From: Elizabeth M. Van Cott, M.D., and Michael Laposata, M.D., Ph.D., “Coagulation.” In: Jacobs DS et al, ed. The Laboratory Test Handbook, 5th Edition. Lexi-Comp, Cleveland, 2001; 327-358.
Related Information
Activated Protein C Resistance and the Factor V Leiden Mutation
Antiphospholipid Antibody (Lupus Anticoagulant and/or Anticardiolipin Antibody)
Antiplasmin
Antithrombin
Heparin Neutralization
Plasminogen
Plasminogen Activator Inhibitor 1
Platelet Hyperaggregation
Protein C
Protein S
Prothrombin G20210A Mutation
Reptilase® Time
Thrombin Time
Synonyms Screen for Hypercoagulation; Thrombophilia Panel; Thrombotic Disease Screen
Applies to Aalpha Fragment; Activated Protein C Resistance; Antithrombin Deficiency; Bbeta 1-42 Fragment; Beta-Thromboglobulin; D-Dimers; Dysfibrinogenemia; FDP; Fibrin Monomer; Fibrinopeptide A; Fibrinopeptide B; Heparin Cofactor II; Hyperhomocyst(e)inemia; PAI-1; PAP; PF4; Plasmin-Antiplasmin Complexes; Platelet Factor 4; Protein C Deficiency; Protein S Deficiency; Prothrombin Fragment 1.2; Thrombin-Antithrombin Complexes; Tissue Plasminogen Activator; tPA
Abstract Testing is often performed in panels, because the presence of more than one predisposition to thrombosis further increases the risk for thrombosis.1,2
Specimen Plasma (and serum if including anticardiolipin antibody and whole blood if including DNA tests)
Container Three blue top (sodium citrate) tubes (and one red top tube if including anticardiolipin antibody)
Collection Routine venipuncture. If a red top tube is being drawn, draw blue top tubes after red top tube. Immediately invert tubes gently at least 4 times to mix. Blue top tubes must be appropriately filled. Deliver tubes immediately to the laboratory.
Storage Instructions Separate plasma from cells as soon as possible. Plasma may be stored on ice for up to 4 hours; otherwise, store frozen.
Causes for Rejection Specimen received more than 4 hours after collection, blue top tubes not filled, blue top tubes clotted
Turnaround Time Several days
Special Instructions Notify laboratory if patient is on any anticoagulant (eg, heparin, warfarin, danaparoid, hirudin, or argatroban). Heparin should be removed from the specimen by the laboratory, and not all tests can be performed when other anticoagulants are present.
Reference Interval See individual tests.
Use Evaluate hypercoagulable states (eg, a young person with spontaneous or recurrent deep venous thrombosis, or a family with multiple members affected by deep venous thrombosis)
Methodology See individual tests.
Additional Information Venous thromboembolism affects 0.1% of the general population in the United States annually, resulting in over 50,000 deaths every year. Hereditary and acquired predisposing conditions are listed in the following tables.
Venous Thrombosis: Hereditary Predisposing Conditions
| Disorder | Prevalence in General Population (%) | Prevalence in Venous Thrombosis (%) |
| Antithrombin deficiency | 0.17 | 1-5 |
| Protein C deficiency | 0.14-0.50 | 3-9 |
| Protein S deficiency | 0.7 | 2-8 |
| Prothrombin G20210A mutation | 2 | 6 |
| Hyperhomocyst(e)inemia (hereditary or acquired) | 5-10 | 10-25 |
| Activated protein C resistance | 5 (Caucasians) | 20-50 |
| Van Cott EM and Laposata M, “Laboratory Evaluation of Hypercoagulable States,”Hematol Oncol Clin North Am, 1998, 12(6):1141-66. | ||
Venous Thrombosis: Acquired Predisposing Conditions
| Advanced age |
| Collagen/vascular disorders |
| Heparin-induced thrombocytopenia |
| Hyperhomocyst(e)inemia |
| Estrogen (oral contraceptives, pregnancy, and estrogen replacement therapy) |
| Hyperviscosity |
| Immobilization |
| Trauma |
| Inflammatory bowel disease |
| Antiphospholipid antibodies |
| Neoplastic disease and chronic disseminated intravascular coagulation (DIC) |
| Nephrotic syndrome |
| Myeloproliferative disorders |
| Paroxysmal nocturnal hemoglobinuria |
| Postoperative status |
| Previous episode of thromboembolism |
| Indwelling catheter |
| Obesity |
A test panel to evaluate a patient with familial venous thrombosis typically includes assays for activated protein C resistance, protein C, protein S, and antithrombin (see table). Activated protein C resistance, discovered in 1993, is the most common known hereditary predisposition to thrombosis. Discovered in 1996, the prothrombin G20210A mutation assay is becoming increasingly included in the test panel as this mutation is one of the most common hereditary predispositions to thrombosis. Assays for antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies) are also recommended, although they are not familial conditions. Homocyst(e)ine is often included, as elevated homocyst(e)ine can be a hereditary or acquired predisposition to venous thrombosis.3,4,5 Elevated homocyst(e)ine is unique among the hypercoagulable states in that it may be treated with vitamins B12, B6 and folate. If all these initial tests are normal and the suspicion for a hereditary hypercoagulable state remains high, assays for plasminogen, dysfibrinogenemia, heparin cofactor II, or platelet hyperaggregability may be considered. These latter four conditions are rare and/or not well characterized. Dysfibrinogenemia test results are characterized by prolonged thrombin time and/or Reptilase® time, and fibrinogen levels higher by antigen assay than by functional assay.
