Detection of Non Inhibitory Binding Antibodies to Von Willebrand Factor Affecting the Clearance of VWF:Ag in Von Willebrand Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2275-2275
Author(s):  
Tobias M Suiter ◽  
Pier Mannuccio Mannucci ◽  
Christine L Kempton ◽  
Michael Laffan ◽  
Edward H Romond ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Von Willebrand Disease ◽  
Inhibitory Antibody ◽  
Screening Assay ◽  
Post Infusion ◽  
Inhibitory Antibodies ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Abstract 2275 Von Willebrand Disease (VWD) is an inherited rare bleeding disorder caused by a deficiency of von Willebrand factor (VWF). VWF, the largest multimeric plasma glycoprotein, facilitates platelet aggregation and stabilizes FVIII in the circulation. Inhibitory antibodies to VWF have been reported in 10% – 15% of type 3 VWD patients repetitively treated with plasma-derived VWF/FVIII concentrates. The clinical impact of non-inhibitory antibodies to VWF has not been previously reported. To investigate the immunogenicity of a novel recombinant human VWF (rhVWF), both total binding anti-VWF antibodies and inhibitory anti-VWF antibodies (VWF:Ristocetin Cofactor Activity [RCo], VWF:Collagen Binding Activity [CB], VWF:FVIII Binding [FVIIIB]) were assessed in a Phase 1 multicenter clinical study. Total binding anti-VWF antibodies were determined by an enzyme-linked immunosorbent assay (ELISA) employing polyclonal anti-human IgG antibodies. Plasma samples were analyzed in two steps employing a screening assay determining the titer of the binding antibodies and in a second step, confirming the specificity of the antibody in a competition assay. Samples were considered positive, when a sample was at least two titer steps lower than the antibody titer detected in the screening assay necessitating a screening titer of at least 1:80. Neutralizing antibodies to the key functional activities of VWF, such as VWF:RCo, VWF:CB and VWF:FVIIIB, were measured by assays based on the Bethesda assay established for quantitative analysis of FVIII inhibitors (Nijmegen modification of the Bethesda assay). To exclude false positive results, the detection limit for anti-VWF inhibitors was set to 1 BU/mL for all 3 assays. Three of 39 subjects screened had a pre-existing high titer non-neutralizing binding antibody (all 1/1280) to VWF. One of these 3 subjects was excluded from the study due to the presence of an inhibitory antibody to VWF:CB (1.3 BU/mL) at screening. Two of the 3 subjects were enrolled and treated with rVWF and/or pdVWF concentrate as part of the safety, tolerability and PK assessments. The high titer binding anti-VWF antibodies were associated with a significant decreased VWF:Ag activity post infusion of either pdVWF or rVWF and consequential decreased activity of VWF:RCo, VWF:CB and FVIII:C. For example, one of the subject had a reduced VWF:Ag incremental recovery of 1.1 IU/dL/(U VWF:RCo/kg) (mean of cohort 1.6 IU/dL/[U VWF:RCo/kg]) and a reduced VWF:Ag t1/2 2.4 hours (mean of cohort t1/2 25.3 hours) post infusion of rhVWF dosed at 50 IU VWF:RCo/kg. Relevant data of all PK assessments and antibody titers will be presented. None of the study subjects developed an inhibitory antibody to either VWF or FVIII and there was no impact on the subsequent treatment of bleeding episodes with commercial pdFVIII/VWF concentrates noted by the treating physician. The clinical relevance of non-neutralizing antibodies to VWF requires additional investigation. Disclosures: Suiter: Baxter Innovations GmbH: Employment. Horling:Baxter Innovations GmbH: Employment. Reipert:Baxter Innovations GmbH: Employment. Turecek:Baxter BioScience: Employment. Varadi:Baxter Innovations GmbH: Employment. Chapman:Baxter Innovations GmbH: Employment. Engl:Baxter Innovations GmbH: Employment. Wong:Baxter Healthcare Corp: Employment. Ewenstein:Baxter Healthcare Corp: Employment.

Recombinant Human Von Willebrand Factor (rhVWF): First-In-Human Study Evaluating Pharmacokinetics, Demonstrating Safety and Tolerability In Type 3 Von Willebrand Disease

