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

von Willebrand disease (VWD) is a bleeding disorder caused by either quantitative (type 1 and 3) or qualitative (type 2) defects of von Willebrand factor (VWF). No single available test provides appropriate information about the various functions of VWF, and the laboratory diagnosis of VWD is based on a panel of tests, including the measurement of factor VIII coagulant activity (FVIIIC), VWF antigen levels (VWF:Ag), VWF activity as measured by the ristocetin co-factor activity (VWF:RCo), the collagen-binding activity of VWF (VWF:CB), VWF multimer analysis, ristocetininduced platelet agglutination (RIPA), the factor-VIII-binding assay of plasma VWF and VWF propeptide levels. Due to the heterogeneity of VWF defects and the variables that interfere with VWF levels, a correct diagnosis of types and subtypes may sometimes be difficult, but is very important for therapy. Furthermore, the RCo assay and the RIPA test are based on platelet agglutination in reaction with the non-physiological antibiotic ristocetin. These tests also have low sensitivity and are difficult to standardise. Therefore, several analyses (tests) are required to diagnose VWD and it is important to be aware of the pitfalls to which these tests are subjected in terms of the diagnosis. In this article, the laboratory diagnosis of patients with type 1, 2A, 2B, 2M, 2N and 3 VWD will be explained by using a modified algorithm that was first proposed by the guidelines for diagnosis and treatment of VWD in Italy.

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Laboratory diagnosis of von Willebrand disease

Hämostaseologie ◽

10.1055/s-0037-1619057 ◽

2010 ◽

Vol 30 (04) ◽

pp. 203-206 ◽

Cited By ~ 11

Author(s):

R. Schneppenheim ◽

J. Patzke

Keyword(s):

Laboratory Diagnosis ◽

Binding Activity ◽

Von Willebrand Disease ◽

Activity Assay ◽

Binding Assays ◽

New Type ◽

Von Willebrand ◽

Made In

SummaryOver the last decade, considerable progress has been made in the laboratory diagnosis of VWD. Precise, sensitive and automated VWF : Ag assays became widely available. The VWF : RCo performance was improved to a certain degree. However, the sensitivity, precision and general availability of automated applications is not yet optimal. Nevertheless, this type of assay is still recognized as superior to other activity assays, e. g. VWF : CBA assays and antibody-binding “activity” assays, for the detection of defects in VWF function.A decision limit of either 30 or 40 IU dl-1 VWF (VWF:RCo or VWF:Ag) is recommended for a diagnosis of type 1 VWD. Type 2 VWD can be differentiated from type 1 by calculating the VWF:RCo/VWF:Ag ratio.Improved and easier to perform multimer analysis and genetic testing are beginning to facilitate the diagnosis of the VWD type 1, 2A, 2B, 2N, 2M or 3. Within type 1 or 2, a decreased VWF survival can be detected by the VWFpp assay and its ratio to VWF : Ag.A new type of VWF activity assay, based on the binding of VWF to a GPIb〈-fragment, has been developed. One assay variant does not need ristocetin as a cofactor anymore. The performance investigations presented so far are very promising. It is probable that these GPIb〈-binding assays will detect functional VWF defects as the VWF : RCo assay, but are much more sensitive and precise. Fully automated applications on routine analyzers are expected to be commercialized soon.

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New advances in the diagnosis of von Willebrand disease

Hematology ◽

10.1182/hematology.2019000064 ◽

2019 ◽

Vol 2019 (1) ◽

pp. 596-600

Author(s):

Ruchika Sharma ◽

Sandra L. Haberichter

Keyword(s):

Diagnostic Algorithm ◽

Laboratory Diagnosis ◽

Binding Activity ◽

Von Willebrand Disease ◽

Assessment Tools ◽

Molecular Testing ◽

Platelet Binding ◽

History Of ◽

Von Willebrand

Abstract von Willebrand disease (VWD) is the most common autosomal inherited bleeding disorder, with an estimated prevalence of 1 in 1000 individuals. VWD is classified into quantitative and qualitative forms. Diagnosis of VWD is complex and requires (1) a personal history of bleeding symptoms, (2) family history of bleeding or VWD, and (3) confirmatory laboratory testing. There are certain bleeding assessment tools to objectively measure bleeding symptoms in patients that have been shown to correlate with the diagnosis as well as the severity of VWD. Laboratory diagnosis requires at least initially a measurement of von Willebrand factor (VWF) antigen levels, VWF platelet binding activity (VWF:RCo, VWF:GPIbM, and VWF:GPIbR), and factor VIII (FVIII) activity. Additional testing to confirm the specific subtype may include VWF collagen binding activity, low-dose ristocetin VWF-platelet binding, FVIII-VWF binding, VWF multimer analysis, and VWF propeptide antigen. Recent advances have been made regarding some of these assays. Molecular testing in VWD is not found to be useful in “low VWF” or most type 1 VWD cases but may be informative in patients with severe type 1 VWD, type 1C VWD, type 2 VWD, or type 3 VWD for accurate diagnosis, genetic counseling, and appropriate treatment. The diagnostic algorithm for VWD is complex, but advances continue to be made in improving VWF functional assays and diagnostic pathways.

