Diagnosing von Willebrand disease: a large reference laboratory's perspective

Area of Science:

• Hematology
• Clinical Pathology
• Diagnostic Laboratory Medicine

Background:

• Von Willebrand disease (vWD) is a prevalent inherited bleeding disorder.
• Accurate diagnosis relies on integrating clinical and laboratory findings.
• Current laboratory evaluation is complex due to assay variety and algorithmic disagreements.

Purpose of the Study:

• To retrospectively analyze laboratory data from 497 patients with suspected vWD.
• To evaluate the correlation between different von Willebrand factor (vWF) assays.
• To determine optimal assay combinations for accurate vWD diagnosis.

Main Methods:

• Retrospective analysis of 497 cases with available vWF multimeric analysis, vWF antigen, ristocetin cofactor activity, and collagen-binding activity assays.
• Comparative analysis of assay results to assess inter-assay correlations.
• Evaluation of assay combinations against multimeric patterns.

Main Results:

• Individual vWF activity or antigen assays can lead to overdiagnosis or underdiagnosis of vWD.
• Incorporating the collagen-binding assay into diagnostic algorithms significantly reduces misdiagnosis and misclassification.
• The collagen-binding assay can substantially decrease the need for vWF multimeric analysis.

Conclusions:

• Relying on single vWF assays for diagnosis is insufficient and prone to error.
• A diagnostic algorithm incorporating vWF antigen, ristocetin cofactor activity, and collagen-binding activity enhances diagnostic accuracy for vWD.
• The collagen-binding assay is a valuable tool for improving vWD diagnosis and streamlining laboratory workflows.