1. Nephrology and Dialysis Unit, Department of Pediatrics, Azienda Ospedaliero Universitaria Sant’Orsola-Malpighi, Bologna, Italy
2. Department of Pediatrics, University of Parma, Parma, Italy
3. Department of Sciences for Health Promotion and Mother and Child Care, University of Palermo, Palermo, Italy
4. Pediatric Unit, Ospedale Mazzoni, Ascoli Piceno, Italy
5. Pediatric Unit, Ospedale S. Bortolo, Vicenza, Italy
6. Pediatric Unit, Ospedale Morgagni-Pierantoni, Forlì, Italy
7. Pediatric Unit, Ospedale degli Infermi, Rimini, Italy
8. Pediatric Unit, Ospedale di Faenza, Ravenna, Italy
9. Pediatric Nephrology and Dialysis Unit, Department of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy