scholarly journals Results of extended phenotyping of von Willebrand disease in the remote diagnostic program in children

2020 ◽  
Vol 19 (4) ◽  
pp. 102-106
Author(s):  
A. V. Poletaev ◽  
E. A. Seregina ◽  
A. V. Pshonkin ◽  
N. A. Karamyan ◽  
D. V. Fedorova ◽  
...  
Keyword(s):  
Binding Activity ◽  
Von Willebrand Disease ◽  
Remote Diagnostics ◽  
Pediatric Hematology ◽  
National Medical ◽  
Fviii Activity ◽  
Initial Decrease ◽  
Von Willebrand ◽  
Work Up

In the course of our earlier data obtained in remote diagnosis of von Willebrand disease (vWD) program, 16 samples were identified for extended laboratory work up in order to clarify a specific subtype of vWD. Purpose of the study: extended phenotyping of blood samples with suspected type 2 vWD. This study is supported by the Independent Ethics Committee and approved by the Academic Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology, and Immunology. Using 16 aliquoted frozen samples, collagen-binding (vWF:CB) and fVIII-binding activity of vWF (vWF:FVIIIB) tests were performed, as well as multimeric analysis of vWF. Isolated fVIII deficiency with no laboratory signs of 2N vWD subtype were detected in 7 (44%) of 16 patients with an initial decrease in the ratio of fVIII activity to vWF antigen. In the remaining 9 patients, vWF:CB was assessed, which showed a decrease in association with collagen in 6 patients, which allows one to suspect type 2A or 2B. In the remaining 3 with normal vWF:CB patients, type 2M was suspected. MA helped to further identify patients with suspected type 2B vWD. The use of remote diagnostics technologies allows phenotyping most forms of vWD even in patients living in regions with limited laboratory capabilities.

RESULTS OF A RETROSPECTIVE COMPARATIVE ANALYSIS OF THE MANIFESTATIONS AND SEVERITY OF HEMORRHAGIC SYNDROME IN CHILDREN WITH GLANZMANN’S THROMBASTHENIA

2021 ◽  
Vol 100 (5) ◽  
pp. 109-116
Author(s):  
M.V. Ustinova ◽  
◽  
D.V. Fedorova ◽  
A.V. Pshonkin ◽  
A.V. Poletaev ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Severe Disease ◽  
Von Willebrand Disease ◽  
Medical Attention ◽  
Pediatric Hematology ◽  
National Medical ◽  
Clinical Observations ◽  
Bleeding Episodes ◽  
Severe Pathology ◽  
Von Willebrand

Glanzmann thrombastenia (GT) refers to a rare and severe pathology of platelets and causes frequent bleeding episodes in children and adults, miscarriage and intracranial hemorrhage in fetuses and newborns from mothers with GT. Objective of the study: to assess the severity of hemorrhagic syndrome in children diagnosed with GT and to conduct a comparative assessment of bleeding in patients with other hereditary thrombocytopathies and von Willebrand disease (VWD). Materials and methods of research: a retrospective analysis of 25 clinical observations of children diagnosed with GT (8 boys and 17 girls) was carried out; the median age at the time of treatment was 5 years, which were observed at the Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology in 2015–2020. Bleeding manifestations were assessed using the Pediatric Bleeding Questionnaire (PBQ) and the International Society on Thrombosis and Haemostasis Bleeding Assessment Tool (ISTH BAT) standard bleeding scales. The analysis of publications presented in the international databases SCOPUS and PUBMED over the past 10 years on modern approaches to GT therapy has been performed. Results: the diagnosis of GT was established in 25 children, the median PBQ score was 7 points compared with the group of children with thrombocytopathies 3 points [IQR 7 (5,5; 10,5) versus 3 (2; 5), p<0,00001] and VWD 4 points [IQR 7 (5,5; 10,5) versus 4 (2; 5,25), p<0,00001]. On the ISTH BAT scale in children with GT 8 points, in groups with thrombocytopathies 3 points [IQR 8 (6,5; 11,5) versus 3 (2; 5), p<0,00001] and VWD 4 points [IQR 8 (6,5; 11,5) versus 4 (2; 5,25), p<0,00001]. In 23 (92%) children, episodes of bleeding required periodic visits for emergency medical care, in 17 (68%) resulted in anemization and iron deficiency. Compared with the group of children with hereditary thrombocytopathies and VWD patients with GT had more severe and frequent bleeding symptoms, which required seeking medical attention. Conclusion: GT is a rare, severe disease in which bleeding is systemic, leads to anemization, causes frequent hospitalizations, which greatly reduces the quality of life of patients.

