von Willebrand factor Ristocetin co-factor activity to von Willebrand factor antigen level ratio for diagnosis of acquired von Willebrand syndrome caused by aortic stenosis.
Res Pract Thromb Haemost
; 8(1): 102284, 2024 Jan.
Article
in En
| MEDLINE
| ID: mdl-38268521
ABSTRACT
Background:
Severe aortic stenosis (AS) causes acquired von Willebrand syndrome by the excessive shear stress-dependent cleavage of high molecular weight multimers of von Willebrand factor (VWF). While the current standard diagnostic method is so-called VWF multimer analysis that is western blotting under nonreducing conditions, it remains unclear whether a ratio of VWF Ristocetin co-factor activity (VWFRCo) to VWF antigen levels (VWFAg) of <0.7, which can be measured with an automated coagulation analyzer in clinical laboratories and is used for the diagnosis of hereditary von Willebrand disease.Objectives:
To evaluated whether the VWFRCo/VWFAg is useful for the diagnosis of AS-induced acquired von Willebrand syndrome.Methods:
VWFRCo and VWFAg were evaluated with the VWF large multimer index as a reference, which represents the percentage of a patient's VWF high molecular weight multimer ratio to that of standard plasma in the VWF multimer analysis.Results:
We analyzed 382 patients with AS having transaortic valve maximal pressure gradients of >30 mmHg, 27 patients with peripheral artery disease, and 46 control patients free of cardiovascular disease with osteoarthritis, diabetes, and so on. We assumed a large multimer index of <80% as loss of VWF large multimers since 59.0% of patients with severe AS had the indices of <80%, while no control patients or patients with peripheral artery disease, except for 2 patients, exhibited the indices of <80%. The VWFRCo/VWFAg ratios, measured using an automated blood coagulation analyzer, were correlated with the indices (rs = 0.470, P < .001). When the ratio of <0.7 was used as a cut-off point, the sensitivity and specificity to VWF large multimer indices of <80% were 0.437 and 0.826, respectively.Conclusion:
VWFRCo/VWFAg ratios of <0.7 may indicate loss of VWF large multimers with high specificity, but low sensitivity. VWFRCo/VWFAg ratios in patients with AS having a ratio of <0.7 may be useful for monitoring the loss of VWF large multimers during their clinical courses.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Diagnostic_studies
Language:
En
Journal:
Res Pract Thromb Haemost
/
Research and practice in thrombosis and haemostasis
Year:
2024
Document type:
Article
Affiliation country:
Country of publication: