Time course of VWF:Ag, FVIII:C, and VWF:RCo levels after administration of DDAVP or Humate-P. (A) DDAVP administration to patient A-III-1 and 3 unrelated patients with type 1 VWD. In all patients, VWF:Ag, VWF:RCo, and FVIII levels rose significantly after DDAVP administration. Although VWF levels in the 3 patients with “type 1 VWD” slowly diminished over time, these levels rapidly decreased in patient AIII-1. Similar results were observed in other affected patients. Inset: Multimer analysis before, 1 hour, and 4 hours after DDAVP administration compared with pooled normal human plasma (NP). (B) VWF:Ag, VWF:RCo, and FVIII levels after Humate-P treatment in patient BI-1 slowly decrease over time. The elimination of plasma VWF multimers in affected family members is significantly increased and may be linked to the patients' endogenously synthesized VWF.