1. Department of Rheumatology, "Asklepieion" General Hospital, Athens, Greece
2. Department of Rheumatology, Agios Andreas Hospital, Patras, Greece
3. Clinical Immunology-Rheumatology Unit, 2nd Department of Medicine and Laboratory, Hippokration General Hospital, National and Kapodistrian University of Athens, Athens, Greece
4. Department of Rheumatology, Patras University Hospital, University of Patras Medical School, Patras, Greece