Characteristics of severe asthma in China with one year follow-up: the C-BIOPRED study

Background: There is little information on the state of asthma, particularly severe asthma, in China. Objectives: To determine the characteristics of severe asthma patients in China and their stability. Methods: We recruited adults with severe asthma (n=349 non-smokers, NSA, & n=114 smokers and ex-smokers, SSA), mild/moderate asthma (MMA; n=97) and healthy controls (HS, n=100) from 33 university hospitals in 15 provinces. Severe asthma was defined by 2014 ERS/ATS guidelines. Results: NSA was mostly female (70%) but SSA exclusively (96.5%), with both groups having most obese subjects (BMI>28) (NSA: 14.6% and SSA: 17.5% versus MMA: 10.3%). NSA and SSA had more symptoms and exacerbations (NSA: 2.36/yr and SSA: 2.46/yr) compared to MMA (1.14) (p<0.001), with worse quality of life, lower FEV1/FVC ratio (60.4 and 57.5% vs 65.8%) and higher levels of anxiety and depression. Blood total IgE and eosinophil (EOS) were higher in both NSA and SSA, and MMA compared with HS, with no significant differences between NSA, SSA and MMA. NSA had higher FeNO compared to SSA. 10.6% and 13.2% of NSA and SSA respectively were on oral corticosteroids. Blood EOS % correlated with FEV1% predicted (r=-0.26 p<0.001) and with FeNO (r=0.36, p<0.001) in severe asthma. At one year follow-up of severe asthma, symptoms, quality of life improved and bronchodilator reversibility decreased from 19.64% to 12.55%, p<0.001. Conclusions: This C-BIOPRED severe asthma cohort has many similarities with other cohorts such as SARP and U-BIOPRED, but with less comorbid features and lower oral corticosteroid usage. There was improvement in asthma control and bronchodilator reversibility at one year. Supported by Astra-Zeneca China.