Volume 41, Issue 6 pp. 762-771
ORIGINAL ARTICLE

Semi-automated von Willebrand factor multimer assay for von Willebrand disease: Further validation, benefits and limitations

Susan Oliver

Susan Oliver

Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, NSW, Australia

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Thiru Vanniasinkam

Thiru Vanniasinkam

School of Biomedical Science, Charles Sturt University, Wagga Wagga, NSW, Australia

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Soma Mohammed

Soma Mohammed

Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, NSW, Australia

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Ronny Vong

Ronny Vong

Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, NSW, Australia

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Emmanuel J. Favaloro

Corresponding Author

Emmanuel J. Favaloro

Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, NSW, Australia

Sydney Centres for Thrombosis and Haemostasis, Westmead Hospital, Westmead, NSW, Australia

Correspondence

Emmanuel J. Favaloro, NSW Health Pathology, Westmead Hospital, Westmead NSW 2145, Australia.

Email: [email protected]

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First published: 11 September 2019
Citations: 20

Abstract

Introduction

Accurate diagnosis of von Willebrand disease (VWD) enables effective patient management. von Willebrand factor (VWF) multimer analysis provides useful information regarding VWF multimer structure, thereby aiding VWD subtyping and management; however, historically technically challenging assays have had limited utility. This study evaluates the Sebia Hydrasys Hydragel-11 semi-automated VWF multimer assay and further validates the Hydragel-5 gel system, as primarily pertaining to VWD diagnostics and monitoring of therapy.

Methods

Provisionally diagnosed (via a reference assay test panel) archived patient samples and prospective test patient samples, including those undergoing desmopressin trial or therapy monitoring, along with commercial and in-house control material and various external quality assessment (EQA) samples, were analysed. VWF multimers were evaluated for presence, loss or partial loss of high molecular weight (HMWM) and intermediate molecular weight (IMWM) multimers by both visual inspection and densitometric scanning, and comparison with reference assay results.

Results

All anticipated multimer patterns were reproduced, with patients generally showing multimer profiles matching expected patterns according to VWD type based on reference test panel ‘diagnosis’. Occasional discrepancies were resolved by retesting. The increase in plasma VWF following desmopressin therapy was also clearly demonstrated. Multimer profiles of EQA samples complemented reference test panel results and matched EQA targets. There were some ‘technical’ limitations noted.

Conclusion

This easy to use, standardised, semi-automated multimer analysis system can demonstrate the multimer profile of VWD patients, thus representing an additional laboratory tool for improved diagnosis, thereby facilitating appropriate patient management.

CONFLICT OF INTEREST

The authors have no competing interests.

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