Type 1 VWD classification revisited: novel insights from combined analysis of the LoVIC and WiN studies.

ABSTRACT: There is significant ongoing debate regarding type 1 von Willebrand disease (VWD) defintion. Previous guidelines recommended patients with von Willebrand factor (VWF) levels <30 IU/dL be diagnosed type 1 VWD, whereas patients with significant bleeding and VWF levels from 30 to 50 IU/dL be diagnosed with low VWF. To elucidate the relationship between type 1 VWD and low VWF in the context of age-induced increases in VWF levels, we combined data sets from 2 national cohort studies: 162 patients with low VWF from the Low VWF in Ireland Cohort (LoVIC) and 403 patients with type 1 VWD from the Willebrand in The Netherlands (WiN) studies. In 47% of type 1 VWD participants, VWF levels remained <30 IU/dL despite increasing age. Conversely, VWF levels increased to the low VWF range (30-50 IU/dL) in 30% and normalized (>50 IU/dL) in 23% of type 1 VWD cases. Crucially, absolute VWF antigen (VWF:Ag) levels and increase of VWF:Ag per year overlapped between low VWF and normalized type 1 VWD participants. Moreover, multiple regression analysis demonstrated that VWF:Ag levels in low VWF and normalized type 1 VWD patients would not have been different had they been diagnosed at the same age (ß = 0.00; 95% confidence interval, -0.03 to 0.04). Consistently, no difference was found in the prevalence of VWF sequence variants; factor VIII activity/VWF:Ag or VWF propeptide/VWF:Ag ratios; or desmopressin responses between low VWF and normalized type 1 VWD patients. In conclusion, our findings demonstrate that low VWF does not constitute a discrete clinical or pathological entity. Rather, it is part of an age-dependent type 1 VWD evolving phenotype. Collectively, these data have important implications for future VWD classification criteria.

Cost-effectiveness of prophylaxis with recombinant vs plasma-derived VWF in severe von Willebrand disease in the United States.

ABSTRACT: We evaluated the cost-effectiveness of prophylaxis with recombinant von Willebrand factor (rVWF) vs with plasma-derived von Willebrand factor (pdVWF) for patients with severe Von Willebrand disease. We found that rVWF is a cost-saving factor replacement compared with pdVWF across all willingness-to-pay thresholds in the United States.

Progress in von Willebrand Disease Treatment: Evolution towards Newer Therapies.

von Willebrand disease (VWD) is a very heterogenous disease, resulting in different phenotypes and different degrees of bleeding severity. Established therapies (i.e., desmopressin, antifibrinolytic agents, hormone therapy for heavy menstrual bleeding, and von Willebrand factor [VWF] concentrates) may work in some subtypes, but not in all patients. In recent years, progress has been made in improving the diagnosis of VWD subtypes, allowing for more specific therapy. The impact of VWD on women's daily lives has also come to the fore in recent years, with hormone therapy, tranexamic acid, or recombinant VWF as treatment options. New treatment approaches, including the replacement of lacking factor VIII (FVIII) function, may work in those subgroups affected by severe FVIII deficiency. Reducing the clearance of VWF is an alternative treatment pathway; for example, rondaptivon pegol is a VWFA1 domain-binding aptamer which not only improves plasma VWF/FVIII levels, but also corrects platelet counts in thrombocytopenic type 2B VWD patients. These approaches are currently in clinical development, which will be the focus of this review. In addition, half-life extension methods are also important for the improvement of patients' quality of life. Targeting specific mutations may further lead to personalized treatments in the future. Finally, a few randomized controlled trials, although relatively small, have been published in recent years, aiming to achieve a higher level of evidence in future guidelines.

Diagnosis and treatment of von Willebrand disease in 2024 and beyond.

