1. Clinical Chemistry Laboratory , Papa Giovanni XXIII Hospital , Piazza OMS , 1 – 24127 Bergamo , Italy , Phone: (+039) 0352674550, Fax: (+039) 0352674939
2. Medical Laboratory Service, San Raffaele Hospital , Milan , Italy
3. Clinical Chemistry Laboratory , Papa Giovanni XXIII Hospital , Bergamo , Italy
4. DASIT Diagnostica, Cornaredo , Milan , Italy
5. Central Laboratory , Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico , Milan , Italy
6. Synlab , Monza , Italy
7. Section of Clinical Biochemistry , University of Verona , Verona , Italy