[1] Univ Florence, Dept Expt & Clin Med, Div Internal Med, AOUC, Largo Brambilla 3, I-50134 Florence, Italy
[2] Univ Aquila, Dept Life Hlth & Environm Sci, Internal Med & Nephrol Div, ASL1 Avezzano Sulmona Laquila, Laquila, Italy
[3] Univ Trieste, Univ Hosp Cattinara, Dept Med Surg & Hlth Sci, Pulmonol Unit, Trieste, Italy
[4] FESCA Federat European Scleroderma Assoc Belgium, GILS Grp Italiano, Lotta Sclerodermia Italy, Milan, Italy
[5] Northern Care Alliance NHS Fdn Trust, Salford Care Org, Dept Rheumatol, Salford, England
[6] Univ Manchester, Div Musculoskeletal & Dermatol Sci, Manchester, England
[7] Johns Hopkins Univ, Dept Med, Div Rheumatol, Baltimore, MD USA