[1] Hosp Sick Children, Div Haematol Oncol, Toronto, ON M5G 1X8, Canada
[2] Pediat Oncol Grp Ontario, Toronto, ON, Canada
[3] London Hlth Sci Ctr, Div Haematol Oncol, Childrens Hosp, London, ON, Canada
[4] Hosp Sick Children, Peter Gilgan Ctr Res & Learning, Program Child Hlth Evaluat Sci, Toronto, ON M5G 1X8, Canada
[5] Dana Farber Canc Inst, Dept Hematol Oncol, Boston, MA 02115 USA
[6] Univ Calif San Francisco, Med Ctr, Div Pediat Allergy Immunol & Bone Marrow Transpla, San Francisco, CA USA
[7] Childrens Hosp Philadelphia, Div Infect Dis, Philadelphia, PA 19104 USA
[8] Aarhus Univ Hosp, Dept Paediat, DK-8000 Aarhus, Denmark
[9] Univ Helsinki, Cent Hosp, Hosp Children & Adolescents, Helsinki, Finland
[10] Univ Med Ctr Schleswig Holstein, Dept Paediat, Kiel, Germany
[11] Univ York, Ctr Reviews & Disseminat, York YO10 5DD, N Yorkshire, England
[12] Univ Utah, Div Pediat Hematol Oncol, Salt Lake City, UT USA
[13] Great Ormond St Hosp Sick Children, Dept Paediat Haematol, London WC1N 3JH, England
[14] Rigshosp, Univ Hosp, Dept Pediat & Adolescent Med, DK-2100 Copenhagen, Denmark
[15] Univ Copenhagen, Inst Clin Med, Copenhagen, Denmark
[16] Univ Groningen, Univ Med Ctr Groningen, Dept Paediat Oncol, NL-9713 AV Groningen, Netherlands
[17] Goethe Univ Frankfurt, Dept Paediat Haematol & Oncol, D-60054 Frankfurt, Germany