A Reliable von Willebrand Factor: Ristocetin Cofactor Enzyme-Linked Immunosorbent Assay to Differentiate between Type 1 and Type 2 von Willebrand Disease

2002 ◽  
Vol 28 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Karen Vanhoorelbeke ◽  
Nancy Cauwenberghs ◽  
Griet Vandecasteele ◽  
Stephan Vauterin ◽  
Hans Deckmyn
Keyword(s):  
Immunosorbent Assay ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Ristocetin Cofactor

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.

PFA-100 monitoring of von Willebrand factor (VWF) responses to desmopressin (DDAVP) and factor VIII/VWF concentrate substitution in von Willebrand disease type 1 and 2

2008 ◽  
Vol 100 (09) ◽  
pp. 462-468 ◽  
Author(s):  
Huub H. D. M. van Vliet ◽  
Mies C. Kappers-Klunne ◽  
Jan J. Michiels ◽  
Frank W. G. Leebeek
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Before And After ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryDose-response relationship was studied between PFA-100 closure times (PFA CTs) and factor (F)VIII-von Willebrand factor (VWF) parameters in patients with von Willebrand disease (VWD) type 1 and type 2 before and after treatment with DDAVP (n=84) or FVIII/VWF concentrate (n=38). DDAVP treatment of patients with VWD type 1 normalised the PFA CTs by increasing VWF levels to normal. Of the 14 patients with VWD type 2, PFA CTs did not normalize in eight. Haemate-P substitution in patients with VWD type 1 induced a less favourable response as compared to DDAVP, because PFA CTs did not correct in all patients. Of 12 patients with VWD type 2 treated with Haemate-P, six showed a correction of PFA CTs (<250 sec), which correlated with the normalisation of the VWF CB/ Ag ratio. In-vitro studies were performed by using whole blood of patients with VWD and adding various amounts of FVIII/VWF concentrate. Addition of Haemate-P induced an increase of the VWF CB/Ag ratio from 0.30 to 0.70 in blood of patients with VWD type 2 with correction of the PFA CTs. Immunate did not result in an increase of VWF CB/Ag ratio in blood of VWD type 2 patients, and the PFA CTs remained prolonged. We conclude that PFA-100 might be an adequate instrument not only for diagnosis but also for monitoring of DDAVP responses and FVIII/ VWF substitution of patients with VWD type 1 and 2,but this is dependent upon the type of VWD and the concentrate used.

Type 2M vWD Resulting from a Lysine Deletion within a Four Lysine Residue Repeat in the A1 Loop of von Willebrand Factor

2000 ◽  
Vol 84 (08) ◽  
pp. 188-194 ◽  
Author(s):  
P. V. Jenkins ◽  
C. Gaucher ◽  
E. Meriane ◽  
P. W. Collins ◽  
K. J. Pasi ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Lysine Residue ◽  
Antigen Level ◽  
The Uk ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Ristocetin Cofactor ◽  
Ristocetin Cofactor Activity

SummaryType 1 von Willebrand disease is characterized by a decreased plasma concentration of functionally normal von Willebrand factor (vWF) whereas type 2M is characterised by an abnormal vWF displaying decreased affinity for platelets. In these two types of patients, the multimeric structure of vWF is normal.We report here the identification, in two unrelated families from the UK and Algeria, of an in-frame 3 bp deletion, at the heterozygous state, resulting in the deletion of a lysine residue within a four lysine repeat at position 642-645 of the mature vWF subunit (del K1405-1408 in prepro vWF). The patients who have a discrepancy between vWF antigen level and vWF ristocetin cofactor activity exhibited decreased ristocetin-induced binding but only a slight decrease in the percentage of high molecular weight (HMW) multimers in plasma.Recombinant vWF harbouring this deletion did not bind to platelet GPIb in the presence of ristocetin or botrocetin although the protein is multimerized. Consequently, this lysine deletion was considered as a type 2M vWD mutation.