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 237-237 ◽  
Author(s):  
Tobias Suiter ◽  
Michael Laffan ◽  
Pier M. Mannucci ◽  
Christine L. Kempton ◽  
Edward H Romond ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Von Willebrand Factor ◽  
Phase 1 ◽  
Von Willebrand Disease ◽  
Fviii Activity ◽  
Post Infusion ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Abstract 237 Von Willebrand Disease (VWD) is an inherited rare bleeding disorder caused by a deficiency of von Willebrand factor (VWF). VWF is the largest soluble multimeric plasma glycoprotein, which facilitates platelet aggregation and stabilizes FVIII in the circulation. Patients with type 3 disease display severe hemorrhagic symptoms, mainly in mucosal tissues, muscle and joints. Replacement of VWF stabilizes endogenous FVIII to hemostatic levels within hours. Commercially available VWF/FVIII concentrates are plasma-derived (pd) and subject to limitations such as donor dependency, risk of blood-borne pathogen transmission, lack of high molecular weight VWF multimers, and variation in multimer composition. A novel recombinant human VWF (rhVWF) has been developed using a plasma-free method, which represents the largest protein ever produced using recombinant technology. Safety, tolerability and pharmacokinetics of the rhVWF combined at a fixed ratio with rFVIII were investigated in a Phase 1 multicenter, international clinical study in 31 patients with type 3 VWD and severe type 1 VWD. Four concentrations of rhVWF (2, 7.5, 20 and 50 IU VWF:RCo/kg) were administered in a dose-escalating manner in separate cohorts. rhVWF was well tolerated, and no thrombotic events, VWF inhibitors or other serious adverse reactions were observed. Pharmacokinetics of rhVWF/rhFVIII (50 IU VWF:RCo/kg and 38.5 IU FVIII/kg) compared with pdVWF/pdFVIII (50 IU VWF:RCo/kg and 21 IU/kg FVIII/kg) were evaluated in a sub-group of 8/31 patients using a randomized, crossover design (8-day minimum washout period). Interim data in 8 subjects show a higher degree of secondary FVIII activity with rhVWF/rhFVIII compared to pdVWF/pdFVIII (see Figure 1) that is not solely due the difference in the rhVVF:FVIII infusion ratio (1.3:1 rhVWF/rhFVIII vs. approximately 2:1 pdVWF/pdFVIII). The pharmacokinetics of the rhVWF:RCo and pdVWF:RCo were comparable and were also reflected in the VWF:Ag and collagen binding activity. Evidence is also provided for the in vivo cleavage of the ultra-high molecular weight multimers of rhVWF by endogenous ADAMTS13. In summary, interim data from the ongoing Phase 1 study, demonstrate that rhVWF is safe and well tolerated, has VWF:RCo pharmacokinetics that are comparable to pdVWF and enhances stabilization of endogenous FVIII. Multiple doses of rhVWF/rhFVIII would be expected to have beneficial effects in major surgery and severe mucosal bleeding events. These data would also support the treatment concept to administer rhVWF alone once a therapeutic baseline level of endogenous FVIII is achieved (after 1–2 doses).Figure 1:Preliminary PK data from 8 subjects post-infusion of either rhVWF/rhFVIII or pdVWF/pdFVIII. Endogenous FVIII activity reached a plateau after 6 hours and remained stable for at least 30 hours. FVIII was still elevated well above baseline at 96 hoursFigure 1:. Preliminary PK data from 8 subjects post-infusion of either rhVWF/rhFVIII or pdVWF/pdFVIII. Endogenous FVIII activity reached a plateau after 6 hours and remained stable for at least 30 hours. FVIII was still elevated well above baseline at 96 hours Disclosures: Suiter: Baxter BioScience: Employment. Laffan:Baxter BioScience: Consultancy. Mannucci:Baxter BioScience: Consultancy. Kempton:Baxter BioScience: Consultancy. Romond:Baxter BioScience: Consultancy. Shapiro: Baxter BioSci- ence: Consultancy. Birschmann:Baxter BioScience: Consultancy. Gill:Baxter BioScience: Consultancy. Ragni:Baxter BioScience: Consultancy. Turecek:Baxter BioScience: Employment. Ewenstein:Baxter Bioscience: Employment. Baxter BioScience:Baxter BioScience: Employment.

BLEEDING TIME IN TREATED PATIENTS WITH SEVERE VON WILLEBRAND DISEASE IS NOT CORRECTED ONLY BY GIVING NORMAL MULTIMERIC PLASMA VON WILLEBRAND FACTOR

1987 ◽  
Author(s):  
P M Mannucci ◽  
M Moia ◽  
D Altieri ◽  
J Monteagudo ◽  
R Castillo
Keyword(s):  
Von Willebrand Factor ◽  
Bleeding Time ◽  
Random Order ◽  
Von Willebrand Disease ◽  
Controlled Study ◽  
Prolonged Bleeding Time ◽  
Post Infusion ◽  
Fraction I ◽  
Von Willebrand ◽  
Willebrand Factor

