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The risk of venous thromboembolism (VTE) is increased during pregnancy and it is further increased together with pregnancy complications in women with personal history of VTE and thrombophilia abnormalities. It is unclear how the use of low-molecular-weight heparin (LMWH) may prevent such complications.To evaluate the potential benefits and risks of the use of LMWH for prevention of pregnancy-related VTE and obstetrical complications in the first pregnancy after a previous VTE.This retrospective cohort study includes fertile women referred to the Thrombosis Center from January 2000 to September 2018 for a thrombophilia work-up, after having had at least one previous VTE and one pregnancy thereafter. Data on pregnancy-related recurrent VTE, pregnancy outcomes and the use of LMWH were collected.Among 208 women, no thrombosis or major bleeding was recorded in 138 pregnancies conducted with LMWH, whereas 10 VTE (14%) were recorded in 70 pregnancies conducted without. Nine women (90%) with recurrent VTE had had a previous hormone-related event. The incidence of miscarriage was lower in pregnancies with LMWH than in those without (11% vs. 26%, relative risk 0.4, 95% confidence interval: 0.2-0.8), whereas late obstetrical complications and terminations were similar in the two groups. The prevalence of terminations was doubled in women with thrombophilia (12%) than in those without (6%).LMWH prophylaxis during pregnancy appears to be effective and safe for the prevention of recurrent VTE and may reduce the incidence of miscarriage.

Background: Cerebral venous thrombosis (CVT) is an uncommon cause of stroke in young adults. We aimed to determine the impact of age, gender and risk factors (including sex-specific) on CVT onset. Methods: We used data from the BEAST (Biorepository to Establish the Aetiology of Sinovenous Thrombosis), a multicentre multinational prospective observational study on CVT. Composite factors analysis (CFA) was performed to determine the impact on the age of CVT onset in males and females. Results: A total of 1309 CVT patients (75.3% females) aged ⩾18 years were recruited. The overall median (IQR-interquartile range) age for males and females was 46 (35–58) years and 37 (28–47) years ( p Conclusions: Women suffer CVT 9 years earlier in comparison to men. Female patients with multiple (⩾1) risk factors suffer CVT ~12 years earlier compared to those with no identifiable risk factors.

Primary brain tumors are associated with an increased risk of pulmonary embolism (PE), particularly in the early post-operative period. The pathophysiological mechanisms of PE are poorly understood. This study aims to describe prospectively extracellular vesicles (EVs) levels and investigate whether or not their variations allow to identify patients at increased risk of post-operative PE. Consecutive meningioma or glioma patients candidate to tumor resection were included in the study if a pulmonary perfusion scan (Q-scan) performed before surgery ruled out PE. EVs derived from platelets (CD41+) or endothelial cells (CD144+), tissue factor-bearing EVs (CD142+) and their procoagulant subtype (annexin V+) were analyzed by flow cytometry before surgery (T0), within 24 h (T1), two (T2) and seven days (T7) after surgery. Q-scan was repeated at T2. Ninety-three patients with meningioma, 59 with glioma and 76 healthy controls were included in the study. CD142+ and annexin V+/CD142+ EVs were increased at T0 in meningioma and glioma patients compared to healthy controls. Twenty-nine meningioma (32%) and 16 glioma patients (27%) developed PE at T2. EVs levels were similar in meningioma patients with or without PE, whereas annexin V+ and annexin V+/CD142+ EVs were significantly higher at T1 and T2 in glioma patients with PE than in those without. Procoagulant EVs, particularly annexin V+/CD142+, increase after surgery and are more prevalent in glioma patients who developed PE after surgery than in those who did not.

