hyperfibrinogenemia

Hyperfibrinogenemia is a medical condition characterized by elevated levels of fibrinogen in the blood. Fibrinogen is a soluble plasma glycoprotein produced by the liver and serves as the precursor of fibrin, the protein that forms a clot. Fibrinogen also acts as an acute-phase reactant, with levels rising in response to inflammation, infection, tissue injury, or stress.

Causes: The majority of cases are acquired and reflect inflammation or other stress. Common causes include acute or chronic infections, autoimmune diseases, malignancy, pregnancy, estrogen use, obesity and metabolic syndrome, smoking, and liver disease. Rare hereditary forms exist but are uncommon.

Pathophysiology: Higher fibrinogen levels increase plasma viscosity and enhance thrombin-driven clot formation and platelet aggregation, contributing to a prothrombotic state in the presence of other risk factors.

Clinical significance: Hyperfibrinogenemia is not a disease in itself but a laboratory finding linked to increased cardiovascular and thrombotic risk in some settings and to the activity of inflammatory conditions. It can be used as a marker to monitor disease activity in certain inflammatory states.

Diagnosis: Diagnosis is by measurement of plasma fibrinogen concentration, using clot-based or immunologic assays. Reference ranges vary by method, but common adult ranges are approximately 2-4 g/L. Clinicians interpret fibrinogen levels alongside other inflammatory markers, such as CRP or ESR, and the clinical context.

Management: Management targets the underlying cause of fibrinogen elevation. Addressing inflammation, infection, or other drivers often reduces fibrinogen levels. In patients with thrombotic risk, standard risk reduction and treatment guidelines apply. There is no specific therapy approved solely to lower fibrinogen levels.