von Willebrand disease (VWD): evidence-based diagnosis and management guidelines, the National Heart, Lung, and Blood Institute (NHLBI) Expert Panel report (USA)

Loss of von Willebrand factor large multimers in patients undergoing hemodialysis: A single-center, retrospective study

INTRODUCTION

Von Willebrand factor (VWF) is produced by vascular endothelial cells as large multimers and is cleaved by ADAMTS13 into an appropriate size in a shear stress-dependent manner. Excessive shear stress enhances VWF cleavage, leading to a hemorrhagic disease known as acquired von Willebrand syndrome. No clear reports on the prevalence of the loss of VWF large multimers in patients receiving hemodialysis are currently available. Therefore, this study investigated the prevalence of the loss of VWF large multimers in patients undergoing hemodialysis.

METHODS

This single-center, retrospective study involved 90 patients undergoing hemodialysis and 32 healthy participants as controls. VWF antigen levels (VWF:Ag), VWF activity (VWF:RCo), and ADAMTS13 activity were measured. VWF multimer analysis was performed by modified western blotting with an agarose gel electrophoresis, followed by densitometric evaluation of band intensities to calculate the VWF large multimer index (VWF-LMI). A VWF-LMI <80 % was defined as the loss of VWF large multimers, and the prevalence of the loss of VWF large multimers was calculated.

RESULTS

VWF:Ag and VWF:RCo levels in patients undergoing hemodialysis were significantly higher than those in healthy individuals (p < 0.01 both) and were negatively correlated with ADAMTS13 activity (p < 0.01, R = -0.353 and p < 0.01, R = -0.392, respectively). A VWF-LMI <80 % was present in 24 of 90 patients.

CONCLUSIONS

The loss of VWF large multimers was identified in 26.7 % of patients receiving hemodialysis. However, the prevalence of the loss of VWF multimers in these patients may be underestimated, as their relatively high VWF activity makes significant bleeding manifestations less likely.

Alterations in von Willebrand Factor Levels in Patients with Malaria: A Systematic Review and Meta-Analysis of Disease Severity

Background and Objectives: Elevated von Willebrand factor (vWF) levels have been reported in malaria, but their relationship with disease severity remains unclear. This study aimed to compare vWF levels between Plasmodium-infected and uninfected individuals and assess changes in severe infections. Materials and Methods: The systematic review was registered in PROSPERO (CRD42024558479). A comprehensive search across six databases identified studies reporting vWF levels in malaria. A meta-analysis was conducted using a random-effects model, with standardized mean difference (SMD) as the effect measure due to varying measurement units. Heterogeneity was assessed using the I2 statistic. Results: Of 1647 identified records, 26 studies met the inclusion criteria. The meta-analysis showed significantly higher vWF levels in Plasmodium-infected individuals compared to uninfected controls (p < 0.001, SMD: 2.689 [95% CI 1.362; 4.017], I2: 98.1%, 12 studies, 3109 participants). However, no significant difference was found between severe and less severe cases (p = 0.051, SMD: 3.551 [95% CI -0.007; 7.109], I2: 99.3%, 8 studies, 1453 participants). Conclusions: vWF levels are significantly elevated in individuals with Plasmodium infections, indicating a potential role in malaria pathophysiology. Although levels tend to be higher in severe cases, current evidence is insufficient to support vWF as a reliable marker for disease severity. Further prospective and well-controlled studies are needed to validate its diagnostic and prognostic value in malaria management.

Emicizumab in Type 3 von Willebrand Disease: Report of a Case with an Alloantibody and Literature Review

Type 3 von Willebrand disease (VWD), the most severe form of VWD, is an inherited recessive bleeding disorder caused by the complete deficiency of von Willebrand factor (VWF). The reported prevalence is 1 per million but varies worldwide according to the frequency of consanguineous marriages. The clinical phenotype is characterized not only by mucocutaneous bleedings, but also by hemarthroses and muscle hematoma, as in patients with moderate hemophilia. Long-term prophylaxis with factor (F)VIII/VWF concentrates is recommended in patients with a history of severe and frequent bleeds. A rare complication of replacement therapy is the development of alloantibodies against VWF, with the consequences of an ineffective therapy and risk of anaphylactic reactions upon treatment. Emicizumab is the first bispecific monoclonal antibody that mimics FVIII coagulant activity and is approved for prophylaxis of bleeding in patients with inherited hemophilia A with or without inhibitors and recently also for acquired hemophilia. In this manuscript we report and discuss available data in the literature on the use of emicizumab in type 3 VWD and describe the case of a female patient with type 3 VWD with a history of alloantibodies against VWF and posttransfusion anaphylaxis, recently and successfully put on off-label prophylaxis with emicizumab.

A Ten-Year Experience with the Diagnosis of Von Willebrand Disease in Mexico Based on a Cost-Effective Strategy

BACKGROUND

Von Willebrand disease (VWD), is the most common inherited bleeding disorder worldwide, but its diagnosis is complicated, expensive, and poorly evaluated in several countries.

OBJECTIVE

To report our long-term experience with the diagnosis of VWD based on a cost-effective strategy.

METHODS

We studied 802 Mexican patients, men and women, children, and adults, with clinical suspicion of VWD. The following tests were performed: blood count, bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen concentration, VWF antigen, ristocetin cofactor activity, collagen binding assay, ristocetin-induced platelet aggregation, FVIII activity, and VWF multimers analysis.

RESULTS

VWD was diagnosed in 639 patients; 582 had type 1 VWD (91.1%). Type 2 VWD was found in 52 patients (8.1%). Type 2A was present in 25 cases (48.1%), while types 2B and 2 M accounted for 21 (40.4) and six (11.5%) cases, respectively. Type 3 VWD was present in five patients (0.8%). The mean age of patients with VWD was 25.3 years (range: 2-71) for males and 22.1 (range: 1-54) for females. The diagnosis was inconclusive in 40 cases (5.0%) and was discarded in 123 (15.3%). Blood group O was the most common among patients with VWD.

CONCLUSION

Using a low-cost diagnostic strategy, we confirmed that VWD is as common in Mexico as in other countries. Review of the patient's history is mandatory when VWD is suspected, although laboratory confirmation may be difficult and expensive. The consequences of a lack of accurate and timely diagnosis affect the promptness and quality of treatment.

Current Diagnosis of von Willebrand Disease in Italy: 3 Years Following the Release of the International Guidelines

The American Society of Hematology-International Society on Thrombosis and Haemostasis-National Hemophilia Foundation-World Federation of Hemophilia 2021 International Guidelines (IGL) on von Willebrand disease (VWD) have pointed out many challenges, mainly in the diagnostic approach of VWD patients. To determine the impact of these IGL on the current clinical and laboratory diagnosis of Italian VWD patients, we have recently conducted a survey among 43 centers affiliated with the Italian Association of Hemophilia Centers (AICE). Directors and colleagues responsible for the management of VWD patients were invited to report in a detailed questionnaire how IGL recommendations about the assessment of the specific activities of von Willebrand Factor (VWF) could be applied at their local sites. Results from such a survey showed that bleeding assessment tools, VWF antigen, and factor VIII procoagulant are currently in use in all centers. The automated assays for platelet-dependent VWF activity with or without ristocetin described in IGL have been used since 2021 in 37/43 (86%) centers. Among other laboratory tests, VWF collagen binding, ristocetin-induced platelet agglutination, multimeric analysis, VWF propeptide, VWF:FVIII binding assay were available in 49, 63, 26, 7, and 28% of AICE, respectively. Analyses of VWF gene defects are available only at 3/43 (7%) centers. Desmopressin (DDAVP) infusion trials at diagnosis, with measurements of VWF activities at 1 and 4 hours post-DDAVP, is currently performed at 38/43 (88%) centers. Based on this information, a simplified clinical diagnosis using a few automated tests before and after DDAVP has been proposed. Such a diagnostic approach will be validated prospectively in a large cohort of Italian VWD patients.