If a patient is undergoing an evaluation for arterial thrombosis, the panel of tests may be different. Antiphospholipid antibodies should be included, as these are associated with arterial and/or venous thrombosis. Homocyst(e)ine levels can also be considered, as the evidence linking hyperhomocyst(e)inemia with arterial thrombosis (particularly coronary artery disease) is even more extensive than it is for venous thrombosis. When arterial thrombosis occurs in the setting of atherosclerosis (eg, coronary artery disease/myocardial infarction, stroke), lipoprotein (a) may be considered in addition to the conventional lipid panel and clinical cardiovascular risk factors (family history, diabetes, hypertension, smoking).6 Other cardiovascular risk markers are under investigation, including C-reactive protein (or other markers of inflammation) and LDL subclasses (small, dense LDL).7,8 The other tests described above for evaluation of venous thrombosis (eg, activated protein C resistance) have an uncertain association with arterial thrombosis. It is possible that the markers of venous thrombosis increase the risk for arterial thrombosis only when a second risk factor for arterial thrombosis is present, such as smoking, hypertension, or hypercholesterolemia.9
Just as deficiencies of certain coagulation factors may cause bleeding, elevated levels of certain coagulation factors have been implicated in thrombotic risk. For example, high levels of fibrinogen and factor VII have been associated with an increased risk of myocardial infarction, and high levels of factor VIII or XI have been implicated in venous thrombosis.10,11,12,13 Coagulation factor levels have not yet been added to many hypercoagulation panels, at least partly because the levels are difficult to interpret in individual patient cases.
Markers of coagulation activation are also commercially available, mostly on a research basis. These tests, when elevated, indicate on-going coagulation activation, as may occur in the setting of thrombosis or disseminated intravascular coagulation (DIC). Such tests, not routinely used clinically, include prothrombin fragment 1.2, fibrinopeptide A, fibrinopeptide B, fibrin monomers, thrombin-antithrombin complexes (TAT), platelet factor 4 (PF4) and beta-thromboglobulin. As prothrombin is converted into thrombin, a peptide is released from prothrombin, called prothrombin fragment 1.2. As fibrinogen is converted into fibrin, two peptides called fibrinopeptide A and fibrinopeptide B are released from fibrinogen. The remaining portion of fibrinogen is called a fibrin monomer. Fibrin monomers then polymerize to form fibrin clot. As thrombin is formed, antithrombin binds to thrombin, forming a thrombin-antithrombin complex (TAT), thereby inhibiting thrombin to prevent excessive clotting. Platelet consumption (thrombocytopenia) and platelet activation markers (eg, platelet factor 4 and beta-thromboglobulin) may also be present. Fibrinogen and antithrombin may be consumed, as well as protein C and protein S.
