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Type 1 von Willebrand disease (VWD) is associated with a reduction in qualitatively normal von Willebrand factor (VWF). Current diagnostic guidelines only take into consideration the contribution of basal VWF levels, despite a lack of correlation with bleeding severity. Defects in stimulated VWF release, which occurs after hemostatic challenge, may contribute to bleeding in type 1 VWD, but the pathogenic mechanisms are poorly defined. In this study, a layered multiomic approach including messenger RNA (mRNA) and microRNA (miRNA) sequencing was used to evaluate transcriptome-wide differences between type 1 VWD- and control-derived endothelial colony forming cells (ECFCs) during basal and stimulated VWF release. ECFCs from 8 patients with type 1 VWD and 4 other patients were included in this study as controls. VWF protein analysis revealed heterogenous responses to stimulation among type 1 VWD and control ECFCs. During basal VWF release, 64 mRNAs and 7 miRNAs were differentially regulated between type 1 VWD and control ECFCs, and 65 putatively pathogenic miRNA-mRNA interactions were identified. During stimulated VWF release, 190 mRNAs and 5 mRNAs were differentially regulated between type 1 VWD and control ECFCs, and 110 putatively pathogenic miRNA-mRNA interactions were identified. Five gene ontology terms including coagulation, regulation of cell shape, and regulation of cell signaling were also differentially regulated in type 1 VWD ECFCs during stimulated release. To our knowledge, we have shown for the first time that transcriptome-wide differences exist between type 1 VWD and control ECFCs. These differences may contribute to bleeding in type 1 VWD, and further investigation may reveal novel biomarkers and therapeutic targets.

BACKGROUND: Heavy menstrual bleeding (HMB) affects a significant number of women with bleeding disorders and has a negative impact on their quality of life. OBJECTIVE: This retrospective study examined the management of patients with inherited bleeding disorders who used medical treatments, alone or in combination, for HMB. METHODS: Chart review was performed on women attending the Women with Bleeding Disorders Clinic in Kingston, Ontario, between 2005 and 2017. Data collected included patient demographics, the reason for presentation and diagnosis, medical history, treatments, and patient satisfaction. RESULTS: One hundred nine women were included in this cohort. Of these, only 74 (68%) were satisfied with medical management, and only 18 (17%) with first-line therapy. Treatments included combined contraceptives (oral pill, transdermal patch, and vaginal ring), progesterone-only pills, tranexamic acid, 52-mg levonorgestrel intrauterine system (LIUS), depomedroxyprogesterone acetate, and desmopressin, either alone or in combination. Satisfactory control of HMB occurred most often with the LIUS. CONCLUSION: In this cohort, managed in a tertiary care Women with Bleeding Disorders Clinic, only 68% of patients had successful control of HMB with medical treatment, and a minority were satisfied with first-line therapy. These data clearly highlight the need for additional research, including treatment approaches and novel therapies for this population.

Type 1 von Willebrand disease (VWD) is associated with a reduction in qualitatively normal von Willebrand factor (VWF). Current diagnostic guidelines only take into consideration the contribution of basal VWF levels, despite a lack of correlation with bleeding severity. Defects in stimulated VWF release, which occurs following hemostatic challenge, may contribute to bleeding in Type 1 VWD, but the pathogenic mechanisms are poorly defined. In the present study, a layered multiomic approach including mRNA and miRNA sequencing was used to evaluate transcriptome-wide differences between Type 1 VWD- and control-derived endothelial colony forming cells (ECFCs) during basal and stimulated VWF release. ECFCs from eight Type 1 VWD patients and four controls were included in this study. VWF protein analysis revealed heterogenous responses to stimulation amongst Type 1 VWD and control ECFCs. During basal VWF release, 64 mRNAs and 7 miRNAs were differentially regulated between Type 1 VWD and control ECFCs and 65 putatively pathogenic miRNA-mRNA interactions were identified. During stimulated VWF release, 190 mRNAs and five mRNAs were differentially regulated between Type 1 VWD and control ECFCs and 110 putatively pathogenic miRNA-mRNA interactions were identified. Five gene ontology terms including coagulation, regulation of cell shape, and regulation of cell signalling were also differentially regulated in Type 1 VWD ECFCs during stimulated release. We have shown for the first time that transcriptome-wide differences exist between Type 1 VWD and control ECFCs. These differences may contribute to bleeding in Type 1 VWD, and further investigation may reveal novel biomarkers and therapeutic targets.

INTRODUCTION Menorrhagia impacts ~40% of adolescent females, with about half having an underlying bleeding disorder, most commonly von Willebrand Disease (VWD). VWD affects ~1 in 1000 individuals, though many are unaware of their condition. Let's Talk Period (LTP) is an online knowledge translation platform aimed at increasing awareness of bleeding disorders symptoms, with a validated self-administered bleeding assessment tool (Self-BAT). AIM To evaluate the effectiveness of the LTP high school outreach program in Grade 9 girls' health classes quantitatively, using baseline, post-presentation, and follow-up quiz scores, and qualitatively, with student and teacher feedback forms. METHODS The 75-minute in-class presentations, developed in alignment with the 2015 Ontario Curriculum for Grade 9 Health and Physical Activity, were led by a haemophilia nurse, clinical research assistant, and undergraduate student from the LTP team. Students completed baseline, post-presentation, and 4-6-week follow-up Kahoot quizzes featuring the same nine questions to evaluate change in knowledge levels and retention. Both student and teacher feedback were collected. RESULTS There was a significant increase (p