Even though it is generally held that cryoprecipitate (cryo) and fraction I-0 correct the prolonged bleeding time (BT) in patients with von Willebrand disease (VWD), perusal of reported data indicates that the correction is usually short lasting and often partial. We decided to do a controlled study of the relationship between the multimeric structure of von Willebrand factor (VWF) in 5 patients with severe VWD after infusion of three plasma concentrates : "wet" cryo, lyophilized (lyo) cryo, and fraction 1-0 given in random order. The dosage of concentrates was tailored to achieve post infusion levels of RiCof above the lower normal limit (50 U/dL) for at least 3 hours. The post-infusion BT values are shown in the table.These findings indicate that the attainment of a normal BT is the exception rather than the rule after infusion of three plasma fractions used for treatment of severe VWD. In all the concentrates the proportions of large VWF multimers, calculated by scanning the electrophoretic gels, were the same as in normal standard plasmas. An intact multimeric structure was recovered in post-infusion plasma of patients treated with wet cryo, whereas there was post infusion loss of large multimers after lyo and fraction I-O. In conclusion, an intact multimeric structure in post infusion plasmas is necessary but not sufficient to sustain a normal BT in VWD patients.

scholarly journals Evaluation of an Automated von Willebrand Factor Activity Assay in von Willebrand Disease

2010 ◽  
Vol 17 (6) ◽  
pp. E25-E29 ◽  
Author(s):  
Marc Trossaërt ◽  
Catherine Ternisien ◽  
Armelle Lefrancois ◽  
Laura Llopis ◽  
Jenny Goudemand ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Screening Strategy ◽  
Von Willebrand Disease ◽  
Activity Assay ◽  
Screening Assay ◽  
Function Analyzer ◽  
Highly Correlated ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

We evaluated the use of the turbidimetric HemosIL von Willebrand Factor (VWF) Activity assay (VWF:Act) on the STA-R automated coagulometer (Stago, Asnières, France) for the diagnosis of von Willebrand disease (VWD). For this, we prospectively screened 268 patients. As a second part, we retrospectively assayed 111 patients with well-defined VWD subtype. In the first prospective study, we demonstrate that in most cases of VWD, VWF ristocetin cofactor activity (VWF:RCo) and VWF:Act are highly correlated but that they both cannot be considered a good screening assay when used alone, since they could miss about 25% of VWF abnormalities. However, the association of VWF:Act analysis and the Platelet Function Analyzer-100 (PFA-100) test constitutes an excellent screening strategy. In our second retrospective study concerning VWD subtypes, VWF:RCo and VWF:Act were well correlated but could be very discrepant, especially for some cases of type 2M VWD. We consider that VWF:RCo remains the “reference assay” for VWD subtype classification.

scholarly journals Von Willebrand factor multimeric assay: novel diagnostics capabilities

2021 ◽  
Vol 8 (2) ◽  
pp. 35-41
Author(s):  
A. V. Poletaev ◽  
E. A. Seregina ◽  
A. V. Pshonkin ◽  
N. A. Karamyan ◽  
D. V. Fedorova ◽  
...  
Keyword(s):  
Factor Viii ◽  
Normal Distribution ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Control Group ◽  
Type I ◽  
Screening Assay ◽  
Acquired Von Willebrand Syndrome ◽  
Von Willebrand ◽  
Willebrand Factor

Introduction. Distinguishing between Von Willebrand disease (vWD) types often requires multimer gel analysis. The current techniques for vWF multimer structure are manual, complicated, non-standardized and time consuming. The aim of this study was to evaluate diagnostic capabilities of new automated vWF multimer screening assay.Materials and methods. Children with vWD, acquired von Willebrand Syndrome (aVWS) and 8 healthy donors as a control group were enrolled in this study. Von Willebrand factor antigen (vWF Ag); ristocetin cofactor activity (VWF:Rco); vWF collagen binding (VWF:CB); ristocetin-induced platelet aggregation (RIPA); factor VIII clotting activity (FVIII:C) and vWF factor VIII binding activity (vWF:FVIIIb) were performed to evaluate vWD. Multimer analysis was carried out using the commercial HYDRAGEL 5 von Willebrand Multimers kit on semi-automatic gel electrophoresis instrument HYDRASYS (SEBIA).Results. The samples from control group had 9—12 bands of vWF multimers with the same distribution as control plasma. Patients with type I vWD had the proportional decrease in the intensity of the bands with preservation of the normal distribution of the band. Patients with type III vWD reveal the complete absence of the multimer bands on the gel. Multimer analysis in type IIA shows the absence of high molecular weight multimer bands. In other patients the distribution of vWF multimers was normal against the changes in functional properties of vWF (types IIM, N). Most of the children with aVWS also revealed normal distribution of vWF multimers, however, in some patients, the slight decrease in large multimeric forms was observed visually on the gel.Conclusion. Multimer analysis allows to visualize the multimer distribution in various types of von Willebrand disease. The method is easy to perform and can be useful for distinguishing between the subtypes of vWD. But only the full test panel including genetic tests would allow the differentiantion of vWD types with high precision.

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.

