Screening for the FV: Q⁵⁰⁶ Mutation – Evaluation of Thirteen Plasma-based Methods for their Diagnostic Efficacy in Comparison with DNA Analysis

Summary

The factor V (FV) mutation Q⁵⁰⁶ that causes resistance to activated protein C (APC) is the genetic defect associated most frequently with venous thrombosis. The laboratory diagnosis can be made by DNA analysis or by clotting tests that measure the degree of prolongation of plasma clotting time upon addition of APC. Home-made and commercial methods are available but no comparative evaluation of their diagnostic efficacy has so far been reported. Eighty frozen coded plasma samples from carriers and non-carriers of the FV: Q⁵⁰⁶ mutation, diagnosed by DNA analysis, were sent to 8 experienced laboratories that were asked to analyze these samples in blind with their own APC resistance tests. The APTT methods were highly variable in their capacity to discriminate between carriers and non-carriers but this capacity increased dramatically when samples were diluted with FV-deficient plasma before analysis, bringing the sensitivity and specificity of these tests to 100%. The best discrimination was obtained with methods in which fibrin formation is triggered by the addition of activated factor X or Russell viper venom. In conclusion, this study provides evidence that some coagulation tests are able to distinguish carriers of the FV: Q⁵⁰⁶ mutation from non-carriers as well as the DNA test. They are inexpensive and easy to perform. Their use in large-scale clinical trials should be of help to determine the medical and economic benefits of screening healthy individuals for the mutation before they are exposed to such risk factors for venous thrombosis as surgery, pregnancy and oral contraceptives.

• References

• 1 Dahlbäck B, Carlsson M, Svensson PJ. Familial thrombophilia due to a previously unrecognized mechanism characterized by a poor anticoagulant response to activated protein C:prediction of a cofactor to activated protein C. Proc Natl Acad Sci USA 1993; 90: 1004-1008
• 2 Koster T, Rosendaal FR, de RondeH, Briët E, Vandenbroucke JP, Bertina RM. Venous thrombosis due to poor response to activated protein C:Leiden thrombophilia study. Lancet 1993; 342: 1503-1506
• 3 Griffin JH, Evatt BL, Wideman C, Fernandez JA. Anticoagulant protein C pathway defective in a majority of thrombophilic patients. Blood 1993; 82: 1989-1993
• 4 Faioni EM, Franchi F, Asti D, Sacchi E, Bemardi F, Mannucci PM. Resistance to activated protein C in nine thrombophilic families:interference in a protein S functional assay. Thromb Haemost 1993; 70: 1067-1071
• 5 Rees DC, Cox M, Clegg JB. World distribution of factor V Leiden. Lancet 1995; 346: 1133-1134
• 6 Bertina RM, Koeleman BPC, Koster T, Rosendaal FR, Dirven RJ, de RondeH, van de, Velden PA, Reitsma PH. Mutation in blood coagulation factor V associated to activated protein C. Nature 1994; 369: 0064-0067
• 7 Zöller B, Svensson PJ, He X, Dahlbäck B. Identification of the same factor V gene mutation in out of thrombosis-prone families with inherited resistance to activated protein C. J Clin Invest 1994; 94: 2521-2524
• 8 Heeb MJ, Kojima Y, Greengard JS, Griffin JH. Activated protein C resistance:molecular mechanisms based on studies using purified GlnFactorV. Blood 1995; 85: 3405-3411
• 9 Rosendaal FR, Koster T, Vandenbroucke JP, Reitsma PH. High risk of thrombosis in patients homozygous for factor V Leiden (activated protein C resistance). Blood 1995; 85: 1504-1508
• 10 Vandenbroucke JP, Koster T, Briet E, Reitsma PH, Bertina RM, Rosendaal FR. Increased risk of venous thrombosis in oral contraceptive users who are carriers of factor V Leiden mutation. Lancet 1994; 344: 1453-1457
• 11 de RondeH, Bertina RM. Laboratory diagnosis of APC-resistance:a critical evaluation of the test and the development of diagnostic criteria. Thromb Haemost 1994; 72: 0880-0886
• 12 Cadroy YSiéP, Boneu B. Frequency of a defective response to activated protein C in patients with history of venous thrombosis. Blood 1994; 83: 2008-2009
• 13 Tosetto A, Rodeghiero F. Diagnosis of APC resistance in patients on oral anticoagulant therapy. Thromb Haemost 1995; 73: 0732-0733
• 14 Cadroy Y, Sie’ P, Alhenc-Gelas M, Aiach M. Evaluation of APC-resistance in the plasma of patients with Q506 mutation of factor V (Factor V Leiden) and treated with oral anticoagulants. Thromb Haemost 1995; 73: 0734-0735
• 15 Rosen S, Johansson K, Lindberg K, Dahlbäck B. Multicenter evaluation of a kit for activated protein C resistance on various coagulation instruments using plasma from healthy individuals. Thromb Haemost 1994; 72: 0255-0260
• 16 Kraus M, Wagner C. Evaluation of APC-sensitivity in normal blood donors using different reagents and instruments. Thromb Res 1994; 76: 0231-0236
• 17 Kraus M, Zander M, Fickenscher K. Coagulation assay with improved specificity to factor V mutants insensitive to activated protein C. Thromb Res 1995; 80: 0255-0264
• 18 Varadi K, Moritz B, Lang H, Bauer KA, Preston EK, Peake I, Rivard GE, Keil B, Schwarz HP. A chromogenic assay for activated protein C resistance. Br J Haematol 1995; 90: 0884-0891
• 19 Exner T, Murray B, Chong BH, Chesterman CN. Improved APC-resistance method based on a Russell’s Viper Venom clotting test. Thromb Haemost 1995; 73: 1119
• 20 Alhenc-Gelas M, Aillaud MF, Bonvarlet MN, Dupuy G, Juhan-Vague I, Aiach M. Specificity of an assay based on a Factor V-depleted plasma in patients carrying the Arg 506 Gin mutation. Thromb Haemost 1996; 75: 0976-0977
• 21 Dahlbäck B. New molecular insights into genetics of thrombophilia. Resistance to activated protein C caused by Arg506 to G1n mutation in factor V as a pathogenetic risk factor for venous thrombosis. Thromb Haemost 1995; 74: 0139-0148
• 22 Dahlbäck B. Are we ready for factor V Leiden screening?. Lancet 1996; 347: 1346-1347