BACKGROUND: Assessment of bleeding phenotype is critically important in the diagnosis of von Willebrand disease (VWD). Despite advances in bleeding assessment tools (BATs), standardized tools to evaluate bleeding following diagnosis (interim bleeding) are lacking. OBJECTIVES: We assessed the clinical utility of an interim bleeding protocol in a multicenter, international study involving patients with VWD. METHODS: The enrolment ISTH BAT formed the original bleeding score (0 BS). At follow-up, the International Society on Thrombosis and Haemostasis BAT was repeated but included only interval bleeding (Interim BS, 1 BS). Both scores were annualized (0 BS/yr, 1 BS/yr). BS were analyzed by VWD subtype, plasma VWF level, sex, and age. RESULTS: Interim BS discriminated by subtype, with significantly increased 0 BS and 1 BS in patients with type 3 VWD. In patients with type 1 VWD, a positive or negative 0 BS did not predict future bleeding, with similar 1 BS/yr (median 1.0 vs. 0.7, p = .2). Despite significantly higher 0 BS in females with type 1 VWD than males (median 7 vs. 5, p = .0012), 1 BS were not significantly different (median 4 vs. 4, p = .16). While 0 BS were lower in children than adults with type 1 VWD, interim BS were similar (median 5 vs. 3, p = .5; 1BS/yr, median 1 vs. 0.8, p = .7). Interestingly, in those with plasma von Willebrand factor:ristocetin cofactor levels >50 IU/dl, interim BS rates were similar to those 30–50 IU/dl (1 BS/yr 0.8 vs. 1.3, p = .5). CONCLUSION: This study provides both a new approach to longitudinal bleeding assessment and insights into the evolution of bleeding in VWD.

BACKGROUND: von Willebrand Factor (VWF) is synthesized by vascular endothelial cells and megakaryocytes. The VWF propeptide is critical for multimerization and acts as an intra-molecular chaperone for mature VWF in sorting to its storage organelles, Weibel-Palade bodies (WPBs). In the Canadian Type 3 VWD study, almost half of the identified variants were in the VWF propeptide and these were associated with an increased bleeding phenotype. OBJECTIVE: To investigate VWF propeptide variants that cause quantitative von Willebrand disease (VWD) by utilizing patient-derived endothelial colony-forming cells (ECFCs). PATIENTS/METHODS: ECFCs were isolated from five Type 3 VWD patients from four families with the following variants: 1) homozygous p.Asp75_Gly178del (deletion of exons 4 and 5 deletion; Ex4-5del); 2) homozygous p.Cys633Arg; 3) homozygous p.Arg273Trp, and 4) p.Pro293Glnfs*164 and p.Gln419* inherited in the compound heterozygous state. Additionally, ECFCs were isolated from six family members (two Type 1 VWD, four unaffected). RESULTS: ECFCs from the Type 3 patient with the compound heterozygous genotype exhibited a true null VWF cellular phenotype, with negligible VWF detected. In contrast, the other three propeptide variants presented a similar expression pattern in homozygous ECFCs where VWF was synthesized but not packaged in WPBs, and variant VWF had an increased association with the endoplasmic reticulum (ER) marker, protein disulfide-isomerase (PDI), indicating an ER-retention phenotype. The biosynthetic phenotype was similar but to a lesser degree in heterozygous ECFCs expressing the non-null variants. CONCLUSION: This study further elucidates the importance of the VWF propeptide in the VWD phenotype using patient-derived cells.

Background Bleeding assessment is part of the diagnostic workup of von Willebrand disease (VWD). Bleeding assessment tools (BATs) have standardized obtaining this information but have been criticized because they are time consuming. Objective To use our legacy data to determine which questions from BATs are the strongest predictors of a VWD diagnosis. Patients/Methods Bleeding score data from 3 different BATs were used. Patients aged

The cause of hemophilia A carrier bleeding is not well established. Desmopressin (DDAVP), used clinically to treat or prevent bleeding, can also be used as a medical stress surrogate. This study’s objective was to compare the response to DDAVP in hemophilia A carriers with that in normal control patients. Bleeding was assessed by the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool (ISTH-BAT). DDAVP (0.3 μg/kg) was administered either IV or subcutaneously (SC), and blood was drawn at baseline and 1, 2, and 4 hours postadministration. Blood was assessed for factor VIII (FVIII) level, von Willebrand factor (VWF) antigen (VWF:Ag), VWF activity (VWF:RCo or VWF:GPIbM), thromboelastography (TEG), and thrombin generation assay (TGA) at all points, and for VWF propeptide (VWFpp):Ag ratio and ABO blood type at baseline. Carriers were older than control patients (median age, 34 and 21 years, respectively; P = .003) and had higher ISTH-BAT bleeding scores (median bleeding score, 8 and 0, respectively; P = .001). Carriers had a significantly reduced FVIII response to DDAVP compared with control patients (P ≤ .0001). When only carriers with normal baseline FVIII levels (n = 10) were included, carriers maintained a reduced FVIII response (P ≤ .0001). Furthermore, participants with abnormal bleeding scores had a significantly lower FVIII response to DDAVP compared with those with normal bleeding scores (P = .036). Hemophilia A carriers have a lower and less sustained FVIII response to DDAVP, suggesting an impaired ability to respond to hemostatic stress, which contributes to bleeding.

