[1] St Olavs Univ Hosp, Dept Hematol, NTNU, Trondheim, Norway
[2] Natl Hosp, Dept Hematol, Copenhagen, Denmark
[3] Univ Lund Hosp, Dept Hematol, Lund, Sweden
[4] Malmo Univ Hosp, Dept Hematol, Malmo, Sweden
[5] Univ Aberdeen, Aberdeen AB9 1FX, Scotland