Alterations of the Tissue-Factor Induced Pathway of Coagulation during Acute Deep Vein Thrombosis (DVT): Significant Increase in Tissue-Factor Pathway Inhibitor (TFPI)

Abstract number: P1345

SidelmannMünsterMünster^1,223 JJAMBH, Bertelsen³ V, Mourits-Andersen⁴ T, Bladbjerg^1,2 EM

^{1,2 1,2232}Department of Clinical Biochemistry, Ribe County Hospital, Esbjerg, Denmark³Department of Radiology, Ribe County Hospital, Esbjerg, Denmark ³³Department of Radiology, Ribe County Hospital, Esbjerg, Denmark ⁴⁴Department of Haematology, Ribe County Hospital, Esbjerg, Denmark

Background:  Case-control studies have established reduced plasma concentration of TFPI as a DVT-risk factor, suggesting TFPI to be part of the pathogenesis of venous thromboembolism. However, the regulation of the tissue-factor induced pathway of coagulation during the acute phase of DVT has not been addressed so far.

Materials and methods:  We determined factor VII clotting activity (FVIIc), factor VII antigen (FVII:Ag), total TFPI and the TFPI -287T/C polymorphism in 21° Consecutive patients, not receiving hormone or anticoagulant therapy, upon admission to hospital with a tentative diagnosis of DVT.

Results:  DVT was identified (phlebography and ultrasound) in 74 patients. The TFPI -287T/C genotypes were equally frequent in patients with and without DVT. The concentration of TFPI was significantly and consistently higher in the patients with DVT (median 89.5 ng/ml) than in the patients without DVT (median 69.0 ng/ml), P < 0.001, irrespective of the -287T/C genotypes. The concentration of FVIIc and FVII:Ag showed no significant differences between the two groups of patients.

Discussion:  The PRIME-study and the LETS-study show that reduced concentration of TFPI is a risk factor for development of myocardial infarction and DVT. These studies, however, were conducted in the non-acute phase of thrombotic disease. In contrast, it has been demonstrated that patients suffering from acute myocardial infarction express significantly increased concentrations of TFPI. Presently, we find a resembling increase in the concentration of TFPI among patients suffering from acute DVT. These findings suggest that TFPI-increase is a feature of acute thrombosis.

Conclusion:  The concentration of TFPI is significantly increased in patients suffering from acute DVT regardless of the genotype of the TFPI -287T/C polymorphism.