Von Willebrand Factor at the Crossroads of Hemostasis and Inflammation

Von Willebrand factor (VWF) is a large multimeric glycoprotein critical for hemostasis, mediating platelet adhesion to injured vessels and stabilizing circulating factor VIII. However, accumulating evidence reveals a complex, context-dependent role for VWF in inflammation and innate immunity that extends well beyond coagulation. VWF acts not only as a biomarker of endothelial activation but also as an active participant in immune responses. VWF directly interacts with major immune cell types-including macrophages, polymorphonuclear leukocytes (neutrophils), and dendritic cells-through both its endothelial-anchored and plasma forms. VWF facilitates leukocyte recruitment and transmigration across the vessel wall, while its interactions also promote macrophage and neutrophil activation as well as NET formation. VWF's immunomodulatory functions are further highlighted by its binding to extracellular DNA, smooth muscle cells, complement components (C1q and C3), and bacterial pathogens under flow conditions. Furthermore, VWF indirectly influences inflammation via its crucial role in Weibel-Palade body formation, a process that co-packages vital inflammatory mediators like P-selectin and angiopoietin-2. Markedly elevated VWF levels are consistently observed across acute and chronic inflammatory conditions such as sepsis, COVID-19, and autoimmune disorders, confirming its relevance as both a diagnostic marker and a therapeutic target. A comprehensive understanding of VWF's diverse functions in vascular inflammation is crucial for developing targeted therapeutics-including nanobodies, ADAMTS13 variants, and VWF interaction inhibitors-capable of modulating pathological thrombo-inflammation while preserving physiological hemostasis.