MANUSCRIPT BACKGROUND AND AIM: The diagnosis and clinical care of patients with von Willebrand disease (VWD) has continued to evolve since the characterization of the von Willebrand factor (VWF) gene in 1985. This condition is almost certainly the most common inherited bleeding disorder, and the major symptomatic burden of the disease is experienced by females during their reproductive years. Diagnosis relies on the identification of a personal and family history of excessive mucocutaneous bleeding, and laboratory features consistent with quantitative and/or qualitative abnormalities of VWF. This review focuses on three aspects of VWD management, with current updates and a look into the future. MANUSCRIPT THEMES: First, we will address the role of genetics in the diagnosis and possible therapies for VWD. With current technologies, VWD genetic diagnosis is usually confined to the confirmation of type 2 subtypes of the disease and type 3 VWD analysis for family planning. While type 3 VWD is a potential candidate for the application of gene therapy, no treatments are currently close to entering the clinic. Second, the peri-procedural management of patients with VWD remains an important element of care. The choice of product, its dose and schedule all require careful consideration depending upon the type and disruptive nature of the planned procedure. Lastly, in addition to gene therapy, several other novel therapeutic interventions are also being developed for bleeding and prophylaxis in VWD. These include a VWF aptamer interfering with VWF clearance and bioengineered forms of VWF.

Diagnosis and treatment challenges in lower resource countries: State-of-the-art.

The 2022 World Federation of Haemophilia Annual Global Survey (AGS) reports that 454,690 patients with inherited bleeding disorders (IBD) have been identified globally. While this represents noteworthy progress, haemophilia epidemiology data indicate that 75% of people with inherited bleeding disorders living in low-income and low-to-middle-income countries have yet to be diagnosed. The AGS also revealed that 11 billion clotting factor units are available to treat haemophilia A and B globally. Due to a lack of finance, these treatments are unavailable to haemophilia in low-income countries with a consequence lack of access equity for haemophilia treatment in these communities. This sobering reality is not limited to haemophilia but applies to von Willebrand Disease (VWD). While VWD is the most prevalent IBD, only 103,844 people living with this condition have been diagnosed globally. Of the diagnosed patients, only a fraction live in low- or middle-income countries. Moreover, the majority of VWD patients are still treated sub-optimally without replacement therapies or prophylaxis, both of which are now accepted as global standards of care. In this state-of-the-art review, the authors reflect on three issues. First, the minimum elements required to diagnose haemophilia in a resource-constrained setting are identified. Second, this review points to the critical stakeholders and outlines their roles in removing access to haemophilia treatment barriers. Finally, the authors examine von Willebrand disease's ongoing diagnostic and treatment challenges and compare these to haemophilia. With the rapidly evolving novel therapies, the therapeutic landscape of all IBD will likely change for the better.

Targeting a higher plasma VWF level at time of delivery in pregnant individuals with von Willebrand disease: Outcomes at a single-institution cohort study.

INTRODUCTION: Guidelines on the management of pregnant individuals with von Willebrand disease (VWD) at the time of delivery recommend that von Willebrand factor (VWF) and factor VIII:C (FVIII:C) levels be ≥50% to prevent postpartum haemorrhage (PPH). Yet, high PPH rates persist despite these levels or with prophylactic factor replacement therapy to achieve these levels. AIMS: The current practice at our centre has been to target peak plasma VWF and FVIII:C levels of ≥100 IU/dL at time of delivery. The objective of this study was to describe obstetric outcomes in pregnant individuals with VWD who were managed at our centre. METHODS: Demographics and outcomes on pregnant individuals with VWD who delivered between January 2015 and April 2023 were collected. RESULTS: Forty-seven singleton deliveries (among 41 individuals) resulting in 46 live births and one foetal death were included. Twenty-one individuals had at least one prior birth by the start date of this study, of which 11 (52.4%) self-reported a history of PPH. Early PPH occurred in 12.8% (6/47) of deliveries. Two individuals required blood transfusion, of which one also had an unplanned hysterectomy and transfer to ICU. There were no thrombotic events reported. CONCLUSION: The strategy of targeting higher peak plasma VWF and FVIII:C levels (≥100 IU/dL) at the time of delivery may be effective in reducing the risk of delivery-associated bleeding complications in VWD patients. Yet, the rate of early PPH remains unsatisfactory compared to the non-VWD population.

Retrospective chart review of GI bleeding in people with von Willebrand disease.

