Protein C Activity

Protein C Activity

What it is

The Protein C Activity test measures how well Protein C, a natural anticoagulant protein in the blood, is functioning. Protein C is made in the liver and plays an important role in controlling blood clot formation by inactivating clotting factors Va and VIIIa. Low activity levels may increase the risk of abnormal blood clots (thrombosis), while normal activity helps maintain healthy blood flow.

Uses

This test is used to:
– Diagnose inherited or acquired Protein C deficiency.
– Evaluate patients with unexplained or recurrent blood clots (deep vein thrombosis or pulmonary embolism).
– Assess clotting risk in patients with a family history of thrombophilia.
– Support diagnosis of conditions like disseminated intravascular coagulation (DIC) or severe liver disease.
– Monitor patients on anticoagulation therapy in certain cases.

Symptoms That May Lead to the Test

Doctors may recommend this test if you have:
– Recurrent or unexplained deep vein thrombosis (DVT).
– Pulmonary embolism (sudden shortness of breath, chest pain, coughing blood).
– Family history of inherited clotting disorders.
– Unusual sites of blood clots (such as cerebral or abdominal veins).
– History of pregnancy complications related to thrombosis.

Abnormal Results

Low Protein C Activity: May indicate inherited Protein C deficiency, liver disease, vitamin K deficiency, severe infection, disseminated intravascular coagulation (DIC), or side effects of warfarin therapy. Inherited deficiency increases lifelong clotting risk.

Normal Activity: Suggests adequate anticoagulant function, lowering the likelihood of Protein C deficiency as a cause of clotting problems.

High Protein C Activity: Rare and usually not clinically significant. Results must always be interpreted with clinical history and other coagulation studies.

Risks

The test requires a routine blood sample. Risks are minimal and may include mild pain, bruising, or dizziness at the puncture site. The laboratory analysis itself poses no direct risks.