1. Central Diagnostic Laboratory, University Medical Center, Utrecht, The Netherlands
2. Laboratory for Clinical Chemistry, Hematology, and Immunology, Diakonessenhuis, Utrecht, The Netherlands
3. Laboratory for Clinical Chemistry and Hematology, Meander Medical Centre, Amersfoort, The Netherlands
4. Laboratory for Medical Microbiology and Immunology, Meander Medical Centre, Amersfoort, The Netherlands