[1] Isala Hosp, Princess Amalia Childrens Ctr, POB 10400, NL-8000 GK Zwolle, Netherlands
[2] Univ Groningen, Univ Med Ctr Groningen, UMCG Postgrad Sch Med, Groningen, Netherlands
[3] Erasmus Univ, Sophia Childrens Hosp, Med Ctr, Dept Pediat Resp Med, Rotterdam, Netherlands
[4] Radboud Univ Nijmegen, Med Ctr, Div Resp Med, Dept Pediat, NL-6525 ED Nijmegen, Netherlands
[5] Med Univ Graz, Dept Paediat & Adolescence Med, Resp & Allerg Dis Div, Graz, Austria
[6] Univ Leicester, Dept Infect Immun & Inflammat, NIHR Resp Biomed Res Unit, Inst Lung Hlth, Leicester, Leics, England
[7] Univ Bristol, Sch Social & Community Med, Bristol, Avon, England
[8] Univ London Imperial Coll Sci Technol & Med, London, England
[9] Royal Brompton Hosp, London SW3 6LY, England
[10] Univ Murcia, Dept Pediat, Div Allergol & Pulmonol, Virgen de la Arrixaca Univ Childrens Hosp, Murcia, Spain
[11] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden
[12] Karolinska Inst, Ctr Allergy Res, Stockholm, Sweden
[13] Univ Gothenburg, Dept Pediat, Queen Silvia Childrens Hosp, Gothenburg, Sweden
[14] Univ Bern, Inst Social & Prevent Med, Bern, Switzerland
[15] Univ Southern Denmark, Kolding Hosp, Paediat Res Unit, Kolding, Denmark
[16] Vilnius Univ, Clin Childrens Dis, Vilnius, Lithuania