1. Rheumatology Unit Department of Internal Medicine, Hospital S. Giovanni di Dio, Azienda Sanitaria di Firenze, 50143 Florence, Italy
2. Rheumatology and Rehabilitation Unit, Salvatore Maugeri Foundation IRCCS, 46042 Mantua, Italy
3. Immunology and Allergology Laboratory Unit, Hospital S. Giovanni di Dio, Azienda Sanitaria di Firenze, 50143 Florence, Italy
4. Rheumatology Unit, Sacco University Hospital, 20127 Milan, Italy
5. Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, London E14DG, UK