[1] NCI, NIH, Bethesda, MD 20892 USA
[2] Univ Coll London Hosp, Dept Haematol, London, England
[3] Univ Calgary, Dept Med Oncol Microbiol & Infect Dis, Calgary, AB, Canada
[4] Univ Paris Diderot, Lab Immunol & Histocompatibilite, Hop St Louis, Paris, France