1. Department of Clinical Chemistry , Erasmus MC, University Medical Center Rotterdam , PO Box 2040, 3000 CA , Rotterdam , The Netherlands , Phone: +31107034509, Fax: +31104367894
2. Department of Clinical Chemistry , Erasmus MC, University Medical Center Rotterdam , Rotterdam , The Netherlands
3. Department of Clinical Chemistry , Maasstad Hospital , Rotterdam , The Netherlands
4. Medisch Spectrum Twente, Medlon BV , Department of Clinical Chemistry and Laboratory Medicine , Enschede , The Netherlands