Replacement therapy in pregnant women with von Willebrand disease during delivery: Factor levels and pharmacokinetics

Limited data are available on VWF activity (VWF:Act) and factor VIII (FVIII:C) levels during delivery after VWF/FVIII concentrate administration in women with von Willebrand disease (VWD). We aimed to evaluate treatment with a specific VWF/FVIII concentrate on factor levels in women with VWD during delivery and the postpartum period. A retrospective single-center study was conducted between January 1, 2008, and August 1, 2022. Pregnant women treated with Haemate®P during delivery were included if they had ≥2 consecutive VWF:Act and FVIII:C measurements post-infusion. VWF:Act/FVIII:C levels were compared to predefined target levels. A population pharmacokinetic (PopPK) model was developed, estimating VWF and FVIII pharmacokinetics after Haemate®P administration. Nineteen women were included. Targeted VWF:Act/FVIII:C peak levels were achieved after the first infusion (≥1.00 IU/mL, n = 12; ≥1.50 IU/mL, n = 5), and all VWF:Act/FVIII:C trough levels remained ≥0.50 IU/mL during first 72 h of treatment. All women had pretreatment FVIII:C levels ≥1.00 IU/mL, except one woman with type 2N, which was significantly higher than FVIII:C levels during the third trimester (median increase: 0.42 IU/mL, interquartile range: [0.12-0.92]). FVIII:C trough levels increased during treatment, median 2.05 IU/mL [1.65-2.71]. Nine women (47%) experienced postpartum hemorrhage and no thrombosis occurred. A one-compartment PopPK model adequately described VWF:Act/FVIII:C levels. Targeted VWF:Act/FVIII:C peak levels were achieved with the prescribed dosing regimens. VWF clearance was similar to that in nonpregnant individuals. Both pretreatment and FVIIIC trough levels during treatment were high with reduced FVIII clearance. Monitoring VWF:Act/FVIII:C levels is recommended for optimizing target levels and enriching the current PopPK model, improving VWF:Act/FVIII:C level predictions, and achieving more effective dosing.

Investigation of a hemophilia family with one female hemophilia A patient and 12 male hemophilia A patients

Hemophilia A (HA) is an X-chromosome-linked recessive genetic disorder. Female carriers may have bleeding symptoms, but rarely have moderate or severe disease. We identified a female patient with moderate HA by pedigree tracking and genetic testing in a HA family involving consanguineous marriage. To investigate the clinical and laboratory data, as well as F8 genetic variant affecting members in her family. We constructed a detailed pedigree diagram and performed coagulation analyses, including factor VIII activity (FVIII:C), FVIII inhibitor, and von Willebrand factor antigen (VWF: Ag) on 20 family members. The genomic DNA of 11 members was screened for intron 1 and intron 22 inversions using long-distance real-time polymerase chain reaction (RT-PCR). Their F8 coding genes were sequenced with an automatic next-generation sequencing. Thirteen HA persons with hemophilia (12 males, one female) and 18 female carriers were identified in the family. VWF: Ag level was normal in all 13 persons with hemophilia and 7 carriers tested. The female HA patient had FVIII:C 1.9 IU/dL and was homozygous for F8:c.1918G > T:p.V640F. Genetic testing is conducive to the diagnosis of hemophilia carriers and persons with hemophilia. F8: c.1918G > T:p.V640F is the pathogenic HA variant in this family. In any hemophilia family, we need to pay more attention to female carriers and patients.

Low von Willebrand factor-unraveling an enigma wrapped in a conundrum

The 2021 ASH ISTH NHF WFH guidelines recommendation that patients with von Willebrand factor (VWF) levels of 30 to 50 IU/dL and an increased bleeding phenotype be categorized as type 1 von Willebrand disease (VWD) rather than Low VWF has proved controversial. However, in support of that decision, recent data have demonstrated that individuals with partial quantitative VWF deficiency exhibit an age-dependent evolving phenotype and confirmed that Low VWF represents a subgroup within heterogeneous type 1 VWD. Nonetheless, type 1 VWD heterogeneity continues to pose significant diagnostic challenges. In this Forum article, we address outstanding issues critical to preventing the inappropriate overdiagnosis of type 1 VWD while maximizing access to healthcare and minimizing diagnostic delays. In addition, we propose an algorithm for type 1 VWD diagnosis. This algorithm pays special attention to individuals with plasma VWF levels in the 30 to 50 IU/dL range who have no or minimal bleeding history and have not yet been exposed to significant hemostatic challenges.

Recombinant von Willebrand factor use in obstetric anesthesia

Background

In pregnant patients with von Willebrand disease who have reduced von Willebrand factor (VWF) activity but normal factor VIII activity, recombinant VWF may be considered to supplement VWF.

Methods

All patients with known diagnosis of von Willebrand disease who were admitted for delivery and received recombinant VWF between October 2019 and March 2023 were included. Demographic data, peripartum course, laboratory data, neuraxial use, and bleeding complications were reviewed.

Results

There were 8 deliveries in 6 patients who had von Willebrand disease and received recombinant VWF during the study period. All patients received neuraxial analgesia or anesthesia after administration of recombinant VWF without complications. No patient required additional recombinant VWF supplementation at delivery.

Conclusion

Recombinant VWF may be an option for peripartum management in parturients with selective reduction in VWF activity and normal factor VIII activity.

Patient-reported data on the severity of Von Willebrand disease

INTRODUCTION

The severity of Von Willebrand disease (VWD) is currently based on laboratory phenotype. However, little is known about the severity of the patient's experience with the disease. The most recent VWD guidelines highlight the need for patient-reported outcomes (PROs) in VWD.

AIM

The study aimed to investigate the patient-perspective on VWD severity and to identify key factors that determine the severity of disease experienced by patients.

MATERIALS AND METHODS

Patients participated in a nationwide cross-sectional study on VWD in the Netherlands (WiN-study). Patients filled in a questionnaire containing questions on the experienced severity of VWD (4-point scale), bleeding score (BS) and quality of life (QoL).

RESULTS

We included 736 patients, median age of 41.0 years (IQR 23.0-55.0) and 59.5% were women. A total of 443 had type 1, 269 type 2 and 24 type 3 VWD. Self-reported severity of VWD was categorized as severe (n = 52), moderate (n = 171), mild (n = 393) or negligible (n = 120). Classification by historically lowest FVIII:C levels < 0.20 IU/mL as a proxy for severe VWD aligned with patient-reported severity classification with a 72% accuracy. Type 3 VWD (OR = 4.02, 95%CI: 1.72-9.45), higher BS (OR = 1.09, 95%CI: 1.06-1.11), female sex (OR = 1.36, 95%CI: 1.01-1.83), haemostatic treatment in the year preceding study inclusion (OR = 1.53, 95%CI: 1.10-2.13) and historically lowest VWF:Act levels (OR = 0.26, 95%CI: 0.07-1.00) were independent determinants of patient-reported severity.

CONCLUSION

This study shows that patient-reported data provide novel insights into the determinants of experienced disease severity. Our findings highlight the need for studies on PROs with validated questionnaires to assess the burden of VWD.

Prevalence and characterization of anti-VWF antibodies in a population of patients with type 3 VWD

ABSTRACT

von Willebrand disease (VWD) is an inherited bleeding disorder caused by quantitative or qualitative defects in the von Willebrand factor (VWF) protein. Type 3 VWD has a severe bleeding phenotype caused by the absence of VWF, in which treatment usually involves replacement therapy with VWF-containing products. The immune system can react to the VWF product and form anti-VWF antibodies to neutralize or clear the VWF, which can compromise efficacy of treatment or lead to anaphylaxis. Current diagnostic testing is limited to the detection of anti-VWF antibodies that neutralize VWF binding to platelets by using a ristocetin cofactor assay. We set out to develop assays to identify both neutralizing and nonneutralizing antibodies to screen, quantify, and characterize anti-VWF antibodies in samples from the Zimmerman Program, a large multicenter study of patients with VWD. We detected anti-VWF immunoglobulin G (IgG) or IgM antibodies in 18% of 49 unrelated individuals with type 3 VWD. The antibodies ranged in concentration and consisted of 33% nonneutralizing and 67% neutralizing to factor VIII, collagen III, platelet glycoprotein Ib alpha (GPIbα), and/or collagen IV binding. Of the positive type 3 VWD samples, 8 of 9 were IgG, which were further subclassified into mostly IgG1 and IgG4 antibodies. Through a series of testing methods, we identified VWF-specific antibodies in 9 unrelated individuals with type 3 VWD with varying demographics, bleeding phenotypes, and genetic variants. This anti-VWF antibody testing strategy provides a useful tool to assess risk and better navigate treatment options for patients with type 3 VWD.

