1 Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy. triggianese@med.uniroma2.it.
2 Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy.
3 Haematology, Department of Biomedicine and Prevention, University Tor Vergata, Rome, Italy.