Persistence of serum antiphospholipid antibodies (aPL) is associated with a high thrombotic risk, both arterial and venous, and with pregnancy complications. Due to the potential morbidity and... Show morePersistence of serum antiphospholipid antibodies (aPL) is associated with a high thrombotic risk, both arterial and venous, and with pregnancy complications. Due to the potential morbidity and mortality associated with the presence of aPL, identifying and recognizing risk factors for the development of aPL and thrombosis in aPL carriers may help to prevent and reduce the burden of disease. Multiple elements are involved in the pathomechanism of aPL development and aPL-related thrombosis such as genetics, malignancy, and infections. This review will address the role of both well-known risk factors and their evolution, and of emerging risk factors, including COVID-19, in the development of aPL and thrombosis in aPL carriers. Show less
Brands, M.R.; Janssen, E.A.M.; Cnossen, M.H.; Smit, C.; Vulpen, L.F.D. van; Valk, P. van der; ... ; Gouw, S.C. 2023
IntroductionCare for adolescents with haemophilia is transferred from paediatric to adult care around the age of 18 years. Transition programs help to prepare adolescents for this transfer and... Show moreIntroductionCare for adolescents with haemophilia is transferred from paediatric to adult care around the age of 18 years. Transition programs help to prepare adolescents for this transfer and prevent declining treatment adherence. Evaluating transition readiness may identify areas for improvement. ObjectiveAssess transition readiness among Dutch adolescents and young adults with haemophilia, determine factors associated with transition readiness, and identify areas of improvement in transition programs. MethodsAll Dutch adolescents and young adults aged 12-25 years with haemophilia were invited to participate in a nationwide questionnaire study. Transition readiness was assessed using multiple-choice questions and was defined as being ready or almost ready for transition. Potential factors associated with transition readiness were investigated, including: socio-demographic and disease-related factors, treatment adherence, health-related quality of life, and self-efficacy. ResultsData of 45 adolescents and 84 young adults with haemophilia (47% with severe haemophilia) were analyzed. Transition readiness increased with age, from 39% in 12-14 year-olds to 63% in 15-17 year-olds. Nearly all post-transition young adults (92%, 77/84) reported they were ready for transition. Transition readiness was associated with treatment adherence, as median VERITAS-Pro treatment adherence scores were worse in patients who were not ready (17, IQR 9-29), compared to those ready for transition (11, IQR 9-16). Potential improvements were identified: getting better acquainted with the adult treatment team prior to transition and information on managing healthcare costs. ConclusionsNearly all post-transition young adults reported they were ready for transition. Improvements were identified regarding team acquaintance and preparation for managing healthcare costs. Show less
One of the most used and versatile methods to study number, dimensions, content and localization of secretory organelles is confocal microscopy analysis. However, considerable heterogeneity exists... Show moreOne of the most used and versatile methods to study number, dimensions, content and localization of secretory organelles is confocal microscopy analysis. However, considerable heterogeneity exists in the number, size and shape of secretory organelles that can be present in the cell. One thus needs to analyze large numbers of organelles for valid quantification. Properly evaluating these parameters requires an automated, unbiased method to process and quantitatively analyze microscopy data. Here, we describe two pipelines, run by CellProfiler software, called OrganelleProfiler and OrganelleContentProfiler. These pipelines were used on confocal images of endothelial colony forming cells (ECFCs), which contain unique secretory organelles called Weibel-Palade bodies (WPBs), and on early endosomes in ECFCs and human embryonic kidney 293T (HEK293T) cells. Results show that the pipelines can quantify the cell count, size, organelle count, organelle size, shape, relation to cells and nuclei, and distance to these objects in both endothelial and HEK293T cells. Additionally, the pipelines were used to measure the reduction in WPB size after disruption of the Golgi and to quantify the perinuclear clustering of WPBs after triggering of cAMP-mediated signaling pathways in ECFCs. Furthermore, the pipeline is able to quantify secondary signals located in or on the organelle or in the cytoplasm, such as the small WPB GTPase Rab27A. Cell profiler measurements were checked for validity using Fiji. To conclude, these pipelines provide a powerful, high-processing quantitative tool for the characterization of multiple cell and organelle types. These pipelines are freely available and easily editable for use on different cell types or organelles. Show less
