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Lai SW, Chang CY, Cheng SN, Hu SH, Lai CY, Chen YC. A Comparative Evaluation of an Automated Functional Assay for Von Willebrand Factor Activity in Type 1 Von Willebrand Disease. Int J Gen Med 2021; 14:5167-5174. [PMID: 34511999 PMCID: PMC8421256 DOI: 10.2147/ijgm.s321605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/25/2021] [Indexed: 11/23/2022] Open
Abstract
Background von Willebrand factor ristocetin cofactor activity (VWF:RCo) is the standard functional assay used for von Willebrand disease (VWD) diagnosis. However, it has some drawbacks including being time consuming and labor intensive and having high inter-laboratory variability. The HemosIL VWF activity assay has the advantages of both high speed and automation. The purpose of this study was to prospectively compare these two functional assays for type 1 VWD detection. Methods Plasma samples from 108 subjects were assessed in this study. HemosIL VWF activity was measured with the HemosIL latex immunoturbidimetric commercial kits by the ACL TOP coagulation analyzer. VWF:RCo was measured by platelet aggregation method. Pearson correlation analyses were performed to estimate the correlation of HemosIL VWF activity with VWF:RCo. Receiver-operator characteristic (ROC) curve analysis was used to evaluate the performance of the two diagnostic tests. Results The correlation coefficient between VWF:RCo and HemosIL VWF activity was 0.874 overall and was 0.761 and 0.811 in the cohorts of type 1 VWD and non-VWD, respectively. The sensitivity and specificity of HemosIL VWF activity assay for type 1 VWD identification were 94.7% and 80.0%, respectively, and the ROC curve of HemosIL VWF activity was larger than that of VWF:RCo (0.928 vs 0.863, p=0.0138). Finally, the positive and negative predictive values of the HemosIL VWF activity assay for type 1 VWD detection were 72.0% and 96.6%, respectively. Conclusion Our results demonstrate that the HemosIL VWF activity assay was an effective method for type 1 VWD screening and diagnosis. It carried good sensitivity and specificity and had a higher ROC curve than VWF:RCo besides showing good correlation with VWF:RCo. With its advantages of greater speed and automated performance, these results suggest that the HemosIL VWF activity assay was reliable and precise in the clinical setting.
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Affiliation(s)
- Shiue-Wei Lai
- Hemophilia Care and Research Center, Tri-Service General Hospital, Taipei, Taiwan.,Division of Hematology/Oncology, Department of Internal Medicine, Tri-service General Hospital, National Defense Medical Center, Taipei, Taiwan.,School of Medicine, Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chia-Yau Chang
- School of Medicine, Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Pediatric Hematology/Oncology, Hemophilia Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Shin-Nan Cheng
- Hemophilia Care and Research Center, Tri-Service General Hospital, Taipei, Taiwan.,Department of Pediatrics, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan.,Department of Pediatrics, National Defense Medical Center, Taipei, Taiwan
| | - Shu-Hsia Hu
- Hemophilia Care and Research Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Chung-Yu Lai
- Graduate Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei City, 114, Taiwan
| | - Yeu-Chin Chen
- Hemophilia Care and Research Center, Tri-Service General Hospital, Taipei, Taiwan.,Division of Hematology/Oncology, Department of Internal Medicine, Tri-service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Ettel M, Nardi MA, McVoy L. Validation of automated latex von Willebrand factor activity assay in a new prospective study including post-treatment patient samples. Int J Lab Hematol 2017; 39:286-292. [PMID: 28120508 DOI: 10.1111/ijlh.12622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 12/06/2016] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Von Willebrand disease (VWD) is the most prevalent inherited bleeding disorder. Diagnosis requires measurement of VWF-platelet binding function, for which VWF ristocetin cofactor activity (VWF:RCo) is the reference method. Recently, an automated latex particle-enhanced immunoturbidimetric von Willebrand factor activity assay (VWF:Ab) has been validated showing superior characteristics. We further validate VWF:Ab in a prospective study including post-treatment patient samples. METHODS A total of 1151 samples were collected from patients tested for VWD, including 119 samples from patients treated with desmopressin or VWF replacement product. All samples were tested for VWF:Ab and VWF:RCo, and the methods were compared using linear regression. Imprecision, linearity and lower detection limit were determined for both assays. RESULTS VWF:Ab showed improved precision compared to VWF:RCo. Linear regression of VWF:Ab and VWF:RCo across all samples exhibited good agreement (R2 = 0.89) with statistical significance (P < 0.001) and bias of -8.7. Concordance was high in classifying samples as normal or abnormal. Analysis of treated samples showed excellent agreement (R2 = 0.91) with statistical significance (P < 0.001) and bias of -4.3. CONCLUSIONS Our analysis validates the VWF:Ab assay in a prospective study of a large cohort of patient samples and extends these results to post-treatment patient samples.