BACKGROUND Patients with aortic stenosis (AS) can experience bleeding complications including gastrointestinal bleeding from angiodysplastic lesions due to acquired von Willebrand syndrome. Studies have pointed to a role for von Willebrand factor (VWF) in angiogenesis. OBJECTIVE The objective of this study was to assess VWF defects in AS patients over time and the impact on angiogenesis using patient-derived endothelial colony-forming cells (ECFCs). PATIENTS/METHODS Plasma sample collection and ECFC isolations were performed before valve replacement surgery, 3 to 5 days after, and 6 months after surgery. Plasma VWF antigen, activity, propeptide, collagen binding, multimers, factor VIII coagulant activity, and ADAMTS13 activity (a disintegrin-like and metalloprotease with thrombospondin type 1 motifs 13) were determined. ECFCs were assessed for VWF and angiopoietin-2 (Ang-2) storage and secretion, cell proliferation, and tubule formation in Matrigel. RESULTS AND CONCLUSIONS Aortic stenosis patients exhibited quantitative and qualitative abnormalities of VWF including significantly increased VWF antigen, activity, and propeptide levels following surgery (P

Introduction von Willebrand disease (VWD) is the most common inherited bleeding disorder known in humans. Currently, studies investigating the health-related quality of life (HR-QoL) in VWD using standardized tools are limited, particularly among patients with mild decreases in von Willebrand factor or activity. Aim To determine HR-QoL and its predictors among patients with mild, moderate and severe forms of VWD. Methods Patients with clinical diagnosis of VWD were recruited from a tertiary Inherited Bleeding Disorder Clinic. Upon informed consent, bleeding scores were obtained via a standardized, self-administered tool. Each participant also completed a HR-QoL questionnaire (SF-36). Analyses included paired t-test, independent t-test, one-way anova and multivariate regression. Results A total of 102 patients were recruited (consent rate = 95%). Participants were 38 years on average (SD 14.8), 78% were female and 80% were diagnosed with VWD Type 1. Compared to age- and sex-matched normative data, VWD patients had clinically and statistically significant reductions in seven of eight HR-QoL domains and the physical and mental component summaries. Adjusted for age, sex, socioeconomic status and rurality, there was a trend towards lower physical component summary with increasing bleeding score, and lower mental domains with iron deficiency status (P = 0.07 and P = 0.08 respectively). Conclusion This study is the first to examine the impact of VWD on HR-QoL across disease severity while incorporating socioeconomic status and rurality. Significant reductions in HR-QoL among VWD patients, especially the relationship between iron status and mental HR-QoL, strengthen the rationale for prospective studies to evaluate the efficacy of iron replacement in this setting.

Essentials von Willebrand factor (VWF) and factor VIII (FVIII) levels are modulated by age and ABO status. The effect of aging and ABO blood type on VWF and FVIII was assessed in 207 normal individuals. Aging and ABO blood type showed combined and bidirectional influences on VWF and FVIII levels. Aging and ABO blood type influence VWF levels through both secretion and clearance mechanisms. SummaryBackground The effect of aging and ABO blood type on plasma levels of von Willebrand factor (VWF) and factor VIII (FVIII) have been widely reported; however, a comprehensive analysis of their combined effect has not been performed and the mechanisms responsible for the age-related changes have not been determined. Objectives To assess the influence of aging and ABO blood type on VWF and FVIII levels, and to evaluate the contribution of VWF secretion and clearance to the age-related changes. Methods A cross-sectional observational study was performed in a cohort of 207 normal individuals, whose levels of VWF, FVIII, VWF propeptide (VWFpp), VWFpp/VWF:Ag ratio and blood type A antigen content on VWF (A-VWF) were quantified. Results Aging and ABO blood type exerted interrelated effects on VWF and FVIII plasma levels, because the age-related increase in both proteins was significantly higher in type non-O individuals (β = 0.011 vs. 0.005). This increase with age in non-O subjects drove the differences between blood types in VWF levels, as the mean difference increased from 0.13 U/mL in the young to 0.57 U/mL in the old. Moreover, A-VWF was associated with both VWF antigen (β = 0.29; 95% confidence interval [CI], 0.09, 0.50) and VWF clearance (β = −0.15; 95% CI, −0.25, −0.06). We also documented an effect of ABO blood type on VWF secretion with aging, as old individuals with blood type non-O showed higher levels of VWFpp (mean difference 0.29 U/mL). Conclusions Aging and ABO blood type have an interrelated effect on VWF and FVIII levels, where the effect of one is significantly influenced by the presence of the other.

BACKGROUND In the pediatric population, pathologic bleeding is often challenging to identify. The pediatric bleeding questionnaire (PBQ) was developed as a screening tool for von Willebrand disease (VWD) but was designed to be self-completed by children above 12 years of age. The study objective was to determine whether a modified Self-PBQ could be completed by 8- to 12-year-old children with adult assistance. PROCEDURE The initial phase involved seven children who underwent cognitive debriefing to identify problems in the questionnaire, resulting in modifications to wording and response options. In phase 2, children completed the modified Self-PBQ independently or with assistance from their parent at five Canadian treatment centers. Parents filled out the Self-PBQ separately to serve as a comparison. Bleeding scores derived from the child self-report were compared to those of the parent proxy. RESULTS Twenty-nine out of 31 patient/parent pairs successfully completed the Self-PBQ. Child and parent scores demonstrated a high level of agreement with an intraclass correlation (ICC) of 0.825. In the age subgroup analysis, the ICC was 0.834 and 0.824 for the 8- to 9-year-old and 10- to 12-year-old groups, respectively. The ICC was also determined in children with type 1 VWD (ICC = 0.829) versus those with more severe bleeding disorders (ICC = 0.802). Thus, age and disease severity had no significant effect on degree of agreement. CONCLUSIONS Our study shows that agreement was maintained even in younger children aged 8-9 years and in children with varying bleeding phenotypes. This supports the administration of the modified Self-PBQ to 8- to 12-year-old children.

We report an 11-month-old boy with severe hemophilia A who had regular exposure to factor VIII (FVIII) intended to reduce the risk of developing an inhibitor. He developed a high-titer inhibitor (peak titer 19 BU) that disappeared within 6 weeks of starting immune tolerance induction (ITI). Anti-FVIII IgG4 peaked briefly compared with anti-FVIII IgG1 and the Bethesda titer. Neither rapid resolution of an inhibitor after prophylaxis nor this behavior of anti-FVIII IgG4 has been previously reported. Transient anti-FVIII IgG4 may be a marker of an attenuated anti-FVIII response induced by prophylactic FVIII therapy.