BackgroundRecombinant factor (F)IX-FIAV has previously been shown to function independently of activated FVIII (FVIIIa) and ameliorate the hemophilia A (HA) phenotype in vitro and in vivo.Objective... Show moreBackgroundRecombinant factor (F)IX-FIAV has previously been shown to function independently of activated FVIII (FVIIIa) and ameliorate the hemophilia A (HA) phenotype in vitro and in vivo.ObjectivesThe aim of this study was to assess the efficacy of FIX-FIAV in plasma from HA patients using thrombin generation (TG) and intrinsic clotting activity (activated partial thromboplastin time [APTT]) analyses.MethodsPlasma obtained from 21 patients with HA (>18 years; 7 mild, 7 moderate, and 7 severe patients) was spiked with FIX-FIAV. The FXIa-triggered TG lag time and APTT were quantified in terms of FVIII-equivalent activity using FVIII calibration for each patient plasma.ResultsThe linear, dose-dependent improvement in the TG lag time and APTT reached its maximum with approximately 400% to 600% FIX-FIAV in severe HA plasma and with approximately 200% to 250% FIX-FIAV in nonsevere HA plasma. The cofactor-independent contribution of FIX-FIAV was therefore suggested and confirmed by the addition of inhibitory anti-FVIII antibodies to nonsevere HA plasma, resulting in a FIX-FIAV response similar to severe HA plasma. Addition of 100% (5 μg/mL) FIX-FIAV mitigated the HA phenotype from severe to moderate (from <0.01% to 2.9% [IQR 2.3%-3.9%] FVIII-equivalent activity), from moderate to mild (3.9% [IQR 3.3%-4.9%] to 16.1% [IQR 13.7%-18.1%] FVIII-equivalent activity), and from mild to normal (19.8% [IQR 9.2%-24.0%] to 48.0% [IQR 34.0%-67.5%] FVIII-equivalent activity). No substantial effects were observed when combining FIX-FIAV with current HA therapies.ConclusionFIX-FIAV is capable of increasing the FVIII-equivalent activity and coagulation activity in plasma from HA patients, thereby mitigating the HA phenotype. Hence, FIX-FIAV could serve as a potential treatment for HA patients with or without inhibitors. Show less
BackgroundRecombinant factor (F)IX-FIAV has previously been shown to function independently of activated FVIII (FVIIIa) and ameliorate the hemophilia A (HA) phenotype in vitro and in vivo.Objective... Show moreBackgroundRecombinant factor (F)IX-FIAV has previously been shown to function independently of activated FVIII (FVIIIa) and ameliorate the hemophilia A (HA) phenotype in vitro and in vivo.ObjectivesThe aim of this study was to assess the efficacy of FIX-FIAV in plasma from HA patients using thrombin generation (TG) and intrinsic clotting activity (activated partial thromboplastin time [APTT]) analyses.MethodsPlasma obtained from 21 patients with HA (>18 years; 7 mild, 7 moderate, and 7 severe patients) was spiked with FIX-FIAV. The FXIa-triggered TG lag time and APTT were quantified in terms of FVIII-equivalent activity using FVIII calibration for each patient plasma.ResultsThe linear, dose-dependent improvement in the TG lag time and APTT reached its maximum with approximately 400% to 600% FIX-FIAV in severe HA plasma and with approximately 200% to 250% FIX-FIAV in nonsevere HA plasma. The cofactor-independent contribution of FIX-FIAV was therefore suggested and confirmed by the addition of inhibitory anti-FVIII antibodies to nonsevere HA plasma, resulting in a FIX-FIAV response similar to severe HA plasma. Addition of 100% (5 μg/mL) FIX-FIAV mitigated the HA phenotype from severe to moderate (from <0.01% to 2.9% [IQR 2.3%-3.9%] FVIII-equivalent activity), from moderate to mild (3.9% [IQR 3.3%-4.9%] to 16.1% [IQR 13.7%-18.1%] FVIII-equivalent activity), and from mild to normal (19.8% [IQR 9.2%-24.0%] to 48.0% [IQR 34.0%-67.5%] FVIII-equivalent activity). No substantial effects were observed when combining FIX-FIAV with current HA therapies.ConclusionFIX-FIAV is capable of increasing the FVIII-equivalent activity and coagulation activity in plasma from HA patients, thereby mitigating the HA phenotype. Hence, FIX-FIAV could serve as a potential treatment for HA patients with or without inhibitors. Show less
