Population Pharmacokinetic Modeling of von Willebrand Factor Activity in von Willebrand Disease Patients after Desmopressin Administration

2020 ◽  
Vol 120 (10) ◽  
pp. 1407-1416
Author(s):  
Nico C. B. de Jager ◽  
Jessica M. Heijdra ◽  
Quincy Kieboom ◽  
Marieke J. H. A. Kruip ◽  
Frank W. G. Leebeek ◽  
...  

Abstract Objective Most von Willebrand disease (VWD) patients can be treated with desmopressin during bleeding or surgery. Large interpatient variability is observed in von Willebrand factor (VWF) activity levels after desmopressin administration. The aim of this study was to develop a pharmacokinetic (PK) model to describe, quantify, and explain this variability. Methods Patients with either VWD or low VWF, receiving an intravenous desmopressin test dose of 0.3 µg kg−1, were included. A PK model was derived on the basis of the individual time profiles of VWF activity. Since no VWF was administered, the VWF dose was arbitrarily set to unity. Interpatient variability in bioavailability (F), volume of distribution (V), and clearance (Cl) was estimated. Results The PK model was developed using 951 VWF activity level measurements from 207 patients diagnosed with a VWD type. Median age was 28 years (range: 5–76), median predose VWF activity was 0.37 IU/mL (range: 0.06–1.13), and median VWF activity response at peak level was 0.64 IU/mL (range: 0.04–4.04). The observed PK profiles were best described using a one-compartment model with allometric scaling. While F increased with age, Cl was dependent on VWD type and sex. Inclusion resulted in a drop in interpatient variability in F and Cl of 81.7 to 60.5% and 92.8 to 76.5%, respectively. Conclusion A PK model was developed, describing VWF activity versus time profile after desmopressin administration in patients with VWD or low VWF. Interpatient variability in response was quantified and partially explained. This model is a starting point toward more accurate prediction of desmopressin dosing effects in VWD.

2008 ◽  
Vol 99 (02) ◽  
pp. 271-278 ◽  
Author(s):  
Olivier D. Christophe ◽  
Beatrijs D. Oortwijn ◽  
Peter J. Lenting ◽  
Cécile V. Denis

SummaryThe life cycle of von Willebrand factor (VWF) comprises a number of distinct steps, ranging from the controlled expression of theVWF gene in endothelial cells and megakaryocytes to the removal of VWF from the circulation. The various aspects of VWF clearance have been the objects of intense research in the last few years, stimulated by observations thatVWF clearance is a relatively common component of the pathogenesis of type 1 von Willebrand disease (VWD). Moreover, improving the survival of VWF is now considered as a viable therapeutic strategy to prolong the half-life of factor VIII in order to optimise treatment of haemophilia A. The present review aims to provide an overview of recent findings with regard to the molecular basis of VWF clearance. A number of parameters have been identified that influence VWF clearance, including its glycosylation profile and a number of VWF missense mutations. In addition, in-vivo studies have been used to identify cells that contribute to the catabolism of VWF, providing a starting point for the identification of receptors that mediate the cellular uptake ofVWF.Finally, we discuss recent data describing chemically modification of VWF as an approach to prolong the half-life of the VWF/FVIII complex.


2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S6-S7
Author(s):  
Joseph Sweeney ◽  
Mohammad Barouqa ◽  
Gregory Krause ◽  
Jesus Gonzalez Lugo ◽  
Shafia Rahman ◽  
...  

Abstract Systemic inflammation and coagulopathy are characteristic hallmarks of COVID19. “COVID coagulopathy” manifests mainly as a prothrombotic state affecting both large and small blood vessels, and presenting as arterial, venous, and microangiopathic thrombotic events with von Willebrand factor (VWF) and soluble thrombomodulin increased in hospitalized patients. The causes of coagulopathy are poorly understood. Aim: To investigate the relationship between von Willebrand factor (VWF) biomarkers, intravascular hemolysis, coagulation, and organ damage in COVID19 patients and to study their association with disease severity and mortality. Methods: 181 hospitalized adult COVID19 patients were randomly selected with a balanced distribution of survivors and non-survivors during the period of March 26th 2020 to May 5th 2020. The medical records and laboratory values were reviewed. Statistical analysis was performed using R studio V.3.6.2. Results: Patients who died (n=90) had significantly lower ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity, elevated lactate dehydrogenase levels, increased schistocyte/RBC fragment counts, and elevated VWF antigen and activity levels compared to patients discharged alive (n=91). In 31 patients, we measured several of these biomarkers on two or more occasions. The trending of ADAMTS13 activity illustrated that it is not steady throughout the hospitalization course. ADAMTS13 activity levels tended to improve and/or reach normal levels in patients that survived, yet ADAMTS13 activity levels worsened in most patients that died. Likewise, the VWF antigen and activity levels tended to decrease in patients that survived whereas tended to increase well above the normal range (2-3 folds) in patients that died. D-Dimer levels trended downwards in survivors, sometimes to levels less than 1 µg/ml, yet tended to increase in patients who died. Given the relationship between ADAMTS13 activity and mortality, we wanted to determine a cut-point of initial ADAMTS13 activity (within 72 hours from admission) to predict mortality. 102 patients in our cohort had an ADAMTS13 activity measurement within this timeframe. We determined that this optimal cut-point of initial ADAMTS13 activity was 43% using Youden’s J statistic. Only 30% of patients who had an ADAMTS13 activity level of less than 43% on admission survived, yet 60% of patients survived who had an ADAMTS13 activity level of greater than 43% on admission. Conclusions: COVID-19 may present with low ADAMTS13 activity in a subset of hospitalized patients. Presence of schistocytes/RBC fragment and elevated D-dimer levels on admission may warrant a work-up for ADAMTS13 activity and VWF antigen and activity levels. These findings indicate the need for future investigation to study the relationship between endothelial and coagulation activation and the efficacy of treatments aimed at prevention and/or amelioration of microangiopathy in COVID-19.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1529-1529
Author(s):  
Leslie Skeith ◽  
M. Dawn Goodyear ◽  
Natalia Rydz ◽  
Man-Chiu Poon

