Plasma von willebrand factor and a disintegrin and metalloproteinase with eight thrombospondin-type 1 motif levels in hemodialysis patients: Relation to vascular access thrombosis

Vascular access complications are major issues in hemodialysis (HD) patients, which increase their morbidity and lessen HD efficiency. The aim of this study was to assess von Willebrand factor (VWF), and a disintegrin and metalloproteinase with eight thrombospondin-type 1 motif (ADAMTS13) levels in HD patients and their association with vascular access thrombosis (VAT). This study included a total of 158 individuals including 128 patients undergoing HD for more than 6 months, subdivided into two groups according to the occurrence of the previous episode of VAT; 60 HD patients with VAT and 68 HD patients without VAT and 30 healthy controls. Plasma ADAMTS13 and VWF levels were assessed by enzyme-linked immunosorbent assay technique. There were higher VWF levels and lower ADAMTS13 in HD patients, compared to healthy controls. Furthermore, VWF levels were significantly higher and ADAMTS13 levels were significantly lower in HD patients with VAT than those without VAT. Further prospective studies with large number of patients are thus needed to show if there is causal relationship between higher VWF levels, lower ADAMTS13, and VAT.