Clinical management of patients with von Willebrand's disease with a VHP vWF concentrate: the French experience

Part of the French clinical experience using the solvent/detergent (S/D) tr eated VHP von Willebrand factor (vWF) concentrate (LFB, Les Ulis, France) c haracterized by a high vWF:RCoF specific activity and a low factor Vm (FVII I) content is reported. Since 1989 this concentrate has been routinely used in clinical practice taking into account the vWF:RCoF given by the manufac turer. Seventy-five patients with von Willebrand disease (type 1: 42, 2 A: 11, 2B: 5, 2N: 6, 3: 4, acquired: 7) were treated on 99 occasions either to control spontaneous bleedings (15) or to prevent haemorrhagic risks associ ated with minor (< 5 days of treatment) (48) or major (5 days of treatment) (36) surgery including seven knee or hip-replacements, Forty lots of conce ntrate were used containing 58 +/- 13 U mL(-1) vWF:RCoF with less than 10 u nits of FVIII per 100 units vWF:RCoF. Patients with type 2N were analysed s eparately, With the exception of gastro-intestinal bleedings, spontaneous b leedings were generally stopped after few infusions of 40-47 U kg(-1) vWF:R CoF. Patients having more than 20 U dL(-1) FVIII were treated on 54 surgica l occasions with one pre-operative infusion (51-55 U kg(-1) vWF:RCoF) which allowed an increase in FVIII concentration to a mean lever of 67-88 U dL(- 1). Patients with less than 20 U dL(-1) were either treated with two preope rative infusions of vWF, 12 or 24 h apart (11 cases) or received a FVIII in jection immediately after the preoperative infusion of vWF (10 cases). Duri ng the postoperative period vWF alone (30-35 U kg(-1) vWF:RCoF) allowed FVI II to be kept at a mean level of 118-138 U dL(-1) not exceeding 180 U dL(-1 ) Patients with type 2N were treated taking in account only their baseline FVIII concentration. No haemorrhagic complications occurred in any of the p atients. Thus it was found to be feasible and practical to manage replaceme nt therapy in patients with von Willebrand disease (whatever the type or th e circumstances) on the basis of the vWF:RCoF activity of the concentrate.