[1] IRCCS Azienda Osped Univ Bologna, Nephrol Dialysis & Kidney Transplant Unit, Bologna, Italy
[2] Univ Padua, Clin Med 1, Dept Med, Padua, Italy
[3] Natl Res Council CNR, Inst Clin Physiol IFC, Clin Epidemiol & Renal Dis & Hypertens Unit, Reggio Di Calabria, Italy
[4] Baylor Coll Med, Nephrol Sect, Houston, TX 77030 USA
[5] Univ Padua, Dept Med, Lab Med Unit, Padua, Italy
[6] Infermi Hosp, Nephrol & Dialysis Unit, AUSL Romagna, Rimini, Italy
[7] Univ Torino Corso Raffaello, Dept Clin & Biol Sci, Turin, Italy
[8] Columbia Univ, Irving Med Ctr, Div Nephrol, New York, NY USA
[9] Natl Res Council CNR, Inst Clin Physiol IFC, Pisa, Italy