Fibrinogen (Factor 1), Acute Phase Protein

Acute-phase protein (Acute Phase Reactants)
- Acute-phase protein is raised in inflammatory conditions.
- When there is an increase in a protein called positive acute-phase protein.
- In the case of a decrease in the acute phase protein, it is called negative phase protein.
- The acute phase proteins (positive) are proteins whose concentration increases in the plasma, and after the disease episode is over, it decreases and may become normal.
Fibrinogen (Factor 1)
Sample
- The patient blood is needed to prepare plasma.
- The sample is stable for 8 hours at room temperature.
- It can be stored for several months at -20 °C.
Indications
- For the evaluation of bleeding disorder.
- If there is excessive bruising.
- In case of bleeding from the gums and nose.
- In the case of Bleeding in the GIT and blood in the stool.
- In the case of blood in the urine.
- If there is a rupture of the spleen.
Precautions
- Avoid clot formation.
- Avoid collecting the blood from the heparinized blood vessel.
- Avoid contamination with tissue that contains tissue thromboplastin.
- Avoid contamination with heparin.
- Blood transfusion in the last month may affect the result.
- Diet rich in Omega-3 and Omega-6 fatty acids reduces the level of fibrinogen.
- Oral contraceptives and estrogen increase the level.
- Drugs like anabolic steroids, phenobarbital, streptokinase, valproic acid, and asparaginase.
Pathophysiology Fibrinogen (Factor 1)
- Fibrinogen (factor 1) is an acute-phase protein.
- This is β-globulin and is usually absent from the serum.
- It is a fibrillary group of glycoproteins.
- This consists of three pairs of polypeptide chains.
- It is synthesized in the liver, the major source of coagulation factors.
- Fibrinogen may act as an acute-phase protein.
- When fibrinogen is transfused:
- 50% disappear in 48 hours.
- 75% disappear in 6 days.
- Half-life is 3.5 to 4 days. (Another source says 100 to 150 hours).
- This is an essential protein for blood clot formation (30% activity for normal coagulation is required).
- It is a complex protein with enzymatic action that is converted into fibrin.
- In the process of clotting, all the fibrinogen in the plasma is converted to fibrin.
- Conversion of fibrinogen into fibrin is the final step in coagulation, and it takes place under the influence of thrombin.
- This is part of the common pathway in coagulation.
- The serum is laking fibrinogen.
- The fibrinogen has a major effect on RBC sedimentation rates by coating the cells.
- This allows the cells to settle (sediment) faster.
- So increased fibrinogen indicate raised ESR.
- Disseminated intravascular coagulopathy (DIC): In this case, fibrinogen is decreased.
Significance of fibrinogen:
- This is raised by inflammation or tissue injury. Fibrinogen plays an important role in the body’s acute reaction in response to trauma or various severe diseases.
- It is a risk factor for coronary heart disease and stroke.
- Snake venom leads to the depletion of fibrinogen.
- Fibrinogen is decreased in the DIC.
- Fibrinogen level increases by cigarette smoking.
- There is an influence fo genetics.
Normal level of Fibrinogen (Factor 1)
- Source 2
- Newborn = 125 to 300 mg/dL
- Adult = 200 to 400 mg/dL (2 to 4 g/L)
- Source 4
- 200 to 400 mg/dL (2 to 4 g/L)
- Another source
- 175 t o 400 mg/dL.
Critical value of Fibrinogen (Factor 1) = <100 mg/dL
An elevated level of Fibrinogen (Factor 1) is seen in:
- Acute infections.
- Myocardial infarction and Sudden cardiac death.
- Patients with malignancies.
- Inflammatory conditions like Rheumatoid arthritis and Glomerulonephritis.
- In the case of traumatic injury.
- Patient with a stroke.
- In pregnancy.
- People who are cigarettes smokers.
- Patients with peripheral artery disease.
- This is raised in acute and chronic inflammation.
- Older age.
- Diabetes mellitus.
A high level of fibrinogen is associated with increased risk of:
- Coronary heart disease.
- Myocardial infarction.
- Stroke.
- Peripheral arterial disease.
Reduced level of fibrinogen is seen in:
- Patients with severe liver diseases.
- Consumptive coagulopathy like DIC.
- Malnourished patients.
- In case of a large volume of blood transfusion.
Afibrinogenemia (Congenital):
- This is rare and usually inherited as an autosomal recessive trait.
- If the parents do not show the disease, they can still have affect children.
- When 2 carriers of autosomal recessive positive parents have children, each child has a:
- 25% chances to be affected.
- 50% chances to be an unaffected carrier.
- 25% chances to be unaffected and not a carrier.
- There is a severe lake of fibrinogen, and blood will not clot.
- Signs and symptoms:
- In the case of afibrinogenemia, if the fibrinogen level is <0.1 g/L, it will have bleeding abnormality from mild to severe.
- This disease is present from birth.
- The first symptom is bleeding from the umbilical cord, which will not stop and is difficult to stop.
- There may be gastrointestinal bleeding.
- There may be nose bleeding (epistaxis) or bleeding from the oral mucosa.
- There may be bleeding episodes, bruises, and poor wound healing.
- Females may have excessive menstruation.
- There may be spontaneous abortion.
- There may be CNS hemorrhage.
- Evidence of bleeding in the joints.
- Diagnosis:
- Following tests are advised:
- Prothrombin time (PT)>
- Activated partial thromboplastin time (APTT).
- Fibrinogen level in the blood.
- Reptilase time.
- Thrombin time.
- Prolonged bleeding tests time and fibrinogen level <0.1 g/L, indicating afibrinogenemia.
Dysfibrinogenemia:
- There is abnormal fibrinogen due to a structural abnormality which results in an abnormal function.
- This may be:
- Congenital or Inherited, there is an increased risk of bleeding, thrombosis, or both in the same patient or family.
- Some of the patients are asymptomatic.
- The prognosis is good. The event of thrombosis and bleeding is mild.
- Acquired fibrinogen is dysfunctional due to autoimmune diseases, liver diseases, plasma cell dyscrasia, or cancers.
- There is more bleeding than thrombosis.
- The prognosis is worse because of liver disease.
- Congenital or Inherited, there is an increased risk of bleeding, thrombosis, or both in the same patient or family.
- This leads to relatively mild hemorrhage in the case of congenital cause.
- Few of these may have a tendency for thrombosis in case of acquired cause.
- Diagnosis:
- Prothrombin time (PT) is prolonged.
- Activated partial thromboplastin (APTT) is also prolonged.
- Thrombin time (TT) is the most sensitive test for dysfibrinogenemia in the case of bleeding tendency and may not be prolonged in the case with a tendency for thrombosis.
- Reptilase time is prolonged.
- Another source: Critical value is <60 mg/dL.
Value for the layman:
- This is advised when there is a history of bleeding or bruises.
- If the patient has epistaxis.