von Willebrand Factor Ristocetin Cofactor Activity (vWF:RCo)
The von Willebrand factor ristocetin cofactor activity index assesses the functionality of the vWF blood clotting protein, which participates in platelet aggregation and primary clot formation.
The study allows detection of hereditary and acquired vWF function disorders, assessment of bleeding tendency, and monitoring of von Willebrand disease therapy efficacy.
Test composition:
• Material: venous blood (plasma)
• Method: coagulometric or turbidimetric method using ristocetin
• Determined indicator: ristocetin cofactor activity index (vWF:RCo) in % of normal
Mechanism of abnormalities: decrease — hereditary vWF defects (von Willebrand disease types 2 and 3), acquired defects, liver diseases, immune degradation.
Biomaterial: Venous blood (plasma)
• Submit blood fasting
• Avoid alcohol for 24 hours
• Avoid physical exertion and stress 30 minutes before the test
Medications:
• If taking anticoagulants, antiplatelet agents, hormonal medications, or potent drugs, inform the doctor before the test.
Prescribed for:
• Suspected von Willebrand disease or other hereditary platelet disorders
• Tendency to frequent or spontaneous bleeding, nosebleeds, gum bleeding
• Monitoring therapy for detected vWF disorders
• Before surgical procedures or after surgery
Recommended for:
• Patients with frequent or unusual bleeding
• People with hereditary predisposition to von Willebrand disease
• Patients before surgery or after injuries
Reference values depend on the laboratory method and are indicated on the result form.
Decreased ristocetin cofactor activity index indicates functional vWF deficiency. Abnormalities require comprehensive assessment by a physician together with the clinical picture.
If abnormalities are detected: hematologist, general practitioner, cardiologist.
