Synonym

• Clauss Thrombin Clotting Rate Assay
• Factor I
• Hypofibrinogenemia test
• Plasma fibrinogen
• Serum fibrinogen

Tubes

• Blue top tube (3.2% sodium citrate)
• 5 mL of venous blood

Additional information

• Prevent venous stasis by avoiding prolonged tourniquet placement for more than a minute
• Handle sample gently to prevent hemolysis
• Send the sample to the lab immediately

Info

• The fibrinogen assay measures the concentration of soluble factor I (fibrinogen) in blood, before it turns into insoluble fibrin and is crosslinked into a fibrin net
• Fibrinogen is a plasma glycoprotein synthesized in the liver
• Fibrinogen is a coagulation factor converted to fibrin by thrombin, which combines with platelets to form a hemostatic plug in the common final pathway of the coagulation cascade system
• In healthy individuals, there is no residual fibrinogen left in serum after clotting has occurred
• Fibrinogen is also an acute-phase protein reactant, elevated in conditions involving tissue damage and inflammation

Clinical

• The clinical utility of the fibrinogen assay include:
• Evaluation of bleeding and clotting disorders caused by fibrinogen abnormalities (part of a coagulation panel)
• Aids in the diagnosis of disseminated intravascular coagulation (DIC)
• Evaluation of congenital or acquired dysfibrinogenemias
• Monitor hemostasis in disorders associated with low fibrinogen levels such as liver disease
• Evaluation of elevated fibrinogen levels that can predispose patients to excessive thrombosis
• Evaluation of a given patient's risk of developing cardiovascular disease
• Aids in the diagnosis of placental abruption
• Very high values (>700 mg/dL) are suggestive of significant risk for coronary artery and cerebrovascular disease
• Very low values (<50 mg/dL) can result in hemorrhage after traumatic surgery

Additional information

• Fibrinogen has a half-life of about 4 days
• Factors interfering with test results include:
• High levels of heparin
• High AT-III levels lowers the fibrinogen
• High fibrinogen split product (FSP) levels lower the fibrinogen
• Placement of the tourniquet for longer than 1 minute can result in venous stasis
• Other factors known to affect fibrinogen assay results include:
• Patients with active bleeding
• Acute infection or illness
• Individuals who have received blood transfusions within past 4 wks
• Related laboratory tests include:
• Activated partial thromboplastin time (aPTT)
• Alanine aminotransferase
• Albumin
• Alkaline phosphatase
• Aspartate aminotransferase
• Bilirubin
• Clot retraction
• D-dimer
• Erythrocyte sedimentation rate (ESR)
• Fibrin degradation products
• g-glutamyl transpeptidase
• Liver biopsy
• Plasminogen
• Prothrombin time (PT)
• Thrombin time (TT)

Nl Result

Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.

High Result

Conditions associated with elevated plasma fibrinogen levels include:

• Inflammation and infection
• Rheumatoid arthritis
• Pneumonia
• Tuberculosis
• Membranoproliferative glomerulonephritis
• Tissue necrosis
• Acute myocardial infarction
• Nephrotic syndrome
• Malignancies
• Multiple myeloma
• Hodgkin's disease
• Stomach cancer
• Breast carcinoma
• Nephrotic carcinoma
• Pregnancy
• Eclampsia
• Stroke
• Smoking
• Older Age
• Drugs
• Acetylsalicylic acid
• Bicalutamide
• Chemotherapeutic drugs
• Estropipate
• Fluvastatin
• Gemfibrozil
• Lovastatin
• Norethandrolone
• Oral contraceptives
• Oxandrolone
• Oxymetholone
• Pyrazinamide
• Streptomycin

Low Result

Conditions associated with decreased plasma fibrinogen levels include:

• Liver disease
• Disseminated Intravascular Coagulopathy (DIC)
• Hemorrhage
• Malignancies
• Prostate
• Pancreas
• Lung
• Primary fibrinolysis
• Bone marrow lesions
• Extracorporeal circulation
• Afibrinogenemia
• Dysfibrinogenemia
• Hypofibrinogenemia
• Malnutrition
• Rapid large volume blood transfusion (stored blood losses fibrinogen)
• Drugs and substance
• 5-fluorouracil
• Alteplase
• Anabolic steroids
• Anistreplase
• Asparaginase
• Atenolol
• Bezafibrate
• Cefamandole
• Clofibrate
• Dextran
• Factor VIIA
• Fenofibrate
• Fish oils
• Gemfibrozil
• Iron
• Kanamycin
• Lamotrigine
• Lovastatin
• Medroxyprogesterone
• Pegaspargase
• Pentoxifylline
• Phosphorus
• Pravastatin
• Prednisone
• Raloxifene
• Reteplase
• Simvastatin
• Streptokinase
• Sulfisoxazole
• Tenecteplase
• Thrombolytics
• Ticlopidine
• Valproic acid

References

• Akakura N et al. The COOH-Terminal Globular Domain of Fibrinogen {gamma} Chain Suppresses Angiogenesis and Tumor Growth. Cancer Res. 2006 Oct 1;66(19):9691-7.
• LabTestsOnline®. Fibrinogen. [Homepage on the Internet]© 2001-2006. Last reviewed on December 27, 2004. Last accessed on October 9, 2006. Available at URL: http://www.labtestsonline.org/understanding/analytes/fibrinogen/test.html
• Lippi G et al. Short-term venous stasis influences routine coagulation testing. Blood Coagul Fibrinolysis. 2005 Sep;16(6):453-8.
• Maksimowicz-McKinnon K et al. Predictors of Carotid Atherosclerosis in Systemic Lupus Erythematosus. J Rheumatol. 2006 Oct 1; [Epub ahead of print].
• Morange PE et al. Haemostatic Factors and the Risk of Cardiovascular Death in Patients With Coronary Artery Disease. The AtheroGene Study. Arterioscler Thromb Vasc Biol. 2006 Oct 5; [Epub ahead of print].
• Selmeci L et al. Human blood plasma advanced oxidation protein products (AOPP) correlates with fibrinogen levels. Free Radic Res. 2006 Sep;40(9):952-8.
• Suontaka AM et al. Changes in functional activities of plasma fibrinogen after treatment with methylene blue and red light. Transfusion. 2003 May;43(5):568-75.
• UTMB Laboratory Survival Guide®. Fibrinogen. [Homepage on the Internet]© 2006. Last reviewed in December 2006. Last accessed on December 11, 2006. Available at URL: http://www.utmb.edu/lsg/LabSurvivalGuide/hem/fibrinogen.htm
• Von Kanel R et al. Altered blood coagulation in patients with post-traumatic stress disorder. Psychosom Med. 2006 Jul-Aug;68(4):598-604.
• Wang Q et al. [Clinical significance of plasma fibrinogen level in patients with colorectal cancer] [Article in Chinese]. Zhonghua Zhong Liu Za Zhi. 2005 Sep;27(9):544-6.