Markers of fibrinolysis are also present in patients with thrombosis or DIC. Tests for these markers are commercially available but, except for the D-dimer and FDP, they are not commonly used clinically. Such tests include: plasminogen, antiplasmin, plasmin-antiplasmin complexes (PAP), tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI-1), Bbeta 1-42 fragment and Aalpha fragment. When fibrinolysis is activated, plasminogen levels may decrease as plasminogen is converted into plasmin. As plasmin degrades fibrin, two peptide fragments, called the Bbeta 1-42 fragment and Aalpha fragment, are released, and FDP and D-dimers are formed. As plasmin is formed, antiplasmin binds to plasmin, forming a plasmin-antiplasmin complex (PAP), thereby inhibiting plasmin to prevent excessive fibrinolysis. Antiplasmin and tPA activity can become decreased, and PAI-1 can increase.
Footnotes
1. Ridker PM, Hennekens CH, Selhub J, et al, “Interrelation of Hyperhomocyst(e)inemia, Factor V Leiden, and Risk of Future Venous Thromboembolism,”Circulation, 1997, 95(7):1777-82.
2. Koeleman BPC, van Rumpt D, Hamulyak K, et al, “Factor V Leiden: An Additional Risk Factor for Thrombosis in Protein S Deficient Families?”Thromb Haemost, 1995, 74(2):580-3.
3. den Heijer M, Blom HJ, Gerrits WBJ, et al, “Is Hyperhomocysteinaemia a Risk Factor for Recurrent Venous Thrombosis?”Lancet, 1995, 345(8954):882-5.
4. den Heijer M, Koster T, Blom HK, et al, “Hyperhomocysteinemia as a Risk Factor for Deep-Vein Thrombosis,”N Engl J Med, 1996, 334(12):759-62.
5. Simioni P, Prandoni P, Burlina A, et al, “Hyperhomocysteinemia and Deep-Vein Thrombosis. A Case Control Study,”Thromb Haemost, 1996, 76(6):883-6.
6. Schlipak MG, Simon JA, Vittinghoff E, et al, “Estrogen and Progestin, Lipoprotein (a), and the Risk of Recurrent Coronary Heart Disease Events After Menopause,”J Am Med Assoc, 2000, 283(14):1845-52.
7. Ridker PM, Hennekens CH, Buring JE, et al, “C-Reactive Protein and Other Markers of Inflammation in the Prediction of Cardiovascular Disease in Women,”N Engl J Med, 2000, 342(12):836-43.
8. Lamarche B, Tchernof A, Moorjani S, et al, “Small, Dense Low-Density Lipoprotein Particles as a Predictor of the Risk of Ischemic Heart Disease in Men. Prospective Results From the Quebec Cardiovascular Study,”Circulation, 1997, 95(1):69-75.
9. Inbal A, Freimark D, Modan B, et al, “Synergistic Effects of Prothrombotic Polymorphisms and Atherogenic Factors on the Risk of Myocardial Infarction in Young Males,”Blood, 1999, 93(7):2186-90.
10. Iacoviello L, Di Castelnuovo A, de Knijff P, et al, “Polymorphisms in the Coagulation Factor VII Gene and the Risk of Myocardial Infarction,”N Engl J Med, 1998, 338(2):79-85.
11. Ma J, Hennekens CH, Ridker PM, et al, “A Prospective Study of Fibrinogen and Risk of Myocardial Infarction in the Physician’s Health Study,”J Am Coll Cardiol, 1999, 33(5):1347-52.
12. van der Meer FJM, Koster T, Vandenbroucke JP, et al, “The Leiden Thrombophilia Study (LETS),”Thromb Haemost, 1997, 78(1):631-5.
13. Meijers JC, Tekelenburg WL, Bouma BN, et al, “High Levels of Coagulation Factor XI as a Risk Factor for Venous Thrombosis,”N Engl J Med, 2000, 342(10):696-701.
References
De Stefano V, Finazzi G, and Mannucci PM, “Inherited Thrombophilia: Pathogenesis, Clinical Syndromes, and Management,”Blood, 1996, 87(9):3531-44.
Simioni P, Sanson BJ, Prandoni P, et al, “Incidence of Venous Thromboembolism in Families With Inherited Thrombophilia,”Thromb Haemost, 1999, 81(2):198-202.
Tripodi A and Mannucci PM, “Markers of Activated Coagulation and Their Usefulness in the Clinical Laboratory,”Clin Chem, 1996, 42(5):664-9.
Van Cott EM and Laposata M, “Laboratory Evaluation of Hypercoagulable States,”Hematol Oncol Clin North Am, 1998, 12(6):1141-66.
