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1.
J Thromb Haemost ; 22(7): 1894-1908, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38679335

ABSTRACT

BACKGROUND: von Willebrand disease (VWD) is the most common inherited bleeding disorder, characterized by either partial or complete von Willebrand factor (VWF) deficiency or by the occurrence of VWF proteoforms of altered functionality. The gene encoding VWF is highly polymorphic, giving rise to a variety of proteoforms with varying plasma concentrations and clinical significance. OBJECTIVES: To address this complexity, we translated genomic variation in VWF to corresponding VWF proteoforms circulating in blood. METHODS: VWF was characterized in VWD patients (n = 64) participating in the Willebrand in the Netherlands study by conventional laboratory testing, DNA sequencing and complementary discovery, and targeted mass spectrometry-based plasma proteomic strategies. RESULTS: Unbiased plasma profiling combined with immune enrichment of VWF verified VWF and its binding partner factor VIII as key determinants of VWD and revealed a remarkable heterogeneity in VWF amino acid sequence coverage among patients. Subsequent VWF proteotyping enabled identification of both polymorphisms (eg, p.Thr789Ala, p.Gln852Arg, and p.Thr1381Ala), as well as pathogenic variants (n = 16) along with their corresponding canonical sequences. Targeted proteomics using stable isotope-labeled peptides confirmed unbiased proteotyping for 5 selected variants and suggested differential proteoform quantities in plasma. The variant-to-wild-type peptide ratio was determined in 6 type 2B patients heterozygous for p.Arg1306Trp, confirming the relatively low proteoform concentration of the pathogenic variant. The elevated VWF propeptide/VWF ratio indicated increased clearance of specific VWF proteoforms. CONCLUSION: This study highlights how VWF proteotyping from plasma could be the first step to bridge the gap between genotyping and functional testing in VWD.


Subject(s)
Proteomics , von Willebrand Diseases , von Willebrand Factor , Humans , von Willebrand Factor/genetics , von Willebrand Factor/analysis , von Willebrand Factor/metabolism , von Willebrand Diseases/diagnosis , von Willebrand Diseases/blood , von Willebrand Diseases/genetics , Proteomics/methods , Netherlands , Phenotype , Female , Factor VIII/genetics , Factor VIII/analysis , Factor VIII/metabolism , Mass Spectrometry , Male , Predictive Value of Tests
2.
Blood ; 143(14): 1414-1424, 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38142407

ABSTRACT

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


Subject(s)
von Willebrand Disease, Type 1 , von Willebrand Diseases , Humans , von Willebrand Factor/genetics , von Willebrand Disease, Type 1/diagnosis , Netherlands/epidemiology , von Willebrand Diseases/diagnosis , von Willebrand Diseases/genetics , Hemorrhage/pathology
3.
J Thromb Haemost ; 21(5): 1177-1188, 2023 05.
Article in English | MEDLINE | ID: mdl-36696188

ABSTRACT

BACKGROUND: The 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. OBJECTIVES: The 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. METHODS: We performed a multicenter, nationwide cross-sectional study embedded in 2 nationwide studies on VWD and hemophilia in the Netherlands. RESULTS: In 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). CONCLUSION: This 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.


Subject(s)
Colorectal Neoplasms , Hemophilia A , von Willebrand Diseases , Humans , Male , Hemophilia A/complications , Hemophilia A/diagnosis , Cross-Sectional Studies , Early Detection of Cancer , Colorectal Neoplasms/complications , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/epidemiology , Predictive Value of Tests , Colonoscopy
4.
Haemophilia ; 28(2): 278-285, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34964530

ABSTRACT

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 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.


Subject(s)
von Willebrand Disease, Type 1 , von Willebrand Disease, Type 3 , von Willebrand Diseases , Adolescent , Adult , Female , Hemorrhage/complications , Humans , Male , Phenotype , Social Participation , von Willebrand Disease, Type 1/complications , von Willebrand Disease, Type 3/complications , von Willebrand Diseases/complications , von Willebrand Factor/genetics
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