Plasma levels of von Willebrand factor in maintenance hemodialysis patients: its relation to vascular access thrombosis

Abstract

Objective The aim of this study was to assess von Willebrand factor (VWF) plasma levels in patients under maintenance hemodialysis (HD) to determine its role in the occurrence of vascular access thrombosis (VAT) in such patients. Background HD process is associated with increasing thrombotic trend especially owing to platelets and clotting factor activation. Vascular access complications increase morbidity and contribute to 20–25% of all hospitalizations in HD patients, of which ~ 85% of these cases are because of thrombosis. VWF is an important component of the hemostatic system and a hypercoagulability state biomarker. Patients and methods This case–control study was conducted on 60 patients on HD for more than 6 months classified into two groups: group I (GI) included 30 patients with VAT, whereas group II (GII) included 30 patients without VAT. Moreover, 20 healthy individuals served as a control group. History taking, clinical examination, and investigations (complete blood count, kidney function tests, liver function tests, lipid profile, fasting blood sugar, postprandial blood sugar, and serum VWF) for all cases were done. Results Mean VWF serum level was found to be higher in HD groups (GI 1361.47 ± 270.38 and GII 950 ± 138.12) than control group (351.5 ± 34.8), with highly statistical significance. A cutoff level of VWF at 1277 ng/ml is accurate (46.67%) for ocurrance of VAT in GI patients, with sensitivity of 93.33%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 93.8%. Conclusion High VWF levels related to development of VAT.