[1] Univ Padua, Dept Paediat, Paediat Pulmonol Unit, I-35128 Padua, Italy
[2] Univ Vienna, Dept Paediat, Vienna, Austria
[3] Med Univ Graz, Dept Paediat, Resp & Allerg Dis Div, Graz, Austria
[4] Univ Bern, Inst Social & Prevent Med, Bern, Switzerland
[5] Univ Geneva, Sch Med, Dept Genet Med & Dev, CH-1211 Geneva, Switzerland
[6] Hosp Sao Joao, Dept Paediat, Oporto, Portugal
[7] Paediat Inst Svabhegy, Budapest, Hungary
[8] Univ Valencia, Dept Paediat, Paediat Pulmonol Unit, Clin Univ Hosp, Valencia, Spain
[9] Emma Childrens Hosp, Acad Med Ctr, Dept Paediat & Neonatol, Amsterdam, Netherlands
[10] Gothenburg Univ, Dept Paediat, Inst Clin Sci, Sahlgrenska Acad, Gothenburg, Sweden
[11] Royal Brompton Hosp, Dept Paediat Resp Med, London SW3 6LY, England
[12] Southampton Univ Hosp NHS Trust, Southampton, Hants, England
[13] Univ Leicester, Div Paediat, Dept Infect Immun & Inflammat, Leicester, Leics, England
[14] Leicester Childrens Hosp, Leicester, Leics, England
[15] Univ Hosp Leuven, Dept Ear Nose & Throat, Louvain, Belgium
[16] Rigshosp, Copenhagen Univ Hosp, Paediat Pulm Serv, DK-2100 Copenhagen, Denmark
[17] Rigshosp, Copenhagen Univ Hosp, Cyst Fibrosis Ctr, Dept Paediat,Clin 1,Juliane Marie Ctr, DK-2100 Copenhagen, Denmark
[18] Univ Hosp Freiburg, Dept Paediat & Adolescent Med, Freiburg, Germany
[19] Univ Hosp Motol, Dept Paediat, Prague, Czech Republic
[20] Charles Univ Prague, Sch Med 2, Prague, Czech Republic