Hemostatic management of von Willebrand disease during childbirth with a plasma-derived von Willebrand factor/factor VIII concentrate

BACKGROUND

Females with von Willebrand disease (VWD) do not show the same increases in von Willebrand factor and factor (F)VIII levels during pregnancy as females without VWD and are at higher risk of excessive bleeding associated with childbirth. Data on hemostatic management for childbirth in VWD patients are limited.

OBJECTIVES

To evaluate the dosing, efficacy, and safety of plasma-derived von Willebrand factor/FVIII (wilate) for prevention of excessive bleeding associated with childbirth in females with any type of VWD.

METHODS

Data for females with VWD who received wilate for hemostatic coverage for childbirth during 2 prospective clinical studies were analyzed.

RESULTS

Ten females with VWD and a mean age at enrolment of 29.6 years were treated with wilate to prevent excessive bleeding associated with childbirth. Two patients had type 1, 4 had type 2 (2 2A, 1 2B, and 1 2M), and 4 had type 3 VWD. Of the 10 deliveries, 5 were by cesarean section. Patients received a mean of 9.5 infusions of wilate over 6.8 exposure days, with a mean total dose of 234 IU/kg per delivery and 25 IU/kg per infusion. Hemostatic management for all deliveries was rated excellent or good, with no excessive bleeding during delivery and no postpartum bleeding during the period of wilate treatment in any patient. Two patients experienced 8 possible or probable treatment-related adverse events; all were mild or moderate and resolved. No thromboembolic events were observed.

CONCLUSION

The results of this case series indicate that wilate provided effective hemostatic cover for childbirth in females with VWD during delivery and postpartum.

Recurrent Auricular Keloid After Childbirth in a Patient With von Willebrand Disease

The authors present a case of a 34-year-old female patient with von Willebrand disease who developed a recurrent right auricular keloid after childbirth. The patient had previously undergone surgical excision of the keloid in 2017, which led to the diagnosis of von Willebrand disease due to uncontrolled bleeding. After a successful pregnancy in 2023, the patient experienced keloid recurrence. Surgical excision and radiotherapy were performed in April 2023, followed by DDAVP administration to control postoperative bleeding. At 1-year follow-up, no recurrence was observed. This case highlights the potential impact of pregnancy on keloid recurrence and the challenges of managing keloids in patients with bleeding disorders.

Analytical and Clinical Validation of a Non-Ristocetin Based VWF Assay on 2 Automated Analyzers in a Large Reference Laboratory

BACKGROUND

Historically, von Willebrand factor (VWF) activity assays utilized ristocetin despite limitations including poor limits of detection and high imprecision. Newer VWF activity assays such as the INNOVANCE® VWF Ac assay, however, do not rely on ristocetin to measure platelet-dependent VWF function. The purpose of this study was to evaluate the analytical and clinical performance of the Siemens Healthineers INNOVANCE VWF Ac Assay on the Siemens BCS® XP and the Sysmex® CS-2500 systems in a large reference laboratory setting.

METHODS

Performance indicators for the INNOVANCE VWF Ac assay were the limit of quantitation (LoQ), precision, and method comparison. Method comparison studies were performed using remnant plasma patient samples from routine coagulation tests and analyzed using both the INNOVANCE VWF Ac assay and the Siemens Healthineers ristocetin-dependent BC von Willebrand Reagent.

RESULTS

Evaluation of the INNOVANCE VWF Ac assay on the BCS® XP and CS-2500 systems demonstrated good precision and a lower LoQ compared to the BC von Willebrand Reagent. Method comparisons support the use of the INNOVANCE VWF Ac assay on the BCS® XP and CS-2500 systems to measure platelet-dependent VWF function. The INNOVANCE VWF Ac assay was able to further assist in von Willebrand disease classification in 6/7 (86%) samples when the result was below the LoQ for the BC von Willebrand Reagent (ristocetin cofactor activity).

CONCLUSIONS

These data are consistent with the 2021 American Society of Hematology/International Society on Thrombosis and Haemostasis/National Hemophilia Foundation/World Federation of Hemophilia von Willebrand disease guidelines that suggest using newer assays such as the INNOVANCE VWF Ac assay in place of ristocetin cofactor activity assays.

A Systematic Review of Efficacy and Safety of Plasma-Derived von Willebrand Factor/Factor VIII Concentrate (Voncento) in von Willebrand Disease

BACKGROUND

 For the treatment of von Willebrand disease (VWD), von Willebrand factor (VWF) concentrates can be used in on-demand, long-term prophylaxis, and surgical prophylaxis regimens.

METHODS

 This systematic literature review was conducted to evaluate the efficacy, consumption, and safety of plasma-derived human coagulation FVIII/human VWF (pdVWF/FVIII; Voncento/Biostate) for the treatment of patients with any inherited VWD type. An electronic search was conducted in MEDLINE and Cochrane Library databases on VWD therapies. All retrieved publications were assessed against predefined inclusion/exclusion criteria following the Cochrane group recommendations. Associated pharmacovigilance data were collected across the same time period.

RESULTS

 Eleven publications from eight study cohorts were identified for data retrieval. All were from multicenter studies and included both pediatric and adult patients. Eight publications included evaluations of the efficacy of pdVWF/FVIII for on-demand treatment, eight included long-term prophylactic treatment, and eight included surgical prophylaxis. Treatment protocols and VWF administration methods differed between studies, as did safety evaluations. The clinical response was rated as excellent/good for on-demand treatment in 66 to 100% of nonsurgical bleeds, 89 to 100% in the treatment of breakthrough bleeds during long-term prophylaxis treatment, and hemostatic efficacy in surgical procedures was 75 to 100%. Pharmacovigilance data confirmed a low incidence of adverse events in treated patients.

CONCLUSION

 This review provides a comprehensive summary of studies that evaluated the use of pdVWF/FVIII in VWD demonstrating the long-term effectiveness and safety of this pdVWF/FVIII across all ages, types of VWD, and treatment settings.

Investigation of von Willebrand factor multimer abnormalities before and after aortic valve replacement using the Hydragel-5 assay

BACKGROUND

Severe aortic stenosis (sAS) is associated with acquired von Willebrand syndrome (AVWS) by loss of high-molecular-weight multimers (HMWM) of von Willebrand factor (VWF), potentially resulting in perioperative bleeding. Analysis of VWF multimers remains challenging. Recently, the new, rapid Hydragel 5 assay has been developed, using electrophoretic protein separation for dividing VWF-multimers into low (LMWM), intermediate (IMWM), and HMWM, the hemostatically active part of VWF. Here, we evaluated its impact on predicting blood loss in presence of AVWS after surgical aortic valve replacement (SAVR).

METHODS

We prospectively examined 52 patients (age: 68 ± 7 years; 54 % male) admitted to SAVR. They were divided in two groups (A: normal VWF, n = 28; B: abnormal VWF, n = 24, defined as VWF-activity/antigen (VWF:Ac/Ag)-ratio < 0.7 and/or HMWM loss). Blood samples and echocardiographic data were collected before, seven days and three months after SAVR. Blood loss and transfusions were recorded.

RESULTS

Baseline characteristics and clinical data were similar in both groups. HMWM loss was present in 38.5 % of all patients. HMWM, the VWF:Ac/Ag- and HMWM/(IMWM+LMWM)-ratios were significantly decreased preoperatively in group B but normalized after SAVR. Bleeding, re-thoracotomy and transfusion rates were comparable. HMWM loss was inversely correlated with the peak aortic gradient (Pmax) and positively with the aortic valve area (AVA), while HMWM/(IMWM+LMWM)-ratio negatively correlated with the mean aortic gradient (Pmean).

