[1] Univ Maryland, Sch Med, Div Transplantat, Baltimore, MD 21201 USA
[2] Univ Careggi, Unita Operat Nefrol Dialisi & Trapianti, Azienda Osped, Florence, Italy
[3] Charite, Dept Nephrol, D-13353 Berlin, Germany
[4] Hosp Clin Barcelona, Serv Nefrol, E-08036 Barcelona, Spain
[5] Univ Wisconsin, Dept Surg, Sch Med & Publ Hlth, Madison, WI USA
[6] Heidelberg Univ, Dept Med, Div Nephrol, D-6900 Heidelberg, Germany