Fibrinogen levels can be measured in venous blood. Normal levels are about 1.5-3 g/L, depending on the method used. In typical circumstances, fibrinogen is measured in citrated plasma samples in the laboratory; however, the analysis of whole-blood samples by use of thromboelastometry (platelet function is inhibited with cytochalasin D) is also possible. Higher levels are, amongst others, associated with cardiovascular disease (>3.43 g/L). It may be elevated in any form of inflammation, as it is an acute-phase protein; for example, it is especially apparent in human gingival tissue during the initial phase of periodontal disease. Fibrinogen levels increase in pregnancy to an average of 4.5 g/l, compared to an average of 3 g/l in non-pregnant people.
It is used in veterinary medicine as an inflammatory marker: In horses, a level above the normal range of 1.0-4.0 g/L suggests some degree of systemic inflammatory response.
Low levels of fibrinogen can indicate a systemic activation of the clotting system, with consumption of clotting factors faster than synthesis. This excessive clotting factor consumption condition is known as disseminated intravascular coagulation or “DIC.” DIC can be difficult to diagnose, but a strong clue is low fibrinogen levels in the setting of prolonged clotting times (PT or aPTT), in the context of acute critical illness such as sepsis or trauma. Besides low fibrinogen level, fibrin polymerization disorders that can be induced by several factors, including plasma expanders, can also lead to severe bleeding problems. Fibrin polymerization disorders can be detected by viscoelastic methods such as thrombelastometry.
- Sample of nacitrate blood plasma
- We perform the test daily