[1] Univ Sao Paulo, BR-05403000 Sao Paulo, Brazil
[2] Royal Free Hosp London NHS Fdn Trust, Katharine Dormandy Haemophilia Ctr, London, England
[3] Royal Free Hosp London NHS Fdn Trust, Thrombosis Unit, London, England
[4] Univ Sao Paulo, Hemophilia Ctr, Clin Hosp, Fac Med, BR-05403000 Sao Paulo, Brazil