[1
]
Division of Rheumatology, University Hospital Zurich, Zurich, Switzerland.
[2
]
Graf Biostatistics, Winterthur, Switzerland.
[3
]
Department of Rheumatology and Clinical Immunology, Justus-Liebig University Giessen,
Kerckhoff-Klinik, Bad Nauheim, Germany.
[4
]
Department of Rheumatology and Immunology, Faculty of Medicine, University of Pécs,
Pécs, Hungary.
[5
]
Centre for Rheumatology, Royal Free and University College London Medical School,
London, UK.
[6
]
Department of Rheumatology, University Hospital Basel, Basel, Switzerland.
[7
]
Bayer Pharma AG, Berlin, Germany.
[8
]
University of Michigan Scleroderma Program, Ann Arbor, Michigan, USA.