[1] Univ Roma La Sapienza, Rheumatol Unit, I-00161 Rome, Italy
[2] Univ Florence, Rheumatol Unit, Florence, Italy
[3] Univ Naples 2, Rheumatol Unit, Naples, Italy
[4] Univ Pisa, Rheumatol Unit, Pisa, Italy
[5] Univ Politecn Marche, Rheumatol Unit, Ancona, Italy
[6] IRCCS Policlin San Matteo Fdn, Rheumatol Unit, Pavia, Italy
[7] Osped Niguarda Ca Granda, Rheumatol Unit, Milan, Italy
[8] Univ Siena, Rheumatol Unit, I-53100 Siena, Italy
[9] Ist Ortoped G Pini, Rheumatol Unit, Milan, Italy
[10] Osped Madonna del Soccorso, Rheumatol Unit, San Benedetto Tronto, AP, Italy
[11] Univ Cagliari, Rheumatol Unit, Cagliari, Italy
[12] Humanitas Clin & Res Ctr, Rheumatol Unit, Rozzano, Italy
[13] Azienda Osped Carlo Poma, Rheumatol Unit, Mantua, Italy
[14] Univ Bari, Rheumatol Unit, Bari, Italy
[15] Hosp GU Gregorio Maranon, Rheumatol Unit, Madrid, Spain