CONCLUSION

HMWM and HMWM/(IMWM+LMWM)-ratio inversely correlate with severity of AS and normalize after SAVR. The Hydragel-5 assay's might be valuable for routine diagnostics to assess bleeding risk and postoperative normalization of AS and VWF abnormalities in SAVR patients.

Improving 1-Deamino-8-D-Arginine Vasopressin (DDAVP) Challenges in Pediatric/Young Adult Patients With Bleeding Disorders: A Quality Improvement Study

Background: Desmopressin (1-deamino-8-D-arginine vasopressin [DDAVP]) has demonstrated efficacy as a treatment option for patients with inherited bleeding disorders. Because of individuals' variable response to the medication, it is recommended to complete a challenge to document appropriate hemostatic response to the medication before recommending its use prior to surgical procedures or treatment of bleeding symptoms. The project aimed to reduce the errors in hemostatic response assessments for patients with bleeding disorders undergoing a DDAVP challenge (process outcome), particularly timing and number of blood samples drawn, from an error rate baseline of 36% to 0% by December 2021 and sustained for one year. Method: Plan-Do-Study-Act methodology was employed for this qualitative improvement initiative. Interventions designed and implemented included: an order set with medication doses and corresponding laboratory orders as clinically indicated for the bleeding disorder indication, clinical procedure guidelines for infusion nurses to follow, hemostasis nurse coordination of appointments with patients, and family education. Results: Baseline data on 22 patients who completed a DDAVP challenge demonstrated a 36% error rate not involving doses of medication administered. Errors encountered included improper timing of laboratory draw after DDAVP administration, incomplete laboratory evaluation, laboratory results displayed incorrectly due to testing orders released at once instead of in a sequential manner. These interventions resulted in a reduction of DDAVP challenge errors to 0% that were sustained for one year. Conclusion: Improvement in procedural medication administration and appropriate laboratory evaluation of patients undergoing a DDAVP challenge leads to a complete and reliable assessment of hemostatic response following medication administration.

Pediatric Epistaxis-Effectiveness of Conservative Management

OBJECTIVES

Epistaxis is an emergency medical condition that sometimes requires admission to the emergency department. Pediatric epistaxis differs from epistaxis in the older population in terms of etiology, severity, and management. Our objective was to identify the distinctive features of pediatric epistaxis and determine the appropriate management.

METHODS

This was a retrospective study of 231 medical records of children (<18 years old) with epistaxis of a total of 1171 cases in the general population who presented to our medical center's emergency department between 2013 and 2018.

RESULTS

Among 231 admissions, 10 children (4.3%) presented more than once. Male patients accounted for the majority of cases (64.5%), and the average age was 9.4 years. Two children were treated with aspirin because of cardiac valve disease. Anterior bleeding was detected in 101 cases (43.7%), whereas posterior origin was observed in 8 cases (3.5%). In 122 cases (52.8%), there was no active bleeding observed. Nose injury was the cause of epistaxis in 24 cases (10.4%), and 16 admissions (6.9%) followed nasal surgical interventions. Nineteen children (8%) had abnormal coagulation tests, and 7 patients (3%) received blood transfusions. Chemical cauterization was performed in 89 cases (39.3%), and anterior packing was needed in only 9 cases (3.9%). Nine children required hospitalization (3.9%), and 2 needed surgical intervention to control bleeding. Compared with the adult population, there were significantly fewer cases of active bleeding, recurrent epistaxis, anterior packing, or need for hospitalization in the pediatric population.

CONCLUSIONS

Epistaxis is significantly less severe in the pediatric population, with only a few cases requiring major intervention. Endoscopic examination of the entire nasal cavity and routine coagulation tests are not mandatory unless there is a history of recurrent epistaxis, known coagulopathy, antiplatelet/anticoagulation therapy, or a suspicion of juvenile idiopathic angiofibroma. We suggest using absorbable packs, which offer advantages over cauterization or nonabsorbable packs.

Laparoscopic liver resection for a patient of hepatocellular carcinoma with von Willebrand disease: a case report

BACKGROUND

The safety of laparoscopic hepatectomy for inherited coagulation disorders is unclear; however, the safety of open hepatectomy has been reported in several studies. Herein, we report the first case of a laparoscopic hepatectomy for a patient with von Willebrand Disease (VWD).

CASE PRESENTATION

A 76-year-old male with a history of chronic hepatitis C and VWD type 2B was advised surgical resection of a 4 cm hepatocellular carcinoma in segment 7 of the liver. The patient was diagnosed with VWD in his 40 s due to gastrointestinal bleeding caused by gastric erosion. The von Willebrand factor (VWF) ristocetin cofactor activity was 30%, and VWF large multimer deficiency and increased ristocetin-induced platelet agglutination were observed. The preoperative platelet count was reduced to 3.5 × 104/μL; however, preoperative imaging findings had no evidence of liver cirrhosis, such as any collateral formations and splenomegaly. The indocyanine green retention rate at 15 min was 10%, and his Child-Pugh score was 5 (classification A). Perioperatively, VWF/factor VIII was administered in accordance with our institutional protocol. A laparoscopic partial hepatectomy of the right posterior segment was performed. The most bleeding during surgery occurred during the mobilization of the right lobe of the liver due to inflammatory adhesion between the retroperitoneum and the tumor. Bleeding during parenchymal transection was controlable. The duration of hepatic inflow occlusion was 65 min. The surgical duration was 349 min, and the estimated blood loss was 2150 ml. Four units of red blood cells and fresh frozen plasma were transfused at the initiation of parenchymal transection, and 10 units of platelets were transfused at the end of the parenchymal transection. On postoperative day 1, the transection surface drainage fluid became hemorrhagic, and emergency contrast-enhanced computed tomography showed extravasation in the greater omentum. Percutaneous transcatheter arterial embolization of the omental branch of the right gastroepiploic artery was performed. No further postoperative interventions were required. The patient was discharged on postoperative day 14.

CONCLUSION

The indications for laparoscopic hepatectomy in patients with VWD should be carefully considered, and an open approach may still be the standard approach for patients with VWD.

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.

Evaluation of an automated von Willebrand factor glycoprotein IbM activity assay compared with 3 alternative von Willebrand factor activity assays

Background

To overcome deficiencies of the traditional von Willebrand factor (VWF) ristocetin cofactor activity assay (VWF:RCo), several automated assays for VWF platelet-binding activity have been developed. Information on the performance of these assays and their diagnostic utility remains limited.

Objectives

To validate the VWF:glycoprotein IbM assay INNOVANCE VWF Ac and compare it with an automated VWF:RCo assay as well as with an automated assay and a manual VWF:Ab assay and to generate reference ranges and analyze reproducibility of the VWF:glycoprotein IbM assay.

Methods

Clinical sites enrolled healthy subjects and patients representing the intended use population; VWF activity assays were performed, and results were analyzed. The performance of the INNOVANCE VWF Ac assay was also compared between the BCS XP System and the CS-2500 and CS-5100 analyzers.

Results

The INNOVANCE VWF Ac assay correlated well with the VWF:RCo assay and the automated HemosIL VWF:Ab assay, with Pearson coefficients of >.9 and a predicted bias of ≤5.0 IU/dL at VWF levels of 30 IU/dL and ≤5.8 IU/dL at the levels of 50 IU/dL, but correlation and bias were not as good when compared with the REAADS manual VWF:Ab assay. Reference ranges observed for healthy subjects correlated well with previously published findings. Reproducibility of the INNOVANCE VWF Ac assay on the BCS XP System and the CS analyzers was excellent, as was correlation among devices.

Conclusion

The characteristics of the INNOVANCE VWF Ac assay regarding comparability with other VWF activity assays, reference ranges, and precision support the use of this assay for evaluation of patients with concern for von Willebrand disease.

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 (β = 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.

Clinical and Laboratory Presentation and Underlying Mechanism in Patients with Low VWF

BACKGROUND

 Low von Willebrand factor (VWF) refers to subjects with plasma levels of 30 to 50 IU/dL. The mechanism of low VWF is poorly understood. We chose to determine the clinical presentation, laboratory phenotype, and underlying mechanisms of low VWF.

