A transcriptome analysis of basal and stimulated VWF release from endothelial cells derived from patients with type 1 VWD.

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.

Evaluating the effectiveness of let's talk period's high school educational outreach program: A pilot study.

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 < 0.001) from baseline to post-presentation scores, with a significant gain in knowledge, for all questions (p < 0.01). Students found content related to the basics and management of menstruation to be most interesting. Many had constructive feedback on how the presentation method could be improved. On average, the presentations were rated an 8.6 of 10 by students and 8.75 of 10 by teachers. CONCLUSION: The LTP high school outreach program effectively increases student knowledge of menorrhagia and bleeding disorders. It was well-received by students and staff alike.

A decreased and less sustained desmopressin response in hemophilia A carriers contributes to bleeding.

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.

Rapid acquisition of immunologic tolerance to factor VIII and disappearance of anti-factor VIII IgG4 after prophylactic therapy in a hemophilia A patient with high-titer factor VIII inhibitor.

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.