1. Division of Rheumatology, AOU Careggi, Department of Experimental and Clinical Medicine, University of Florence, Via delle Oblate 4, 50141 Florence, Italy
2. Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
3. Rheumatology Unit, Hospital Guglielmo da Saliceto, 29121 Piacenza, Italy