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Fibrinogen
Medical expert of the article
Last reviewed: 05.07.2025
Fibrinogen (factor I) is a protein synthesized mainly in the liver. In the blood it is in a dissolved state, but as a result of an enzymatic process under the influence of thrombin and factor XIIIa it can be converted into insoluble fibrin.
Fibrinogen is an acute phase protein, and its plasma concentration increases with infection, inflammation, trauma, and stress. Fibrinogen synthesis is stimulated by hormones (insulin, progesterone), fatty acids, and FDP. However, the main stimulator of fibrinogen synthesis is the secretion of IL-6 by macrophages and monocytes in response to FDP phagocytosis. Fibrinogen concentration in blood plasma is increased in smokers and diabetics. With an increase in fibrinogen concentration, the risk of cardiovascular diseases increases. Fibrinogen concentration is higher in women than in men, and its increase with age is more noticeable in them.
Reference values (norm) of fibrinogen concentration in blood plasma
Age |
Fibrinogen concentration |
|
Mg/dl |
G/l |
|
Newborns Adults |
125-300 200-400 |
1.25-3 2-4 |
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