1. Clinical Chemistry Laboratory, Hospital Papa Giovanni XXIII , Bergamo , Italy
2. Laboratory Medicine, San Bassiano Hospital , AULSS 7 Pedemontana, Via dei Lotti, 40 , 36061 Bassano del Grappa , Italy
3. General Laboratory , University Hospital Careggi , Florence , Italy
4. Section of Clinical Biochemistry , University Hospital of Verona , Verona , Italy