[1] Guangzhou Med Univ, Guangzhou Inst Resp Hlth, Dept Resp & Crit Care Med, State Key Lab Resp Dis,Natl Clin Res Ctr Resp Dis,, Guangzhou 510180, Guangdong, Peoples R China
[2] Zhengzhou Univ, Affiliated Hosp 1, Dept Resp & Crit Care Med, Zhengzhou 450052, Henan, Peoples R China
[3] Southern Med Univ, Nanfang Hosp, Dept Resp & Crit Care Med, Chron Airways Dis Lab, Guangzhou 510180, Peoples R China
[4] Guangzhou Med Univ, Guangzhou Inst Resp Hlth, Dept Allergy & Clin Immunol, State Key Lab Resp Dis,Natl Clin Res Ctr Resp Dis,, Guangzhou 510180, Guangdong, Peoples R China