1 Rheumatology Unit, Department of Medicine, Surgery and Neuroscience, Azienda Ospedaliera Universitaria Senese, Policlinico Le Scotte, Viale Bracci 1, 53100, Siena, Italy.
2 Section of Biochemistry, Department of Medical Biotechnologies, University of Siena, 53100, Siena, Italy.
3 Rheumatology Unit, Department of Medicine, Surgery and Neuroscience, Azienda Ospedaliera Universitaria Senese, Policlinico Le Scotte, Viale Bracci 1, 53100, Siena, Italy. saracheleschi@hotmail.com.