The 536C→T Transition in the Human Tissue Factor Pathway Inhibitor (TFPI) Gene Is Statistically Associated with a Higher Risk for Venous Thrombosis

1999 ◽  
Vol 82 (07) ◽  
pp. 1-5 ◽  
Author(s):  
Michael Schmidt ◽  
Christian Götting ◽  
Britt Schwenz ◽  
Stefan Lange ◽  
Gert Müller-Berghaus ◽  
...  

SummaryTissue factor pathway inhibitor (TFPI) is an important regulator in the extrinsic blood coagulation pathway. Although the regulatory biochemical role of TFPI is evident, the clinical significance of this proteinase inhibitor remains to be elucidated. The definition of a clinical TFPI deficiency seems to be more complex than that of other coagulation inhibitors because the activity and concentration of circulating TFPI can not be considered a true measure of in vivo levels. Its determination in plasma samples by immunological methods or functional assays has been shown to be inadequate in the detection of a clinical deficiency.Therefore, we screened genomic DNA samples of blood donors and thrombotic patients for alterations in the TFPI gene to assess the influence of a modified TFPI in venous thromboembolic diseases. We detected a single nucleotide substitution in exon 7 (536C→T) leading to a proline to leucine exchange at amino acid position 151 of the protein ([P151L]TFPI) and found the prevalence of heterozygous carriers in German unrelated blood donors to be 0.2% (n = 5120).Four unrelated persons out of 14 probands carrying the genetic variation could be linked to venous thrombosis. For calculation of a potential risk for venous thrombosis for carriers of the mutation we investigated healthy blood donors about thrombotic events. 7 out of 308 blood donors were found to have a history of venous thrombosis, one of them carried the TFPI mutation. Statistical calculation showed a significant relative risk for venous thrombosis for individuals with the trait (odds ratio, 9.3; confidence interval, 1.8-48.6; p <0.01).

1997 ◽  
Vol 78 (02) ◽  
pp. 864-870 ◽  
Author(s):  
Hideki Nagase ◽  
Kei-ichi Enjyoji ◽  
Yu-ichi Kamikubo ◽  
Keiko T Kitazato ◽  
Kenji Kitazato ◽  
...  

SummaryDepolymerized holothurian glycosaminoglycan (DHG) is a glycosaminoglycan extracted from the sea cucumber Stichopus japonicusSelenka. In previous studies, we demonstrated that DHG has antithrombotic and anticoagulant activities that are distinguishable from those of heparin and dermatan sulfate. In the present study, we examined the effect of DHG on the tissue factor pathway inhibitor (TFPI), which inhibits the initial reaction of the tissue factor (TF)-mediated coagulation pathway. We first examined the effect of DHG on factor Xa inhibition by TFPI and the inhibition of TF-factor Vila by TFPI-factor Xa in in vitro experiments using human purified proteins. DHG increased the rate of factor Xa inhibition by TFPI, which was abolished either with a synthetic C-terminal peptide or with a synthetic K3 domain peptide of TFPI. In contrast, DHG reduced the rate of TF-factor Vila inhibition by TFPI-factor Xa. Therefore, the effect of DHG on in vitroactivity of TFPI appears to be contradictory. We then examined the effect of DHG on TFPI in cynomolgus monkeys and compared it with that of unfractionated heparin. DHG induced an increase in the circulating level of free-form TFPI in plasma about 20-fold when administered i.v. at 1 mg/kg. The prothrombin time (PT) in monkey plasma after DHG administration was longer than that estimated from the plasma concentrations of DHG. Therefore, free-form TFPI released by DHG seems to play an additive role in the anticoagulant mechanisms of DHG through the extrinsic pathway in vivo. From the results shown in the present work and in previous studies, we conclude that DHG shows anticoagulant activity at various stages of coagulation reactions, i.e., by inhibiting the initial reaction of the extrinsic pathway, by inhibiting the intrinsic Xase, and by inhibiting thrombin.


2021 ◽  
Vol 5 (2) ◽  
pp. 391-398
Author(s):  
Dino Mehic ◽  
Alexander Tolios ◽  
Stefanie Hofer ◽  
Cihan Ay ◽  
Helmuth Haslacher ◽  
...  