BackgroundThe population-based colorectal cancer (CRC) screening program in individuals aged 55 to 75 years in the Netherlands uses fecal immunochemical testing (FIT), to detect hemoglobin in feces... Show moreBackgroundThe population-based colorectal cancer (CRC) screening program in individuals aged 55 to 75 years in the Netherlands uses fecal immunochemical testing (FIT), to detect hemoglobin in feces, followed by colonoscopy in individuals with a positive FIT.ObjectivesThe objectives of this study are to assess the false-positive rate, detection rate, and positive predictive value of FIT for CRC and advanced adenoma (AA) in patients with Von Willebrand disease (VWD) or hemophilia.MethodsWe performed a multicenter, nationwide cross-sectional study embedded in 2 nationwide studies on VWD and hemophilia in the Netherlands.ResultsIn total, 493 patients with hemophilia (n = 329) or VWD (n = 164) were included, of whom 351 patients participated in the CRC screening program (71.2%). FIT positivity and false-positive rate in patients with hemophilia and VWD were significantly higher than those in the general population (14.8% vs. 4.3%, p < .001 and 10.3% vs. 2.3%, p <.001, respectively). In patients with hemophilia, the detection rate of CRC/AA was significantly higher than that in the general male population (4.5% vs. 1.8%, p = .02), and the positive predictive value of FIT for CRC/AA was comparable (32.3% vs. 39.7%, n.s.). In patients with VWD, the detection rate was similar to that of the general population (0.8% vs. 1.4%, n.s.), whereas the positive predictive value was significantly lower than that in the general population (6.3% vs. 36.8%, p = .02).ConclusionThis study indicates that despite a high false-positive rate of FIT in patients with inherited bleeding disorders, the detection rate of CRC and/or AA in hemophilia patients is high. FIT performs different in patients with hemophilia or VWD compared with the general population. Show less
Zwagemaker, A.F.; Kloosterman, F.R.; Gouw, S.C.; Boyce, S.; Brons, P.; Cnossen, M.H.; ... ; DYNAMO Study Grp 2023
BackgroundType 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... Show moreBackgroundType 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.ObjectiveThe objective of this study was to assess the prevalence of anti-VWF alloantibodies in subjects with type 3 VWD enrolled in the 3WINTERS-IPS.MethodsAn 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.ResultsIn 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).ConclusionsAnti-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. Show less
Monahan, R.C.; Voorde, L.J.J. van de; Fronczek, R.; Bresser, J. de; Eikenboom, J.; Kloppenburg, M.; ... ; Steup-Beekman, G.M. 2023
Background: The short-term and long-term outcome of inflammatory neuropsychiatric SLE (NPSLE) with immunosuppressive treatment is largely unknown. We used clinical data from our tertiary referral... Show moreBackground: The short-term and long-term outcome of inflammatory neuropsychiatric SLE (NPSLE) with immunosuppressive treatment is largely unknown. We used clinical data from our tertiary referral centre for NPSLE to investigate the type of inflammatory NPSLE manifestations, type of immunosuppressive treatment prescribed for these manifestations and clinical outcomes. Methods: All patients with SLE visiting the Leiden University Medical Centre NPSLE clinic between 2007 and 2021 receiving immunosuppressive therapy for neuropsychiatric symptoms were included. Clinical, immunological and radiological information was collected in as standardised way during a 1-day multidisciplinary assessment. In a multidisciplinary consensus meeting, the presence of NPSLE and the type of NPSLE manifestations and treatment were determined. For this study, short-term (0-6 months) and long-term outcomes (7-24 months) of the NP symptoms were assessed by two independent readers and scored on a 7-point Likert scale, ranging from death to resolved. Results: In total, 95 out of 398 (24%) patients visiting the NPSLE clinic between 2007 and 2021 received any form of immunosuppressive treatment for 101 separate NPSLE events. The most common NP manifestation was cognitive dysfunction (50%) as identified by formal cognitive assessment, often present in combination with other NPSLE manifestations. Treatment modalities were induction (24%), induction and maintenance (73%) and other therapy (3%). The treatments mostly consisted of (combinations of) prednisone (97%), methylprednisolone (53%), azathioprine (generally 2 mg/kg daily) (49%) and cyclophosphamide (generally induction 750 mg/m(2) every 4 weeks for 24 weeks or 500mg biweekly for 12 weeks) (42%). Short-term outcome showed improvement on the Likert scale in 73% (improved: 22%, much improved: 29%, resolved: 22%), no change in 21% and worsening in 6% of patients. Long-term outcome was available for 78 out of 101 events and showed improvement in 70% (improved: 14%, much improved: 28%, resolved: 28%), no change in 17%, worsening in 10% and death in 3% of patients (none directly NPSLE-related). Conclusion: The outcome of inflammatory NPSLE after immunosuppressive treatment is generally good, with improvement of neuropsychiatric symptoms occuring in approximately 70% of events. Show less
