Clinical And Airway Inflammatory Features Of Asthmatic Patients Sensitive To Cold Stimulation

Objective:To explore the clinical symptoms,lung function and airway inflammatory characteristics of asthmatic patients who are sensitive to cold stimulation.Methods:Eighty patients with newly diagnosed bronchial asthma or acute exacerbation（mild to moderate）of previously diagnosed bronchial asthma without receiving regular treatment were selected from the respiratory department of our hospital.According to whether cold air stimulation could induce respiratory symptoms,the cases were divided into cold insensitive group（45 cases）and cold sensitive group（35 cases）.All patients were treated with inhaled corticosteroid+long-actingβ₂ receptor agonist and montelukast sodium tablets,added short-actingβ₂ receptor agonist or（and）systemic glucocorticoid if necessary.Asthma Control Test was administered pre-treatment and at 3 months post-treatment to collect the clinical symptoms;spirometry was performed to determine the impairment and recovery of lung function;Complete Blood Count、induced sputum cell counts、IgE in serum and cytokines in induced sputum were examined to determine the characteristics of airway inflammation,and statistical analysis was performed.Results:The number of acute exacerbation in the cold sensitive group was more than that in the cold insensitive group within 1 year before the visit（p<0.05）.However,there was no significant difference between two groups using SABA and glucocorticoid during the treatment period（3 months）to control symptoms（p>0.05）.The ACT score of cold sensitive group was lower than that of cold insensitive group before and after treatment（p<0.01）.The loss of lung function before treatment was more obvious than that of the insensitive group（p<0.01）,the recovery of lung function after treatment was worse than the insensitive group（p<0.05）.There was no significant difference in the percentage of blood and induced sputum eosinophils between two groups before and after treatment（p>0.05）.However,the percentage of neutrophils in sensitive group was significantly higher than that in insensitive group（p<0.01）.According to the results of induced sputum cell counts,the cold insensitive group was mainly composed of eosinophilic subtype,however,the neutrophilic subtype in cold sensitive group accounted for 42.86%,which was significantly higher than the cold insensitive group（p=0.03）.The proportion of eosinophilic subtype in cold sensitive group was only 31.43%,which was significantly lower than the cold insensitive group（p=0.01）.The expressions of blood IgE and IL-4 and IL-5 in Induced sputum at 3 months post-treatment in two groups were lower than that before treatment（p<0.01）,and IFN-γwas higher than that before treatment（p<0.01）.However,the expression of IgE and cytokines in cold sensitive group was higher than that in cold insensitive groups before and after treatment,the change of cytokines was no significant difference（p>0.05）.Whether in cold sensitive group or insensitive group,there was no significant difference in the expression of IL-17A at 3 months post-treatment compared with that before treatment（p>0.05）.But the expression of IL-17A of the cold sensitive group was significantly higher than cold insensitivity group before and after treatment（p<0.01）.Conclusion:Asthmatic patients who are sensitive to cold stimulation often have recurrent and/or aggravated symptoms,and their lung function is significantly impaired,the airway inflammatory phenotype is dominated by neutrophilic subtype which is different from classic asthma.