Abstract High levels of tissue factor pathway inhibitor (TFPI), caused by a longer TFPIα half-life after binding to a factor V splice variant and variants in the F5 gene, were recently identified in 2 families with an as-yet-unexplained bleeding tendency. This study aimed to investigate free TFPIα in a well-characterized cohort of 620 patients with mild to moderate bleeding tendencies and its association to genetic alterations in the F5 gene. TFPIα levels were higher in patients with bleeding compared with healthy controls (median [interquartile range], 8.2 [5.5-11.7] vs 7.8 [4.3-11.1]; P = .026). A higher proportion of patients had free TFPIα levels more than or equal to the 95th percentile compared with healthy controls (odds ratio [OR] [95% confidence interval (CI)], 2.82 [0.98-8.13]). This was pronounced in the subgroup of patients in whom no bleeding disorder could be identified (bleeding of unknown cause [BUC; n = 420]; OR [95% CI], 3.03 [1.02-8.98]) and in platelet function defects (PFDs) (n = 121; OR [95% CI], 3.47 [1.09-11.08]). An increase in free TFPIα was associated with a mild delay in thrombin generation (prolonged lag time and time to peak), but not with alterations in routinely used global clotting tests. We could neither identify new or known genetic variations in the F5 gene that are associated with free TFPIα levels, nor an influence of the single-nucleotide variant rs10800453 on free TFPIα levels in our patient cohort. An imbalance of natural coagulation inhibitors such as TFPIα could be an underlying cause or contributor for unexplained bleeding, which is most probably multifactorial in a majority of patients.


2005 ◽  
Vol 280 (23) ◽  
pp. 22308-22317 ◽  
Author(s):  
Cristina Lupu ◽  
Xiaohong Hu ◽  
Florea Lupu

Tissue factor pathway inhibitor (TFPI) blocks tissue factor-factor VIIa (TF-FVIIa) activation of factors X and IX through the formation of the TF-FVIIa-FXa-TFPI complex. Most TFPI in vivo associates with caveolae in endothelial cells (EC). The mechanism of this association and the anticoagulant role of caveolar TFPI are not yet known. Here we show that expression of caveolin-1 (Cav-1) in 293 cells keeps TFPI exposed on the plasmalemma surface, decreases the membrane lateral mobility of TFPI, and increases the TFPI-dependent inhibition of TF-FVIIa. Caveolae-associated TFPI supports the co-localization of the quaternary complex with caveolae. To investigate the significance of these observations for EC we used RNA interference to deplete the cells of Cav-1. Functional assays and fluorescence microscopy revealed that the inhibitory properties of TFPI were diminished in EC lacking Cav-1, apparently through deficient assembly of the quaternary complex. These findings demonstrate that caveolae regulate the inhibition by cell-bound TFPI of the active protease production by the extrinsic pathway of coagulation.


Blood ◽  
2000 ◽  
Vol 95 (6) ◽  
pp. 1973-1978 ◽  
Author(s):  
Guyu Ho ◽  
Masaaki Narita ◽  
George J. Broze ◽  
Alan L. Schwartz

Abstract Tissue factor pathway inhibitor (TFPI) plays a key role in the regulation of tissue factor-initiated blood coagulation secondary to loss of the integrity of the blood vessel wall. TFPI is a naturally occurring Kunitz-type protease inhibitor that inhibits coagulation factor Xa and, in a factor Xa-dependent manner, mediates feedback inhibition of the factor VIIa/tissuefactor catalytic complex. In vivo full-length TFPI is thought to be primarily bound to the vascular endothelium and the high affinity binding requires an intact carboxy terminus. Here we describe a full-length TFPI molecule, expressed in mouse C127 cells (TFPIC127), which exhibits virtually no cellular binding yet contains the intact carboxy terminus. This TFPI (TFPIC127) is neither internalized nor degraded via the TFPI endocytic receptor, LDL-receptor–related protein. Pharmacokinetic studies of TFPIC127 in vivo demonstrate a 10-fold prolongation in the plasma half-life, compared with that of bacterial recombinant TFPI.


2001 ◽  
Vol 113 (2) ◽  
pp. 537-543 ◽  
Author(s):  
Ali Amini-Nekoo ◽  
T. Simon Futers ◽  
Marco Moia ◽  
Pier M. Mannucci ◽  
Peter J. Grant ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document