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Affiliation(s)
- M Ettel
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - M A Nardi
- Department of Pathology, New York University School of Medicine, New York, NY, USA.,Department of Pediatrics, New York University School of Medicine, New York, NY, USA
| | - L McVoy
- Department of Pathology, New York University School of Medicine, New York, NY, USA
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Lasne D, Dey C, Dautzenberg MD, Cherqaoui Z, Monge F, Aouba A, Torchet MF, Geloen D, Landais P, Rothschild C. Screening for von Willebrand disease: contribution of an automated assay for von Willebrand factor activity. Haemophilia 2011; 18:e158-63. [PMID: 21951857 DOI: 10.1111/j.1365-2516.2011.02662.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Measuring von Willebrand factor (VWF) activity is essential to the diagnosis of von Willebrand disease (VWD). The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). However, that test is technically challenging and has high intra- and inter-assay variabilities. The HemosIL VWF activity (VWF:AC) is a fully automated assay, recently proposed as a good alternative to VWF:RCo for VWD diagnosis. This study was undertaken to assess this new method. First, the analytical performance of VWF:AC on an automated coagulo-meter (ACLTop) was determined, and then this new method was compared with VWF:RCo and the platelet function analyzer (PFA100) for 160 patients referred for VWD screening. The VWF:AC achieved acceptable precision with within-run and between-run coefficients of variation ranging from 2.3% to 14.1%, and linearity from 10% to 100%. Despite some marked differences between VWF:AC and VWF:RCo for 10 plasmas tested, their agreement for VWD diagnosis was good. The VWF:AC had sensitivity similar to that of PFA100 (close to 100%), but better specificity (97.7% vs. 66% or 60%, depending on the cartridge used). The good analytical performance, and the sensitivity and specificity of VWF:AC to detect VWF deficiency renders it a suitable method for VWD screening. Our findings support VWF:AC use for the diagnostic work-up of VWD, paying close attention to concomitant clinical signs and bleeding score, as recommended for VWD.
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Affiliation(s)
- D Lasne
- Laboratoire d'Hématologie, Hôpital Necker, AP-HP, Paris, France.
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Evaluation of von Willebrand factor activity in factor VIII/von Willebrand factor concentrates with the automated von Willebrand factor: activity IL test. Blood Coagul Fibrinolysis 2010; 21:221-8. [PMID: 20179578 DOI: 10.1097/mbc.0b013e3283367917] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Truss NJ, Beavis J, MacCallum PK, Harrison P, Warner TD. Rapid and accurate method for the von Willebrand factor ristocetin cofactor assay using 96-well microtiter plates. J Thromb Haemost 2009; 7:1226-8. [PMID: 19422441 DOI: 10.1111/j.1538-7836.2009.03466.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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CHEN YC, CHAO TY, CHENG SN, HU SH, LIU JY. Prevalence of von Willebrand disease in women with iron deficiency anaemia and menorrhagia in Taiwan. Haemophilia 2008; 14:768-74. [DOI: 10.1111/j.1365-2516.2008.01777.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Hertzberg MS, Mammen J, McCraw A, Nair SC, Srivastava A. Achieving and maintaining quality in the laboratory. Haemophilia 2007; 12 Suppl 3:61-7. [PMID: 16683998 DOI: 10.1111/j.1365-2516.2006.01278.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In order to ensure the delivery of a service of the highest possible quality, it is an essential requirement that laboratories undertake strict internal quality control (QC) measures as well as participate in external quality assessment (EQA) schemes. For any given test, a critical part of the internal QC process involves the establishment of reference intervals using samples taken from normal individuals, and then calculating limits representing the 95% range. This forms the basis for assessment of abnormal test results, which will in turn impact on laboratory performance in proficiency testing exercises in EQA programmes. Whereas for plasma-based assay systems, variability in performance in EQA exercises is usually determined by measurement of a coefficient of variation (CV), results of genetic testing is usually measured in absolute terms. Despite this, results of genetic EQA programmes confirm that errors in testing do occur, as much because of inadvertent sample switching and transcription errors as to analytical mistakes. EQA programmes involving identification of mutations by DNA sequencing, such as haemophilia, is made difficult by the high information content of sequence data. Nevertheless, results show that errors are usually made in the naming of the mutations, indicating that this is an evolving and poorly standardized area. Developing countries face particular challenges in the encouragement of laboratories to participate in local EQA programmes, as well as in relation to the logistical issues of sample provision, distribution and result collation in an effective and affordable manner.
