[1] IRCCS, Policlin San Matteo, Unit Nephrol Dialysis & Transplantat, I-27100 Pavia, Italy
[2] Univ Pavia, I-27100 Pavia, Italy
[3] Regina Margherita Childrens Univ Hosp, Dept Nephrol Dialysis & Tranplantat, Turin, Italy
[4] G Gaslini Childrens Hosp, Dept Nephrol, Genoa, Italy
[5] Childrens Hosp & Res Inst Bambin Gesu, Div Nephrol, Rome, Italy
[6] Univ Bari, Dept Emergency, I-70121 Bari, Italy
[7] Univ Bari, Div Nephrol Dialysis & Transplantat, I-70121 Bari, Italy
[8] IRCCS, Policlin San Matteo, Unit Biometry & Clin Epidemiol, Pavia, Italy