INTRODUCTION: Gastrointestinal (GI) bleeding events (BEs) in von Willebrand disease (VWD) are difficult to diagnose and often recurrent. Limited data from clinical trials has led to lack of consensus on treatment options. AIM: Describe current treatments and outcomes for GI BEs in people with VWD. METHODS: This retrospective, observational, multicentre chart review study was conducted from January 2018 through December 2019 and included patients with inherited VWD with ≥1 GI BE in the preceding 5 years. Baseline characteristics, number and aetiology of BEs, associated GI-specific morbidities/lesions, treatment and outcomes were analysed descriptively. RESULTS: Sixty bleeds were reported in 20 patients with type 1 (20%), type 2 (50%) and type 3 (30%) VWD. During the 5-year study period, 31 (52%) BEs had one identified or suspected cause; multiple causes were reported in 11 (18%). Most GI BEs (72%) were treated with a combination of von Willebrand factor (VWF), antifibrinolytics and/or other haemostatic or non-haemostatic treatments. Time to resolution did not differ by VWF treatment use; however, BEs treated with non-VWF treatments tended to resolve later. In patients with GI-specific morbidities/lesions, 84% resolved with first-line treatment; time to resolution tended to be longer than in patients without such morbidities/lesions. Thirteen BEs occurred in patients receiving prophylaxis and 47 in patients receiving on-demand treatment; 18 BEs resulted in a switch to prophylaxis after bleed resolution. CONCLUSIONS: This study confirms the unmet need for the management of recurrent GI BEs in people with VWD and the need for prospective data, especially on prophylaxis.

Acquired bleeding disorders.

Acquired bleeding disorders can develop in previously healthy people irrespective of age or gender but are particularly common in patients with certain underlying conditions. Here, we review recent advances in the management of acquired haemophilia A (AHA), acquired von Willebrand syndrome (AVWS), and patients with hemostatic abnormalities due to chronic liver disease (CLD). Patients with AHA can now benefit from prophylaxis with emicizumab, a therapeutic antibody that mimics the function of activated coagulation factor VIII. The treatment of AVWS remains challenging in many situations and requires careful consideration of the underlying condition. Haemostatic abnormalities in CLD are often compensated by proportional reduction in pro and anti-haemostatic factors resulting in sustained or even increased thrombin generation. Consequently, bleeding in CLD is rarely caused by haemostatic failure and infusion of plasma or coagulation factor concentrates may not be effective.

Impact of inherited bleeding disorders on maternal bleeding and other pregnancy outcomes: A population-based cohort study.

INTRODUCTION: Increasing rate of postpartum haemorrhage (PPH) has been observed between 2003 and 2010 in Canada. Inherited bleeding disorders contribute to the risk of PPH. AIM: To identify the trend in PPH in the last decade, assess the impact of bleeding disorders on pregnancy outcomes and evaluate their coagulation workup during pregnancy. METHODS: We conducted a population-based retrospective cohort study using the Alberta Pregnancy Birth Cohort from 2010 to 2018. We included women with von Willebrand disease (VWD) and haemophilia, identified by previously validated algorithm and matched with controls. Logistic regression was used to compute odds of PPH and other pregnancy outcomes. RESULTS: We identified 311,330 women with a total of 454,400 pregnancies with live births. The rate of PPH did not change significantly from 10.13 per 100 deliveries (95% CI 10.10-10.16) in 2010-10.72 (95% CI 10.69-10.75) in 2018 (p for trend = .35). Women with bleeding disorders were significantly more likely to experience PPH (odds ratio [OR] 2.3; 95% CI 1.5-3.6), antepartum haemorrhage (OR 2.9; 95% CI 1.5-5.9) and red cell transfusion (OR 2.8; 95% CI 1.1-7.0). We observed a nonsignificant rise in the rate of PPH in women with VWD and haemophilia. Only 49.5% pregnancies with bleeding disorders had third trimester coagulation factor levels checked. Higher odds of PPH and antepartum haemorrhage were observed even with factor levels ≥0.50 IU/mL in third trimester. CONCLUSION: Despite comprehensive care in women with bleeding disorders, they are still at higher risk of adverse pregnancy outcomes compared to population controls.

