Inflammatory and pulmonary function characteristics of bronchial asthma induced by COVID‑19 infection

Bronchial asthma, a widely prevalent respiratory disease influencing individuals of all age groups worldwide, has been increasingly recognized as a global concern. While there exists a potentially heightened risk of severe coronavirus disease 2019 (COVID-19) in asthmatic patients, particularly those with non-allergic asthma, it is uncertain whether COVID-19 infection-induced bronchial asthma has its own unique clinical characteristics. The present study aimed to compare and analyze the pulmonary function and eosinophilic inflammation indices of patients with COVID-19 infection-induced bronchial asthma and those with typical bronchial asthma, and further deepen the understanding of COVID-19 infection-induced bronchial asthma. A retrospective analysis was conducted on the pulmonary function and inflammatory characteristics of 116 patients diagnosed with COVID-19 infection-induced bronchial asthma and treated in outpatient clinics after March 2023, as well as 113 patients with typical bronchial asthma diagnosed and treated from January 2022 to November 2022. The main clinical characteristics were cough, sputum, chest tightness, dyspnea and wheezing. There was no significant difference in clinical characteristics between the two groups. The results indicated that there was no significant difference in the total IgE, the absolute value and percentage of eosinophil, transoral FeNO, and trans-nasal FeNO in the peripheral blood samples of patients in the COVID-19 infection-induced bronchial asthma group compared with the typical bronchial asthma group. Although there was no significant difference between the two groups in the rates of impairment in ventilation function, reserve function, and small airway function, significant differences were identified in various indicators, including forced expiratory volume in 1 sec as a percentage of the predicted value (FEV1%), residual volume/total lung capacity (RV/TLC), peak expiratory flow (PEF), maximal expiratory flow rate at 75% (MEF75), maximal voluntary ventilation (MVV), FEV * 30, and residual volume (RV) between the two groups. The findings indicated that patients with COVID-19 infection-induced bronchial asthma exhibited a comparatively inferior pulmonary function versus those with typical bronchial asthma. However, it is important to note that the clinical impact of this disparity was not statistically significant.