MATERIAL AND METHODS

 We included 250 patients characterized with low VWF. The International Society on Thrombosis and Haemostasis Bleeding Assessment Tool (ISTH-BAT) was used to assess clinical symptoms. To determine the underlying mechanisms of low VWF, we used as markers the VWF propeptide (VWFpp) assay and FVIII:C/VWF:Ag ratio for VWF synthesis and the VWFpp/VWF:Ag ratio for VWF clearance. Results were compared with those of 120 healthy controls. Cases with abnormal screening tests were further evaluated for coagulation factor levels and platelet disorders.

RESULTS

 The median age of the cohort was 35 years (range 3-85), 21% were children (n = 53), 34% were adult males (n = 85), and 45% (n = 112) were adult females. According to the ISTH-BAT, abnormal bleeding was found in 35% of children, 47% of males, and 49% of females. No association was found between VWF activity levels and ISTH-BAT. Patients showed an overall decreased VWF synthesis/secretion and an enhanced VWF clearance was identified in 33% of them. In 89 patients (36%), there were other hemostasis-related defects, but there was no difference in the ISTH-BAT between the two groups.

CONCLUSION

 Our findings indicate that reduced VWF synthesis/secretion and enhanced VWF clearance are major mechanisms of low VWF levels. Patients with low VWF have significant bleeding manifestations. While other hemostasis defects occurred together with low VWF, this combination did not exacerbate clinical symptoms.

Perioperative hemostasis management in patients with von Willebrand disease: an institutional experience

OBJECTIVES

Patients with von Willebrand disease (vWD) undergoing surgery are routinely treated with von Willebrand factor (vWF)/factor VIII (FVIII) concentrate to control bleeding risk, but consensus is lacking on optimal dosing. This study aimed to evaluate the efficacy and safety of tailored doses of vWF/FVIII concentrate according to intervention-associated bleeding risk in vWD patients undergoing surgery.

METHODS

This was a retrospective analysis of vWD patients who underwent surgical procedures at a haemophilia centre. Patients received vWF/FVIII concentrate with dosage and duration of treatment dependent on intervention type (dental, gynaecological, abdominal or orthopaedic/traumatic) and bleeding risk (moderate/high).

RESULTS

Eighty-three surgical procedures (42 patients) were included. Median preoperative loading doses of vWF/FVIII concentrate were 29.9 IU/kg and 35.7 IU/kg for interventions with moderate ( n  = 16) or high ( n  = 67) bleeding risk, respectively. The median perioperative dose was highest in orthopaedic or trauma-related surgery (140 IU/kg) and lowest in dental or gynaecological interventions (76.4 IU/kg and 80.0 IU/kg, respectively). During follow-up, no bleeding or other complications were observed in 95% of patients.

CONCLUSIONS

Individually tailored doses of vWF/FVIII concentrate according to intervention-associated bleeding risk were effective in preventing postoperative bleeding, with few complications observed. These doses may be used as guidance in routine clinical care.

Clinical relevance of genetic variants in the von Willebrand factor according to in-silico methods

Clinical interpretation of genetic variants in the context of the patient's phenotype is a time-consuming and costly process. In-silico analysis using in-silico prediction tools, and molecular modeling have been developed to predict the influence of genetic variants on the quality and/or quantity of the resulting translated protein, and in this way, to alert clinicians of disease likelihood in the absence of previous evidence. Our objectives were to evaluate the success rate of the in-silico analysis in predicting the disease-causing variants as pathogenic and the single-nucleotide variants as neutral, and to establish the reliability of in-silico analysis for determining pathogenicity or neutrality of von Willebrand factor gene-associated genetic variants. Using in-silico analysis, we studied pathogenicity in 31 disease-causing variants, and neutrality in 61 single-nucleotide variants from patients previously diagnosed as type 2 von Willebrand disease. Disease-causing variants and non-synonymous single-nucleotide variants were explored by in-silico tools that analyze the amino acidic sequence. Intronic and synonymous single-nucleotide variants were analyzed by in-silico methods that evaluate the nucleotidic sequence. We found a consistent agreement between predictions achieved by in-silico prediction tools and molecular modeling, both for defining the pathogenicity of disease-causing variants and the neutrality of single-nucleotide variants. Based on our results, the in-silico analysis would help to define the pathogenicity or neutrality in novel genetic variants observed in patients with clinical and laboratory phenotypes suggestive of von Willebrand disease.

The common VWF variant p.Y1584C: detailed pathogenic examination of an enigmatic sequence change

BACKGROUND

As knowledge of the human genome has advanced, so too has the recognition that interpretation of the pathogenic nature of sequence variants can be challenging. The von Willebrand factor (VWF) gene exhibits a significant degree of sequence variability, and the first VWF variant associated with type 1 von Willebrand disease (VWD), c.4751 A>G, p.Y1584C, was described in 2003. However, since that time, the pathogenic nature of this variant has remained unclear, being assigned properties ranging from a risk factor to a pathogenic variant.

OBJECTIVES

To provide additional evaluation on the interpretation of pathogenicity for this common VWF variant.

METHODS

Fifty-eight subjects with only the p.Y1584C variant were recruited from 2 cohort studies (the Zimmerman Program and the Canadian type 1 VWD study). Clinical and laboratory phenotypes were assessed.

RESULTS

The prevalence of the p.Y1584C variant in our cohorts was 23- to 27-fold higher than that in large normal population databases. Significantly more p.Y1584C subjects had an abnormal bleeding score when compared to Y1584 individuals. In comparison with a group of 35 subjects without the p.Y1584C variant, subjects with the variant had lower mean VWF:antigen and VWF:ristocetin cofactor values and significantly higher VWF propeptide/VWF:antigen ratios suggestive of enhanced clearance.

CONCLUSION

Collectively, the results of this analysis suggest that p.Y1584C is likely pathogenic, however, due to influences such as incomplete penetrance, variable expressivity, and other genetic modifiers like ABO blood group, the straightforward assignment of pathogenicity to this variant is inevitably challenging.

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.

Orthognathic Surgery in Patients With Von Willebrand's Disease: A Report of Four Cases and Literature Review

Von Willebrand's disease (VWD), characterized by quantitatively or qualitatively abnormal von Willebrand factor (VWF), is the most common inherited bleeding disorder. There is limited evidence of treatment using orthognathic surgery in patients with VWD. This report focuses on four patients with VWD who underwent orthognathic surgery and received Factor VIII/VWF concentrates (Confact F) preoperatively. One patient with type 3 (severe) VWD underwent delayed extubation owing to laryngeal edema and exhibited epistaxis thereafter. No perioperative complications were observed in any of the other patients. Two of the four patients were diagnosed with VWD during preoperative screening. Most young adults do not experience general anesthesia and, therefore, may not have undergone blood tests at a hospital. Thus, preoperative screening and adoption of a multidisciplinary approach to orthognathic surgery is important in patients with bleeding disorders such as VWD. Close communication between anesthetists, surgeons, and hematologists is essential to ensure effective management during the perioperative period.

The Role of the von Willebrand Factor Collagen-Binding Assay (VWF:CB) in the Diagnosis and Treatment of von Willebrand Disease (VWD) and Way Beyond: A Comprehensive 36-Year History

The von Willebrand factor (VWF) collagen binding (VWF:CB) assay was first reported for use in von Willebrand diagnostics in 1986, by Brown and Bosak. Since then, the VWF:CB has continued to be used to help diagnose von Willebrand disease (VWD) (correctly) and also to help assign the correct subtype, as well as to assist in the monitoring of VWD therapy, especially desmopressin (DDAVP). However, it is important to recognize that the specific value of any VWF:CB is predicated on the use of an optimized VWF:CB, and that not all VWF:CB assays are so optimized. There are some good commercial assays available, but there are also some "not-so-good" commercial assays available, and these may continue to give the VWF:CB "a bad reputation." In addition to VWD diagnosis and management, the VWF:CB found purpose in a variety of other applications, from assessing ADAMTS13 activity, to investigation into acquired von Willebrand syndrome (especially as associated with use of mechanical circulatory support or cardiac assist devices), to assessment of VWF activity in disease states in where an excess of high-molecular-weight VWF may accumulate, and lead to increased (micro)thrombosis risk (e.g., coronavirus disease 2019, thrombotic thrombocytopenic purpura). The VWF:CB turns 37 in 2023. This review is a celebration of the utility of the VWF:CB over this nearly 40-year history.

