Objective To investigate the clinical characteristics of neutrophilic asthma ( NA) .
Methods NA patients were collected from the out-patient and in-patient departments of Respiratory Diseases of Xinqiao Hospital between January 2010 and December 2010. The results of the medical records,pulmonary function tests, and induced sputum cytology were analyzed retrospectively.
Results The NA patients with neutrophil percent ≥ 61% accounted for 33. 1% ( 51 /154 ) of all the asthmatics patients detected by induced sputumin the same period, and 45 cases with complete records were included. Of the 45 cases recruited, 20 cases ( 44. 4% ) were in-patients,2 cases ( 4. 4% ) were with controlled asthma, 3 cases ( 6. 7% ) were with cough variant asthma, 30 cases ( 66. 7% ) were female, 12 cases ( 26. 7% ) were atopic patients, and 27 cases ( 60% ) had acute exacerbation. The age of onset of 35 patients ( 77. 8% ) were after 12 years. FEV1% pred lt; 60% and gt; 80% was obtained in 55. 9% ( 19/34) and 14. 7% ( 5 /34) of patients respectively. The result of bronchodilator test was positive in 64% ( 16/25) of patients, and mean increase in FEV1 was 11. 7% . The percentage of neutrophil and eosinophil was ( 74. 5 ±9. 1) % and ( 2. 4 ±2. 5) % respectively in induced sputum, and 35. 6% ( 16/45) of the patients had increased eosinophil percentage ( gt;3% ) .
Conclusions In our study, most of NA is severe and acute exacerbation asthma, and its clinical features are various. The mechanismand clinical significance of increased neutrophils in asthmatic patients are unclear and more studies are needed.
Citation： WANG Yan,WANG Bing,CHEN Huaping,TANG Xianjun,ZHANG Qiao,CHENG Xiaoming,LIN Kexiong,MA Qianli,WANG Changzheng.. Characteristics of Neutrophilic Asthma:A Clinical Investigation. Chinese Journal of Respiratory and Critical Care Medicine, 2011, 10(4): 317-320. doi: Copy