Von Willebrand factor propeptide in vascular disorders

Von Willebrand factor (VWF) is a multifunctional plasma protein that plays a prominent role in haemostasis. In endothelial cells, processing of its pr ecursor pro-VWF results in the formation of two large polypeptides, mature VWF and a propeptide. These proteins are co-secreted on an equimolar basis but are cleared from the circulation at different rates. VWF levels are fre quently elevated in response to vascular disorders. Similarly, propeptide l evels are increased under these conditions, although primarily in fulminant vascular disease, such as thrombotic thrombocytopenic purpura and septicem ia. In chronic vascular disease, e.g. diabetes or peripheral vascular disea se, propeptide levels are much less elevated. The differential response of VWF and propeptide levels to vascular disease could provide a means to asse ss the extent and time course of endothelial cell activation. After secreti on, the propeptide may play a role in modulating cellular adhesion processe s. Thus, enhanced propeptide secretion seems not to be of merely diagnostic significance.