HEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY von Willebrand Factor Propeptide in Vascular Disorders: A Tool to Distinguish Between Acute and Chronic Endothelial Cell Perturbation

Before de novo synthesized von Willebrand factor (vWF) leaves the endothelial cell, it undergoes endoproteolytic cleavage of its propeptide (vW antigen II). The processed vWF and propeptide are either released constitutively or, following activation of the endothelium, released through the regulated pathway. In a recent study (Borchiellini et al, Blood 88:2951, 1996), we showed that the half-life of mature vWF and of its propeptide differ fourfold to fivefold. We postulated that the molar ratio of the propeptide to mature vWF could serve as a tool to assess the extent of endothelial cell activation under physiologic and clinical conditions. To test this hypothesis, we measured mature vWF and propep-tide in patients with documented acute and chronic vascular disease, including patients with thrombotic thrombocytope-nic purpura (TTP), acute septicemia, and diabetes mellitus