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Affiliation(s)
- M S Hertzberg
- Department of Haematology, ICPMR and Haematology RCPA QAP, Westmead Hospital, Westmead, NSW, Australia.
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De Vleeschauwer A, Devreese K. Comparison of a new automated von Willebrand factor activity assay with an aggregation von Willebrand ristocetin cofactor activity assay for the diagnosis of von Willebrand disease. Blood Coagul Fibrinolysis 2006; 17:353-8. [PMID: 16788311 DOI: 10.1097/01.mbc.0000233365.10981.08] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
von Willebrand disease (VWD) is caused by quantitative and/or qualitative defects of von Willebrand factor (VWF). The HemosIL von Willebrand Factor Activity assay, a new automated immunological test to measure VWF activity, was implemented on STAC and compared with the von Willebrand ristocetin cofactor activity (VWF:RCo) aggregation method. Imprecision and dilution studies were also performed. Within-run imprecision was 17.2% and between-run imprecision was 8.3% (coefficients of variation). Dilution studies showed a linearity between 12.5 and 100%. Passing and Bablok regression comparing the HemosIL von Willebrand Factor Activity assay and the aggregation method yielded a slope of 1.25 (95% confidence interval: 1.11-1.38) and intercept of -1.40 (95% confidence interval: -8.07 to 0.00). The correlation coefficient was 0.84 (95% confidence interval: 0.78-0.89). With a cut-off value of 50% for VWF activity, the assay has a sensitivity of 94.1% and a specificity of 92.8%, compared with the VWF:RCo aggregation assay with a cut-off value of 60% producing a sensitivity of 100.0% (specificity 87.6%). With a cut-off value of 60%, the HemosIL von Willebrand Factor Activity assay on STAC is a reliable assay for VWD. VWF:RCo or other functional testing is still required to confirm the diagnosis and for further classification of VWD.
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Affiliation(s)
- An De Vleeschauwer
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University Hospital, Ghent, Belgium
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van den Besselaar AMHP, Haas FJLM, Kuypers AWHM. Harmonisation of factor VIII:C assay results: study within the framework of the Dutch project 'Calibration 2000'. Br J Haematol 2006; 132:75-9. [PMID: 16371022 DOI: 10.1111/j.1365-2141.2005.05829.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a Dutch project for harmonisation of factor VIII coagulant activity (FVIII:C) assays, the commutability of potential calibrators for FVIII:C was assessed by means of a 'twin-study design', which is in essence a multi-centre, split-patient sample, between-field-methods protocol. Commutability was defined as the degree to which a material yielded the same numerical relationships between results of measurements by a given set of measurement procedures as those between the expectations of the relationships for the same procedures applied to those types of material for which the procedures were intended. The study consisted of the simultaneous analysis of fresh frozen patient plasmas and three potential calibrators for FVIII:C by 16 Dutch laboratories forming eight couples. The state-of-the-art intra-laboratory standard deviation was used to assess the commutability of the potential calibrators. One potential calibrator was used to harmonise FVIII:C assay results in a Dutch field study. The inter-laboratory coefficient of variation of two test samples could be reduced significantly, but no significant effect was observed with three other test samples. We recommend that at least three different sample dilutions be used in each FVIII:C assay, in agreement with previous recommendations.
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Affiliation(s)
- Anton M H P van den Besselaar
- Department of Haematology, Haemostasis and Thrombosis Research Centre, Leiden University Medical Centre, Leiden, The Netherlands.
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Abstract
AbstractMild bleeding disorders are a common reason for a referral to a hematologist and these conditions can be challenging to evaluate. Recent research has highlighted that some bleeding symptoms are quite common in the general population and that there is clinical variability in symptom expression among individuals with defined bleeding problems. Moreover, bleeding risks for many bleeding disorders are unknown. This article reviews symptoms and problems that can be considered suspicious of a mild form of bleeding disorder and the diagnostic investigations useful to evaluate these problems. A stepwise approach is presented for the diagnostic evaluation, to allow detection of common and rare coagulation and fibrinolytic defects, and adequate assessments of potential von Willebrand factor and platelet problems. Some common problems in the diagnosis and management of mild bleeding problems are reviewed, including the common failure to establish a diagnosis with testing. An approach is proposed for translation of knowledge to patients who are challenged by mild bleeding problems.
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Affiliation(s)
- Catherine P M Hayward
- McMaster University, Health Sciences Center, 1200 Main St., West, Room 2N31, Hamilton, Ontario L8N 3Z5, Canada.
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