aDepartment of Nephrology, S. Massimo Hospital, Penne,
bDepartment of General Medicine, Dialysis Unit, S. Immacolata Hospital, Guardiagrele,
cDepartment of Clinical Pathology, S. Massimo Hospital, Penne,
dDepartment of Nephrology, General Hospital, Vasto,
eDepartment of Physiology, Faculty of Medicine, University of Padova, Italy;
fNephrology Division, Lyon South,
gUniversity Medical Center, Lyon, France