[1] Univ Cambridge, Dept Haematol, Cambridge, England
[2] Croatian Inst Transfus Med, Zagreb, Croatia
[3] Ctr Hemoterapia Castilla & Leon, Valladolid, Spain
[4] German Red Cross, Inst Transfus Med, Plauen, Germany
[5] Rigshosp, Dept Clin Immunol, DK-2100 Copenhagen, Denmark
[6] Reg Blood Ctr, Oviedo, Spain
[7] Inst Hematol & Transfus Med, Warsaw, Poland
[8] Arhus Univ Hosp, Dept Clin Immunol, Aarhus, Denmark
[9] Univ Giessen, Inst Med Virol, D-35390 Giessen, Germany
[10] Inst Publ Hlth, MRC, Biostat Unit, Cambridge, England
[11] Natl Hlth Serv Blood & Transplant England, Cambridge, England
[12] Sci Affairs Consultant, Paris, France
[13] Paul Ehrlich Inst, Langen, Germany