Abstract There is little safety data available on the use of epidural analgesia during pregnancy in women with von Willebrand disease (VWD), a common disorder comprising up to 0.1% of the population. Despite physiological increases in von Willebrand factor antigen and activity levels to normal or near levels during third trimester in Type 1 VWD patients, epidural analgesia use is varied and often withheld. We conducted a cross-sectional questionnaire in order to further characterize the local practice and provide additional safety data on epidural use in the VWD population. We invited all women with VWD followed by the Southern Alberta Rare Blood and Bleeding Disorders Comprehensive Care Program to participate in an online or paper questionnaire. The questionnaire was part of a larger study identifying pregnancy complications in VWD, with additional questions collected on the diagnosis and severity of VWD, epidural use and associated outcomes, as well as the perceived contraindications of epidural analgesia. All questions were pre-tested by hematologists, obstetricians and laypeople. With patient consent, supplemental data was collected from clinic and hospital records. We included patients who were 18 years of age or older with a diagnosis of VWD, defined as von Willebrand factor (VWF) antigen and activity levels less than 50 percent or a historical diagnosis, in combination with a bleeding score of 4 or more (condensed MCMDM-1 bleeding questionnaire). Patients were excluded if they had no past pregnancies, no mailing address, or had an alternative bleeding disorder. Confidence intervals for proportions were calculated using the Wilson’s score method. Of the 98 women with VWD who met the study inclusion criteria, 31 (32%) completed the questionnaire. There were 25 (81%) diagnosed with Type 1, 5 (16%) with Type 2, and 1 (3%) with Type 3 VWD. The mean bleeding score was 10.3 (SD 3.6). There were a total of 83 pregnancies (mean 2.7, range 1-6), with 60 deliveries assessed because of 20 pregnancy losses, 2 elective terminations, and 1 patient currently pregnancy. Of the 60 deliveries, the rate of epidural use was 28.3% (95% confidence interval 18.5-40.8, n=17). All epidural analgesia use was reported in women with Type 1 VWD. Of the 43 pregnancies without an epidural, the stated reasons were as follows: 10 because of concern for bleeding (23.3%), 25 because of personal preference (58.1%), 7 ‘other’ (16.3%), and 1 participant without a response (2.3%). In the 10 pregnancies where an epidural was not used due to bleeding concerns, 6 patients had Type 1 VWD and 1 patient had Type 2N VWD. The outcome of epidural use in the VWD population was reassuring, 2 women reported their epidural analgesia to be ineffective, and 4 women reported neurological symptoms such as numbness, tingling or weakness. All neurological symptoms were temporary with no persistent deficits or documented complication of bleeding. Due to the retrospective nature of this study, VWF antigen and activity levels at the time of delivery were not available, limiting the conclusions that can be made on the safety of epidural use based on VWF levels. It is our local practice to proceed with epidural analgesia if a patient’s VWF antigen and activity levels measured in third trimester are greater than 50%. For VWF levels less than 50%, epidural analgesia would only be considered with appropriate DDAVP or factor concentrate replacement. In summary, our local rate of epidural use was close to 30% in the VWD population, which was primarily composed of Type 1 VWD patients. Outcome data is reassuring, but a larger cohort study is needed to further quantify rare risks such as neuraxial bleeding. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5067-5067
Author(s):  
Emily K. Rimmer ◽  
Dawn Zawadski ◽  
Tracy Voth ◽  
Michael Gousseau ◽  
Donald S Houston

