[1] Nordland Hosp, Dept Resp Med, Bodo, Norway
[2] Oslo Univ Hosp, Dept Resp Med, Rikshosp, Oslo, Norway
[3] Univ Oslo, Inst Clin Med, Oslo, Norway
[4] Silkeborg Reg Hosp, Diag Ctr, Silkeborg, Denmark
[5] Karolinska Inst, Dept Med Solna, Resp Med Unit, Stockholm, Sweden
[6] Karolinska Univ Hosp, Dept Resp Med & Allergy, Stockholm, Sweden
[7] Karolinska Inst, Dept Med Solna, Stockholm, Sweden
[8] Herlev & Gentofte Hosp, Dept Resp Med, Copenhagen, Denmark
[9] Aarhus Univ, Ctr Rare Lung Dis, Dept Resp Dis & Allergy, Dept Clin Med,Ctr Rare Lung Dis, Aarhus, Denmark