1. Department of Pathobiology and Laboratory Medicine; University Health Network; Toronto General Hospital; Toronto ON Canada
2. Department of Pathology; Oslo University Hospital; Oslo Norway
3. Department of Pathology; Karolinska University Hospital; Stockholm Sweden
4. Laboratory Services (Hospital District of Helsinki and Uusimaa Laboratory); Helsinki University Central Hospital; Helsinki Finland
5. Department of Clinical Immunology section 7631; Copenhagen University Hospital Rigshospitalet; Copenhagen Denmark
6. Fimlab, Laboratories Ltd; Tampere Finland
7. University of Umeå; Umeå Sweden
8. Aarhus University; Hospital Skejby; Aarhus Denmark
9. Children′s Hospital; University of Helsinki and Helsinki University Hospital; Helsinki Finland
10. University Hospital Rigshospitalet; Copenhagen Denmark
11. Landspitali-University Hospital; Reykjavik Iceland
12. University Children's Hospital; Uppsala Sweden
13. Oslo University Hospital Rikshospitalet; Oslo Norway
14. Department of Clinical Chemistry and Transfusion Medicine; Institute of Biomedicine; Sahlgrenska Academy at University of Gothenburg; Gothenburg Sweden
15. Department of Clinical Chemistry; Sahlgrenska University Hospital; Gothenburg Sweden
16. Queen Silvia Children's Hospital; Sahlgrenska University Hospital; Gothenburg Sweden