scholarly journals Phage Display Broadly Identifies Inhibitor-reactive Regions in von Willebrand Factor

2021 ◽  
Author(s):  
Andrew Yee ◽  
Manhong Dai ◽  
Stacy E. Croteau ◽  
Jordan A. Shavit ◽  
Steven W. Pipe ◽  
...  

SummaryBackgroundCorrection of von Willebrand factor (VWF) deficiency with replacement products containing VWF can lead to the development of anti-VWF alloantibodies (i.e., VWF inhibitors) in patients with severe von Willebrand disease (VWD).ObjectiveLocate inhibitor-reactive regions within VWF using phage display.MethodsWe screened a phage library displaying random, overlapping fragments covering the full length VWF protein sequence for binding to a commercial anti-VWF antibody or to immunoglobulins from three type 3 VWD patients who developed VWF inhibitors in response to treatment with plasma-derived VWF. Immunoreactive phage clones were identified and quantified by next generation DNA sequencing (NGS).ResultsNGS markedly increased the number of phage analyzed for locating immunoreactive regions within VWF following a single round of selection and identified regions not recognized in previous reports using standard phage display methods. Extending this approach to characterize VWF inhibitors from three type 3 VWD patients (including two siblings homozygous for the same VWF gene deletion) revealed patterns of immunoreactivity distinct from the commercial antibody and between unrelated patients, though with notable areas of overlap. Alloantibody reactivity against the VWF propeptide is consistent with incomplete removal of the propeptide from plasma-derived VWF replacement products.ConclusionThese results demonstrate the utility of phage display and NGS to characterize diverse anti-VWF antibody reactivities.

2021 ◽  
Vol 47 (02) ◽  
pp. 192-200
Author(s):  
James S. O'Donnell

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.


Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 308-313 ◽  
Author(s):  
WF Bahou ◽  
EJ Bowie ◽  
DN Fass ◽  
D Ginsburg

von Willebrand disease (vWD), one of the most common bleeding disorders in humans, is manifested as a quantitative or qualitative defect in von Willebrand factor (vWF), an adhesive glycoprotein (GP) with critical hemostatic functions. Except for the rare severely affected patient with a gene deletion as etiology of the disease, the molecular basis for vWD is not known. We studied the molecular basis for vWD in a breeding colony of pigs with a disease closely resembling the human disorder. The porcine vWF gene is similar in size and complexity to its human counterpart, and no gross gene deletion or rearrangement was evident as the pathogenesis of porcine vWD. A restriction fragment- length polymorphism (RFLP) within the porcine vWF gene was identified with the restriction endonuclease HindIII, and 22/35 members of the pedigree were analyzed for the polymorphic site. Linkage between the vWF locus and the vWD phenotype was established with a calculated LOD score of 5.3 (1/200,000 probability by chance alone), with no crossovers identified. These findings indicate that porcine vWD is due to a molecular defect within (or near) the vWF locus, most likely representing a point mutation or small insertion/deletion within the vWF gene.


Author(s):  
И.В. Куртов ◽  
Е.С. Фатенкова ◽  
Н.А. Юдина ◽  
А.М. Осадчук ◽  
И.Л. Давыдкин

Болезнь Виллебранда (БВ) может представлять определенные трудности у рожениц с данной патологией. Приведены 2 клинических примера использования у женщин с БВ фактора VIII свертывания крови с фактором Виллебранда, показана эффективность и безопасность их применения. У одной пациентки было также показано использование фактора свертывания крови VIII с фактором Виллебранда во время экстракорпорального оплодотворения. Von Willebrand disease presents a certain hemostatic problem among parturients. This article shows the effectiveness and safety of using coagulation factor VIII with von Willebrand factor for the prevention of bleeding in childbirth in 2 patients with type 3 von Willebrand disease. In one patient, the use of coagulation factor VIII with von Willebrand factor during in vitro fertilization was also shown.


2021 ◽  
Vol 14 (8) ◽  
pp. e241613
Author(s):  
Vaishnavi Divya Nagarajan ◽  
Asha Shenoi ◽  
Lucy Burgess ◽  
Vlad C Radulescu

An 18-year-old man with a history of type 3 von Willebrand disease (VWD) presented with a spontaneous pyohaemothorax. Type 3 VWD may present with both mucocutaneous and deep-seated bleeds, such as visceral haemorrhages, intracranial bleeds and haemarthrosis. There have been very few cases described in children of spontaneous pyohaemothorax. Management of this patient was challenging due to risks of bleeding following surgical drainage, requiring constant replacement with von Willebrand factor concentrate, while monitoring factor VIII levels to balance the risks of thrombosis.


