1. Department of Paediatrics and Adolescent Medicine Rigshospitalet University of Copenhagen CopenhagenDenmark
2. Department of Clinical Immunology, Rigshospitalet University of Copenhagen Copenhagen Denmark
3. Department of Paediatrics Institution of Clinical Sciences Sahlgrenska University Hospital Gothenburg Sweden
4. Children and Adolescent Health Aarhus University Hospital Aarhus Denmark
5. Department of Women's and Children's Health Uppsala University Uppsala Sweden
6. Paediatric Haematology and Oncology Unit Kuopio University Hospital Kuopio Finland
7. Department of Paediatrics Oslo University Hospital Oslo Norway
8. Children's Clinic Haukeland University Hospital Bergen Norway
9. Division of Paediatric Haematology, Oncology and Stem Cell Transplantation, Children and Adolescents Helsinki University Hospital Helsinki Finland
10. Institute of Clinical Medicine Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark