[1] Guangzhou Med Univ, Affiliated Hosp 1, Natl Clin Res Ctr Resp Dis, State Key Lab Resp Dis, Guangzhou 510182, Guangdong, Peoples R China
[2] Guangzhou Med Univ, Affiliated Hosp 1, Dept Pediat, Guangzhou 510120, Guangdong, Peoples R China
[3] Sun Yat Sen Univ, Sun Yat Sen Mem Hosp, Dept Pediat, Guangzhou 510120, Guangdong, Peoples R China