Background The prevalence of older patients with acquired thrombotic thrombocytopenic purpura (TTP) is increasing. There is scarce information on the prevalence of multimorbidity, polypharmacy and age-related diseases in aging TTP patients. This study aimed to evaluate the prevalence of multimorbidity and polypharmacy in a population of acquired TTP patients aged 65 years or more compared with a group of age-matched controls. Methods Acquired TTP patients enrolled in the Milan TTP registry from December 1st 1999 to March 31th 2018 and aged 65 years or more at the date of last follow-up were evaluated. Controls were Italian healthy individuals recruited from 2006 to March 31th 2018 among friends and non-consanguineous relatives of patients tested for thrombophilia screening at the Angelo Bianchi Bonomi Hemophilia and Thrombosis Center of Milan. Results 36 TTP patients and 127 age-matched controls were included. Compared with controls, TTP patients had a higher prevalence of multimorbidity and polypharmacy. They also showed a higher prevalence of autoimmune diseases, osteoporosis and arterial hypertension and were more chronically treated with corticosteroids and antiplatelets for primary cardiovascular prevention. All these results were confirmed after adjusting for sex. Compared with the general elderly population, TTP patients showed a higher prevalence of ischemic heart disease and stroke. Conclusions Our findings suggest that a careful comprehensive geriatric assessment of acquired TTP patients is necessary. It is important to look for other autoimmune diseases and such age-related comorbidities as osteoporosis, arterial hypertension, ischemic heart disease and cerebrovascular disease.

Introduction von Willebrand disease (VWD) diagnosis starts with first level tests: factor VIII coagulant activity, VWF antigen (VWF:Ag) and platelet-dependent VWF activity (VWF:RCo, VWF:Ab, VWF:GPIbR or VWF:GPIbM). The VWF collagen binding (VWF:CB) assay measures the binding capacity of von Willebrand factor (VWF) to collagen. Aim To assess, in previously diagnosed VWD patients, the performance of a fully automated chemiluminescent test panel including VWF:Ag, VWF:GPIbR and VWF:CB assays. Methods The patients, historically evaluated using in-house VWF:Ag and VWF:CB assays and an automated latex enhanced immunoassay VWF:GPIbR method, were re-evaluated using the VWF test panel HemosIL AcuStar. Results The VWF:GPIbR/VWF:Ag and VWF:CB/VWF:Ag obtained by means of AcuStar showed an overall good concordance with the corresponding data obtained at the time of the historical diagnosis. When discrepancies occurred, these were generally due to the lower VWF:CB/VWF:Ag obtained with AcuStar as compared with that obtained with the historical methods and this affected particularly the diagnosis of VWD type 2M. Together, the AcuStar VWF:GPIbR/VWF:Ag and VWF:CB/VWF:Ag were able to distinguish type 1 from types 2A, 2B and 2M, whereas no distinction was possible between type 2A and 2B. Conclusion The AcuStar panel offers a good performance in the differential diagnosis between VWD type 1 and 2A/2B patients. A high rate of coincidence with historical diagnosis was obtained for VWD types 3, 2A/2B and 1. Even though in some cases more tests (eg, RIPA/multimeric analysis) are needed to complete an accurate VWD classification, the AcuStar panel is considered a sensitive, rapid and reliable tool to diagnose VWD patients.

Hypercoagulability and endothelial dysfunction related to inflammation have been clearly demonstrated in COVID-19. However, their influence on thromboembolism, lung alterations and mortality in low-intensity-care patients with COVID-19 is not completely clarified. Our aims were to evaluate the prevalence of deep vein thrombosis (DVT) with compressive ultrasound (CUS); to describe lung ultrasound (LUS) features; and to study coagulation, inflammatory and endothelial perturbation biomarkers in COVID-19 patients at low-intensity care unit admission. The predictive value of these biomarkers on mortality, need for oxygen support and duration of hospitalization was also evaluated. Of the 65 patients included, 8 were non-survivors. CUS was negative for DVT in all patients. LUS Soldati and Vetrugno scores were strongly correlated (rho = 0.95) with each other, and both significantly differed in patients who needed oxygen therapy vs. those who did not (Soldati p = 0.017; Vetrugno p = 0.023), with coalescent B lines as the most prevalent pattern in patients with a worse prognosis. Mean (SD) levels of thrombomodulin and VCAM-1 were higher in non-survivors than in survivors (7283.9 pg/mL (3961.9 pg/mL) vs. 4800.7 pg/mL (1771.0 pg/mL), p = 0.004 and 2299 ng/mL (730.35 ng/mL) vs. 1451 ng/mL (456.2 ng/mL), p < 0.001, respectively). Finally, in a multivariate analysis model adjusted for age, sex and Charlson score, VCAM-1 level increase was independently associated with death [OR 1.31 (1.06, 1.81; p = 0.036)]. In conclusion, in a cohort of mild COVID-19 patients, we found no DVT events despite the highly abnormal inflammatory, endothelial and coagulation parameters. The presence of lung alterations at admission could not predict outcome. The endothelial perturbation biomarker VCAM-1 emerged as a promising prognostic tool for mortality in COVID-19.

