[1] Geisel Sch Med Dartmouth, Sect Pulm & Crit Care Med, Hanover, NH 03755 USA
[2] Univ Groningen, Univ Med Ctr Groningen, Dept Pulm Med & TB, Groningen, Netherlands
[3] Univ Groningen, Univ Med Ctr Groningen, Groningen Res Inst Asthma & COPD, Groningen, Netherlands
[4] Univ N Carolina, Sch Med, Dept Med, Pulm Dis & Crit Care Med, Chapel Hill, NC 27599 USA
[5] Mainz Univ Hosp, Dept Pulm, D-55131 Mainz, Germany
[6] Novartis Pharmaceut, E Hanover, NJ USA