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) treated VHP von Willebrand factor (vWF) concentrate (LFB, Les Ulis, France) characterized by a high vWF:RCoF specific activity and a low factor VIII (FVIII) content is reported. Since 1989 this concentrate has been routinely used in clinical practice taking into account the vWF:RCoF given by the manufacturer. Seventy-five patients with von Willebrand disease (type 1: 42, 2A: 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 associated with minor (< 5 days of treatment) (48) or major (5 days of treatment) (36) surgery including seven knee or hip-replacements. Forty lots of concentrate were used containing 58 +/- 13 U mL-1 vWF:RCoF with less than 10 units of FVIII per 100 units vWF:RCoF. Patients with type 2N were analysed separately. With the exception of gastro-intestinal bleedings, spontaneous bleedings were generally stopped after few infusions of 40-47 U kg-1 vWF:RCoF. Patients having more than 20 U dL-1 FVIII were treated on 54 surgical occasions with one preoperative infusion (51-55 U kg-1 vWF:RCoF) which allowed an increase in FVIII concentration to a mean level of 67-88 U dL-1. Patients with less than 20 U dL-1 were either treated with two preoperative infusions of vWF, 12 or 24 h apart (11 cases) or received a FVIII injection immediately after the preoperative infusion of vWF (10 cases). During the postoperative period vWF alone (30-35 U kg-1 vWF:RCoF) allowed FVIII 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 patients. Thus it was found to be feasible and practical to manage replacement therapy in patients with von Willebrand disease (whatever the type or the circumstances) on the basis of the vWF:RCoF activity of the concentrate.