1. Department of Internal Medicine, Azienda Ospedaliera S. Gerardo, Presidio Ospedaliero ‘Bassini’, Cinisello Balsamo, Milan, Italy,
2. Pathology Service, Ospedale Maggiore della Carità, Novara, Italy
3. Allergy and Clinical Immunology Unit, Department of Internal Medicine, University of Milan, Milan, Italy