Laboratory diagnosis of von Willebrand disease

2010 ◽  
Vol 30 (04) ◽  
pp. 203-206 ◽  
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.

scholarly journals Bleeding Symptoms and von Willebrand Factor Levels: 30-Year Experience in a Tertiary Care Center

2019 ◽  
Vol 25 ◽  
pp. 107602961986691
Author(s):  
Chatphatai Moonla ◽  
Benjaporn Akkawat ◽  
Yaowaree Kittikalayawong ◽  
Autcharaporn Sukperm ◽  
Mukmanee Meesanun ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Care Center ◽  
Tertiary Care ◽  
Bleeding Risk ◽  
Binding Activity ◽  
Von Willebrand Disease ◽  
Von Willebrand ◽  
Willebrand Factor

Correlations between bleeding symptoms and von Willebrand factor (VWF) levels may help to predict hemorrhagic severity in the Westerners with von Willebrand disease (VWD), but data in Asians are lacking. In this study, Thai patients with VWF levels <50 IU/dL without any secondary causes were enrolled from 1988 to 2018 to determine the relationship between VWF levels and hemorrhagic manifestations. According to the current concept, we reclassified VWD and low VWF by VWF levels ≤30 and 30 to 50 IU/dL, respectively. Type 2 VWD was diagnosed if VWF activity to antigen ratio was ≤0.6. Bleeding severity was determined by the condensed MCMDM-1VWD bleeding score (BS). Among 83 patients, VWF activities showed negative correlations with BS ( P = .001), which were higher in type 2 (median: 7, interquartile range [IQR]: 5-11) compared with type 1 VWD (median: 3, IQR: 2-4) and low VWF (median: 4, IQR: 2-8). Bleeding symptoms were indistinguishable between type 1 VWD and low VWF using the 30 IU/dL cutoff point. However, VWF ristocetin cofactor activity or gain-of-function mutant glycoprotein Ib binding activity <36.5 IU/dL and VWF collagen binding activity <34.5 IU/dL could predict increased bleeding risk (BS ≥3) by 92.3% specificity and 70.0% sensitivity ( P < .0001).

scholarly journals The current status of remote diagnosis of von Willebrand disease in children in Russia

2020 ◽  
Vol 19 (3) ◽  
pp. 54-60 ◽  
Author(s):  
A. V. Poletaev ◽  
E. A. Seregina ◽  
D. V. Fedorova ◽  
P. A. Zharkov
Keyword(s):  
Factor Viii ◽  
Russian Federation ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Remote Diagnosis ◽  
Factor Viii Activity ◽  
Pediatric Hematology ◽  
National Medical ◽  
The Russian Federation ◽  
Von Willebrand

The diagnosis of von Willebrand disease (vWD) in children remains a challenge in many regions of our country. This encouraged the Russian Hemophilia Society to create, in 2019, a special diagnostic programme offering remote diagnosis of vWD to patients in regions. Objectives: An interim evaluation of the effectiveness of the programme for remote diagnosis of vWD in children. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. Under this programme, if advised by a hematologist at the place of residence, a patient's peripheral blood was collected, frozen and sent to the Clinical Hemostasis Laboratory at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. Over the period from 11.04.2019 to 07.08.2020, we received 72 frozen peripheral blood samples from children under the age of 18 sent from 21 regions of the Russian Federation. Von Willebrand factor (vWF) ristocetin cofactor activity, vWF antigen levels as well as coagulation factor VIII activity were measured. Out of the 72 samples, only one (1.4%) was inadequate. Reduced vWF activity (30–50%) was observed in 16.7% of cases, and another 16.7% of patients had vWF activity < 30%. VWF antigen levels were 30–50 % in 13.9 % of patients and < 30% in 9.7% of cases. Among the patients with vWF activity < 30%, 1 patient (8.3%) had type 1 vWD, 10 patients (83.3%) – type 2 vWD, 1 child (8.3%) – type 3 vWD. Six children (8.3%) demonstrated reduced factor VIII activity while maintaining normal vWF activity and antigen levels. The coagulation factor VIII activity/vWF antigen ratio was decreased in 8 children (11.1%). The vWD remote diagnosis programme has allowed us to detect abnormalities in 30 patients (41.7%), 16.7% of whom demonstrated laboratory features characteristic of vWD. Eighteen children (25%) require further, more comprehensive laboratory testing. This programme has great potential, especially in underpopulated regions where the development of local diagnostic capabilities may not be economically viable.

