1. Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
2. Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
3. Pathology Research Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
4. Hematology Research Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China