[1] Univ Catholique Louvain, Haemostasis & Thrombosis Unit, Clin Univ St Luc, Dept Haematol, B-1200 Brussels, Belgium
[2] Royal Free Hosp, Haemophilia Ctr, London NW3 2QG, England
[3] Royal Free Hosp, Haemostasis Unit, London NW3 2QG, England
[4] Royal Free Hosp, Dept Histopathol, London NW3 2QG, England
[5] Royal Free Hosp, Dept Thorac Med, London NW3 2QG, England