Response to DDAVP in children with von Willebrand disease type 2

2009 ◽  
Vol 29 (02) ◽  
pp. 143-148 ◽  
Author(s):  
U. Budde ◽  
K. Beutel ◽  
W.-A. Hassenpflug ◽  
H. Hauch ◽  
T. Obser ◽  
...  
Keyword(s):  
Disease Type ◽  
Von Willebrand Disease ◽  
Molecular Defect ◽  
Variable Response ◽  
Functional Parameters ◽  
Functional Defect ◽  
Biologic Response ◽  
High Level ◽  
Von Willebrand

SummaryWe have prospectively evaluated the biologic response to desmopressin (DDAVP) in 28 children with type 2 von Willebrand disease (VWD) in correlation with the phenotype and the molecular defect of VWF. The diagnosis of VWD type 2 was mainly based on VWF functional parameters and/or an aberrant VWF multimer pattern. Seventeen different mutations were identified (6 of them novel). No response with respect to the functional parameters VWF:RCo and/or VWF:CB was seen in patients with severe abnormality of the VWF multimer pattern. One patient with VWD type 2A phenotype IIC Miami did not respond with respect to VWF:CB, but showed a good response of VWF:Ag and FVIII:C as expected. Interestingly he showed a persistently high level of VWF:Ag and FVIII:C up to 4 hours after DDAVP infusion. Patients with minor alterations of multimer structure and particular mutations responded well to DDAVP, whereas patients with normal multimer structure but a defect in platelet dependent functional parameters did not respond with VWF:RCo. Conclusion: Children with VWD type 2 show a variable response to desmopressin depending on the mutation that correlates with the functional defect and the presence or absence as well as the half-life of large VWF multimers. Our data emphasize the usefulness of DDAVP testing even in patients with VWD type 2, possibly with the exception of VWD type 2B.

The Interaction of Botrocetin with Normal or Variant von Willebrand Factor (Types IIA and IIB) and Its Inhibition by Monoclonal Antibodies that Block Receptor Binding

1992 ◽  
Vol 68 (04) ◽  
pp. 464-469 ◽  
Author(s):  
Y Fujimura ◽  
S Miyata ◽  
S Nishida ◽  
S Miura ◽  
M Kaneda ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Von Willebrand Factor ◽  
Binding Activity ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Normal Individuals ◽  
Rag 1 ◽  
The One ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe have recently shown the existence of two distinct forms of botrocetin (one-chain and two-chain), and demonstrated that the two-chain species is approximately 30 times more active than the one-chain in promoting von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib. The N-terminal sequence of two-chain botrocetin is highly homologous to sea-urchin Echinoidin and other Ca2+-dependent lectins (Fujimura et al., Biochemistry 1991; 30: 1957–64).Present data indicate that purified two-chain botrocetin binds to vWF from plasmas of patients with type IIA or IIB von Willebrand disease and its interaction is indistinguishable from that with vWF from normal individuals. However, an “activated complex” formed between botrocetin and IIB vWF expresses an enhanced biological activity for binding to GP Ib whereas the complex with IIA vWF has a decreased binding activity. Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GPIb, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. This suggests that they recognize an epitope(s) on the vWF molecule in close proximity to the botrocetin binding site.

scholarly journals Evidence for the Misfolding of the A1 Domain within Multimeric von Willebrand Factor in Type 2 von Willebrand Disease

