1. Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy
2. Ospedale Policlinico San Martino IRCCS, 16132 Genoa, Italy
3. Internal Medicine Department, San Paolo Hospital, 17100 Savona, Italy
4. Department of Clinical and Experimental Medicine, School and Operative Unit of Allergy and Clinical Immunology, University of Messina, 98125 Messina, Italy