Background We previously described the association between rare ADAMTS13 single nucleotide variants (SNVs) and deep vein thrombosis (DVT). Moreover, DVT patients with at least one rare ADAMTS13 SNV had a lower ADAMTS13 activity than non-carriers. Aims To confirm ADAMTS13 variants association with DVT and reduced plasma ADAMTS13 activity levels in a larger population. To investigate the role of VWF and F8 variants. Methods ADAMTS13, VWF and F8 were sequenced using next-generation sequencing in 594 Italian DVT patients and 571 controls. Genetic association testing was performed using logistic regression and gene-based tests. The association between rare ADAMTS13 variants and the respective plasmatic activity, available for 365 cases and 292 controls, was determined using linear regression. All analyses were age-, sex- adjusted. Results We identified 48 low-frequency/common and 272 rare variants. Nine low-frequency/common variants had a PADAMTS13 (rs28641026, rs28503257, rs685523, rs3124768, rs3118667, rs739469, rs3124767; all protective) and 2 in VWF (rs1800382 [risk], rs7962217 [protective]). Rare ADAMTS13 variants were significantly associated with DVT using the burden, variable threshold (VT) and UNIQ (PVWF and F8 variants were not associated with DVT. Carriers of rare ADAMTS13 variants had lower ADAMTS13 activity than non-carriers (ß -6.2, 95%CI -11,-1.5). This association was stronger for DVT patients than controls (ß -7.5, 95%CI -13.5,-1.5 vs. ß -2.9, 95%CI -10.4,4.5). Conclusions ADAMTS13 and VWF low-frequency/common variants mainly showed a protective effect, although their association with DVT was not confirmed. DVT patients carrying a rare ADAMTS13 variants had slightly reduced ADAMTS13 activity levels, but a higher DVT risk. Rare VWF and FVIII variants were not associated with DVT suggesting that other mechanisms are responsible for the high VWF and FVIII levels measured in DVT patients.

Objective Cerebral venous thrombosis (CVT) is an uncommon form of stroke affecting mostly young individuals. Although genetic factors are thought to play a role in this cerebrovascular condition, its genetic etiology is not well understood. Methods A genome-wide association study was performed to identify genetic variants influencing susceptibility to CVT. A 2-stage genome-wide study was undertaken in 882 Europeans diagnosed with CVT and 1,205 ethnicity-matched control subjects divided into discovery and independent replication datasets. Results In the overall case-control cohort, we identified highly significant associations with 37 single nucleotide polymorphisms (SNPs) within the 9q34.2 region. The strongest association was with rs8176645 (combined p = 9.15 x 10(-24); odds ratio [OR] = 2.01, 95% confidence interval [CI] = 1.76-2.31). The discovery set findings were validated across an independent European cohort. Genetic risk score for this 9q34.2 region increases CVT risk by a pooled estimate OR = 2.65 (95% CI = 2.21-3.20, p = 2.00 x 10(-16)). SNPs within this region were in strong linkage disequilibrium (LD) with coding regions of the ABO gene. The ABO blood group was determined using allele combination of SNPs rs8176746 and rs8176645. Blood groups A, B, or AB, were at 2.85 times (95% CI = 2.32-3.52, p = 2.00 x 10(-16)) increased risk of CVT compared with individuals with blood group O. Interpretation We present the first chromosomal region to robustly associate with a genetic susceptibility to CVT. This region more than doubles the likelihood of CVT, a risk greater than any previously identified thrombophilia genetic risk marker. That the identified variant is in strong LD with the coding region of the ABO gene with differences in blood group prevalence provides important new insights into the pathophysiology of CVT. ANN NEUROL 2021