The Genetic Defect of Type I von Willebrand Disease “Vicenza” Is Linked to the von Willebrand Factor Gene

1993 ◽  
Vol 69 (02) ◽  
pp. 173-176 ◽  
Author(s):  
Anna M Randi ◽  
Elisabetta Sacchi ◽  
Gian Carlo Castaman ◽  
Francesco Rodeghiero ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Von Willebrand Factor ◽  
Autosomal Dominant ◽  
Genetic Defect ◽  
Von Willebrand Disease ◽  
Type I ◽  
Bleeding Tendency ◽  
Factor Gene ◽  
Low Levels ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryType I von Willebrand disease (vWD) Vicenza is a rare variant with autosomal dominant transmission, characterized by the presence of supranormal von Willebrand factor (vWF) multimers in plasma, similar to those normally found in endothelial cells and megakaryocytes. The patients have very low levels of plasma vWF contrasting with a mild bleeding tendency. The pathophysiology of this subtype is still unknown. The presence of supranormal multimers in the patients’ plasma could be due to a mutation in the vWF molecule which affects post-translational processing, or to a defect in the cells’ processing machinery, independent of the vWF molecule. In order to determne if type I vWD Vicenza is linked to the vWF gene, we studied six polymorphic systems identified within the vWF gene in two apparently unrelated families with type I vWD Vicenza. The results of this study indicate a linkage between vWF gene and the type I vWD Vicenza trait. This strongly suggests that type I vWD Vicenza is due to a mutation in one of the vWF alleles, which results in an abnormal vWF molecule that is processed to a lesser extent than normal vWF.

Characterization of Partial Gene Deletions in Type III von Willebrand Disease with Alloantibody Inhibitors

1994 ◽  
Vol 72 (02) ◽  
pp. 180-185 ◽  
Author(s):  
David J Mancuso ◽  
Elodee A Tuley ◽  
Ricardo Castillo ◽  
Norma de Bosch ◽  
Pler M Mannucci ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Pcr Analysis ◽  
Gene Deletions ◽  
Factor Gene ◽  
Type Iii ◽  
Large Deletions ◽  
Von Willebrand ◽  
Willebrand Factor

Summaryvon Willebrand factor gene deletions were characterized in four patients with severe type III von Willebrand disease and alloantibodies to von Willebrand factor. A PCR-based strategy was used to characterize the boundaries of the deletions. Identical 30 kb von Willebrand factor gene deletions which include exons 33 through 38 were identified in two siblings of one family by this method. A small 5 base pair insertion (CCTGG) was sequenced at the deletion breakpoint. PCR analysis was used to detect the deletion in three generations of the family, including two family members who are heterozygous for the deletion. In a second family, two type III vWD patients, who are distant cousins, share an -56 kb deletion of exons 22 through 43. The identification and characterization of large vWF gene deletions in these type III vWD patients provides further support for the association between large deletions in both von Willebrand factor alleles and the development of inhibitory alloantibodies.

Autoantibody Selectively Inhibits Binding of von Willebrand Factor to Glycoprotein Ib. Recognition Site Is Located in the A1 Loop of von Willebrand Factor

1997 ◽  
Vol 77 (04) ◽  
pp. 760-766 ◽  
Author(s):  
Hiroshi Mohri ◽  
Etsuko Yamazaki ◽  
Zekou Suzuki ◽  
Toshikuni Takano ◽  
Shumpei Yokota ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Significant Inhibition ◽  
Von Willebrand Disease ◽  
Recognition Site ◽  
Severe Bleeding ◽  
Bleeding Tendency ◽  
Virtual Absence ◽  
Heavy Chains ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryA 20-year-old man with severe von Willebrand disease recently presented a progressive bleeding tendency, characterized recurrent subcutaneous hemorrhages and cerebral hemorrhage. Mixing and infusion studies suggested the presence of an inhibitor directed against vWF:RCo activity of von Willebrand factor (vWF) without significant inhibition of the FVIII:C. The inhibitor was identified as an antibody of IgG class. The inhibitor inhibited the interaction of vWF in the presence of ristocetin and that of asialo-vWF with GPIb while it partially blocked botrocetin-mediated interaction of vWF to GPIb. The inhibitor reacted with native vWF, the 39/34kDa fragment (amino acids [aa] 480/ 481-718) and the recombinant vWF fragment (MalE-rvWF508-704), but not with Fragment III-T2 (heavy chains, aa 273-511; light chains, aa 674-728). A synthetic peptide (aa 514-542) did not inhibit vWF-inhibitor complex formation. We conclude that this is the first autoantibody of class IgG from human origin that recognizes the sequence in the A1 loop of vWF, resulting in a virtual absence of functional vWF and a concomitant severe bleeding tendency although recognition site is different from the residues 514-542 which is crucial for vWF-GPIb interaction.

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.

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