[1] Boston Univ, Sch Med, Ctr Pulm, Boston, MA 02118 USA
[2] Boston Univ, Sch Publ Hlth, Boston, MA USA
[3] Duke Univ, Dept Med, Durham, NC USA
[4] Duke Univ, Med Ctr, Durham, NC USA
[5] NHLBI, Pulm & Vasc Med Branch, NIH, Bethesda, MD 20892 USA
[6] Univ Pittsburgh, Med Ctr, Div Pulm Allergy & Crit Care Med, Pittsburgh, PA USA
[7] Boston Univ, Sch Med, Ctr Human Genet, Boston, MA 02118 USA
[8] Boston Univ, Sch Med, Dept Med, Div Hematol & Oncol, Boston, MA 02118 USA