Primary brain tumors are associated with an increased risk of pulmonary embolism (PE), particularly in the early post-operative period. The pathophysiological mechanisms of PE are poorly understood. This study aims to describe prospectively extracellular vesicles (EVs) levels and investigate whether or not their variations allow to identify patients at increased risk of post-operative PE. Consecutive meningioma or glioma patients candidate to tumor resection were included in the study if a pulmonary perfusion scan (Q-scan) performed before surgery ruled out PE. EVs derived from platelets (CD41

Background: Deep vein thrombosis (DVT) is a common multi-factorial disease with a partially understood aetiology. Although the roles of high factor (F)VIII and von Willebrand factor (VWF) levels are recognized, that of ADAMTS13 is still unclear.Aim: To assess the association between ADAMTS13 activity levels, VWF antigen (VWF:Ag) and FVIII coagulant activity (FVIII:C) levels and DVT.Materials and methods: 365 Italian DVT patients and 292 ageand sex-matched controls were considered. Plasma ADAMTS13 activity was measured using FRETS-VWF73 assay. VWF:Ag and FVIII:C were measured using immunoassay and one-stage clotting assay (ACL TOP analyzer), respectively. Quartile analyses were performed to evaluate the individual association between ADAMTS13 activity, VWF:Ag, FVIII:C and DVT. The combined effect of high VWF levels ( 4th quartile) and low ADAMTS13 levels (< 1st quartile) was evaluated using binary variables. All models were ageand sex-adjusted. Estimated risks were reported as Odds ratio (OR) with 95% confidence intervals (CI).Results: ADAMTS13 activity was lower in DVT patients (94% vs. 98% of controls). Patients with an ADAMTS13 activity

We investigated longitudinally the behaviour of anti-factor VIII (anti-FVIII) IgG subclasses for 6 months from inhibitor development in 43 patients from the Survey of Inhibitors in Plasma-Products Exposed Toddlers (SIPPET) trial who developed persistent or transient inhibitors. We first analysed 43 patients within 60 days post inhibitor detection. Then, 14 of these 43 patients were studied at five time points over 6 months. Our study showed that during the first 60 days, the risk of inhibitor persistence increased with the concomitant presence of an increasing number of IgG subclasses. Over the 6-month period post inhibitor detection, only the IgG2 subclass could be considered a hallmark of inhibitor persistence.

Summary Background Inherited quantitative (type I) deficiency of plasma antithrombin is associated with a high risk of venous thromboembolism, which further increases in pregnancy. Inherited thrombophilia also increases the risk of obstetrical complications, but data on maternal and fetal outcomes in women with antithrombin deficiency are scarce. The aim of this study was to evaluate the risk of pregnancy-associated venous thromboembolism and obstetrical complications in women with type I antithrombin deficiency. Methods In this single-centre, retrospective cohort study, women who had been referred to our Hemophilia and Thrombosis Centre, Milan, Italy for a thrombophilia work-up from Jan 1, 1980, to Jan 1, 2018, with type I antithrombin deficiency and who had had at least one pregnancy were included. Women with type II anthithrombin deficiency were excluded from the study. Data on pregnancy-associated venous thromboembolism, pregnancy outcomes, and the use of low-molecular-weight heparin (LMWH) were collected to evaluate the risk of pregnancy-associated venous thromboembolism and obstetrical complications with or without use of LMWH. Findings 126 women had been referred to the hospital, of whom 88 (70%) had had at least one pregnancy. Eight were excluded because of referral for venous thromboembolism during pregnancy or the puerperium, resulting in 80 (63%)women evaluated for the risk of venous thromboembolism. One woman was excluded because of referral for obstetrical complications, resulting in 87 (69%) evaluated for risk of obstetrical complications. We observed three events of venous thromboembolism in 43 pregnancies in women treated with LMWH (7·0%, 95% CI 1·8–17·8), and 17 events in 146 pregnancies in women who did not receive LMWH (11·6%, 7·2–17·6; relative risk [RR] 0·6, 95% CI 0·2–1·9; p=0·57). The risk of venous thromboembolism without LMWH was 5·4% (95% CI 0·9–16·7) in women with a negative family history of venous thromboembolism, and 11·8% (6·4–19·6) in those with a positive family history of venous thromboembolism. Of the 87 women evaluated for the risk of obstetrical complications, miscarriages occurred in 6 (13%) of 45 pregnant women treated with LMWH and 32 (20%) of 161 women who did not receive LMWH (terminations excluded). Late obstetrical complications occurred in 11 (24%) of women treated with LMWH and nine (6%) in those who did not receive LMWH (RR 4·4, 95% CI 1·9–9·9; p=0·0006). Interpretation Our results confirm that women with type I antithrombin deficiency have a high risk of first or recurrent venous thromboembolism during pregnancy. The risk of venous thromboembolism is highest in women with a positive family history of the condition, but still relevant in those with a negative family history, suggesting that LMWH prophylaxis should also be considered in these patients. Funding None.

