Clinical and immunological characteristics of severe bronchial asthma with Aspergillus sensitization

Aim: to assess the clinical and immunological characteristics of patients with severe bronchial asthma (BA) with Aspergillus sensitization and to study the possibilities of applying basophil activation test (BAT) using flow cytometry to detect mycogenic sensitization. Patients and Methods: 93 patients with severe BA were examined. Therapy had 4 or 5 steps according to GINA 2019 recommendations. TARC (thymus and activation-regulated chemokine) content, the number of eosinophils, the levels of total IgE and specific IgE to 10 allergens were determined in blood serum by enzyme immunoassay. BAT with Aspergillus fumigatus allergen was performed in vitro using flow cytometry. Results: Aspergillus sensitization was detected in 33 (35.4%) patients with severe BA. In patients with BA and Aspergillus sensitization, the disease course was uncontrolled, and patients in this group were credibly more likely to receive oral glucocorticosteroids. The number of basophils (activated by the A. fumigatus allergen) and the stimulation index in patients with BA and Aspergillus sensitization were significantly higher than in patients with BA (9.9 (6.0–24.0) % vs. 3.6 (2.0–5.4) %; (p=0.000) and 4.25 (2.49–9.30) vs. 0.94 (0.75–1.16); (p=0.000)). Significant differences in TARC content were obtained in the groups of patients with severe BA and Aspergillus sensitization and patients with BA (625.0 (418.4–875.0) pg/mg versus 406.0 (210.0–561.0) pg/mg; p=0.001). A negative correlation was determined between TARC levels and a decrease in forced expiratory volume in 1 second (FEV1) (r=-0.70, p<0.05), and between positive correlation and absolute eosinophil count (r=0.81, p<0.05) and level of specific IgE to Aspergillus (r=0.36, p<0.05). Conclusion: Aspergillus sensitization is associated with an uncontrolled BA course. An additional method for diagnosing mycogenic sensitization is the BAT. The TARC concentration can serve as a biomarker of an active inflammatory response. KEYWORDS: Aspergillus spp., severe bronchial asthma, mycogenic sensitization, basophil activation test, TARC. FOR CITATION: Kozlova Ya.I., Frolova E.V., Uchevatkina A.E. et al. Clinical and immunological characteristics of severe bronchial asthma with Aspergillus sensitization. Russian Medical Inquiry. 2021;5(1):10–16. DOI: 10.32364/2587-6821-2021-5-1-10-16.