[1] Oslo Univ Hosp, Dept Transplant Med, Oslo, Norway
[2] Univ Oslo, Fac Med, Oslo, Norway
[3] Univ Hosp Bern, Dept Clin Chem, CH-3010 Bern, Switzerland
[4] UiT Arctic Univ Norway, Metab & Renal Res Grp, Tromso, Norway
[5] Calcisco SA, Bern, Switzerland
[6] Univ Oslo, Sch Pharm, Oslo, Norway