Essentials The role of cerebral venous thrombosis (CVT) recanalization on neurologic outcome is still debated. We studied a large cohort of 508 CVT patients with 419 patient years of radiological follow-up. Recanalization rate is high during the first months after CVT and neurologic outcome is favorable. High recanalization grade of CVT independently predicts good neurological outcome. Summary: Background Studies with limited sample size and with discordant results described the recanalization time-course of cerebral venous thrombosis (CVT). The neurological outcome after a first episode of CVT is good, but the role of recanalization on neurological dependence is still debated. Objectives The aim of the study is to assess the recanalization rate after cerebral venous thrombosis (CVT) and its prognostic role in long-term neurological outcome. Patients/Methods In a retrospective observational multicenter cohort study, patients with an acute first episode of CVT with at least one available imaging test during follow-up were enrolled. Patency status of the vessels was categorized as complete, partial or not recanalized. Neurological outcome was defined using the modified Rankin scale (mRS) as good (mRS = 0–1) or poor (mRS = 2–6). Results Five-hundred and eight patients (median [IQR] age, 39 [28.5–49] years; 26% male) were included. Complete or partial recanalization was not differently represented in patients undergoing scans at different periods of time (from 28-day to 3 month-period up to a 1–3 year-period). mRS at the time of follow-up imaging was available in 483 patients; 92.8% of them had a mRS of 0-1. CVT recanalization (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.59–4.13) was positively associated, whereas cancer (OR, 0.29; 95% CI, 0.09–0.88), and personal history of venous thromboembolism (VTE) (OR, 0.36; 95% CI, 0.14–0.92) were negatively associated as independent predictors of favorable (mRS = 0–1) outcome at follow-up. Conclusions Most patients with a first CVT had complete or partial recanalization at follow-up. Recanalization was independently associated with a favorable neurological outcome.

Background Red cell distribution width (RDW) is a marker of cardiovascular diseases and venous thromboembolism, but its role in cerebral vein thrombosis (CVT) is unknown. Aims To investigate whether high values of RDW are associated with an increased risk of CVT. Methods A case–control study of CVT patients (≥ 18 years-old) referred to our center contrasted with healthy individuals. Odds ratios (ORs) were calculated for RDW values > 90th percentile by multivariable logistic regression and adjusted for demographic characteristics, hemorheological parameters, renal function, fibrinogen and CRP. Quartiles based on the distribution of RDW values were used in an additional model to assess a dose–response relationship. The risk of CVT associated with the combined presence of high RDW and either thrombophilia abnormalities or oral contraceptive use was also estimated. Results 143 cases (median age 36 years, 18–79) and 352 controls (42 years, 18–80) were investigated. RDW values > 90th percentile (> 14.6%) were associated with an increased risk of CVT (OR 2.44, 95% CI 1.39–4.28). The association remained after further adjustment for hemorheological parameters (OR 3.73, 95% CI 1.72–8.09), inflammatory markers (OR 3.77, 95% CI 1.72–8.25) and renal function (OR 3.62, 95% CI 1.53–8.55). The risk appeared restricted to these extreme levels (> 14.6%), as there was no graded association between values of RDW and CVT risk over quartiles. There was a synergistic effect on the risk of CVT for the combination of high RDW and thrombophilia abnormalities (OR 33.20, 95% CI 6.95–158.55) or oral contraceptive use (OR 37.99, 95% CI 8.78–164.45). Conclusions Values of RDW > 90th percentile are associated with CVT.

