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HelpMayo Test ID FIBAG Fibrinogen Antigen, Plasma
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube: Light-blue top (3.2% sodium citrate at 9:1 ratio)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot plasma into plastic vial. Send refrigerated.
Useful For
Evaluation of fibrinogen deficiency
Measuring fibrinogen in patients with elevated plasma levels of fibrin degradation products, patients receiving heparin, and in patients with antibodies to thrombin (following surgical use of topical bovine thrombin)
Identifying afibrinogenemia, hypofibrinogenemia, and dysfibrinogenemia when ordered in combination with fibrinogen activity (FIBTP / Fibrinogen, Plasma)
Method Name
Immunoturbidimetric
Reporting Name
Fibrinogen Antigen, PSpecimen Type
Plasma Na CitSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Na Cit | Refrigerated (preferred) | 14 days | |
| Frozen | 30 days | ||
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Clinical Information
Fibrinogen (clotting factor I) is an essential protein responsible for blood clot formation. In the final step of the coagulation cascade, thrombin converts soluble fibrinogen into insoluble fibrin strands that crosslink and form a clot.
Fibrinogen is synthesized in the liver and has a biological half-life of 3 to 5 days in the circulating plasma. Fibrinogen deficiencies can be congenital or acquired and lead to prolonged coagulation times. Isolated fibrinogen deficiency is an extremely rare inherited coagulation disorder.
Acquired fibrinogen deficiency is most commonly caused by, acute or decompensated intravascular coagulation and fibrinolysis. Other causes of fibrinogen deficiency include advanced liver disease, L-asparaginase therapy, or fibrinolytic agents (eg, streptokinase, urokinase, tissue plasminogen activator).
Reference Values
≥18 years: 196-441 mg/dL
Reference values have not been established for patients that are less than 18 years of age.
Interpretation
This method measures the total amount of fibrinogen protein (ie, fibrinogen antigen) present in the plasma.
Adequate fibrinogen antigen levels in a context of low fibrinogen activity suggests a dysfibrinogenemia.
Fibrinogen antigen levels lower than 100 mg/dL are associated with an increased risk of bleeding.
Cautions
Differentiation of congenital from acquired defects of fibrinogen requires clinical correlation and the results of standard clotting-based fibrinogen activity (FIBTP / Fibrinogen, Plasma) testing.
Fibrinogen is an acute phase reactant; plasma levels can be increased by inflammatory illnesses, nephrotic syndrome, liver disease, pregnancy, estrogen therapy, and/or compensated intravascular coagulation.
Clinical Reference
1. de Moerloose P, Casini A, Neerman-Arbez M. Congenital fibrinogen disorders: an update. Semin Thromb Hemost. 2013;39(6):585-595
2. Mackie I, Casini A, Pieters M, Purthi R, Reilly-Stitt C, Suzuki A. International council for standardisation in haematology recommendations on fibrinogen assays, thrombin clotting time and related tests in the investigation of bleeding disorders. Int J Lab Hematol. 2024;46(1): 20-32. doi:10.1111/ijlh.14201
Method Description
The K-ASSAY Fibrinogen test analyzes the quantitative determination of fibrinogen in human plasma by immunoturbidimetric analysis. Samples and antibody reagent are automatically pipetted into individual cuvettes. Following an initial incubation and measurement of sample blank, antiserum is added to the cuvettes. The sample (antigen) solution and antiserum are then mixed in the reaction cuvettes. Insoluble antigen-antibody complexes form. The immune complexes cause an increase in light scattering, which correlates with the concentration of plasma fibrinogen. The absorbance of the solution is measured.(Package insert: K-ASSAY Fibrinogen. Kamiya Biomedical Company; 03/2023)
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
85385
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| FIBAG | Fibrinogen Antigen, P | 3256-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| FIBAG | Fibrinogen Antigen, P | 3256-5 |