2020 ◽  
Vol 432 (2) ◽  
pp. 305-323 ◽  
Author(s):  
Alexander Tischer ◽  
Maria A. Brehm ◽  
Venkata R. Machha ◽  
Laurie Moon-Tasson ◽  
Linda M. Benson ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

Toward Personalized Treatment for Patients with Low von Willebrand Factor and Quantitative von Willebrand Disease

2021 ◽  
Vol 47 (02) ◽  
pp. 192-200
Author(s):  
James S. O'Donnell
Keyword(s):  
Von Willebrand Factor ◽  
Bleeding Risk ◽  
Von Willebrand Disease ◽  
Personalized Treatment ◽  
Treatment Plans ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

AbstractThe biological mechanisms involved in the pathogenesis of type 2 and type 3 von Willebrand disease (VWD) have been studied extensively. In contrast, although accounting for the majority of VWD cases, the pathobiology underlying partial quantitative VWD has remained somewhat elusive. However, important insights have been attained following several recent cohort studies that have investigated mechanisms in patients with type 1 VWD and low von Willebrand factor (VWF), respectively. These studies have demonstrated that reduced plasma VWF levels may result from either (1) decreased VWF biosynthesis and/or secretion in endothelial cells and (2) pathological increased VWF clearance. In addition, it has become clear that some patients with only mild to moderate reductions in plasma VWF levels in the 30 to 50 IU/dL range may have significant bleeding phenotypes. Importantly in these low VWF patients, bleeding risk fails to correlate with plasma VWF levels and inheritance is typically independent of the VWF gene. Although plasma VWF levels may increase to > 50 IU/dL with progressive aging or pregnancy in these subjects, emerging data suggest that this apparent normalization in VWF levels does not necessarily equate to a complete correction in bleeding phenotype in patients with partial quantitative VWD. In this review, these recent advances in our understanding of quantitative VWD pathogenesis are discussed. Furthermore, the translational implications of these emerging findings are considered, particularly with respect to designing personalized treatment plans for VWD patients undergoing elective procedures.

scholarly journals Acquired von Willebrand disease caused by an autoantibody selectively inhibiting the binding of von Willebrand factor to collagen

Blood ◽  
1994 ◽  
Vol 84 (10) ◽  
pp. 3378-3384 ◽  
Author(s):  
PJ van Genderen ◽  
T Vink ◽  
JJ Michiels ◽  
MB van 't Veer ◽  
JJ Sixma ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Binding Activity ◽  
Von Willebrand Disease ◽  
Low Grade ◽  
Bleeding Tendency ◽  
Glycoprotein Ib ◽  
Acquired Von Willebrand Disease ◽  
Recurrent Epistaxis ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract An 82-year-old man with a low-grade malignant non-Hodgkin lymphoma and an IgG3 lambda monoclonal gammopathy presented a recently acquired bleeding tendency, characterized by recurrent epistaxis, easy bruising, and episodes of melena, requiring packed red blood cell transfusions. Coagulation studies showed a von Willebrand factor (vWF) defect (Ivy bleeding time, > 15 minutes; vWF antigen [vWF:Ag], 0.08 U/mL; ristocetin cofactor activity [vWF:RCoF], < 0.05 U/mL; collagen binding activity [vWF:CBA], 0.01 U/mL; absence of the high molecular weight multimers of vWF on multimeric analysis). Mixing experiments suggested the presence of an inhibitor directed against the vWF:CBA activity of vWF without significantly inhibiting the FVIII:C, vWF:Ag, and vWF:RCoF activities. The inhibitor was identified as an antibody of the IgM class by immunoabsorption of vWF and inhibitor-vWF complexes from the plasma of the patient. Subsequent immunoprecipitation experiments using recombinant fragments of vWF showed that the inhibitor reacted with both the glycoprotein Ib binding domain (amino acids [aa] 422–826) and the A3 (aa 909–1112) domain of vWF, but not with the A2 (aa 716–908) or D4 (aa 1183–1535) domains. We conclude that the IgM autoantibody inhibits the vWF:CBA activity by reacting with an epitope present on both the glycoprotein Ib and A3 domains of vWF.

Sign in / Sign up

Export Citation Format

Share Document