[1] Univ Cincinnati, Dept Internal Med, Div Allergy Immunol, Cincinnati, OH USA
[2] Univ Cincinnati, Div Pulm Med, Cincinnati, OH USA
[3] Univ Cincinnati, Dept Environm Hlth, Cincinnati, OH USA
[4] Rush Univ, Med Ctr, Childrens Hosp, Div Asthma Res, Chicago, IL 60612 USA
[5] Rush Univ, Med Ctr, Div Microbiol & Immunol, Chicago, IL 60612 USA