Fibrinogen

What is the purpose of the test?

A fibrinogen test measures the concentration of this protein in the blood and examines its clot-forming capability. This test serves various purposes, including diagnosing, monitoring, and screening conditions that impact blood clotting.

What is the diagnosing part?

Diagnosis involves a thorough evaluation to identify the underlying cause of your symptoms. If you're experiencing excessive bleeding or blood flow blockages, the diagnostic process may include assessing fibrinogen levels and its clot-forming capacity. Typically, fibrinogen testing follows initial tests or examinations that have ruled out alternative explanations for these symptoms.

What is the monitoring part?

Monitoring involves conducting periodic tests to track the advancement of a disease or gauge your response to treatment. If you've been diagnosed with a fibrinogen disorder and are undergoing fibrinogen replacement therapy, obtaining regular measurements of fibrinogen levels is standard practice.

What is the monitoring part?

Screening involves conducting tests to evaluate your likelihood of having a health issue before any symptoms arise. In certain cases, fibrinogen testing may be requested for individuals scheduled for surgery to determine if they are at an increased risk of experiencing excessive bleeding.

What is the Screening part?

Screening involves conducting tests to assess your risk of developing a health issue before any symptoms appear. In some instances, fibrinogen testing may be recommended for individuals preparing for surgery to determine if they have an elevated risk of experiencing excessive bleeding.

What does the test show?

Fibrinogen testing involves measuring fibrinogen levels and assessing its ability to facilitate the proper formation of blood clots.

Fibrinogen, a protein produced in the liver and in the bloodstream, is crucial in stopping bleeding when an injury occurs. In conjunction with other clotting factors and platelets, fibrinogen collaborates to create a blood clota conglomeration of blood cells, platelets, and proteinscapable of halting the bleeding.

During this coagulation process, the body signals another clotting factor, thrombin, to bind with fibrinogen. This interaction leads to the formation of fibrin, a substance that constructs a robust network of microscopic threads, reinforcing the blood clot.

Fibrinogen testing employs two methods concurrently:

1. Fibrinogen Antigen Test: This test measures the quantity of fibrinogen in a blood sample, typically reported in milligrams per deciliter (mg/dL). The fibrinogen antigen test is usually performed when the fibrinogen activity test yields an abnormal result, helping to distinguish whether the low activity is due to a reduced quantity or abnormal functionality of fibrinogen.
2. Fibrinogen Activity Test: This test gauges the time it takes for fibrinogen to facilitate clot formation. Thrombin is introduced to a prepared blood sample, instigating the coagulation process within a test tube. The amount of active or functional fibrinogen integrated into the blood clot is assessed and reported in milligrams per deciliter (mg/dL). Most laboratories offer a clotting-based activity test and report the results in the same units.

When should I do this test?

Fibrinogen testing is typically performed to assess blood clotting ability, especially in signs indicating abnormal clotting or blood vessel blockages such as thrombosis.

Healthcare providers may also order a fibrinogen test if the PT or PTT tests results suggest prolonged clotting times, even in the absence of symptoms.

Fibrinogen testing serves various diagnostic purposes, including:

1. Disseminated intravascular coagulation (DIC): This serious condition involves excessive production of thrombin and fibrin, leading to a significant drop in fibrinogen levels. Fibrinogen testing, along with other blood tests, helps confirm DIC diagnoses.
2. Liver diseases: Since the liver produces fibrinogen and most other clotting factors, evaluating fibrinogen levels can assess liver health and the risk of bleeding in certain patients.
3. Inherited fibrinogen disorders: Rare genetic conditions can alter fibrinogen production and function, potentially causing abnormal bleeding or clotting. Personal or family histories of fibrinogen disorders may prompt testing for diagnosis and treatment planning.
4. Other acquired fibrinogen disorders: Some cancers, autoimmune diseases, and specific medications can disrupt blood clotting. Fibrinogen testing helps assess the impact of these conditions on blood clotting.

Individuals with fibrinogen disorders may undergo testing to evaluate bleeding risk or plan treatment, often involving supplemental fibrinogen replacement therapy. Routine fibrinogen testing is crucial during pregnancy for those with a history of abnormal bleeding or previous pregnancy complications related to fibrinogen disorders.

Can I take the test at home?

A fibrinogen test cannot be performed at home. Unlike certain other coagulation tests, fibrinogen testing requires specialized laboratory equipment and can only be conducted in a clinical laboratory setting by trained professionals.

What should I do before the test?

There is no specific preparation needed for a blood draw for fibrinogen testing. However, to ensure the accuracy of the test results, it's important to inform your doctor about any prescription or over-the-counter medications you are currently taking, particularly anticoagulant medications that could potentially impact your fibrinogen levels.

How can the result be interpreted?

A report of your fibrinogen levels typically provides the amount of active (or functional) fibrinogen in milligrams per deciliter (mg/dL), which is then compared to a reference range. Reference ranges may vary slightly between laboratories but serve as a standard for comparing your fibrinogen level to those of a larger population of healthy individuals. According to the American Board of Internal Medicine, the reference range for fibrinogen is typically 200-400 mg/dL. Discussing your specific test results with your doctor is essential, as reference ranges can differ based on laboratory protocols and equipment.

Fibrinogen testing results are typically categorized as above, below, or within the reference range. However, fibrinogen levels are often compared with other coagulation tests like PT and PTT to properly evaluate abnormal blood clotting.

Abnormally low fibrinogen levels can impede the formation of blood clots, potentially leading to unexpected and excessive bleeding. Fibrinogen disorders involve abnormalities in the function and/or quantity of fibrinogen. These disorders can be genetic, inherited from a parent, or acquired due to injury or illness. Abnormalities in fibrinogen are classified as follows:

1. Afibrinogenemia: A rare condition where the body produces no functional fibrinogen.
2. Hypofibrinogenemia: A deficiency of fibrinogen characterized by chronic levels below the lower limit of normal reference, affecting both activity and antigen levels.
3. Dysfibrinogenemia: Dysfunction of fibrinogen where antigen levels may be normal, but the protein doesn't function correctly, resulting in decreased activity.
4. Hypodysfibrinogenemia: Involves a decrease in both the amount of fibrinogen and its clotting function.

Abnormally high fibrinogen levels can occur as a natural response to injury, acute stress, infection, or inflammation. Elevated fibrinogen levels can also be linked to factors like pregnancy, aging, tobacco use, obesity, and insulin resistance. Higher fibrinogen levels are associated with an increased risk of stroke or heart disease, although whether fibrinogen directly causes these conditions is not definitively established.

Interpreting your fibrinogen test results can aid in diagnosis and treatment planning. It's crucial to consult with a healthcare provider who can help you understand how these results relate to your specific health situation.