1 4th Department of Internal Medicine, National and Kapodistrian University of Athens School of Medicine, Attikon University General Hospital, Chaidari, Greece.
2 Department of Rheumatic and Immunologic Diseases, Orthopedic & Rheumatologic Institute, Cleveland Clinic, Cleveland, OH, United States.
3 Department of Infectious Disease, Cleveland Clinic, Cleveland, OH, United States.
4 Joint Rheumatology Program, Clinical Immunology-Rheumatology Unit, 2nd Department of Medicine and Laboratory, National and Kapodistrian University of Athens School of Medicine, Athens, Greece.