2020 ◽  
Vol 31 (1) ◽  
pp. 77-79
Author(s):  
Barbara Faganel Kotnik ◽  
Karin Strandberg ◽  
Maruša Debeljak ◽  
Lidija Kitanovski ◽  
Janez Jazbec ◽  
...  

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 308-313 ◽  
Author(s):  
WF Bahou ◽  
EJ Bowie ◽  
DN Fass ◽  
D Ginsburg

Abstract von Willebrand disease (vWD), one of the most common bleeding disorders in humans, is manifested as a quantitative or qualitative defect in von Willebrand factor (vWF), an adhesive glycoprotein (GP) with critical hemostatic functions. Except for the rare severely affected patient with a gene deletion as etiology of the disease, the molecular basis for vWD is not known. We studied the molecular basis for vWD in a breeding colony of pigs with a disease closely resembling the human disorder. The porcine vWF gene is similar in size and complexity to its human counterpart, and no gross gene deletion or rearrangement was evident as the pathogenesis of porcine vWD. A restriction fragment- length polymorphism (RFLP) within the porcine vWF gene was identified with the restriction endonuclease HindIII, and 22/35 members of the pedigree were analyzed for the polymorphic site. Linkage between the vWF locus and the vWD phenotype was established with a calculated LOD score of 5.3 (1/200,000 probability by chance alone), with no crossovers identified. These findings indicate that porcine vWD is due to a molecular defect within (or near) the vWF locus, most likely representing a point mutation or small insertion/deletion within the vWF gene.


Blood ◽  
2001 ◽  
Vol 97 (7) ◽  
pp. 2059-2066 ◽  
Author(s):  
Reinhard Schneppenheim ◽  
Ulrich Budde ◽  
Tobias Obser ◽  
Jacqueline Brassard ◽  
Kerstin Mainusch ◽  
...  

Abstract Dimerization defects of von Willebrand factor (vWF) protomers underlie von Willebrand disease (vWD) type 2A, subtype IID (vWD 2A/IID), and corresponding mutations have been identified at the 3′ end of the vWF gene in exon 52. This study identified and expressed 2 additional mutations in this region, a homozygous defect in a patient with vWD type 3 (C2754W) and a heterozygous frameshift mutation (8566delC) in a patient with vWD type 2A, subtype IIE. Both mutations involve cysteine residues that we propose are possibly essential for dimerization. To prove this hypothesis, transient recombinant expression of each of the 2 mutations introduced in the carboxy-terminal vWF fragment II and in the complete vWF complementary DNA, respectively, were carried out in COS-7 cells and compared with expression of vWD 2A/IID mutation C2773R and the wild-type (WT) sequence in COS-7 cells. Recombinant WT vWF fragment II assembled correctly into a dimer, whereas recombinant mutant fragments were monomeric. Homozygous expression of recombinant mutant full-length vWF resulted in additional dimers, probably through disulfide bonding at the amino-terminal multimerization site, whereas recombinant WT vWF correctly assembled into multimers. Coexpression of recombinant mutant and recombinant WT vWF reproduced the multimer patterns observed in heterozygous individuals. Our results suggest that a common defect of vWF biosynthesis—lack of vWF dimerization—may cause diverse types and subtypes of vWD. We also confirmed previous studies that found that disulfide bonding at the vWF amino-terminal is independent of dimerization at the vWF carboxy-terminal.


Blood ◽  
2015 ◽  
Vol 126 (15) ◽  
pp. 1753-1761 ◽  
Author(s):  
Sandra L. Haberichter

Abstract von Willebrand factor (VWF) is a large multimeric glycoprotein that mediates the attachment of platelets to damaged endothelium and also serves as the carrier protein for coagulation factor VIII (FVIII), protecting it from proteolytic degradation. Quantitative or qualitative defects in VWF result in von Willebrand disease (VWD), a common inherited bleeding disorder. VWF is synthesized with a very large propeptide (VWFpp) that is critical for intracellular processing of VWF. VWFpp actively participates in the process of VWF multimerization and is essential for trafficking of VWF to the regulated storage pathway. Mutations identified within VWFpp in VWD patients are associated with altered VWF structure and function. The assay of plasma VWFpp has clinical utility in assessing acute and chronic vascular perturbation associated with diseases such as thrombotic thrombocytopenic purpura, sepsis, and diabetes among others. VWFpp assay also has clear utility in the diagnosis of VWD subtypes, particularly in discriminating true type 3 subjects from type 1C (reduced plasma survival of VWF), which is clinically important and has implications for therapeutic treatment.


2012 ◽  
Vol 108 (10) ◽  
pp. 662-671 ◽  
Author(s):  
Hamideh Yadegari ◽  
Julia Driesen ◽  
Anna Pavlova ◽  
Arijit Biswas ◽  
Hans-Jörg Hertfelder ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document