decreased circulating protein level abnormal circulating von Willebrand factor level decreased circulating von Willebrand factor level 2020-09-21T10:24:39Z MP:0031164 MPheno.ontology reduced blood level of the large multimeric glycoprotein produced by vascular endothelial cells and megakaryocytes that chaperones blood coagulation cofactor factor VIII and tethers platelets to the injured blood vessel wall decreased plasma VWF level reduced circulating VWF level reduced plasma von Willebrand factor level reduced plasma VWF level decreased plasma von Willebrand factor level reduced circulating vWF level reduced plasma vWF level decreased plasma vWF level