Abdominoplasty in a Patient With Type 3 von Willebrand Disease: A Case Report

ABSTRACT

von Willebrand disease (vWD) is an inherited bleeding disorder that is characterized by a quantitative or qualitative deficiency of the von Willebrand factor (vWF). Type 3 is the most severe form of vWD with a near-complete absence of vWF and a significantly increased risk of excessive bleeding and hematoma during a surgical procedure. To date, no data on surgical and hemostatic management of a type 3 vWD patient undergoing body-contouring surgery has been published. We report the case of a 47-year-old woman with type 3 vWD requiring medically indicated abdominoplasty after massive weight loss due to bariatric surgery. The case was successfully managed with individualized bodyweight-adapted substitution of recombinant vWF vonicog alfa and tranexamic acid under close monitoring of vWF and factor VIII activity. For further risk stratification, we propose the multidisciplinary treatment of patients with severe vWF undergoing elective plastic surgery in specialized centers providing around-the-clock laboratory testing and access to a blood bank. In addition, strict hemostasis during surgery and early postoperative mobilization with fitted compression garments are recommended to further reduce the risk of bleeding and thromboembolic complications.

Von Willebrand Factor (VWF) multiplex activity assay differentiation of type 1 von Willebrand Disease (VWD) and variant VWD

INTRODUCTION

VWD diagnosis is challenging requiring multiple VWF activity tests using many individual assays. We have developed an ELISA-based VWF Multiplex Activity Assay (VWF-MAA) to address this concern; however, the ability of the VWF-MAA to discriminate between type 1 VWD, variant VWD, and normal subjects has not been evaluated.

AIM

To evaluate the VWF-MAA and its ability to differentiate between type 1 VWD, variant VWD and normal subjects in individuals undergoing an initial laboratory evaluation for bleeding.

METHODS

A total of 177 plasma samples from the Zimmerman Program: Comparative Effectiveness in the Diagnosis of VWD were evaluated from 11 centres across the US and Canada. The VWF-MAA was compared to Versiti Blood Research Institute (VBRI) and Local Center (LC) assigned VWD diagnosis.

RESULTS

Overall, 129/177 (72.9%) were correctly assigned as normal (non-VWD), type 1, or variant VWD compared to the VBRI assigned diagnosis. VWF-MAA assigned non-VWD accurately in 29/57 (50.9%) samples, and type 1 VWD accurately in 93/110 (84.6%) samples. Considering LC diagnosis where there was agreement with VWF-MAA and not VBRI diagnosis, type 1 VWD was accurate in 105/110 (95.5%) samples. Bland-Altman analysis demonstrated good correlation between laboratory methods. VWD, types 2A, 2B, 1C VWD were also assigned by the VWF-MAA.

CONCLUSIONS

We demonstrate that the VWF-MAA has utility in differentiating type 1 VWD, variant VWD and normal subjects in individuals undergoing an initial laboratory evaluation for bleeding.

Management of pregnant women who have bleeding disorders

Bleeding disorders, including von Willebrand disease (VWD), hemophilia, other coagulation factor deficiencies, platelet disorders, defects of fibrinolysis, and connective tissue disorders, have both maternal and fetal implications. Successful management of bleeding disorders in pregnant women requires not only an understanding of bleeding disorders but also an understanding of when and how bleeding occurs in pregnancy. Bleeding does not occur during a normal pregnancy with a healthy placenta. Bleeding occurs during pregnancy when there is an interruption of the normal utero-placental interface, during miscarriage, during an ectopic pregnancy, or at the time of placental separation at the conclusion of pregnancy. Although mild platelet defects may be more prevalent, the most commonly diagnosed bleeding disorder among women is VWD. Other bleeding disorders are less common, but hemophilia carriers are unique in that they are at risk of bleeding themselves and of giving birth to an affected male infant. General guidance for maternal management of a woman who is moderately or severely affected includes obtaining coagulation factor levels at a minimum in the third trimester; planning for delivery at a center with hemostasis expertise; and anticipating the need for hemostatic agents. General guidance for fetal management includes pre-pregnancy counseling; the option of preimplantation genetic testing for hemophilia; delivery at a tertiary care center with pediatric hematology and newborn intensive care; consideration of cesarean delivery of a potentially severely affected infant; and avoidance of invasive procedures such as scalp electrodes and operative vaginal delivery in any potentially affected infant.

Switch to pdVWF:pdFVIII concentrate for prophylaxis in a paediatric patient with Type 3 von Willebrand disease: a case report

OBJECTIVES

To report the long-term prophylaxis management of a child with type 3 von Willebrand disease by switching to Wilate (Octapharma AG), a plasma-derived, double virus-inactivated concentrate of freeze-dried of a 1 to 1 ratio of active Von Willebrand Factor and Factor VIII (pdVWF:pdFVIII) recently marketed as Eqwilate in France.

METHODS

This is a case report of 12.6-year-old boy with congenital Type 3 VWD who had a history of frequent bleeds. Prophylaxis started at the age of 38 months with FVIII-poor pdVWF concentrate (Wilfactin, LFB) and FVIII (Wilstart, LFB). Pharmacokinetics and thrombin generation assay were performed. Annualized bleeding rate was derived from the bleeding episodes documented in the medical record during a 24-month period before and after starting pdVWF:pdFVIII concentrate.

RESULTS

Both product injections promptly raised the endogenous thrombin potential (ETP). However, the maximal concentration of formed thrombin was higher following pdVWF:pdFVIII injection. Due to a high bleeds frequency and better results regarding FVIII levels and thrombin generation, the prophylaxis regimen was changed to the same dose and frequency of pdVWF:pdFVIII concentrate (42 IU/kg per day, three times a week). During the last 24 months, annualized total, trauma, and spontaneous bleeding rates were 7.5, 4.5, and 3, respectively. These rates decreased to 2, 1.5, and 0.5 respectively during the next two years. The mother reported a marked improvement in the quality of life of his son and hers.

CONCLUSION

Switch to pdVWF:pdFVIII concentrate for long-term prophylaxis in a young type 3 VWD patient was safe and effective in reducing bleeds.

A case of delayed postoperative bleeding after excision of endometrial polyp using resectoscope in an infertile woman with von Willebrand disease:a case report and literature review

Von Willebrand disease (VWD) is a bleeding disorder caused by a congenital quantitative reduction, deficiency, or qualitative abnormality of the von Willebrand factor (VWF). Here, we report a case of delayed postoperative bleeding in an infertile woman with endometrial polyps complicated by VWD. The patient was a 39-year-old infertile woman with type 2A VWD. At 38 years of age, she was referred to our hospital for infertility and heavy menstrual bleeding. Hysteroscopy revealed a 15-mm polyp lesion in the uterus. The patient was scheduled for transcervical resection (TCR) of the endometrial polyp. Gonadotropin-releasing hormone agonists were preoperatively administered to prevent menstruation. The VWF-containing concentrate was administered for 3 days according to guidelines. The patient was discharged on postoperative day 3 after confirming the absence of uterine bleeding. Uterine bleeding began on postoperative day 6. The patient was readmitted on postoperative day 7 and treated with VWF-containing concentrate for 5 days, after which hemostasis was confirmed. TCR surgery for endometrial lesions is classified as a minor surgery, and guidelines recommend short-term VWF-containing concentrate replacement. However, it should be kept in mind that only short-term VWF-containing concentrate replacement may cause rebleeding postoperatively.

Neurological Complications Associated with Hereditary Bleeding Disorders

PURPOSE OF REVIEW

Hereditary bleeding disorders may have a wide variety of clinical presentations ranging from mild mucosal and joint bleeding to severe central nervous system (CNS) bleeding, of which intracranial hemorrhage (ICH) is the most dreaded complication. In this review, we will discuss the pathophysiology of specific hereditary bleeding disorders, namely, hemophilia A, hemophilia B, and von Willebrand disease (vWD); their clinical manifestations with a particular emphasis on neurological complications; a brief overview of management strategies pertaining to neurological complications; and a review of literature guiding treatment strategies.

