1. Paediatrics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy
2. Department of Medical and Surgical Sciences (DIMEC), University of Bologna, 40138 Bologna, Italy
3. Clinica Pediatrica, Azienda Ospedaliero-Universitaria, Medicine and Surgery Department, Università di Parma, 43126 Parma, Italy