[1] Maggiore Hosp, Angelo Bianchi Bonomi Hemophilia & Thrombosis Ctr, Milan, Italy
[2] Maggiore Hosp, IRCCS, Dept Internal Med, Fdn Luigi Villa, Milan, Italy
[3] Univ Milan, Milan, Italy
[4] Royal Free Hosp, Hemophilia Ctr, London NW3 2QG, England
[5] Royal Free Hosp, Dept Hematol, Hemostasis Unit, London NW3 2QG, England
[6] UCL, Sch Med, London W1N 8AA, England