Abstract Introduction: Type 3 Von Willebrand Disease (VWD) is a rare autosomal recessive bleeding disorder characterized by a complete deficiency of von Willebrand factor (VWF) and markedly reduced levels of FVIII, which confers a severe bleeding phenotype. Conventional management is with plasma-derived von Willebrand factor / FVIII concentrates. These products do not fully correct the bleeding diathesis, for several possible reasons: (a) platelets remain deficient in VWF; (b) subendothelial matrix remains deficient in VWF; and (c) available products lack the highest molecular weight VWF multimers. Because of the low prevalence of type 3 VWD, reports on surgical procedures are scarce. We reviewed the literature and identified one case report of a patient with type 3 VWD who underwent tonsillectomy (Alusi et al. 1995). That case was complicated by major intra-operative bleeding as well as prolonged hemorrhage in the two weeks following surgery, despite factor replacement with concentrate, cryoprecipitate, platelet transfusion and tranexamic acid. We report on the management of a patient with type 3 VWD undergoing a tonsillectomy, which demonstrates the importance of local measures in hemostatic control. Case: A 29 year old woman with Type 3 VWD (baseline VWF:Ag 4 IU/dL, VWF:RCoF <5 IU/dL, FVIII 1 IU/dL) had a 2 year history of recurrent tonsillar hemorrhage despite regular prophylaxis with plasma-derived VWF concentrate (Humate-P®). Each episode occurred in the absence of trauma or infection, and bleeding was difficult to control despite Humate-P and tranexamic acid. Lee et al. (2010) have previously reported that VWD is a cause of spontaneous tonsillar hemorrhage. Due to the recurrent nature of the bleeding episodes, a tonsillectomy was recommended. In preparation for the surgical procedure, we performed pharmacokinetic studies, which revealed a yield of VWF activity of 2.35IU/dL per U/kg and a half-life of VWF activity of 8.8 hours. We administered an initial loading dose of 63IU/kg (RCoF) of Humate-P preoperatively, achieving a VWF activity level (by latex agglutination: HemosIL vWF activity, Instrumentation Laboratories) of 126%. The tonsillectomy was uneventful, and the estimated blood loss intra-operatively was <50 mL. Surgical hemostasis was augmented by administration of tranexamic acid 1000mg intravenously pre-operatively and by continuous infusion intra-operatively, as well as 5 mL of fibrin sealant (Tisseel) administered to each tonsillar bed. A dose of Humate-P of 22.6 IU/kg was given post-operatively, and subsequent doses of 11.3 IU/kg were given q 4 hourly to maintain trough VWF activity of approximately 100IU/dL. Post-operative doses of tranexamic acid were omitted due to a transcribing error until day #3. On day #4 the Humate P dosing was reduced to 11.5U/kg q6h, which maintained trough VWF activity levels of approximately 50%. No bleeding occurred until post-operative day #9, when the eschar at the wound side detached. Bleeding continued despite re-bolus of Humate-P (23IU/kg) followed by resumption of q4h dosing, administration of tranexamic acid topically in the form of a 5% solution in addition to systemic administration, and application of topical silver nitrate. Hypotension transiently developed and the hemoglobin fell from 106 to 66g/L, requiring a return to the operating room. Further application of fibrin sealant promptly secured hemostasis. Conclusion: Surgery in a patient with type 3 VWD requires careful planning and collaboration between hematologists with expertise in bleeding disorders, the bleeding disorders nursing staff and surgical team. This case highlights the importance of monitoring for an extended period post-operatively, and demonstrates that bleeding can occur despite maintaining adequate VWF levels. Topical measures such as fibrin sealant play a key role in controlling bleeding in this context. Disclosures No relevant conflicts of interest to declare.


1992 ◽  
Vol 68 (04) ◽  
pp. 464-469 ◽  
Author(s):  
Y Fujimura ◽  
S Miyata ◽  
S Nishida ◽  
S Miura ◽  
M Kaneda ◽  
...  

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.


1993 ◽  
Vol 69 (02) ◽  
pp. 173-176 ◽  
Author(s):  
Anna M Randi ◽  
Elisabetta Sacchi ◽  
Gian Carlo Castaman ◽  
Francesco Rodeghiero ◽  
Pier Mannuccio Mannucci

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.


1994 ◽  
Vol 72 (02) ◽  
pp. 180-185 ◽  
Author(s):  
David J Mancuso ◽  
Elodee A Tuley ◽  
Ricardo Castillo ◽  
Norma de Bosch ◽  
Pler M Mannucci ◽  
...  

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.


1997 ◽  
Vol 77 (04) ◽  
pp. 760-766 ◽  
Author(s):  
Hiroshi Mohri ◽  
Etsuko Yamazaki ◽  
Zekou Suzuki ◽  
Toshikuni Takano ◽  
Shumpei Yokota ◽  
...  

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.


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

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.


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