VPB0840 - Correlation study between VWF: RCO ristocetin cofactor activity and ISTH-BAT in von Willebrand disease

Background: the Willebrand ristocetin cofactor (VWF: RCO) measures the ability of VWF to bind to platelets in the presence of ristocetin, it is a specific test that allows the diagnosis of von Willebrand disease, the ISTH hemorrhagic score -BAT allows clinical evaluation of bleeding symptomatology. The question is, does the clinical ISTH-BAT score have the same diagnostic value as ristocetin cofactor activity?

Aims: To study the correlation between ristocetin cofactor (VWF: RCO) and the clinical ISTH-BAT score.

Methods: In our series of 20 patients with von Willebrand disease, the study of the correlation between the cofactor activity of ristocetin VWF: RCO and the clinical haemorrhagic score ISTH-BAT

Results: The correlation between the cofactor activity of ristocetin VWF: RCO and the clinical haemorrhagic score ISTH-BAT shows an inverse correlation, the more the VWF activity: RCO is lower the higher the ISTH-BAT score is according to the following regression equation: ISTH-BAT score = - 0.016 × (VWF: RCO) + 0.364. This correlation is medium (r = 0.42).The correlation study between the RCO: FVW activity and the clinical ISTH-BAT score, shows that the clinical ISTH-BAT score is partly explained by the RCO: FVW, despite the small number (only 20 patients). Therefore, the ISTH-BAT clinical score may have a positive predictive value in the diagnosis of von Willebrand disease.

Conclusion(s): the ISTH-BAT clinical score represents a very important clinical element for the diagnosis of von Willebrand disease. This score represents the first assessment of hemostasis in the face of any suspicion of the disease, this score can advantageously replace our failures in biology, especially in the most remote areas.