Objective Our objective was to generate, optimize, and validate a self-administered pediatric bleeding questionnaire (Self-PBQ) as a screening tool for von Willebrand disease (VWD) in children referred to the hematology clinic for the first time. Study Design The Self-PBQ was generated by combining the validated expert-administered PBQ and the International Society on Thrombosis and Hemostasis (ISTH) bleeding assessment tool (BAT). Medical terminology was translated into lay language requiring a grade 4 reading level. In Phase 1, the Self-PBQ was optimized and the level of agreement between the Self-PBQ and the expert-administered PBQ was determined. Phase 2 established the normal range of bleeding scores (BSs) of the Self-PBQ. Phase 3 examined the Self-PBQ as a screening tool for first-time referrals to the hematology clinic. Results The Self-PBQ is a reliable surrogate for the expert-administered PBQ with an excellent intraclass correlation (ICC) of 0.917. The Self-PBQ was scored with the PBQ and the ISTH-BAT scoring systems, for which its normal BS ranges are –1 to 2 or 0 to 2, respectively. A positive Self-PBQ BS (≥3) had a sensitivity of 78%, a specificity of 37%, a positive predictive value of 0.18, and a negative predictive value of 0.91 for identifying VWD in children being investigated by a hematologist for a bleeding disorder. Conclusion The Self-PBQ generates comparable BSs to the expert-administered PBQ and is a reliable, reasonably sensitive screening tool to incorporate into the assessment of children presenting to a hematologist for the investigation of an inherited bleeding disorder.

Introduction There has been increasing recognition in recent years that female carriers of haemophilia manifest abnormal bleeding; however, data on the use of bleeding assessment tools in this population are lacking. Aim Our objective was to validate the ISTH-BAT in haemophilia carriers to describe bleeding symptoms and allow for comparisons with factor levels and other patient groups. Methods This was a prospective, observational, cross-sectional study performed by members of Global Emerging HEmostasis Panel (GEHEP). Unselected consecutive haemophilia carriers were recruited and a CRF and the ISTH-BAT were completed by study personnel. Results A total of 168 haemophilia carriers were enrolled: 155 haemophilia A and 13 haemophilia B. The mean age was 40 years (range: 20–82). Carriers had higher mean bleeding scores (BS) compared with age-matched controls (n = 46; 5.7 vs. 1.43; P haemophilia carriers > Type 3 VWD OC > controls. Understanding the performance of the ISTH-BAT in this population is a critical step in future research aimed at investigating the underlying pathophysiology of abnormal bleeding, with the ultimate goal of optimizing treatment.

Introduction Women with inherited bleeding disorders are at increased risk for bleeding complications during pregnancy and the postpartum period, particularly postpartum haemorrhage (PPH). Aim This retrospective study evaluates pregnancy management through the Inherited Bleeding Disorders Clinic of Southeastern Ontario, the clinical factors associated with pregnancy-related abnormal bleeding and assesses tranexamic acid use in the postpartum treatment of bleeding disorder patients. Methods A chart review of 62 pregnancies, from 33 women, evaluated patient characteristics (age, haemostatic factor levels) and delivery conditions (mode of delivery, postpartum treatment) in relation to abnormal postpartum bleeding. Results This cohort revealed increased risk of immediate PPH with increased age at delivery (mean age: 30.1 years with PPH, 26.5 years without PPH, P < 0.013), and birth by vaginal delivery (P < 0.042). Low von Willebrand factor (VWF) antigen or factor VIII (FVIII) in the third trimester was not associated with an increased risk of PPH; however, low VWF:RCo was associated with increased immediate PPH despite treatment with continuous factor infusion (P < 0.042). Women treated with tranexamic acid postpartum had less severe bleeding in the 6-week postpartum (P < 0.049) with no thrombotic complications. Conclusions This study contributes to the growing body of work aimed at optimizing management of bleeding disorder patients through pregnancy and the postpartum period, showing patients are at a higher risk of PPH as they age. Risk factors such as low third trimester VWF:RCo have been identified. Treatment with tranexamic acid in the postpartum period is associated with a reduced incidence of abnormal postpartum bleeding.

