Abstract | INTRODUCTION: METHODS: After validating that the assay could be performed on an instrument from a different manufacturer, we compared VWF:Ac to VWF ristocetin cofactor activity (VWF:RCo) findings, including ratios of activity/ antigen, for 100 healthy controls and 262 consecutive clinical samples from 217 patients (197 adults, 64 children, n = 1 age unknown) referred for VWF testing. RESULTS: There was excellent correlation (R(2) = 0.96) between VWF:Ac results run at two different sites on two different instruments. VWF:Ac had greater precision and sensitivity to low levels of VWF than the VWF:RCo method. Although there was good correlation between VWF:Ac and VWF:RCo results among healthy controls and patient subjects, VWF:Ac results were undetectable and/or significantly lower than VWF:RCo among patients who had types 2A, 2B, or 2M VWD. Additionally, a higher proportion of patient samples were classified as showing qualitative defects using the VWF:Ac compared with VWF:RCo method. While most samples drawn on VWD therapy had similar VWF levels by VWF:Ac and VWF:RCo, a type 2B VWD subject on replacement had much lower activity estimated by VWF:Ac. CONCLUSION: We conclude that Innovance(®) VWF Ac is suitable for the diagnosis, classification, and monitoring of VWD, and that it has a number of advantages over VWF:RCo method.
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Authors | L Graf, K A Moffat, S A Carlino, A K C Chan, A Iorio, A Giulivi, C P M Hayward |
Journal | International journal of laboratory hematology
(Int J Lab Hematol)
Vol. 36
Issue 3
Pg. 341-51
(Jun 2014)
ISSN: 1751-553X [Electronic] England |
PMID | 24750681
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © 2014 John Wiley & Sons Ltd. |
Chemical References |
- von Willebrand Factor
- Ristocetin
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Topics |
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Automation, Laboratory
- Child
- Child, Preschool
- Female
- Hematologic Tests
(methods, standards)
- Humans
- Infant
- Infant, Newborn
- Male
- Middle Aged
- Quality Control
- Reproducibility of Results
- Ristocetin
- Young Adult
- von Willebrand Diseases
(blood, diagnosis, genetics)
- von Willebrand Factor
(genetics)
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