RECENT FINDINGS

ICH is the most significant cause of morbidity and mortality in patients with hemophilia. Adequate control of bleeding with the administration of specific factors or blood products, identification of risk factors for bleeding, and maintaining optimal coagulant activity are essential for appropriately managing CNS bleeding complications in these patients. The administration of specific recombinant factors is tailored to a patient's pharmacokinetics and steady-state levels. During acute bleeding episodes, initial factor activity should be maintained between 80 and 100%. Availability of monoclonal antibody Emicizumab has revolutionized prophylactic therapies in patients with hemophilia. Management of ICH in patients with vWD involves using plasma-derived factor concentrates, recombinant von Willebrand factor, and supportive antifibrinolytic agents individualized to the type and severity of vWD. Hemophilia and vWD are the most common hereditary bleeding disorders that can predispose patients to life-threatening CNS complications-intracranial bleeds, intraspinal bleeding, and peripheral nerve syndromes. Early care coordination with a hematologist can help develop an effective prophylactic regimen to avoid life-threatening bleeding complications in these patients. Further research is needed to evaluate using emicizumab as an on-demand treatment option for acute bleeding episodes in patients with hemophilia.

Pharmacologically Treated Anxiety and Depression in People Diagnosed with von Willebrand Disease: Matched Cohort Study

Background

People diagnosed with von Willebrand disease (VWD) have reduced quality of life versus the general population, and there is limited evidence of increased rates of anxiety and/or depression among people diagnosed with VWD.

Aim

To understand the association between VWD and mental health outcomes.

Design and Setting

A retrospective cohort study was conducted using the UK Clinical Practice Research Datalink (CPRD) GOLD database (1988-2016).

Methods

People diagnosed with VWD were matched 1:10 to randomly selected people in the database without VWD based on sex, birth year ±2 years, CPRD record start year ±2 years, and general practice attended. Individuals were followed from VWD diagnosis or match date to censoring (first event date, CPRD end date, or death). Treated anxiety and treated depression were identified by a diagnostic Read Code and a prescription for anxiety/depression medication recorded within 90 days of each other, after VWD diagnosis/match date.

Results

Treated anxiety was recorded in 89 of 1119 (8.0%) people diagnosed with VWD and 624 of 10,423 (6.0%) without VWD (age- and sex-adjusted incidence rate ratio [IRR], 1.37; 95% confidence interval [CI], 1.10-1.71). Treated depression was recorded in 119 of 1083 (11.0%) people diagnosed with VWD and 846 of 9845 (8.6%) without VWD (adjusted IRR, 1.35; 95% CI, 1.11-1.63). Females aged 20-39 and 0-19 years were at greatest risk for treated anxiety and treated depression, respectively.

Conclusion

Higher rates of treated anxiety and depression were observed among people diagnosed with versus without VWD, predominantly in young females.

Evaluation of a 13-Month-Old Anemic Child With Gushing Gums

While it is common practice for adults to brush their teeth twice a day and instill in their children the importance of setting hygiene routines centered around brushing their teeth, infants and toddlers are often overlooked. Infants begin teething around four to seven months of age; during this period of tooth eruption, their gums are highly susceptible to bacterial build-up, causing problems long before oral hygiene comes to mind. We describe a case of a 13-month-old child presenting with bleeding gums and worsening anemia. After blood tests, iron supplementation, and a referral to a pediatric hematologist-oncologist out of concern for a potential bleeding disorder, this patient was diagnosed with normochromic, normocytic anemia caused by bleeding due to infectious gingivitis. After the completion of antibiotic therapy and changes to the patient's routine to incorporate appropriate oral hygiene, the anemia resolved. Generally benign, gingivitis induced by plaque biofilm can advance to more severe forms of periodontal disease, leading to receding gums and abscesses, thus reinforcing the importance of promoting adequate oral hygiene in all ages regardless of dentition. Additionally, educating primary-care providers on pediatric gingivitis allows for the inclusion of this diagnosis on differentials, limiting extensive blood tests and specialist appointments.

Laboratory diagnosis of von Willebrand disease in the age of the new guidelines: considerations based on geography and resources

von Willebrand disease (VWD) is considered the most common bleeding disorder and arises from deficiency and/or defect in the adhesive plasma protein von Willebrand factor (VWF). Diagnosis of VWD requires clinical assessment and is facilitated by laboratory testing. Several guidelines for VWD diagnosis exist, with the latest American Society of Hematology, International Society on Thrombosis and Haemostasis, National Hemophilia Foundation, and World Federation of Hemophilia 2021 guidelines presenting 11 recommendations, some of which have drawn controversy. In the current narrative review, we provide additional context around difficulties in laboratory diagnosis/exclusion/typing of VWD, with a focus on developing countries/resource-poor settings. In particular, there are many variations in assay methodology, and some methods express high assay variability and poor low-level VWF sensitivity that compromises their utility. Although we favor an initial 4-test assay panel, comprising factor (F) VIII coagulant activity, VWF antigen, VWF glycoprotein Ib binding (VWF:GPIbR or VWF:GPIbM favored over VWF Ristocetin cofactor) and VWF collagen binding, we also provide strategies for laboratories only able to incorporate an initial 3-test assay panel, as favored by the latest guidelines, to improve diagnostic accuracy.

Patient-centered care in von Willebrand disease: are we there yet?

INTRODUCTION

Von Willebrand Disease is the most common inherited bleeding disorder. Paradoxically, affected individuals are often misdiagnosed and experience substantial diagnostic delay. There are sex-specific health disparities in VWD rooted in the stigmatization of vaginal bleeding, which leads to symptom dismissal, lack of timely access to care and lower health-related quality of life.

AREAS COVERED

Following the core elements of patient-centered care - respect for patient preferences, values, and needs, we describe the current state of VWD care. Challenges of diagnostic delay, serial misrecognition of abnormal bleeding, and symptom dismissal are barriers that disproportionately affect women with VWD. These negative effects are further amplified in individuals living in low- and middle-income countries. We describe the importance of coordinated multidisciplinary care, as well as the need for patient education and empowered self-advocacy.

EXPERT OPINION

While tremendous work has been done to improve the diagnosis and management of VWD, timely and high-quality research is urgently needed to address care gaps. Systemic changes such as resource investment, dedicated research funding for novel treatment modalities, and effective knowledge translation strategies to address structural barriers are needed to facilitate effective patient-centered care for VWD.

Desmopressin (DDAVP) use in patients with von Willebrand disease: A single-centre retrospective review of test response and clinical outcomes

INTRODUCTION

Peri-procedural management of von Willebrand disease (VWD) utilizes von Willebrand factor (VWF) concentrates or desmopressin (DDAVP) to increase VWF levels. DDAVP is safe, easily administered, and inexpensive. Currently, a consensus definition for adequate DDAVP response is lacking, and outcomes of peri-procedural DDAVP use in VWD patients are seldom reported.

AIM

This single-centre retrospective review aims to characterize DDAVP-responsiveness and assess clinical outcomes of peri-procedural DDAVP use in VWD.

PATIENTS AND METHODS

We reviewed records for all our adult VWD patients (age ≥18 years) who underwent DDAVP challenge testing between January 2007 and January 2022. DDAVP-responsiveness was assessed using six definitions. Bleeding outcomes following procedures covered by DDAVP were classified as excessive or expected bleeding.

RESULTS

Eighty-four of 94 (89.4%) patients were DDAVP-responsive by our definition (1-h VWF Activity/Factor VIII ≥0.50 IU/mL). However, the proportion of DDAVP-responders varied from 53.2% to 91.5%, depending on the literature definition used. Ninety-nine procedures pre-treated with DDAVP were performed during the study period. Eighty-six (86.7%) procedures (31 major; 55 minor) were covered with only DDAVP ± tranexamic acid (TXA). Excessive bleeding occurred following 4/31 major procedures and 2/55 minor procedures (both performed in a single patient with a bleeding score of 16). When covered with DDAVP+Factor ± TXA, one each of 10 major and 3 minor procedures (performed in 2 patients with bleeding scores 15-16) resulted in post-procedural bleeding.