Type I von Willebrand disease (VWD) is the most frequent bleeding disorder, with a prevalence of 10-50 cases per 10,000 persons. VWD usually shows an autosomal dominant inheritance pattern, at least in families having VWF:Ag levels below 30 IU/dL. There is considerable uncertainty whether patients having only mildly reduced VWF levels (in the range 30-50 IU/dL) should be diagnosed as having VWD or if they should be considered as a separate clinical entity, broadly referred to as "reduced VWF patients." We hypothesize that these patients may have a clinically distinct bleeding pattern, in terms of presenting symptoms at diagnosis, bleeding severity, and possibly even clinical. We pooled data from three cohorts of patients. The MCMDM-1 VWD Study is a multicenter survey on type 1 VWD that recruited 154 type 1 VWD families from nine European countries. The Kingston cohort recruited consecutive patients with type 1 VWD diagnosed in Kingston, Canada and includes patients screened because of bleeding symptoms or family history of VWD over a 10 year period. The Zimmerman Program for the Molecular and Clinical Biology of VWD is a multicenter study that enrolled VWD patients mostly from US clinical centres, primarily carrying a diagnosis of type 1 VWD (315 families) but also including type 2 and type 3 subjects. For the present study, only patients with a confirmed diagnosis of type 1 VWD were retained. From the three cohorts, demographic, laboratory and clinical data were abstracted, including severity of bleeding symptoms classified according to the MCMDM-1 study criteria. Only data from index cases and affected family members were retained for the present analysis. Bleeding symptoms receiving a score >=2 (and therefore requiring some type of medical intervention) were classified as "clinically relevant". VWF:Ag and VWF:RCo were measured centrally by the reference core lab of each of the three studies, against the WHO International Standard. For this purpose of the present study, Type 1 VWD is defined as VWF:Ag levels (or VWF:RCo for the Zimmerman Program) below 30 IU/dL; affected family members and index cases with VWF:Ag levels equal or above 30 IU/dL were classified as "low-VWF" patients. Pooled data from the three studies resulted in 1411 patients. At multivariate analysis, blood group O females with lower bleeding scores were the characteristics associated with the "low-VWF" patients; interestingly, the number of clinically relevant bleeding symptoms was associated with the phenotype independently from the total bleeding score. For all considered bleeding symptoms, VWD patients had a higher prevalence of relevant bleeding, with the notable exception of menorrhagia. Particularly in index cases, menorrhagia but also post-surgical bleeding was increased in patients having the "low-VWF" phenotype, although only for menorrhagia the difference was statistically significant (p=0.022). Unsupervised cluster analysis of symptom distribution disclosed three subgroups of patients. The first two were composed by males (first group) or females (second group), both having few or none bleeding symptoms. The third identified by unsupervised cluster analysis group was composed of highly symptomatic patients, predominantly women. In these patients, mucous ("wet") bleeding (epistaxis and menorrhagia) was common together with post-surgical or extraction bleeding. This pattern was not correlated with mean VWF:Ag level or "low-VWF" or Type 1 VWD phenotype. We conclude that "low-VWF" patients are more frequently blood group O, older females, with lower average bleeding scores and number of symptoms and possibly selected because of menorrhagia. A group of "severe bleeders" may be identified (n=270, 19%), having a similar distribution of "low VWF" and "VWD" phenotypes. Disclosures Tosetto: Stago, Novo-Nordisk, BMS: Speakers Bureau; Werfen: Other: Member of Advisory Board, Speakers Bureau. Eikenboom:CSL: Research Funding. James:CSL Behring: Research Funding; Shire: Research Funding; Bayer: Research Funding. Montgomery:BCW: Patents & Royalties: GPIbM assay patent to the BloodCenter of Wisconsin.

Given the challenges involved in obtaining accurate bleeding histories, attempts at standardization have occurred and the value of quantifying hemorrhagic symptoms has been recognized.An extensive validated bleeding questionnaire (MCMDM-1VWD) was condensed by eliminating all details that did not directly affect the bleeding score (BS) and the correlation between the two versions was tested. Additionally, the diagnostic utility of the condensed version was prospectively tested.Data on 259 individuals who were administered the questionnaire are presented here; 217 being prospectively investigated for von Willebrand disease (VWD) (group 1) and 42 previously known to have type 1, 2 or 3 VWD (group 2). Of the 217 prospectively investigated, 35 had positive BS (or =4) and 182 had negative scores. Seven individuals (all with positive BS) had laboratory results consistent with type 1 VWD. This results in a sensitivity of 100% and a specificity of 87%. The positive predictive value is 0.20 and the negative predictive value is 1. The correlation between the full MCMDM-1VWD and condensed versions is excellent (Spearman's 0.97, P0.001, linear regression r(2) = 96.4). Inter-observer reliability for the condensed version is reasonable (Spearman's 0.72, P0.001 and intra-class correlation coefficient 0.805, P0.001). There was a significant difference in BS between subtypes of VWD, with type 3type 2type 1 VWD (anova P0.001). There is a strong inverse relationship between VWF:Ag level and BS (Spearman's -0.411, P0.001).The Condensed MCMDM-1VWD Bleeding Questionnaire is an efficient, effective tool in the evaluation of patients for VWD.

In a normal population, VWF plasma levels (VWF:Ag) and VWF activity (VWF:RCo) increase by approximately 0.17 and 0.15 IU mL(-1) per decade, but the influence of age is unknown in patients with type 1 von Willebrand disease (VWD). In a retrospective cohort study, the medical records of 31 type 1 VWD patients over the age of 30, who had been followed for ≥5 years, were reviewed for baseline clinical data and previously performed VWF:Ag, VWF:RCo and factor VIII levels (C). VWF multimer analysis was normal in 28/31 cases performed. Mean age at diagnosis was 33 (range 16-60 years), and duration of follow-up ranged from 5 to 26 years (mean 11 years). Patients had 2-10 time points of VWD testing (mean of 5.2). The mean VWF:Ag, VWF:RCo andC at time of diagnosis were 0.44 IU mL(-1) 0.34 IU mL(-1) and 0.75 IU mL(-1) . At last follow-up, the mean VWF:Ag, VWF:RCo andC were significantly increased to 0.71 IU L(-1) , 0.56 IU mL(-1) and 0.90 IU mL(-1) (P ≤ 0.001,0.001, and 0.0081 respectively). Here 18/31 patients had VWF:Ag, VWF:RCo andC levels that increased into the normal range. The rate of change in VWF:Ag, VWF:RCo and FVIII was 0.30 IU mL(-1) (0.21-0.39, CI 95%, P0.0001), 0.20 IU mL(-1) per decade (0.13-0.27, CI 95%, P = 0.0001) and 0.20 IU mL(-1) (0.11-0.29, CI 95%, P = 0.0011). Patients with type 1 VWD experience age-related increases to VWF:Ag and VWF:RCo which can result in normalization of VWF levels. Further studies are required to determine if the bleeding phenotype resolves with the increases in VWF:Ag and VWF:RCo levels.