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Outgrowing the laboratory diagnosis of type 1 von Willebrand disease: A two decade study

American Journal of Hematology ◽

10.1002/ajh.24962 ◽

2017 ◽

Vol 93 (2) ◽

pp. 232-237 ◽

Cited By ~ 5

Author(s):

Mouhamed Yazan Abou-Ismail ◽

Gbolahan O. Ogunbayo ◽

Michelle Secic ◽

Peter A. Kouides

Keyword(s):

Laboratory Diagnosis ◽

Von Willebrand Disease ◽

Von Willebrand

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Resemblance to vWD Types and Laboratory Diagnosis of Obligatory Carriers of Type 3 von Willebrand Disease

Clinical and Applied Thrombosis/Hemostasis ◽

10.1177/1076029610379847 ◽

2010 ◽

Vol 17 (6) ◽

pp. E21-E24

Author(s):

Mehmet Akin ◽

Deniz Yilmaz Karapinar ◽

Can Balkan ◽

Yilmaz Ay ◽

Kaan Kavakli

Keyword(s):

Von Willebrand Factor ◽

Laboratory Diagnosis ◽

Von Willebrand Disease ◽

Fast Method ◽

Close Relatives ◽

Type 3 ◽

Von Willebrand ◽

Willebrand Factor ◽

Severe Type

Objectives: It is important to diagnose obligatory carrier (OC) type 3 von Willebrand Disease (vWD) in countries, such as Turkey, where marriages between relatives is common. However, mild bleeding or no bleeding in such patients complicates the diagnosis of the disease. It is not clear how the diagnosis of OC type 3 vWD will be made based on FVIII:C (Factor VIII activity), vWF:Ag (von Willebrand factor antigen), vWF:RCo (von Willebrand factor ristocetin cofactor activity), and PFA (platelet function analyzer )-100 parameters. Therefore, the purpose of the study is to investigate how OC type 3 vWD diagnoses may be established by studying laboratory phenotypes of close relatives of patients with diagnosed 3 vWD. Patients and Methods: 8 patients with type 3 vWD (index cases) and 20 patients who were defined as OCs type 3 vWD were enrolled into the study. Result: 10 cases had similarity with mild type VWD, 4 cases had similarity with moderate type 1 vWD, 4 other cases had type 1 or 2 vWD similarities, 1 case had similarity with severe type 1 vWD, and 1 case also had similarity with severe type 1 or type 2 vWD; regarding their laboratory phenotypic characteristics. Conclusion: we identified that OC type 3 vWD is similar specifically to type 1 vWD in terms of laboratory phenotypic character, and we suggest that it may be used with PFA-100 as an easy and fast method in screening relatives.

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Von Willebrand Factor (VWF) Propeptide and Factor VIII (FVIII) Levels Identify the Contribution of Decreased Synthesis and/or Increased Clearance Mechanisms in the Pathogenesis of Type 1 Von Willebrand Disease (VWD) in the Zimmerman Program

Blood ◽

10.1182/blood.v128.22.874.874 ◽

2016 ◽

Vol 128 (22) ◽

pp. 874-874

Author(s):

Sandra L Haberichter ◽

Pamela A Christopherson ◽

Veronica H Flood ◽

Joan Cox Gill ◽

Kenneth D Friedman ◽

...

Keyword(s):