Introduction Oral contraceptive (OC) use increases the risk of venous thromboembolism (VTE), but the effect of duration of use remains to be elucidated. Patients and methods This case-control study was aimed to investigate the duration of OC use on the risk of VTE according to women age, periods of use, prevalence of other risk factors and the role of thrombophilia abnormalities. Seven-hundred patients and 209 controls who used OC were stratified into short users (≤ 1 year), long users (1 to 5 years), and very long users (> 5 years). Results and conclusions Compared to non-users, the odds ratio (OR) for VTE was 9.0 (95% CI 6.9–12.2) in short, 6.5 (95% CI 4.8–83.7) in long and 5.9 (95% CI 4.4–8.1) in very long users. The risk of VTE in short users was highest in women ≤ 30 years and in the first year of use (OR 13.1, 95% CI 7.7–22.4) and decreased afterward (OR 7.7, 95% CI 5.0–11.9). This trend was not observed in women > 30 years. Compared to non-carriers and non-users, a joint effect of thrombophilia abnormalities and OC use on VTE risk was observed particularly in short users (OR 62.2, 95% CI 29.8–129.6), but also afterward (OR 25.4, 95% CI 16.5–39.2). Other transient risk factors for VTE were present in 25% of very long and 16% of short users. In conclusion, the risk of VTE in OC users decreases over time only before 30 years and in first users. Thrombophilia abnormalities strongly interact with the duration of OC use in determining VTE.

Introduction von Willebrand disease (VWD) is the most common inherited bleeding disorder. The age of bleeding onset is highly variable, also in patients with similar degree of severity. Aim The primary aim of this study was to evaluate whether baseline factor VIII (FVIII) plasma levels correlate with age at first bleeding in patients with extremely low levels of VWF:RCo (

Venous thromboembolism (VTE) is a common complication of cancer that severely increases morbidity and mortality. Patients with intracranial tumors are more likely to develop VTE than patients with cancers at other sites. Conversely, limited tools exist to identify patients with high thrombotic risk. Upon activation, neutrophils release their content through different mechanisms triggering thrombosis. We explored the ability of microRNAs (miRNAs) and plasma markers of neutrophil activation measured before surgery to predict the risk of early post-surgical pulmonary embolism (PE) in glioma and meningioma patients. We recruited and prospectively followed 50 patients with glioma and 50 with meningioma, 34% of whom in each group developed an early objectively-diagnosed post-surgical PE. We measured miRNA expression and neutrophil markers (cell-free DNA, nucleosomes, calprotectin and myeloperoxidase) before surgery. In glioma patients, we adjusted and validated a predictive model for post-surgical PE with 6 miRNAs: miR-363-3p, miR-93-3p, miR-22-5p, miR-451a, miR-222-3p and miR-140-3p (AUC = 0.78, 95% Confidence Interval (CI) [0.63, 0.94]) and another with cfDNA and myeloperoxidase as predictors (AUC = 0.71, 95%CI [0.52, 0.90]). Furthermore, we combined both types of markers and obtained a model with myeloperoxidase and miR-140-3p as predictors (AUC = 0.79, 95%CI [0.64, 0.94]). In meningioma patients we fitted and validated a predictive model with 6 miRNAs: miR-29a-3p, miR-660-5p, miR-331-3p, miR-126-5p, miR-23a-3p and miR-23b-3p (AUC = 0.69, 95%CI [0.52, 0.87]). All our models outperformed the Khorana score. This is the first study that analyzes the capability of plasma miRNAs and neutrophil activation markers to predict early post-surgical PE in glioma and meningioma patients. The estimation of the thrombotic risk before surgery may promote a tailored thromboprophylaxis in a selected group of high-risk patients, in order to minimize the incidence of PE and avoid bleedings.