Monahan, R.C.; Voorde, L.J.J. van de; Fronczek, R.; Bresser, J. de; Eikenboom, J.; Kloppenburg, M.; ... ; Steup-Beekman, G.M. 2023
Background The short-term and long-term outcome of inflammatory neuropsychiatric SLE (NPSLE) with immunosuppressive treatment is largely unknown. We used clinical data from our tertiary referral... Show moreBackground The short-term and long-term outcome of inflammatory neuropsychiatric SLE (NPSLE) with immunosuppressive treatment is largely unknown. We used clinical data from our tertiary referral centre for NPSLE to investigate the type of inflammatory NPSLE manifestations, type of immunosuppressive treatment prescribed for these manifestations and clinical outcomes.Methods All patients with SLE visiting the Leiden University Medical Centre NPSLE clinic between 2007 and 2021 receiving immunosuppressive therapy for neuropsychiatric symptoms were included. Clinical, immunological and radiological information was collected in as standardised way during a 1-day multidisciplinary assessment. In a multidisciplinary consensus meeting, the presence of NPSLE and the type of NPSLE manifestations and treatment were determined. For this study, short-term (0–6 months) and long-term outcomes (7–24 months) of the NP symptoms were assessed by two independent readers and scored on a 7-point Likert scale, ranging from death to resolved.Results In total, 95 out of 398 (24%) patients visiting the NPSLE clinic between 2007 and 2021 received any form of immunosuppressive treatment for 101 separate NPSLE events. The most common NP manifestation was cognitive dysfunction (50%) as identified by formal cognitive assessment, often present in combination with other NPSLE manifestations. Treatment modalities were induction (24%), induction and maintenance (73%) and other therapy (3%). The treatments mostly consisted of (combinations of) prednisone (97%), methylprednisolone (53%), azathioprine (generally 2 mg/kg daily) (49%) and cyclophosphamide (generally induction 750 mg/m2 every 4 weeks for 24 weeks or 500mg biweekly for 12 weeks) (42%). Short-term outcome showed improvement on the Likert scale in 73% (improved: 22%, much improved: 29%, resolved: 22%), no change in 21% and worsening in 6% of patients. Long-term outcome was available for 78 out of 101 events and showed improvement in 70% (improved: 14%, much improved: 28%, resolved: 28%), no change in 17%, worsening in 10% and death in 3% of patients (none directly NPSLE-related).Conclusion The outcome of inflammatory NPSLE after immunosuppressive treatment is generally good, with improvement of neuropsychiatric symptoms occuring in approximately 70% of events. Show less
Zwagemaker, A.F.; Kloosterman, F.R.; Coppens, M.; Gouw, S.C.; Boyce, S.; Bagot, C.N.; ... ; Fijnvandraat, K. 2022
Background: Desmopressin is an important treatment option in nonsevere hemophilia A because it has several benefits compared with factor (F) concentrates, including no inhibitor risk and much lower... Show moreBackground: Desmopressin is an important treatment option in nonsevere hemophilia A because it has several benefits compared with factor (F) concentrates, including no inhibitor risk and much lower costs. Despite these advantages, data are limited on the real-world use of desmopressin in the treatment of bleeds. Objective: To describe the clinical use of desmopressin in relation to other therapeutic modalities in the treatment of bleeding episodes in patients with nonsevere hemophilia A. Methods: Patients with nonsevere hemophilia A aged 12-55 years were included from the DYNAMO cohort study. Data on the desmopressin test response and treated bleeding events in the period January 2009 to July 2020 were retrospectively collected from medical files. An adequate desmopressin test response was defined based on a peak FVIII level of >= 30 IU/dl. Results: A total of 248 patients with a median age of 38 years (interquartile range 25-49) were