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

Summary

Tissue 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).

• References

• 1 Bajaj MS, Kuppuswamy MN, Saito H, Spitzer SG. Cultured normal hepatocytes do not synthesize lipoprotein-associated coagulation inhibitor: Evidence that endothelium is the principle site of its synthesis. Proc Natl Acad Sci USA 1990; 88: 8869-73.
• 2 Sandset PM, Abildgaard U. Extrinsic pathway inhibitor: The key to feedback control of blood coagulation initiated by tissue thromboplastin. Haemostasis 1991; 21: 219
• 3 Girard TJ, Warren LA, Novotny WF, Likert KM, Brown SG, Miletich JP, Broze GJ. Functional significance of the Kunitz-type inhibitor domains of lipoprotein-associated coagulation inhibitor. Nature 1989; 338: 518-20.
• 4 Broze Jr GJ, Warren LA, Novotny WF, Higuchi DA, Girard JJ, Miletich JP. The lipoprotein-associated coagulation inhibitor that inhibits the factor VII-tissue factor complex also inhibits factor Xa: Insight into its possible mechanism of action. Blood 1984; 71: 335
• 5 Rapaport I S, Rao LVM. The tissue factor pathway: How it has become a “Prima Ballerina”. Thromb Haemost 1995; 74: 7-17.
• 6 Broze Jr GJ. Tissue factor pathway inhibitor. Haemostaseologie 1997; 17: 73-7.
• 7 Dahlbäck B. Inherited thrombophilia: Resistance to activated protein C as a pathogenic factor of venous thromboembolism. Blood 1995; 85: 607-14.
• 8 Bertina RM, Koeleman BPC, Koster T, Rosendaal FR, Dirven RJ, de Ronde H, van der Velden PA, Reitsma PH. Mutation in Blood coagulation factor V associated with resistance to activated protein C. Nature 1994; 369: 64-7.
• 9 Saiki RK, Gelfand DH, Stoffel S, Scharf SJ, Higuchi R, Horn GT, Mullis KB, Erlich HA. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. Science 1988; 239: 487-91.
• 10 van der Logt CPE, Reitsma PH, Bertina RM. Intron-exon organization of the human gene coding for the lipoprotein-associated coagulation inhibitor: The factor Xa dependent inhibitor of the extrinsic pathway of coagulation. Biochemistry 1991; 30: 1571-7.
• 11 Bassam BJ, Caetano-Anollés G, Gresshoff PM. Fast and sensitive silver staining of DNA in polyacrylamid gels. Analyt Biochem 1991; 196: 80-3.
• 12 Beauchamp NJ, Daly ME, Hampton KK, Cooper PC, Preston FE, Peake IR. High prevalence of a mutation in the factor V gene within the U.K. population: Relationship to activated protein C resistance and familial thrombosis. Brit J Haematol 1994; 88: 219-22.
• 13 Poort RS, Rosendaal FR, Reitsma PH, Bertina RM. A common genetic variation in the 3’-untranslated region of the prothrombin gene is associated with elevated plasma prothrombin levels and an increase in venous thrombosis. Blood 1996; 88: 3698-703.
• 14 Girard TJ, Eddy R, Wesselschmidt RL, MacPhail LA, Likert KM, Byers MG, Shows TB, Broze Jr GJ. Structure of the human lipoprotein-associated coagulation inhibitor gene. J Biol Chem 1991; 266: 5036-41.
• 15 Wesselschmidt R, Likert K, Girard T, Wun T-C, Broze Jr GJ. Tissue factor pathway inhibitor: The carboxy-terminus is required for optimal inhibition of factor Xa. Blood 1992; 79: 2004-10.
• 16 Enjyoji K-I, Myata T, Kamikubo Y-I, Kato H. Effect of heparin on the inhibition of factor Xa by tissue factor pathway inhibitor: A segment, Gly²¹²-Phe²⁴³, of the third Kunitz domain is a heparin-binding site. Biochemistry 1995; 34: 5725-35.
• 17 Broze Jr GJ, Lange GW, Duffin KL, MacPhail L. Heterogeneity of plasma tissue factor pathway inhibitor. Blood Coag Fibrinol 1994; 5: 551-9.
• 18 Nakahara Y, Miyata T, Hamuro T, Funatsu A, Miyagi M, Tsunasawa S, Kato H. Amino acid sequence and carbohydrate structure of a recombinant human tissue factor pathway inhibitor expressed in chinese hamster ovary cells: One N- and two O-linked carbohydrate chains are located between Kunitz domains 2 and 3 and one N-linked carbohydrate chain is in Kunitz domain 2. Biochemistry 1996; 35: 6450-9.
• 19 Sandset PM, Bendz B. Tissue factor pathway inhibitor: Clinical deficiency states. Thromb Haemost 1997; 78: 467-70.