[1] Univ Iceland, Fac Med, Reykjavik, Iceland
[2] Landspitali Univ Hosp, Reykjavik, Iceland
[3] Mem Sloan Kettering Canc Ctr, Dept Med, Myeloma Serv, 1275 York Ave, New York, NY 10021 USA
[4] Karolinska Univ Hosp, Dept Med, Div Hematol, Stockholm, Sweden
[5] Karolinska Inst, Stockholm, Sweden