included. An adequate desmopressin test response was documented in 25% and 73% of patients with moderate and mild hemophilia, respectively. In adequate responders, 51% of bleeds were exclusively treated with FVIII concentrates, 24% exclusively with desmopressin, 21% with a combination of both and 4% with other treatments. In 54% of bleeds treated with a single dose of factor concentrates, the expected FVIII level after desmopressin exceeded the level targeted. Conclusion: Most bleeds in patients with an adequate response to desmopressin are treated with factor concentrates. These findings may indicate a suboptimal use of desmopressin and that barriers to the use of desmopressin should be explored. Show less
von Willebrand Disease (VWD) is associated with significant morbidity because of excessive bleeding. Early diagnosis and treatment are important to prevent and treat these symptoms. We... Show morevon Willebrand Disease (VWD) is associated with significant morbidity because of excessive bleeding. Early diagnosis and treatment are important to prevent and treat these symptoms. We systematically reviewed the accuracy of any von Willebrand factor (VWF) activity assay in the diagnosis and classification of patients for VWD. We searched Cochrane Central, MEDLINE, and EMBASE for eligible studies. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 and the certainty of evidence using the GRADE framework. We pooled estimates of sensitivity and specificity. The review included 77 studies that evaluated the use of newer tests of VWF platelet binding activity (VWF:GPIbR, VWF:GPIbM) and VWF:RCo for the diagnosis of VWD (13 studies), VWF propeptide to VWF:Ag ratio, and desmopressin trial for the diagnosis of type 1C VWD (5 studies), VWF multimer analysis and VWF:CB/VWF:Ag ratio for the classification of type 2 VWD (11 studies), genetic testing and ristocetin-induced platelet aggregation to diagnose type 2B VWD (14 studies), genetic testing and FVIII:VWF binding to diagnose type 2N VWD (17 studies). Based on available diagnostic test accuracy, there appear to be comparable test accuracy results between newer tests of platelet binding activity of VWF function and VWF:RCo. The findings of these reviews support VWF multimer analysis or VWF:CB/VWF:Ag to diagnose type 2 VWD. The desmopressin trial test with 1- and 4-hour postinfusion blood work is the test of choice to confirm increased VWF clearance in patients with suspected VWD type 1C. Additionally, genetic testing is most useful in diagnosing type 2B VWD and has a role in the diagnostic algorithm of suspected type 2N VWD. Show less
Genotyping is not routinely performed at diagnosis of von Willebrand disease (VWD). Therefore, the association between genetic variants and pathogenic mechanism or the clinical and laboratory... Show moreGenotyping is not routinely performed at diagnosis of von Willebrand disease (VWD). Therefore, the association between genetic variants and pathogenic mechanism or the clinical and laboratory phenotype is unknown in most patients, especially in type 1 VWD. To investigate whether genotyping adds to a better understanding of the pathogenic mechanisms and variability in phenotype, we analyzed the VWF gene in 390 well-defined VWD patients, included in the WiN study. A VWF gene variant was found in 155 patients (61.5%) with type 1, 122 patients (98.4%) with type 2, and 14 patients (100%) with type 3 VWD. Forty-eight variants were novel. For each VWF gene variant, the pathogenic mechanisms associated with reduced VWF levels was investigated using the FVIII:C/VWF:Ag and VWFpp/VWF:Ag ratios. In type 1 VWD, reduced synthesis or secretion of VWF was most frequently found in patients with nonsense variants, frameshift variants, and deletions, whereas rapid clearance of VWF was mainly found in patients with missense variants. Furthermore, type 1 VWD patients with and without a VWF gene variant were clearly distinct in their clinical features such as age of diagnosis, laboratory phenotype, and bleeding phenotype. In type 2 VWD, 81% of variants were associated with an increased clearance of VWF. To conclude, we identified the pathogenic mechanisms associated with various VWF gene variants in type 1, 2, and 3 VWD patients. Additionally, major differences in the phenotype of type 1 VWD patients with and without a variant were observed, which may be of importance for clinical management. Show less
Grewal, N.; Yousef, D.; Palmen, M.; Klautz, R.; Eikenboom, J.; Wink, J. 2022