A Compound Heterozygosis of Two Novel Mutations in vWF Exacerbates vWD in a Chinese Pedigree.

BACKGROUND: von Willebrand disease (vWD), caused by mutations in the von Willebrand factor (vWF) coding gene, is a disease characterized by abnormal coagulation activity and a severe tendency for hemorrhage. Therefore, identifying mutations in vWF is important for diagnosing congenital vWD. METHODS: We studied a 23-year-old male vWD patient and his parents. Clotting methods were used to determine activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen (FIB) levels, FVIII activity. Chromogenic substrate method was used to determine vWF antigen and activity. The platelet count was determined. Mutations were searched using whole-exome sequencing and certified by Sanger sequencing. Clinical data, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen levels, FX activity, FX antigen levels, and the platelet count were collected. A mixing study was performed to eliminate the presence of coagulation factor inhibitors and lupus anticoagulants. Mutations were screened by using whole-exome sequencing (WES) and were verified by using Sanger sequencing. RESULTS: The proband showed severely decreased vWF antigen, vWF activity, and FVIII activity. RIPA (RISTO-CETIN-induced platelet aggregation) was 0%. Data from WES showed that the proband carried compound heterozygous variants vWF: NM_000552.5 (c.3213C>A p.Cys1071Ter) and vWF: NM_000552.5 (c.6598+2T>C). The proband's mother carried variant vWF: NM_000552.5 (c.3213C>A p.Cys1071Ter) while the proband's father carried variant vWF: NM_000552.5 (c.6598+2T>C). All laboratory test indexes of the proband's parents, including vWF antigen, vWF activity, and FVIII activity, were within the normal ranges. CONCLUSIONS: We identified a compound heterozygosis with two novel mutations in vWF (c.3213C>A, c.6598+2T >C) in a family pedigree, and our results demonstrate that the compound heterozygous mutations probably exacerbate vWD.

Outcomes Following Total Hip Arthroplasty in Patients Who Have Von Willebrand Disease Depend on Postoperative Anticoagulation.

BACKGROUND: Von Willebrand disease (VWD) is the most common congenital bleeding disorder. This autosomal dominant condition arises from quantitative or qualitative defects of Von Willebrand factor. To our knowledge, this study leveraged a national database to characterize the largest VWD cohort of total hip arthroplasty (THA) patients to date, assessing 90-day postoperative adverse events and 5-year revision-free survival. METHODS: Adult patients who underwent primary THA for osteoarthritis were identified from January 2010 to October 2021 in a nationwide database. Patients who had and did not have VWD were matched (4:1) on age, sex, and Elixhauser Comorbidity Index and compared with multivariable logistic regression. Patients were then categorized based upon venous thromboembolism (VTE) chemoprophylaxis prescription patterns to compare bleeding and thrombotic adverse events. RESULTS: Of 544,851 THA patients, VWD was identified in 309 patients (0.06%). The matched cohorts contained 1,221 patients who did not have VWD and 306 patients who have VWD. On multivariable analysis, VWD patients had increased odds of 90-day VTE (odds ratio [OR] = 1.86) and hematoma (OR = 3.40) (P < .05 for all). No difference in 5-year revision-free survival was found. The VWD patients receiving aspirin or no prescriptions had greater odds of VTE (OR = 2.39, P = .048). Those on other chemoprophylaxis agents had greater odds of hematoma (OR = 4.84, P = .006). CONCLUSIONS: Patients with VWD undergoing THA had increased odds of 90-day VTE if using aspirin or no prescriptions, or hematoma if using other chemoprophylaxis. There is a delicate balancing act of clotting versus bleeding that must be considered in managing such patients, but it was reassuring that no difference in overall 5-year revision-free survival was found.

DILEMMAS ABOUT THE SELECTION OF ANESTHESIA FOR ELECTIVE CESAREAN SECTION IN PREGNANT WOMEN WITH MYOTONIC DYSTROPHY TYPE 2 AND SUSPECTED von WILLEBRAND DISEASE: A CASE REPORT.