Underlying Mechanism ◽

Laboratory Diagnosis ◽

Von Willebrand Disease ◽

Sequence Variant ◽

Specific Marker ◽

Common Precursor ◽

True Type ◽

The Mean ◽

Von Willebrand

Abstract Laboratory diagnosis of VWD is challenging, with multiple tests required to obtain an accurate assessment. Plasma VWF level represents a balance between synthesis, secretion, and clearance. Although synthesized together, VWFpp and VWF circulate in plasma independently with differing half-lives. Plasma VWFpp level is used to assess synthesis/secretion, VWFpp/VWF:Ag ratio to indicate clearance of VWF, and FVIII/VWF:Ag ratio to assess VWF synthesis and clearance. We sought to identify the underlying VWD pathophysiology in subjects enrolled in the Zimmerman Program including 245 healthy controls, 175 "low VWF" (VWF:Ag 30-50), 69 type 1 (VWF:Ag<30), 57 type 1C (VWF:Ag<30 and VWFpp/VWF:Ag>3), and 9 type 1-severe (1S) (VWF:Ag<5). FVIII levels were significantly reduced (p < 0.0001) in VWD subjects compared to controls. The mean FVIII/VWF:Ag ratio in "low VWF" (1.5), types 1 (2.4), 1C (2.9), and 1S (8.7) were significantly different from controls (p < 0.0001). VWFpp levels in all subjects were significantly lower than controls with type 1S subjects demonstrating the most reduced levels. The mean VWFpp/VWF:Ag was significantly increased compared to controls in type 1 (1.9) and 1C (8.4) subjects. VWFpp level, VWFpp/VWF:Ag and FVIII/VWF:Ag were used to define the underlying pathophysiology in VWD subtypes. A VWFpp/VWF:Ag > 3.0 indicates increased VWF clearance. VWFpp level < 50 IU/dL or FVIII/VWF:Ag > 2.0 indicate reduced VWF synthesis/secretion. A combination of increased clearance/reduced secretion may be identified or neither mechanism. Only 9% of "low VWF" subjects had increased FVIII/VWF:Ag, while 15% had decreased VWFpp suggesting reduced secretion. Other unidentified mechanisms may explain the majority of these "low VWF" cases. In type 1, 38 had increased FVIII/VWF:Ag and 48 had reduced VWFpp indicating reduced secretion in 55-70% of cases. In type 1C, all had increased VWFpp/VWF:Ag, 44 had increased FVIII/VWF:Ag and 19 reduced VWFpp. Reduced secretion may play a role in 33 -77% of these subjects, in addition to increased VWF clearance. All 9 type 1S had reduced VWFpp and 8/9 had increased FVIII/VWF, indicating a reduced secretion mechanism in nearly all cases. To assess the influence of sequence variant (SV) location on VWF synthesis/secretion, levels were analyzed by presence or absence of SV and SV location by VWF domain. 62% of the VWD cohort had SV identified (23% with >1 SV) while 38% had no SV. Of those with SV, 52% had increased FVIII/VWF:Ag and 48% had decreased VWFpp, suggesting reduced secretion; 31% had increased VWFpp/VWF:Ag indicative of increased clearance; and 32% had neither mechanism. In the group with no SV, only 7% had increased FVIII/VWF:Ag and 17% had decreased VWFpp while 77% had neither mechanism identified. Of those subjects with reduced secretion as indicated by increased FVIII/VWF:Ag, the majority of SV were found in A1 (29%), D3 (22%) and D1 (13%) which was similar to those with reduced secretion indicated by decreased VWFpp level in A1 (25%), D3 (21%) and D1 (15%). An increased VWFpp/VWF:Ag ratio predicting increased clearance was found in patients with SV in D3, A1 and D4 domains. Patients with both increased clearance and reduced secretion had SV in A1 (53%), D3 (19%) and D4 (11%). Subjects who had neither mechanism identified had SV in A2 (25%), C1-C6 (18%) and D2 (16%), suggesting these SV are associated with other, yet unidentified mechanisms. Although VWFpp level and FVIII/VWF:Ag are both thought to indicate VWF synthesis/secretion, some discrepancies were observed. VWFpp level may be the more specific marker, as VWFpp and VWF share a common precursor protein. Reduced secretion plays a role in nearly all type 1S, 70% of type 1, and 15% of "low VWF" subjects. Additionally, SV in A1, D3, and D4 may be associated with decreased secretion and/or increased clearance while those in D1 may be associated with decreased secretion alone. No SV were found in 85% of "low VWF" subjects that is consistent with the observation that the majority of these cases (81%) had neither decreased secretion nor increased clearance mechanisms identified. The mechanistic cause of bleeding in these patients remains undefined. Assay of VWFpp and corresponding VWF:Ag ratios may help to define the underlying mechanism in VWD subjects and identify true type 1C VWD patients, which is clinically important for therapeutic treatment. Disclosures Flood: CSL Behring: Consultancy; Baxalta: Consultancy. Friedman:Shire: Consultancy; NovoNordisk: Consultancy; CSL Behring: Consultancy; Alexion: Speakers Bureau.

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Performance and Clinical Utility of a Commercial von Willebrand Factor Collagen Binding Assay for Laboratory Diagnosis of von Willebrand Disease

Clinical Chemistry ◽

10.1373/clinchem.2006.070730 ◽

2006 ◽

Vol 52 (10) ◽

pp. 1965-1967 ◽

Cited By ~ 9

Author(s):

Joanna Popov ◽

Olga Zhukov ◽

Susan Ruden ◽

Terry Zeschmann ◽

Anthony Sferruzza ◽

...

