2 R&D Allergy & Immunology Unit, Laboratorios LETI S.L.U., Madrid, Spain.
3 Pneumology and Allergy Service, Hospital Clinic, Barcelona, Spain.
4 Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Barcelona, Spain.