With advancement of medicine in the field of diagnostics and treatment of women suffering from certain genetic disorders, more and more women have attained reproductive age and desired fertility. Maintaining pregnancy, as well as bringing it to an end poses a real challenge not only for obstetricians, but also for anesthesiologists involved in the procedure. In our case report, we describe anesthetic management of a female patient suffering from myotonic dystrophy type 2 and suspected von Willebrand's disease, and undergoing elective cesarean section. It is acknowledged that both diseases have their own peculiarities and specificities related to anesthesia and require careful consideration when it comes to selecting it. Bearing in mind the advantages and disadvantages of certain types of anesthesia, we believe that in this case, general anesthesia was a better choice compared to the regional techniques of anesthesia.

von Willebrand disease: A guide for the internist.

von Willebrand disease (VWD), the most common inherited bleeding disorder, results when patients either do not make enough von Willebrand factor (VWF) or make defective VWF. The pathophysiology of this disorder is complex but needs to be understood to interpret the diagnostic tests. Most patients have mild to moderate symptoms and can be adequately counseled and managed by a general internist, but some need to consult a hematologist. We review the pathophysiology of VWD, its subtypes, common presentations of each subtype, diagnostic testing, and management of mild as well as severe clinical manifestations of VWD.

Bleeding Disorder of Unknown Cause: A Diagnosis of Exclusion.

Patients with an unexplained mild to moderate bleeding tendency are diagnosed with bleeding disorder of unknown cause (BDUC), a classification reached after ruling out other mild to moderate bleeding disorders (MBD) including von Willebrand disease (VWD), platelet function defects (PFDs), coagulation factor deficiencies (CFDs), and non-hemostatic causes for bleeding. This review outlines our diagnostic approach to BDUC, a diagnosis of exclusion, drawing on current guidelines and insights from the Vienna Bleeding Biobank (VIBB). According to guidelines, we diagnose VWD based on VWF antigen and/or activity levels ≤50 IU/dL, with repeated VWF testing if VWF levels are <80 IU/dL. This has been introduced in our clinical routine after our findings of diagnostically relevant fluctuations of VWF levels in a high proportion of MBD patients. PFDs are identified through repeated abnormalities in light transmission aggregometry (LTA), flow cytometric mepacrine fluorescence, and glycoprotein expression analysis. Nevertheless, we experience diagnostic challenges with regard to reproducibility and unspecific alterations of LTA. For factor (F) VIII and FIX deficiency, a cutoff of 50% is utilized to ensure detection of mild hemophilia A or B. We apply established cutoffs for other rare CFD being aware that these do not clearly reflect the causal role of the bleeding tendency. Investigations into very rare bleeding disorders due to hyperfibrinolysis or increase in natural anticoagulants are limited to cases with a notable family history or distinct bleeding phenotypes considering cost-effectiveness. While the pathogenesis of BDUC remains unknown, further explorations of this intriguing area may reveal new mechanisms and therapeutic targets.

The Utility of Thromboelastography in Monitoring Von Willebrand Disease: A Case Report.

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. It is primarily attributed to malfunctioning or deficient Von Willebrand factor (VWF). Thromboelastography (TEG) has emerged as a valuable tool for assessing coagulation dynamics and guiding transfusion therapy in bleeding patients. Given this, we present a case study of a 23-year-old pregnant female with a past medical history of type 2B VWD, wherein TEG was employed to optimize disease screening and therapy monitoring while minimizing costs and preventing complications associated with low platelet counts. This case underscores the potential utility of TEG in enhancing the care of VWD patients, particularly in unique critical settings such as pregnancy.