Bleeding Assessment Tools (BATs) have been developed to aid in the standardized evaluation of bleeding symptoms. The Vicenza Bleeding Questionnaire (BQ), published in 2005, established a common framework and scoring key that has undergone subsequent modification over the years, culminating in the publication of the ISTH-BAT in 2010. Understanding the normal range of bleeding scores is critical when assessing the utility of a BAT. Within the context of The Merging Project, a bioinformatics system was created to facilitate the merging of legacy data derived from four different (but all Vicenza-based) BATs; the MCMDM1-VWD BQ, the Condensed MCMDM-1VWD BQ, the Pediatric Bleeding Questionnaire and the ISTH-BAT. Data from 1040 normal adults and 328 children were included in the final analysis, which showed that the normal range is 0–3 for adult males, 0–5 for adult females and 0–2 in children for both males and females. Therefore, the cut-off for a positive or abnormal BS is ≥4 in adult males, ≥6 in adult females and ≥3 in children. This information can now be used to objectively assess bleeding symptoms as normal or abnormal in future studies.

Background: Undiagnosed bleeding disorders can pose significant health risks, especially for women. As many as 1 in 1000 individuals have a bleeding disorder, many of whom are undiagnosed. Lack of understanding about the difference between normal and abnormal bleeding, particularly menstrual bleeding, is a barrier to diagnosis. Recently, a self-administered bleeding assessment tool (Self-BAT) was validated as a screening tool for von Willebrand disease (VWD). Objective: Our objective was to increase awareness of undiagnosed bleeding disorders through the use of an informational website (http://letstalkperiod.ca) targeted at women in their reproductive years. Here we report the results from the first 10 weeks of this knowledge translation project. Methods:The Let's Talk Period website was built in consultation with a medical communications company, with the aim of clearly presenting key messages around menstrual bleeding. Focus groups with young women were held to determine optimal communication strategies and an iterative process of expert review was undertaken prior to launch. Upon completion of the integrated Self-BAT application, the result of whether the bleeding score is normal or abnormal is displayed to the user, along with a recommendation to seek medical attention if the score is positive/abnormal (≥6 for adult females,≥4 for adult males, ≥3 for individuals < 18 years). Queen's University Legal Department provided advice regarding website disclaimers. Research Ethics Board approval was sought but deemed unnecessary, given that no identifiable information is collected. Website users must electronically indicate that they have read and understood a disclaimer about the use of the Self-BAT application before being granted access, and must enter their age and gender. The website was promoted through an interview with the senior author that aired on Canadian national television in the context of a segment on VWD. Additional promotion occurred using social media such as Facebook and Twitter, as well as during local interviews at Queen's University and Kingston General Hospital. The social media networks of the Canadian Hemophilia Society, the World Federation of Hemophilia, the Foundation for Women and Girls with Blood Disorders were also engaged to promote the website. Results: For the 10-week period beginning May 14, 2016 there were 4,907 page views and 3,001 sessions initiated by 2,597 individual users from 62 countries. The average session length was 1 minute and 12 seconds; 15 were longer than 30 minutes. The majority of sessions (60%) were initiated in Canada. Table 1 outlines the countries with the highest volume of website visits. A total of 460 individuals, 438 (95%) of whom were female, completed the online Self-BAT. Individuals ranged in age from 12 to 71 years (mean 36 years). Individuals aged 35 to 44 years represented the largest proportion of users who completed the Self-BAT (31%), followed by those aged 25 to 34 years (28%). The mean Self-BAT score was 6 and scores ranged from 0 to 44. Abnormal age and gender specific Self-BAT scores were reported in 45% of the respondents (n=209), of which 98% were female. Of the individuals with abnormal Self-BAT scores the most commonly reported symptoms (Table 2) were menorrhagia (99%), post-partum hemorrhage (84%), bleeding from the oral cavity (78%), cutaneous bleeding (74%) and epistaxis (56%). Frequency of specific symptoms of menorrhagia are outlined in Table 3. The most common symptom of post-partum hemorrhage reported was bleeding longer than 6 weeks after delivery (16%). Surgery or ICU admission post-partum was required in 3 women. Conclusion: Initial results from the first 10 weeks of an informational website demonstrated that this platform is capable of reaching users from around the world. We have demonstrated that an online screening tool will be used by individuals concerned about abnormal bleeding. In women, the predominant symptoms of abnormal bleeding reported were menorrhagia and post-partum hemorrhage. In future, we plan to expand the educational content of the Let's Talk Period website, including information directed at medical professionals and a regular blog directed at the public. Additionally, we plan to seek research ethics approval for knowledge translation research tracking the outcomes of abnormal bleeding scores in local website users. Disclosures James: Bayer: Research Funding; CSL Behring: Research Funding; Octapharma: Research Funding; Biogen: Consultancy; Basalt: Consultancy.

