| Objective:1.To investigate the efficacy and safety of bronchial thermoplasty in the treatment of severe bronchial asthma.2.To study the changes of local airway tissue structure and inflammation in patients with severe asthma and the effect of BT on T lymphocytes in bronchoalveolar lavage solution.Methods:1.The study subjects were severe asthma patients admitted to the department of respiratory and critical care medicine of North Jiangsu People’s hospital from November1,2020 to December 30,2022.A total of 12 patients were selected to complete bronchial thermoplasty according to the inclusion and exclusion criteria.Groups was divided by self-control method and divided into baseline group(before the first treatment)based on the first treatment cycle,4 weeks after the first treatment(before the second treatment),8 weeks after the first treatment(before the third treatment),and 32weeks after the first treatment.2.General clinical data of enrolled patients were collected as required,including asthma medication,asthma onset time and so on.Before the first treatment and within32 weeks after the first treatment,the ACT score,ACQ score,the number of acute attacks,asymptomatic days,the use of first aid drugs(inhaled drugs,oral drugs,intravenous drugs)were evaluated,and the chest CT,peripheral blood eosinophil percentage,neutrophil percentage and lymphocyte percentage were collected.3.The pulmonary function was calculated before the first treatment and 32 weeks after the first treatment,including first second forced expiratory volume,first second forced expiratory volume/forced vital capacity,forced vital capacity,peak expiratory flow rate and maximum ventilation volume.4.Bronchoalveolar lavage samples were collected from the left and right lower lobes before each BT,and the samples were analyzed by flow cytometry.5.The right lower lobe bronchial biopsies were collected from the same airway before the first treatment and the third treatment,respectively,and the biopsies were used for histological staining.6.Statistics of adverse respiratory events after treatment,including wheezing,cough,chest discomfort,dyspnea,blood in sputum,hemoptysis,pharynx discomfort,atelectasis,bronchospasm,lower respiratory tract infection,upper respiratory tract infection and other adverse reactions.Results:1.Patient baseline data:from November 1,2020 to December 30,2022,we included 12 patients with refractory asthma who underwent bronchial thermoplasty in the department of respiratory and critical care medicine of North Jiangsu People’s hospital.2.The scores of ACT and ACQ before and after BT treatment were significantly improved,the days of asymptomatic were significantly increased,the times of acute attack and the use of first aid drugs were significantly decreased(P<0.05).The percentage of neutrophils and eosinophils in peripheral blood decreased before and after BT treatment,while the percentage of lymphocytes did not change significantly,and there was no significant difference.FEV1,FVC,FEV1/FVC,PEF and MVV increased significantly before and after BT treatment,and pulmonary function was significantly improved.3.Goblet cell hyperplasia,eosinophil and lymphocyte infiltration,and obvious hyperplasia of smooth muscle cells were more frequently observed in the airway mucosa biopsy of patients before BT.Smooth muscle cells in patients were significantly reduced after BT,while submucosal inflammatory cells were decreased in 9 patients(75%),and the other 3 patients had no significant change in submucosal inflammation(25%).4.Compared with before treatment,there was no significant difference in the proportion of CD4~+T lymphocytes in alveolar lavage fluid after 4 weeks of BT treatment(P>0.05),but there was significant difference after 8 weeks of BT treatment(P<0.05).The percentage of CD8~+T lymphocytes was significantly different after 4weeks of BT treatment(P<0.05),and significantly different after 8 weeks of BT treatment(P<0.01).There was no significant difference in the results of CD3~+T lymphocytes,CD19~+B lymphocytes and CD16~+56~+NK lymphocytes after 4 and 8 weeks of BT treatment.5.After 32 weeks of the first BT,CT showed 3 mild bilateral exudation(25%)and 10 mild bronchial dilation(83%).6.During BT treatment,a total of 43 respiratory adverse events occurred:68%were mild,26%were moderate and 6%were severe.The most common are wheezing,cough,chest discomfort,pharynx discomfort.One week after treatment,the adverse respiratory events were wheezing,cough,chest discomfort,pharynx discomfort and upper respiratory tract infection,all of which were mild to moderate.No patient was admitted to hospital again because of respiratory adverse events after 1 week of treatment,and the respiratory adverse events basically disappeared after 1 month of treatment.Conclusions:1.BT provides meaningful treatment for patients with severe asthma,improves the quality of life at the same time,and can effectively reduce the number of acute episodes.2.Most symptomatic patients with severe asthma can safely tolerate BT,indicating that BT has a good safety.3.Smooth muscle cells and submucosal inflammatory cells were significantly reduced in airway biopsy after BT treatment,which is beneficial to improve the mechanism of BT treatment for severe asthma and can guide more personalized asthma treatment plan.4.BT treatment not only induces structural changes,but may also have important immunomodulatory effects that significantly inhibit asthma-induced inflammatory responses. |
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