Application of genetic testing for the diagnosis of von Willebrand disease.

von Willebrand disease (VWD) is the most frequent inherited bleeding disorder, with an estimated symptomatic prevalence of 1 per 1000 in the general population. VWD is characterized by defects in the quantity, quality, or multimeric structure of von Willebrand factor (VWF), a glycoprotein being hemostatically essential in circulation. VWD is classified into 3 principal types: low VWF/type 1 with partial quantitative deficiency of VWF, type 3 with virtual absence of VWF, and type 2 with functional abnormalities of VWF, being classified as 2A, 2B, 2M, and 2N. A new VWD type has been officially recognized by the ISTH SSC on von Willebrand factor which has also been discussed by the joint ASH/ISTH/NHF/WFH 2021 guidelines (ie, type 1C), indicating patients with quantitative deficiency due to an enhanced VWF clearance. With the advent of next-generation sequencing technologies, the process of genetic diagnosis has substantially changed and improved accuracy. Therefore, nowadays, patients with type 3 and severe type 1 VWD can benefit from genetic testing as much as type 2 VWD. Specifically, genetic testing can be used to confirm or differentiate a VWD diagnosis, as well as to provide genetic counseling. The focus of this manuscript is to discuss the current knowledge on VWD molecular pathophysiology and the application of genetic testing for VWD diagnosis.

Early diagnosis of persons with von Willebrand disease using a machine learning algorithm and real-world data.

BACKGROUND: Von Willebrand disease (VWD) is underdiagnosed, often delaying treatment. VWD claims coding is limited and includes no severity qualifiers; improved identification methods for VWD are needed. The aim of this study is to identify and characterize undiagnosed symptomatic persons with VWD in the US from medical insurance claims using predictive machine learning (ML) models. RESEARCH DESIGN AND METHODS: Diagnosed and potentially undiagnosed VWD cohorts were defined using Komodo longitudinal US claims data (January 2015-March 2020). ML models were built using key characteristics predictive of VWD diagnosis from the diagnosed cohort. Two ML models predicted VWD diagnosis with the highest accuracy in females (random forest; 84%) and males (gradient boosting machine; 85%). Undiagnosed persons suspected to have VWD were identified using an 80% cutoff probability; profiles of key characteristics were constructed. RESULTS: The trained ML models were applied to the undiagnosed cohort (28,463 females; 20,439 males) with suspected VWD. Fifty-two percent of undiagnosed females had heavy menstrual bleeding, a key pre-diagnosis symptom. Undiagnosed males tended to have more frequent medical procedures, hospitalizations, and emergency room visits compared with undiagnosed females. CONCLUSIONS: ML algorithms successfully identified potentially undiagnosed symptomatic people with VWD, although many may remain undiagnosed and undertreated. External validation of the algorithms is recommended.

Type 2M/2A von Willebrand disease: a shared phenotype between type 2M and 2A.

ABSTRACT: Four variants have been continuously subjected to debate and received different von Willebrand disease (VWD) classifications: p.R1315L, p.R1315C, p.R1374H, and p.R1374C. We chose to comprehensively investigate these variants with full set of VWD tests, protein-modeling predictions and applying structural biology. Patients with p.R1315L, p.R1315C, p.R1374H, and p.R1374C were included. A group with type 2A and 2M was included to better understand similarities and differences. Patients were investigated for phenotypic assays and underlying disease mechanisms. We applied deep protein modeling predictions and structural biology to elucidate the causative effects of variants. Forty-three patients with these variants and 70 with 2A (n = 35) or 2M (n = 35) were studied. Patients with p.R1315L, p.R1374H, or p.R1374C showed a common phenotype between 2M and 2A using von Willebrand factor (VWF):GPIbR/VWF:Ag and VWF:CB/VWF:Ag ratios and VWF multimeric profile, whereas p.R1315C represented a type 2M phenotype. There was an overall reduced VWF synthesis or secretion in 2M and cases with p.R1315L, p.R1374H, and p.R1374C, but not in 2A. Reduced VWF survival was observed in most 2A (77%), 2M (80%), and all 40 cases with p.R1315L, p.R1374H, and p.R1374C. These were the only variants that fall at the interface between the A1-A2 domains. p.R1315L/C mutants induce more compactness and internal mobility, whereas p.R1374H/C display a more extended overall geometry. We propose a new classification of type 2M/2A for p.R1315L, p.R1374H, and p.R1374C because they share a common phenotype with 2M and 2A. Our structural analysis shows the unique location of these variants on the A1-A2 domains and their distinctive effect on VWF.