CONCLUSIONS

Peri-procedural DDAVP prophylaxis appears to be effective among individuals with VWD. Beyond DDAVP-responsiveness, patient bleeding history and procedure invasiveness should be considered in determining suitability for DDAVP prophylaxis.

Acute Chest Pain—Diagnostic Accuracy and Pre-Hospital Use of Anticoagulants and Platelet Aggregation Inhibitors

BACKGROUND

Acute chest pain (aCP) can be a symptom of life-threatening diseases such as acute coronary or aortic syndrome, but often has a non-cardiac cause. The recommendations regarding pre-hospital drug treatment of patients with aCP are ambiguous.

METHODS

A retrospective cohort study was conducted of 822 patients with aCP who were attended by emergency physicians. The cause of aCP was classified as follows: acute coronary syndrome without ST-segment elevation (NSTE-ACS), acute aortic syndrome, hypertensive crisis, cardiac arrhythmias, musculoskeletal, or other. The suspected and discharge diagnoses were compared, and the pre-hospital administration of acetylsalicylic acid (ASA) and unfractionated heparin (UFH) was analyzed. Furthermore, the parameters that improved diagnostic accuracy were investigated.

RESULTS

The positive predictive value of the diagnosis assigned by the emergency physician (EP diagnosis) was 39.7%. NSTEACS was the most commonly suspected cause of aCP (74.7%), but was confirmed after hospital admission in only 26.3% of patients. ASA was administered in 51%, UFH in 55%, and both substances in 46.4% of cases. A large proportion of patients received anticoagulants in the pre-hospital setting although the discharge diagnosis was not NSTE-ACS: ASA 62.9%, UFH 66.0%, both substances 56.5%.

CONCLUSION

ASA and UFH are often given to EP-accompanied patients with aCP despite the low accuracy of diagnosis in the pre-hospital setting. Pre-hospital measurement of high-sensitivity troponin T (hs Trop-T) might improve discrimination between NSTE-ACS and other causes of aCP. This is important, as the current guidelines contain no clear recommendations for prehospital drug treatment in NSTE-ACS.

von Willebrand factor neutralizing and non-neutralizing alloantibodies in 213 subjects with type 3 von Willebrand disease enrolled in 3WINTERS-IPS

BACKGROUND

Type 3 von Willebrand disease (VWD) is the most severe form of this disease owing to the almost complete deficiency of von Willebrand factor (VWF). Replacement therapy with plasma-derived products containing VWF or recombinant VWF rarely cause the development of alloantibodies against VWF that may be accompanied by anaphylactic reactions.

OBJECTIVE

The objective of this study was to assess the prevalence of anti-VWF alloantibodies in subjects with type 3 VWD enrolled in the 3WINTERS-IPS.

METHODS

An indirect in-house enzyme-linked immunosorbent assay has been used to test all the alloantibodies against VWF. Neutralizing antibodies (inhibitors) have been tested with a Bethesda-based method by using a VWF collagen binding (VWF:CB) assay. Samples positive for anti-VWF antibodies were further tested with Bethesda-based methods by using the semiautomated gain-of-function glycoprotein-Ib binding (VWF:GPIbM) and a VWF antigen (VWF:Ag) enzyme-linked immunosorbent assay.

RESULTS

In total, 18 of the 213 (8.4%) subjects tested positive for anti-VWF antibodies and 13 of 213 (6%) had VWF:CB inhibitors. These 13 were among the 18 with anti-VWF antibodies. Of the 5 without VWF:CB inhibitors, 3 had non-neutralizing antibodies, 1 only inhibitor against VWF:GPIbM, and one could not be tested further. Ten of the 13 subjects with VWF:CB inhibitors also had VWF:GPIbM inhibitors, 6 of whom also had VWF:Ag inhibitors. Subjects with inhibitors were homozygous for VWF null alleles (11/14), homozygous for a missense variant (1/14), or partially characterized (2/14).

CONCLUSIONS

Anti-VWF antibodies were found in 8.4% of subjects with type 3 VWD, whereas neutralizing VWF inhibitors were found in 6%, mainly in subjects homozygous for VWF null alleles. Because inhibitors may be directed toward different VWF epitopes, their detection is dependent on the assay used.

A comparative study in patients with type 2 von Willebrand disease using 4 different platelet-dependent von Willebrand factor assays

Background

Several assays are now available to evaluate platelet-dependent von Willebrand factor (VWF) activity.

Objective

To report the results obtained using 4 different assays in patients with von Willebrand disease (VWD) carrying variants mainly in the A1 domain, which is critical for VWF binding to glycoprotein Ib (GPIb) and ristocetin.

Methods

We evaluated 4 different assays, 2 gain-of-function mutant GPIb binding (VWF:GPIbM) and 2 ristocetin cofactor (VWF:RCo) assays, in 76 patients with type 2 VWD. Patients and healthy controls were tested using VWF:GPIbM enzyme-linked immunosorbent assay (ELISA), VWF:GPIbM automated, VWF:RCo aggregometric, and VWF:RCo automated assays.

Results

There was a good correlation (Pearson's r>0.82) and agreement (Bland-Altman plots assessment) between the 4 assays, although several outliers existed among the type 2B without high-molecular-weight multimers (HMWM). The VWF activity/VWF:antigen ratios, calculated for each assay, were used to establish the percentage of a correct diagnosis of type 2 (ratio<0.60) in these patients: VWF:RCo aggregometric, 2A(100%), 2M(78%), 2M/2A(100%), 2B(68%); VWF:RCo automated, 2A(88%), 2M(89%), 2M/2A(100%), 2B(63%); VWF:GPIbM ELISA, 2A(96%), 2M(67%), 2M/2A(67%), 2B(0%); VWF:GPIbM automated, 2A(73%), 2M(44%), 2M/2A(75%), 2B(84%). In type 2B patients with HMWM, all assays gave a ratio ≥0.60.

Conclusion

The VWF:GPIbM-automated assay is the most effective to diagnose as type 2 the 2B variants, whereas the VWF:RCo assays are the most effective in detecting 2M and 2M/2A variants. The VWF:GPIbM ELISA greatly overestimates the activity of the type 2B patients lacking HMWM. In this study, the use of a VWF activity/VWF:antigen ratio cut-off of 0.70 halved the number of misdiagnosed patients.

Prevalence of Bleeding Symptoms in Denmark Using the Patient-administered Bleeding Assessment Tool (self-BAT)

INTRODUCTION

The patient-administered bleeding assessment tool (self-BAT) is a screening tool developed to identify individuals in need of work-up for bleeding disorders. Nonetheless, large studies on self-BAT scores on healthy individuals according to gender and age are lacking.

AIM

Determine cut-offs for abnormal total score of self-BAT and investigate the prevalence of bleeding symptoms in blood donors and individuals representative of the general Danish population.

METHODS

Blood donors, 15,600 children (<18 years) and 18,200 adults from the general Danish population, were invited to complete a Danish version of the self-BAT. To determine cut-offs for abnormal total self-BAT score, findings from healthy young children (0-11 years old), healthy adolescents (12-17 years old), healthy adult women and healthy adult men were used.

RESULTS

Among healthy young children (244 girls, 260 boys), healthy adolescents (58 girls, 83 boys), healthy women (n = 437) and healthy men (n = 278) from the general population, along with healthy blood donors (116 women, 176 men), the 95^th percentile for total score was two for young girls, three for young boys, four for adolescent girls, three for adolescent boys, eight for women and four for men.

CONCLUSION

Our findings indicate that the abnormal total self-BAT score is ≥3 for girls aged 0-11 years old, ≥4 for boys aged 0-11 years old, ≥5 for girls aged 12-17 years old, ≥4 for boys aged 12-17 years old, ≥9 for women and ≥5 for men. To establish the accuracy of these cut-offs for diagnosing bleeding disorders, further studies are needed.