Background: Hemophilia carriers report abnormal bleeding, even when factor VIII or IX levels are normal. Information comparing bleeding events between carriers and women with other inherited bleeding disorders is lacking. Purpose: The purpose of our study was to characterize bleeding in hemophilia carriers using the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool (ISTH-BAT) and to compare it with bleeding in normal controls, women with Type 1 VWD and Type 3 VWD obligate carriers (OC). Method: This was a prospective, observational, cross-sectional study performed by members of GEHEP (Global Emerging HEmostasis Panel). Study participants were recruited from GEHEP members' clinics in North America (Kingston, Canada, Detroit and Philadelphia, USA), Europe (Malaga, Spain; Milan, Italy; Munich, Germany; Oslo, Norway) and South Africa (Johannesburg). Potential participants were identified through local patient databases and approached during clinic visits. All participants signed informed consent. Hemophilia carriers were defined by a documented FVIII or FIX mutation and/or by an appropriate family history (daughter of a man with hemophilia or mother of two sons with hemophilia or mother of one son with hemophilia with at least one other affected male relative). Demographic information was collected using a CRF and the ISTH-BAT was completed for each participant by study personnel. Existing ISTH-BAT data for women with Type 1 VWD, Type 3 VWD OC and age-matched female controls were used for comparison. Results: A total of 329 participants were included in this study; 168 hemophilia carriers, 83 women with Type 1 VWD, 32 Type 3 VWD OC and 46 female normal controls. Hemophilia carriers and normal controls were similar in age (40.1 vs 41.6, p=0.445). The mean overall ISTH-BAT bleeding score (BS) was significantly higher in carriers than in controls (5.7 vs 2.48, p Conclusion: In summary, our study showed that hemophilia carriers report significantly more bleeding by overall ISTH-BAT BS than age-matched female controls. Carriers experience both mucocutaneous bleeding as well as musculoskeletal bleeding. They score higher for mucocutaneous bleeding when compared with controls and when compared with Type 3 VWD OC. Overall Type 1 VWD patients experience more severe mucocutaneous bleeding than hemophilia carriers. However, hemophilia carriers report more musculoskeletal bleeding in the form of hemarthrosis and hematomas than all other groups. A comparison of overall ISTH-BAT BS between groups shows that bleeding in women with Type 1 VWD > hemophilia carriers > Type 3 VWD OC > controls. Additional research into the underlying pathophysiology of this abnormal bleeding is a critical next step in understanding and determining how to appropriately manage these patients. Disclosures Bidlingmaier: Novo Nordisk: Honoraria; Sobi: Honoraria; Pfizer: Honoraria; Biotest: Honoraria; Baxalta: Honoraria; Bayer: Honoraria; CSL Behring: Honoraria, Research Funding. Mingot-Castellano:Amgen: Consultancy; Pfizer: Consultancy; Novo Nordisk: Consultancy, Research Funding; Baxalta: Consultancy, Research Funding; Novartis: Consultancy; Bayer: Consultancy, Research Funding. Chitlur:Novo Nordisk: Consultancy; Baxalta: Honoraria; Bayer: Honoraria; Biogen-Idec: Honoraria; Pfizer: Honoraria. Fogarty:Bayer Healthcare: Membership on an entity's Board of Directors or advisory committees, Research Funding; Baxter/Baxalta: Membership on an entity's Board of Directors or advisory committees, Research Funding; Biogen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Chugai: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Pfizer: Employment, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spark Therapeutics: Research Funding. Cuker:T2 Biosystems: Research Funding; Genzyme: Consultancy; Biogen-Idec: Consultancy, Research Funding; Amgen: Consultancy; Stago: Consultancy. Mancuso:Bayer Healthcare: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Baxalta: Consultancy, Speakers Bureau; CSL Behring: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novo Nordisk: Consultancy, Speakers Bureau; Sobi/Biogen Idec: Consultancy, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kedrion: Consultancy. Holme:Baxalta, now part of Shire: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Investigator Clinical Studies. Mathew:Bayer: Employment. James:CSL Behring: Research Funding; Octapharma: Research Funding; Biogen: Consultancy; Basalt: Consultancy; Bayer: Research Funding.

The rigorous assessment of bleeding symptoms is a key component in establishing a diagnosis in patients suspected of having von Willebrand disease (VWD) and other inherited bleeding disorders. Multiple bleeding questionnaires have been developed and validated to capture bleeding history phenotypes for assessing patients with bleeding disorders. In this study we developed a prediction model based on Naïve Bayes decision tree classifier by analyzing various phenotypic attributes derived from multiple bleeding questionnaires. We evaluated the classification effectiveness derived from the top 25 attributes with highest discriminations on prediction of VWD. We used data from 952 patients and the classifier achieved a precision of 95%, recall of 94%, and a Receiving Operating Curve (ROC) area under the curve of 0.97.

von Willebrand factor (vWF) antigen levels are elevated in patients with end-stage kidney disease (ESKD). We determined the quantitative and qualitative abnormalities of vWF and factors influencing vWF proteolysis in participants with ESKD compared with age-matched controls and determined the association between abnormalities in vWF and mortality over 4 years of follow-up. vWF : Ag and von Willebrand factor propeptide (vWFpp) levels, vWF functional activity (vWF :RCo), vWF multimer profiles, ADAMTS-13, thrombospondin 1 (TSP-1), and interleukin 6 (IL-6) were evaluated before and after a single hemodialysis treatment in 55 individuals with vascular disease and an age-matched group of controls (n = 21). vWF : Ag and vWF activity were significantly higher in the ESKD patients and levels increased further following the dialysis procedure. The percentage of high molecular weight multimers (%HMWMs) was significantly elevated in the ESKD patients compared with controls. TSP-1 was lower and IL-6 was higher providing possible explanation for the increase in %HMWM in ESKD. The %HMWM dropped significantly in the postdialysis sample. Mortality at 4 years was significantly associated with vWF : Ag. There are higher plasma vWF : Ag levels and a small increase in HMWMs in the ESKD milieu. The acute drop in the %HMWM of vWF postdialysis appears to be due to shear forces encountered during the dialysis procedure. The contribution of these abnormalities to either a pro-thrombotic and/or pro-bleeding phenotype in this population requires further study.

Metabotropic glutamate receptors (mGluRs), which are coupled to second messenger pathways via G proteins, modulate glutamatergic and GABAergic neurotransmission. Because of their role in modulating neurotransmission, mGluRs are attractive therapeutic targets for anxiety disorders. Previously we showed that mGluR8(-/-) male mice showed higher measures of anxiety in the open field and elevated plus maze than age-matched wild-type mice. In this study, we assessed the potential effects of acute pharmacological modulation of mGluR8 on measures of avoidable and unavoidable anxiety. In addition to wild-type mice, we also tested apolipoprotein E-deficient (Apoe(-/-)) mice, as these mice show increased levels of anxiety-like behaviors and therefore might show an altered sensitivity to mGluR8 stimulation. mGluR8 stimulation with the specific agonist DCPG, or modulation with AZ12216052, a new, positive allosteric modulator of mGluR8 reduced measures of anxiety in both wild-type mice. The effects of mGluR8 positive allosteric modulators, which only affect neurotransmission in the presence of extracellular glutamate, seem particularly promising for patients with anxiety disorders showing benzodiazepine insensitivity.