Desmopressin parenteral bei VWD 1, VWD 2A und Thrombozytopathie

2011 ◽  
Vol 31 (S 01) ◽  
pp. S29-S33 ◽  
Author(s):  
H. Pollmann ◽  
B. Siegmund
Keyword(s):  
Side Effects ◽  
Disease Type ◽  
Von Willebrand Disease ◽  
Occlusion Time ◽  
Almost All ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Ristocetin Cofactor

SummaryDesmopressin (DDAVP, Minirin® parenteral), which induces the release of von-Willebrand factor from endogenous stores, is indicated in von Willebrand disease type 1 (VWD 1). In the present study effectiveness of DDAVP was tested and side effects were recorded in patients with VWD 1, von Willebrand disease type 2 (VWD 2) or thrombocytopathy (TCP). Patients, methods Subjects were analysed prior to and after Minirin parenteral infusion (0.4 μg/kg body weight (b.w.) over 60 minutes) for partial thromboplastin time (PTT, seconds), ADP/epinephrine triggered plateletfunction analyzer (PFA-100) occlusion time (seconds), factor VIII activity (FVIII, %), VWF as ristocetin cofactor activity (VWF:RCo, %) and VWF antigen (VWF:Ag, %). Side effects of DDAVP during operative interventions were recorded per questionnaires by the patients. Results The mean ± standard deviation dose (n = 165 patients) of Minirin parenteral administered was 0.37 ± 0.02 μg/kg b.w., most often upcoming dental operations (57%) necessitated testing. Coagulation parameters of patients with VWD 1 or TCP normalised in almost all patients, but only in approximately 50% of patients with VWD 2 respectively. Appraisal of effectiveness of Minirin parenteral as good was 96% in case of VWD 1 and 95 % in case of TCP. During minor surgeries (n = 23) in 91% of the patients no complications and in 2 patients (9%) postoperative haemorrhages without need for further interventions occurred, but 83% of the patients reported adverse reactions in the questionnaires, although Minirin parenteral was well tolerated by all patients during DDAVP efficacy tests. Conclusion Desmopressin is well tolerated and affective in patients with VWD 1 and thrombocytopathy.

Mutation distribution in the von Willebrand factor gene related to the different von Willebrand disease (VWD) types in a cohort of VWD patients

2012 ◽  
Vol 108 (10) ◽  
pp. 662-671 ◽  
Author(s):  
Hamideh Yadegari ◽  
Julia Driesen ◽  
Anna Pavlova ◽  
Arijit Biswas ◽  
Hans-Jörg Hertfelder ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Splice Site ◽  
Von Willebrand Disease ◽  
Missense Mutations ◽  
Large Deletions ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryVon Willebrand disease (VWD) is the most common inherited bleeding disorder caused by quantitative or qualitative defects of the von Willebrand factor (VWF). VWD is classified into three types – type 1 (partial quantitative deficiencies), type 2 (qualitative defects) and type 3 (complete deficiency of VWF). In this study we explored genotype and phenotype characteristics of patients with VWD with the aim of dissecting the distribution of mutations in different types of VWD. One hundred fourteen patients belonging to 78 families diagnosed to have VWD were studied. Mutation analysis was performed by direct sequencing of the VWF. Large deletions were investigated by multiplex ligation-dependent probe amplification (MLPA) analysis. The impact of novel candidate missense mutations and potential splice site mutations was predicted by in silico assessments. We identified mutations in 66 index patients (IPs) (84.6%). Mutation detection rate was 68%, 94% and 94% for VWD type 1, 2 and 3, respectively. In total, 68 different putative mutations were detected comprising 37 missense mutations (54.4%), 10 small deletions (14.7%), two small insertions (2.9%), seven nonsense mutations (10.3%), five splice-site mutations (7.4%), six large deletions (8.8%) and one silent mutation (1.5%). Twenty-six of these mutations were novel. Furthermore, in type 1 and type 2 VWD, the majority of identified mutations (74% vs. 88.1%) were missense substitutions while mutations in type 3 VWD mostly caused null alleles (82%). Genotyping in VWD is a helpful tool to further elucidate the pathogenesis of VWD and to establish the relationship between genotype and phenotype.

