Determination of vWF, ADAMTS-13 and Thrombospondin-1 in Venous Thromboembolism and Relating Them to the Presence of Factor V Leiden Mutation.

Thrombophilia in venous thromboembolism (VTE) is multifactorial. Von Willebrand factor (vWF) plays a major role in primary hemostasis. While elevated vWF levels are well documented in VTE, findings related to its cleaving protease (ADAMTS-13) are contradicting. The aim of this study was to determine vWF, ADAMTS-13, and the multifactorial Thrombospondin-1 (TSP-1) protein levels in patients after 3-6 months following an unprovoked VTE episode. We also explored a possible association with factor V Leiden (FVL) mutation. vWF, ADAMTS-13 and TSP-1 were analyzed using ELISA kits in 60 VTE patients and 60 controls. Patients had higher levels of vWF antigen ( = .021), vWF collagen-binding activity ( = .008), and TSP-1 protein ( < .001) compared to controls. ADAMTS-13 antigen was lower in patients ( = .046) compared to controls but ADAMTS-13 activity was comparable between the two groups ( = .172). TSP-1 showed positive correlation with vWF antigen (rho = 0.303,  = .021) and negative correlation with ADAMTS-13 activity (rho = -0.244,  = .033) and ADAMTS-13 activity/vWF antigen ratio (rho = -0.348,  = .007). A significant association was found between the presence of FVL mutation and VTE (odds ratio (OR): 9.672 (95% confidence interval (CI) 2.074-45.091-  = .004), but no association was found between the mutation and the studied proteins ( > .05). There appears to be an imbalance between vWF and ADAMTS-13 in VTE patients even after 3-6 months following the onset of VTE. We report that the odds of developing VTE in carriers of FVL mutation are 9.672 times those without the mutation, but the presence of this mutation is not associated with the studied proteins.