1. Department of Pediatrics Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
2. Haemodiagnostic Laboratory, Department of Haematology Aarhus University Hospital Aarhus Denmark
3. Haematolology‐Pathology Research Laboratory Research Unit for Haematology and Research Unit for Pathology, University of Southern Denmark and Odense University Hospital Odense Denmark
4. Department of Clinical Chemistry Sahlgrenska University Hospital Gothenburg Sweden
5. Department of Laboratory Medicine Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
6. Laboratory Medicine Program University Health Network, Toronto General Hospital Toronto Ontario Canada
7. Department of Pediatrics Aarhus University Hospital Aarhus Denmark
8. Department of Pediatrics and Adolescent Medicine Rigshospitalet, University of Copenhagen Copenhagen Denmark
9. Department of Pediatrics Landspitali University Hospital Reykjavik Iceland
10. Department of Clinical Immunology Copenhagen University Hospital Rigshospitalet Copenhagen Denmark
11. Department of Immunology Oslo University Hosptial Oslo Norway