Background Cerebral vein thrombosis (CVT) is a rare, life-threatening disease affecting one adult per 100,000 per year. Genetic risk factors are deficiencies of the natural anticoagulant proteins antithrombin, protein C, protein S or single nucleotide polymorphisms such as factor V Leiden and prothrombin 20210A. In 20% of patients, the cause of CVT remains unknown. Aim To identify novel genetic risk factors for CVT using targeted next-generation DNA sequencing (NGS). Methods We investigated 171 CVT patients and 298 healthy controls. Patients were selected using the following criteria: objective diagnosis of CVT, no active cancer. We performed targeted NGS analysis of the protein-coding regions of 734 candidate genes related to hemostasis and inflammation, 150 ancestry informative markers and 28 thrombosis-associated variants. Results We identified 3723 common and low frequency variants with minor allele frequency (MAF) >1% in 590 genes. Single variant association testing using logistic regression analysis identified rs8176719 insertion/deletion (indel) variant in the ABO gene associated with CVT (age and sex adjusted OR 2.03; 95% CI 1.52–2.73; P = 2.07 × 10−6; Bonferroni P = 0.008). In addition, we identified 8839 rare variants (MAF ≤ 1%) in 723 genes. Gene-based association analysis of these rare variants using a burden test revealed only a tentative association of non-coding variants located in the F8 locus with CVT. Conclusion Targeted NGS identified a common indel variant rs8176719 in the ABO gene. Gene-based tests of association failed to reveal genomic loci with a cumulative burden of rare variants associated with CVT.

An increased von Willebrand factor propeptide (VWFpp) to VWF antigen (VWF:Ag) ratio (VWFpp/VWF:Ag) indicates an enhanced clearance of VWF. This finding has been described in von Willebrand disease (VWD) and in acquired von Willebrand syndrome (AVWS). A distinction between these two diseases, one congenital and the other acquired, is primarily based on family and personal history of bleeding. However, if this information is scanty, the diagnosis might be challenging due to the lack of an effective diagnostic biomarker. In this cross-sectional study, we assessed the ability of VWFpp/VWF:Ag for the differential diagnosis between VWD and AVWS. VWFpp/VWF:Ag was measured in a group of 153 patients (125 with VWD and 28 with AVWS). Most patients with AVWS and VWD showed an increased VWFpp/VWF:Ag, although to variable degrees. A marked increase of VWFpp/VWF:Ag was mainly associated with the diagnosis of AVWS and VWD type 1 Vicenza. A receiver operating characteristic curve was used to identify the optimal cutoff of VWFpp/VWF:Ag for discrimination of patients with a modestly increased (most VWD cases) versus those with a markedly increased clearance (AVWS and VWD type 1 Vicenza), and this cutoff was identified at the value of 3.9 (sensitivity: 0.70, specificity: 0.97). The ROC curve sorting from a logistic model containing VWFpp/VWF:Ag, age, and sex had an area under the curve (AUC) of 0.88 (95% confidence interval: 0.80–0.95). A subsequent molecular evaluation discriminated VWD type 1 Vicenza from AVWS. In conclusion, VWFpp/VWF:Ag appears helpful to discriminate patients with a markedly increase VWF clearance (AVWS or VWD type 1 Vicenza) from those with a modestly increased clearance (most VWD patients).

Essentials Ehlers-Danlos Syndrome (EDS) is a rare heterogeneous group of inherited collagen disorders. A cohort of EDS patients was investigated for bleeding tendency and hemostatic abnormalities. EDS is associated with an increased risk of bleeding. EDS patients have platelet function abnormalities, whose severity correlates with bleeding risk. SUMMARY: Background Ehlers-Danlos syndrome (EDS) includes a heterogeneous group of connective tissue disorders affecting skin, bones, vessels, and other organs. Patients with EDS have an increased risk of bleeding, but a comprehensive study of hemostasis in EDS patients is lacking. Objective To investigate the bleeding tendency of a cohort of patients with EDS by using the Bleeding Assessment Tool of the ISTH, the bleeding severity score (BSS). Methods The BSS was defined as abnormal when it was ≥ 4 in men and ≥ 6 in women. Patients with a bleeding tendency were compared with those without in terms of type and number of hemostatic abnormalities. Results Fifty-nine of 141 patients with EDS (41.7%) had an abnormal BSS. Prothrombin time and activated partial thromboplastin time were slightly prolonged in 10 patients (7.1%) because of mild coagulation factor deficiencies, which were not responsible for the bleeding diathesis. von Willebrand factor antigen, ristocetin cofactor, endogenous thrombin potential and platelet count were normal in all patients. At least one platelet function abnormality was found in 53 patients (90%) with an abnormal BSS and in 64 (78%) with a normal BSS (adjusted odds ratio [OR] 2.55, 95% confidence interval [CI] 0.87-7.48). The risk of bleeding progressively increased with the number of platelet function abnormalities, reaching an OR of 5.19 (95% CI 1.32-20.45) when more than three abnormalities were detected. Conclusions Our results show that nearly half of patients with EDS have an abnormal BSS, which, in 90% of cases, appear, at least in part, to be attributable to platelet function abnormalities. Abnormalities of primary hemostasis may contribute to the risk of bleeding in patients with EDS.