Background Challenges in reporting subjective hemorrhagic symptoms consistently has led to the need for standardized, quantitative Bleeding Assessment Tools (BATs), some of which assign Bleeding Scores (BSs). The ISTH-BAT (International Society on Thrombosis and Hemostasis – Bleeding Assessment Tool (Rodeghiero et al JTH 2010; 8:2063)) aimed to consolidate and optimize advances made by its predecessors, which were based on the 2005 “Vicenza Bleeding Questionnaire”. It is important to note, however, that the scoring systems differ among the BATs, with each bleeding symptom scored from 0 to +3 for the original Vicenza, -1 to +4 for the MCMDM-1VWD and Condensed MCMDM-1VWD Bleeding Questionnaires and the PBQ (Pediatric Bleeding Questionnaire), and 0 to +4 for the ISTH-BAT. As a result, the normal ranges of BSs vary among questionnaires. To date, the normal range for the ISTH-BAT has not been established; the objective of this study was to determine the normal range of bleeding scores for the ISTH-BAT for both adults and pediatric patients. Patients and Methods BS data from different studies, originally generated using 4 different Vicenza-based BATs, were compiled using a bioinformatics system created to facilitate the collation and analysis using different scoring systems. Demographic and BS data, along with blood group, VWF:Ag/VWF:RCo/FVIII:C (when available) were collected from all enrolled subjects. Data were derived from multiple studies; all defined normal subjects as those without a known problem with bleeding or bruising. All BATs were expert-administered. The normal range for both adults and pediatrics was determined by: 1) removing outliers > 3 SD away from the mean and then, 2) selecting the mid-95th %ile. Results 1,422 normal subjects were included (adult: n=1,079, pediatric: n=343). Adult data were collected using MCMDM-1VWD (n=294), Condensed MCMDM-1VWD (n=660), and ISTH-BAT (n=125), while pediatric data were collected using PBQ (n=324) and ISTH-BAT (n=19). 48 adults were removed from the analysis because they had BSs > 6.3, (i.e., >3 SD away from the mean), leaving n=1,031 for determination of the normal range. For children, BSs > 3.5 were judged to be outliers and therefore 18 children were removed, leaving n=325 children for determination of the normal range. The remaining adults had a mean age of 43 yrs (range 18 – 88) with 695 females and 336 males. The remaining children had a mean age of 9 yrs (range 0.4 – 17 yrs), with 169 females and 156 males. The relationship between BSs and demographic and lab data are given in Table 1. For the ISTH-BAT, the normal range of BSs was 0 - 4 in adults (meaning that for individuals 18 yrs or older, a BS 5 or greater is positive or abnormal) and 0 - 2 in children (meaning that for individuals < 18 yrs, a BS 3 or greater is positive or abnormal). Conclusion The newly established normal BS ranges can now be used to objectively assess the bleeding symptoms of individuals by administration of the ISTH-BAT. They also highlight the strength of merging existing datasets to generate meaningful results. By making these data accessible to all investigators using the web-based ISTH-BAT system housed at Rockefeller University we hope to aid investigators initiating new studies and facilitate correlating bleeding symptoms with genotypic, molecular, and environmental data. Disclosures: Mauer: CSL Behring: Honoraria. James:CSL Behring: Honoraria, Research Funding; Octapharma: Honoraria, Research Funding; Baxter: Honoraria; Bayer: Honoraria.

Abstract 1296 Poster Board I-318 Background Patients with inherited bleeding disorders undergoing surgery typically receive therapy to correct the deficient factor to a level of ∼1.0 IU/mL. There is a paucity of well-constructed descriptive data quantifying the changes in coagulation that occur in response to surgical stress in normal individuals, however. Additionally, von Willebrand factor (VWF) and factor VIII (FVIII) are acute phase reactants, and thus, supratherapeutic levels of these proteins that might develop in response to the surgical stress would predispose patients to thrombotic events. Aim: With this in mind, our objective was to quantify the changes in hemostatic variables that occur in response to elective orthopedic surgery in normal individuals. Methods Eligible subjects > 18 years of age undergoing total knee or total hip replacement were recruited. Exclusion criteria included a known bleeding disorder, hormone replacement therapy, use of oral contraceptives or pregnancy. Following informed consent, blood samples were drawn at five time points: 1) baseline - in clinic 1-2 weeks pre-operatively (pre-op), 2) pre-op the morning of surgery – same day admitting center, 3) intra-operatively (intra-op) – 30 minutes after the start of surgery, 4) 30 minutes post-operatively (post-op) - recovery room, and 5) post-op day one (POD 1) – on the ward. Samples were analyzed for complete blood counts (CBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), VWF antigen (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo), FVIII coagulant activity (FVIII:C) and whole blood thromboelastography (TEG) without tissue factor activation. Repeated measures analysis of variance was used to evaluate trends over time; paired samples t-tests were done to maximize the sample size for pairwise comparisons. Results 37 subjects were recruited (25 females, 12 males) with a mean age of 64 years (range 33 – 87). Means and ranges for all laboratory parameters are displayed in Table 1 in addition to statistical analysis of the change in all variables over the 5 time points. Statistically significant changes were seen in all variables except PTT and TEG angle. In general, VWF and FVIII indices decreased during surgery (presumably due to consumption) and then increased in the post-operative period (presumably due to a stress response). A great deal of variability was seen in post-operative levels of VWF and FVIII between individuals with some showing borderline low levels and some achieving very high levels. Conclusion These data establish a baseline on which to reconsider current strategies for the peri-operative management of patients with inherited bleeding disorders, and provide relevant information when considering the relative risks of bleeding or thrombosis associated with surgery. Disclosures No relevant conflicts of interest to declare.