Keyword(s):

Binding Assay ◽

Binding Capacity ◽

Laboratory Diagnosis ◽

Von Willebrand Disease ◽

Collagen Binding ◽

Von Willebrand ◽

Ristocetin Cofactor ◽

Probable Type

Abstract Background: Von Willebrand disease (VWD) diagnosis and classification usually require a combination of nonspecific and VW-factor (VWF)-specific assays. We evaluated the analytical performance of a commercially available collagen-binding assay (CBA) and its usefulness in conjunction with other assays for laboratory diagnosis of VWD. Methods: We used a commercial CBA ELISA (Life Technologies) to evaluate 3085 plasma samples. We used standard procedures to perform other assays, including factor VIII activity (FVIII:C), VWF antigen (VWF:Ag), ristocetin cofactor activity, VWF collagen binding capacity (VWF:CB), and VWF multimeric analysis. Results: CBA intra- and interassay CVs were <6% and <13%, respectively. Reference intervals were 45%–198% for VWF:CB and 0.75–1.32 for the VWF:CB/Ag ratio. Of 3085 samples tested, 235 (8%) had results commonly associated with VWD. Multimer analysis and phenotypic data in 156 samples identified VWD types as: 91 (58%) type 1, 62 (40%) type 2, and 3 (2%) type 3. Of the 91 type 1 samples, proportional decreases in functional activity were seen in 75 samples (82%) according to CBA and in 63 samples (69%) according to the ristocetin cofactor assay. Of the type 2 samples, 10 were further identified as probable type 2A, 26 as probable type 2B, 12 as probable type 2M, and 14 could not be subtyped. VWF:CBA/Ag ratios <0.5 occurred in 83% of VWD type 2A and 2B samples, indicating characteristic functional discordance. Mean (SD) VWF:CB values were significantly higher in individuals without group O blood [113 (45)] than in those with group O blood [83 (32)] (t-test, P = 0.007). Conclusions: The commercial CBA assay produces reliable results and is useful for laboratory diagnosis of VWD.

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Laboratory Diagnosis and Molecular Basis of Mild von Willebrand Disease Type 1

Acta Haematologica ◽

10.1159/000214847 ◽

2009 ◽

Vol 121 (2-3) ◽

pp. 85-97 ◽

Cited By ~ 6

Author(s):

Jan Jacques Michiels ◽

Zwi Berneman ◽

Alain Gadisseur ◽

Marc van der Planken ◽

Wilfried Schroyens ◽

...

Keyword(s):

Molecular Basis ◽

Laboratory Diagnosis ◽

Disease Type ◽

Von Willebrand Disease ◽

Von Willebrand

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Screening for haemorrhagic disorders in paediatric patients by means of a questionnaire

Hämostaseologie ◽

10.1055/s-0037-1621503 ◽

2009 ◽

Vol 29 (S 01) ◽

pp. S87-S89 ◽

Cited By ~ 4

Author(s):

I. Music ◽

M. Novak ◽

B. Acham-Roschitz ◽

W. Muntean

Keyword(s):

Predictive Value ◽

Laboratory Diagnosis ◽

Von Willebrand Disease ◽

Control Group ◽

Older Children ◽

Mild Disease ◽

History Of ◽

Von Willebrand ◽

Specific Symptoms ◽

Infants And Young Children

SummaryAim: In children, screening for haemorrhagic disorders is further complicated by the fact that infants and young children with mild disease in many cases most likely will not have a significant history of easy bruising or bleeding making the efficacy of a questionnaire even more questionable. Patients, methods: We compared the questionnaires of a group of 88 children in whom a haemorrhagic disorder was ruled out by rigorous laboratory investigation to a group of 38 children with mild von Willebrand disease (VWD). Questionnaires about child, mother and father were obtained prior to the laboratory diagnosis on the occasion of routine preoperative screening. Results: 23/38 children with mild VWD showed at least one positive question in the questionnaire, while 21/88 without laboratory signs showed at least one positive question. There was a trend to more specific symptoms in older children. Three or more positive questions were found only in VWD patients, but only in a few of the control group. The question about menstrual bleeding in mothers did not differ significantly. Sensitivity of the questionnaire for a hemostatic disorder was 0.60, while specifity was 0.76. The negative predictive value was 0.82, but the positive predictive value was only 0.52. Conclusions: Our small study shows, that a questionnaire yields good results to exclude a haemostatic disorder, but is not a sensitive tool to identify such a disorder.

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