Elevated von Willebrand factor levels in multiple myeloma: dysregulated mechanisms of both secretion and clearance

•Plasma VWF antigen and FVIII:C levels are raised in patients with active multiple myeloma (MM), irrespective of therapy •High VWF propeptide and reduced propeptide/antigen ratios suggest endothelial activation and impaired VWF clearance in MM •Increased VWF propeptide is seen in precursor MM, strengthening the hypothesis of hypercoagulability in MGUS/smouldering MM •VWF multimer distribution is not altered in MM disease and accordingly, ADAMTS13 activity is not impaired