in A fumigatus–sensitized and nonsensitized patients with CF without ABPA. Itraconazole treatment did not affect A fumigatus sensitization. Conclusion: Combining the BAT with routine serologic testing allows classification of patients with CF into 3 groups: nonsensitized, A fumigatus–sensitized, and ABPA. Accurate and prompt identification of A fumigatus–associated clinical status might allow early and targeted therapeutic intervention, potentially improving clinical outcomes.