1. Department of Pediatrics; Bronovo hospital; Den Haag The Netherlands
2. Department of Pediatrics Medisch Spectrum Twente; Enschede The Netherlands
3. Department of Immunohematology Diagnostics; Sanquin Diagnostic Services; Amsterdam The Netherlands
4. Department of Clinical Chemistry; Bronovo hospital; Den Haag The Netherlands
5. Department of Clinical Chemistry; MEDLON; Enschede The Netherlands
6. Department of Clinical Chemistry; Medisch Spectrum Twente; Enschede The Netherlands