1. Department of Laboratory Medicine , AZ St-Jan Hospital Bruges-Ostend , Bruges , Belgium
2. Reproductive Immunology and Transplantation , Vrije Universiteit Brussel , Brussels , Belgium
3. Department of Laboratory Medicine , University Hospital Ghent , Ghent , Belgium
4. Department of Diagnostic Sciences , Ghent University , Ghent , Belgium
5. Sciensano , Quality of Laboratories , Brussels , Belgium
6. Department of Oral Biology , University of Florida , Gainesville , FL , USA
7. Laboratory of Clinical Pathology , Azienda Sanitaria Universitaria Integrata di Udine , Tolmezzo , Italy
8. Department of Rheumatology and Clinical Immunology, Faculty of Medicine, School of Health Sciences , University of Thessaly , Volos , Greece
9. University General Hospital of Larissa , Larissa , Greece
10. Rheumatology Division, Escola Paulista de Medicina , Universidade Federal de Sao Paulo , Sao Paulo , Brazil
11. Immunology Division , Fleury Medicine and Health Laboratories , Sao Paulo , Brazil
12. Imunologia , Pontificia Universidade Catolica de Goias , Goiânia , Brazil
13. Department of Laboratory Diagnostics , University Hospital Centre Zagreb , Zagreb , Croatia
14. Central Laboratory , East Tallinn Central Hospital , Tallinn , Estonia
15. Department of Clinical Chemistry , CHU Sart-Tilman , Liège , Belgium
16. Laboratory Medicine , Centro de Medicina Laboratorial Germano de Sousa , Lisboa , Portugal
17. Department of Laboratory Medicine , GZA Hospital , Antwerp , Belgium
18. Department of Laboratory Medicine , OLV Hospital Aalst , Aalst , Belgium
19. Clinical and Diagnostic Immunology, Department of Microbiology, Immunology and Transplantation , KU Leuven , Leuven , Belgium
20. Department of Laboratory Medicine , UZ Leuven , Leuven , Belgium