Introduction Extracorporeal circulation (ECC) in cardiac surgery is performed under systemic heparinization. Adequacy of heparin therapy and anticoagulation during ECC is assessed by activated... Show moreIntroduction Extracorporeal circulation (ECC) in cardiac surgery is performed under systemic heparinization. Adequacy of heparin therapy and anticoagulation during ECC is assessed by activated clotting time (ACT), although there are concerns regarding the reliability of this measure. The ACT can be affected by factors other than heparin anticoagulation. A novel factor that should be considered is the influence of a COVID-19 infection. More than half of the hospitalized COVID-19 patients develop coagulation abnormalities with dysregulated coagulation test results. Patients recently recovered from COVID-19 may still demonstrate some forms of coagulation disorder affecting the ACT. This case describes an inaccurate point-of-care ACT testing in a patient with previous COVID-19 infection undergoing cardiac surgery with ECC and the alternative coagulation testing performed. Case presentation A 77-years-old Caucasian male presented with symptomatic severe mitral valve regurgitation for which he underwent surgery. Medical history revealed a COVID-19 infection one month before surgery. Pre-operative hematological lab results were normal and baseline ACT during surgery was 100 s. To achieve an adequate ACT of > 400 s, multiple doses of heparin were needed and after administration of a triple dose (75,000 IE heparin in total) this adequate ACT was achieved. In the meanwhile we measured anti-Xa level and APTT, which were at adequate levels when ACT was still < 400 s. Discussion This case emphasizes the need of alternative methods for monitoring heparin therapy in case ACT does not respond adequately. Another point to highlight in this case is the poorly correlated relation between ACT and APTT and anti-Xa in light of the recent COVID-19 infection. Although studies have shown that COVID-19 infection can cause coagulopathy and altered hemostatic parameters, ACT has never been investigated in COVID-19 patient. Understanding the correlation between ACT, APTT and anti-Xa in COVID-19 patients is mandatory. Show less
Swinkels, M.; Atiq, F.; Burgisser, P.E.; Moort, I. van; Meijer, K.; Eikenboom, J.; ... ; WiN Study Grp 2022
Von Willebrand disease (VWD) is a bleeding disorder caused by quantitative (type 1 or 3) or qualitative (type 2A/2B/2M/2N) defects of circulating von Willebrand factor (VWF). Circulating VWF levels... Show moreVon Willebrand disease (VWD) is a bleeding disorder caused by quantitative (type 1 or 3) or qualitative (type 2A/2B/2M/2N) defects of circulating von Willebrand factor (VWF). Circulating VWF levels not always fully explain bleeding phenotypes, suggesting a role for alternative factors, like platelets. Here, we investigated platelet factor 4 (PF4) in a large cohort of patients with VWD. PF4 levels were lower in type 2B and current bleeding phenotype was significantly associated with higher PF4 levels, particularly in type 1 VWD. Based on our findings we speculate that platelet degranulation and cargo release may play a role across VWD subtypes. Show less
Heesterbeek, M.R.; Luijten, M.A.J.; Gouw, S.C.; Limperg, P.F.; Fijnvandraat, K.; Coppens, M.; ... ; Haverman, L. 2022
Background Type 3 von Willebrand disease (VWD) is a severe bleeding disorder caused by the virtually complete absence of von Willebrand factor (VWF). Pathophysiological mechanisms of VWD like... Show moreBackground Type 3 von Willebrand disease (VWD) is a severe bleeding disorder caused by the virtually complete absence of von Willebrand factor (VWF). Pathophysiological mechanisms of VWD like defective synthesis, secretion, and clearance of VWF have previously been evaluated using ratios of VWF propeptide (VWFpp) over VWF antigen (VWF:Ag) and factor (F)VIII coagulant activity (FVIII:C) over VWF:Ag. Objective To investigate whether the VWFpp/VWF:Ag and FVIII:C/VWF:Ag ratios may also be applied to understand the pathophysiological mechanism underlying type 3 VWD and whether VWFpp is associated with bleeding severity. Methods European and Iranian type 3 patients were enrolled in the 3WINTERS-IPS study. Plasma samples and buffy coats were collected and a bleeding assessment tool was administered at enrolment. VWF:Ag, VWFpp, FVIII:C, and genetic analyses were performed centrally, to confirm patients' diagnoses. VWFpp/VWF:Ag and FVIII:C/VWF:Ag ratios were compared among different variant classes using the Mann-Whitney test. Median differences with 95% confidence intervals (CI) were estimated using the Hodges-Lehmann method. VWFpp association with bleeding