Response of von Willebrand Factor Parameters to Desmopressin in Patients with Type 1 and Type 2 Congenital von Willebrand Disease: Diagnostic and Therapeutic Implications

2002 ◽  
Vol 28 (2) ◽  
pp. 111-132 ◽  
Author(s):  
Jan J. Michiels ◽  
Ann van de Velde ◽  
Huub H.D.M. van Vliet ◽  
Marc van der Planken ◽  
Wilfried Schroyens ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Therapeutic Implications ◽  
Von Willebrand ◽  
Willebrand Factor

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 Course of von Willebrand Factor and Factor VIII Activity in Patients with von Willebrand Disease during Pregnancy

2019 ◽  
Vol 142 (2) ◽  
pp. 71-78 ◽  
Author(s):  
Christiane Delbrück ◽  
Wolfgang Miesbach
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Factor Viii Activity ◽  
Third Trimester ◽  
Coagulation Parameters ◽  
The Third ◽  
Von Willebrand ◽  
Willebrand Factor

Introduction: Women with von Willebrand disease (VWD) are at a higher risk of bleeding, which might affect the health of mother and child during pregnancy and the intra- and postpartum periods. This retrospective cohort study evaluates changes in the coagulation parameters von Willebrand factor antigen (VWF:Ag), von Willebrand ristocetin cofactor (VWF:RCo), and Factor VIII activity (FVIII:C) during pregnancy in patients with VWD. In total, 44 pregnancies of 38 patients were assessed (VWD type 1 n = 32, type 2A n = 3, type 2B n = 1, type 2 subtype unidentified n = 2). The patients’ median age at childbirth was 32 years (range 22–40). Results: A significant increase in coagulation parameters was found in patients with VWD type 1 (VWF:Ag, VWF:RCo, and FVIII:C p = 0.000). In the third trimester, VWF:Ag and FVIII:C normalized in all patients with VWD type 1; in 3 patients VWF:RCo remained below the normal range. Patients with VWD type 2 showed a significant increase of VWF:Ag (p = 0.003) and FVIII:C (p = 0.011), and a non-significant increase of VWF:RCo (p = 0.097). In 4 of 9 pregnancies of patients with VWD type 2, all surveyed coagulation parameters normalized until the third trimester. Conclusion: For the majority of the observed patients, the von Willebrand parameters increased during pregnancy.

Novel evaluation method for densitometric curves of von Willebrand Factor multimers and a new parameter (MMW) to describe the degree of multimersation

2009 ◽  
Vol 102 (08) ◽  
pp. 412-417 ◽  
Author(s):  
Miklós Udvardy ◽  
Katalin Szekeres-Csiki ◽  
Jolán Hársfalvi
Keyword(s):  
Von Willebrand Factor ◽  
Evaluation Method ◽  
Lower Boundary ◽  
Normal Activity ◽  
Platelet Lysate ◽  
Von Willebrand Disease ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Ristocetin Cofactor

SummaryVon Willebrand factor (VWF) is built up from a varying number of subunits, of which the larger molecules have higher haemostatic activity. Von Willebrand disease (VWD) and thrombotic thrombocytopenic purpura are the best known disorders with pathognomonic changes of the highly multimerised VWF forms. There is an established method to calculate the relative amount of large oligomers. Our aim is to quantify the degree of VWF multimerisation as well, to complete the densitometric analysis of VWF electrophoresis. After optimisation, we have defined this new parameter (MMW) as the molecular weight corresponding to the lower boundary of the largest 25% of VWF protein. MMW was significantly different (p<.0001) in platelet lysate, normal samples and VWD type 2 samples (10.4, 6.3, 2.1, respectively). There was strong correlation between the MMW and the amount of large multimers in normal samples (r2=0.98) and in platelet lysate. However MMW was higher in latelet lysate, in which VWF is not cleaved by ADAMTS-13, than in healthy samples with the same amount of large multimers. Comparison of the new parameter and the collagen binding and ristocetin cofactor activity of VWF, showed that the functional tests are at least partially determined by the multimerisation; however, about 15% of VWD samples had normal activity to antigen ratios. The quantification of multimerisation aids the classification in these cases, especially at low antigen concentrations, and also might help in the detection of thrombotic conditions.

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