[1] AMGEN Ltd, Ctr Observat Res, Uxbridge, Middx, England
[2] Dorset Cty Hosp, Dorchester, England
[3] Nottingham Univ Hosp, Nottingham, England
[4] Fdn IRCCS Casa Sollievo Sofferenza, Nephrol & Dialysis Unit, San Giovanni Rotondo, Italy
[5] Hosp Univ Girona, Serv Nefrol, Girona, Spain
[6] Necker Enfant Malad Hosp, Serv Nephrol Dialyse, Paris, France
[7] Catholic Univ Louvain, Clin Univ St Luc, Dept Nephrol, Brussels, Belgium
[8] Vrinnevisjukhuset, Med Kliniken, Norrkoping, Sweden
[9] Univ Hosp Leuven, Div Nephrol, Leuven, Belgium
[10] Fdn Privada Hosp Mollet, Barcelona, Spain
[11] Arbor Res Collaborat Hlth, Ann Arbor, MI USA
[12] Amgen GmbH, Rotkreuz, Switzerland
[13] UCL, Sch Pharm, London, England