symptoms was assessed using Spearman's rank correlation. Results Homozygosity/compound heterozygosity for missense variants showed higher VWFpp level and VWFpp/VWF:Ag ratio than homozygosity/compound heterozygosity for null variants ([VWFpp median difference, 1.4 IU/dl; 95% CI, 0.2-2.7; P = .016]; [VWFpp/VWF:Ag median difference, 1.4; 95% CI, 0-4.2; P = .054]). FVIII:C/VWF:Ag ratio was similarly increased in both. VWFpp level did not correlate with the bleeding symptoms (r = .024; P = .778). Conclusions An increased VWFpp/VWF:Ag ratio is indicative of missense variants, whereas FVIII:C/VWF:Ag ratio does not discriminate missense from null alleles. The VWFpp level was not associated with the severity of bleeding phenotype. Show less
Introduction The negative impact of haemophilia on social participation is well established in previous studies, however, the impact of Von Willebrand disease (VWD) on social participation has not... Show moreIntroduction The negative impact of haemophilia on social participation is well established in previous studies, however, the impact of Von Willebrand disease (VWD) on social participation has not been studied. Aim To compare the social participation of a large cohort of VWD patients in the Netherlands with the general Dutch population. In addition, to identify factors associated with social participation in VWD. Methods Patients participating in the "Willebrand in the Netherlands" study completed an extensive questionnaire on educational level, absenteeism from school or work, and occupational disabilities. Results Seven-hundred and eighty-eight VWD patients were included (mean age 38.9 years, 59.5% females), of whom 136 children < 16 years. Adult patients with type 3 VWD more often had a low educational level (52.9%) compared to type 1 (40.2%), type 2 VWD (36.8%) and the general population (36.4%) (p = .005). Moreover, in patients aged >= 16 years the days lost from school and/or work in the year prior to study inclusion differed significantly between the VWD types (p = .011). Using negative binomial regression analysis, the occurrence of bleeding episodes requiring treatment in the year preceding study inclusion was significantly associated with the number of days lost from school and/or work among patients aged >= 16 years. Multivariable logistic regression analysis showed that a higher total bleeding score, older age and presence of at least one comorbidity were significantly associated with occupational disability in patients aged >= 16 years. Conclusion Our study shows that social participation was lower in type 3 VWD and VWD patients with a more severe bleeding phenotype. Show less
Introduction: Persons with hemophilia and hepatitis C virus (HCV) infection have a lower health-related quality of life (HRQoL) than those never HCV infected. However, it is unknown whether HRQoL... Show moreIntroduction: Persons with hemophilia and hepatitis C virus (HCV) infection have a lower health-related quality of life (HRQoL) than those never HCV infected. However, it is unknown whether HRQoL after HCV eradication is comparable to individuals never HCV infected. We aimed to compare HRQol. between HCV-cured and never chronically HCV-infected persons with hemophilia.Methods: All persons with hemophilia in the Netherlands were invited for a nationwide study conducted in 2018-2019. For the current analysis, participants born before 1992 with data on HRQoL and HCV status were included. HCV status was collected from medical records. HRQoL was measured by RAND-36 questionnaire, with a minimally important difference set at 4.0 points. Multivariable linear regression was used to adjust for age, hemophilia severity, HIV status, and self-reported joint impairment.Results: In total, 486 persons were eligible; 180 were HCV cured and 306 never chronically HCV infected. Compared with those never HCV infected, HCV-cured individuals were older (57 vs. 53 years), more often had severe hemophilia (67% vs. 21%), and reported more impaired joints (median 3 vs. 0). Compared with those never HCV infected, adjusted RAND-36 domain scores of HCV-cured individuals cured were lower on all RAND-36 domains except Pain, ranging from a difference of 4.5 (95% CI, -8.8 to -0.3) for Physical functioning to 11.3 (95% CI, -19.4 to -3.1) for Role limitations due to physical problems.Conclusion: Despite effective HCV treatment, HRQoL of HCV-cured persons with hemophilia is still lower than HRQoL of those never chronically HCV-infected on all RAND-36 domains. This implies that careful psychosocial follow-up and support are indicated. Show less
