Quantitative impact of using different criteria for the laboratory diagnosis of type 1 von Willebrand disease.

Abstract

INTRODUCTION:

Only ± 50% of patients with type 1 von Willebrand disease (VWD) have recognized molecular defects and diagnosis still rests on demonstrating low plasma von Willebrand factor (VWF) protein/function. However, no generalized consensus exists regarding the type and number of VWF variables that should be considered for diagnosis.

AIM:

To compare the quantitative impact of four different criteria to diagnose type 1 VWD.

METHODS:

We tested four laboratory criteria on 4298 laboratory studies during a 5-year period. The first was the National Heart, Lung, and Blood Institute recommendation, which diagnoses type 1 VWD with plasma VWF antigen (VWF:Ag) and VWF ristocetin cofactor (VWF:RCo) < 30 IU dL(-1) and possible VWD/'low VWF' with values between 30 and 50 IU dL(-1) . Second, diagnosis was established when two of three variables, VWF:Ag, VWF:RCo, VWF collagen binding assay (VWF:CB), were ≤ 2.5th percentile. Diagnostic criterion for possible VWD/'low VWF' using percentiles was also described. The third criterion (European Group on von Willebrand Disease, EUVWD), uses a plasma level of VWF:RCo (or VWF:CB) ≤ 40 IU dL(-1) for diagnosis. Finally, the Zimmerman Program for the Molecular and Clinical Biology of VWD (ZPMCBVWD) diagnoses VWD if VWF:Ag or VWF:RCo are ≤ 40 IU dL(-1) .

RESULTS:

The three assays had high correlation and excellent agreement at levels < 120 IU dL(-1) . The National Heart, Lung, and Blood Institute recommendation was followed to diagnose 122 (2.8%) patients with type 1 VWD and 704 (16.4%) with possible VWD/'low VWF.' Using percentiles, the diagnosis of type 1 VWD increased to 280 (6.5%) patients; 169 (3.9%) patients had possible VWD and 180 (4.2%) patients had 'low VWF.' Diagnoses using EUVWD and ZPMCBVWD criteria increased to 339 (7.9%) and 357 (8.3%) patients, respectively.

DISCUSSION:

Identical data, analyzed using different criteria, led to almost three-fold difference (2.8-8.3%) in diagnostic rate. This increase is mostly explained by increasing the cut-off values of VWF measurements from < 30 to ≈ 40 IU dL(-1) . Further refinement of the laboratory diagnosis of type 1 VWD is a priority.

• Authors: T Quiroga, M Goycoolea, S Belmont, O Panes, E Aranda, P Zúñiga, J Pereira, D Mezzano
• Journal: Journal of thrombosis and haemostasis : JTH (J Thromb Haemost) Vol. 12 Issue 8 Pg. 1238-43 (Aug 2014) ISSN: 1538-7836 [Electronic] England
• PMID: 24796601 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 International Society on Thrombosis and Haemostasis.

Chemical References

• Autoantigens

Topics

• Autoantigens (blood)
• Clinical Laboratory Techniques
• Humans
• Retrospective Studies
• von Willebrand Disease, Type 1 (blood, diagnosis)