Background Acute pulmonary embolism (PE) is burdened by high mortality, especially within 30 days from the diagnosis. The development and the validation of predictive models for the risk of early mortality allow to differentiate patients who can undergo home treatment from those who need admission into intensive care units. Methods To validate the prognostic model for early mortality after PE diagnosis proposed by the European Society of Cardiology (ESC) in 2014, we analyzed data of a cohort of 272 consecutive patients with acute PE, observed in our hospital during a 10-year period. Moreover, we evaluated the additional contribution of D-dimer, measured at PE diagnosis, in improving the prognostic ability of the model. All cases of PE were objectively diagnosed by angiography chest CT scan or perfusion lung scan. Results The overall mortality rate within 30 days from PE diagnosis was 10% (95% confidence interval [CI]: 6.4–13.5%). According to the ESC prognostic model, the risk of death increased 3.23 times in the intermediate-low-risk category, 5.55 times in the intermediate-high-risk category, and 23.78 times in the high-risk category, as compared with the low-risk category. The receiver operating characteristic analysis showed a good discriminatory power of the model (area under the curve [AUC] = 0.77 [95% CI: 0.67–0.87]), which further increased when D-dimer was added (AUC = 0.85 [95% CI: 0.73–0.96]). Conclusion This study represents a good validation of the ESC predictive model whose performance can be further improved by adding D-dimer plasma levels measured at PE diagnosis.

Summary Background Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Type 2B patients can be discriminated from other qualitative VWD variants by using ristocetin-induced platelet agglutination (RIPA) test. The major limitation of RIPA is the requirement of fresh blood sample. Objectives In this study, we evaluated the VWF gain-of-function mutant GPIb binding (VWF:GPIbM) and VWF:RCo assays to investigate whether the VWF:GPIbM/VWF:RCo ratio was able to identify the type 2B variant among an heterogeneous VWD population, previously characterized following the ISTH-SSC guidelines. Patients/methods Seventy-six VWD patients and 31 healthy subjects were evaluated by using VWF:Ag, VWF:RCo, and VWF:GPIbM assays. Results The mean (minimum–maximum values) VWF:GPIbM/VWF:RCo ratio was higher in type 2B patients (2.53, 0.84–6.11) than in healthy controls (1.05, 0.87–1.34), type 1 (0.85, 0.51–1.15), 2A (1.20, 0.36–2.82), and 2M (1.07, 0.91–1.38) (P

Background An association between high red cell distribution width (RDW) and venous thromboembolism (VTE) has been observed. However, it is not known whether this association differs within various manifestations of VTE, nor if there is an interaction between RDW and thrombophilia abnormalities on the risk of VTE. Aims To investigate whether RDW is a marker of the risk of VTE; to identify subgroups of patients in which the association between RDW and VTE is stronger; to investigate a possible interaction between RDW and thrombophilia abnormalities. Methods Case–control study on 730 patients with a first objectively-confirmed VTE episode (300 unprovoked and 430 provoked) consecutively referred to our Center between 2007 and 2013, and 352 healthy controls. Blood was taken for a thrombophilia work-up and a complete blood count, including RDW, at least three months after VTE. Results Individuals with RDW above the 90 th percentile (> 14.6%) had a 2.5-fold increased risk of VTE compared to those with RDW ≤ 90 th percentile, independently of age, sex, body mass index, other hematological variables and renal function (adjusted odds ratio: 2.52 [95%CI:1.42-4.47]). The risk was similar for unprovoked and provoked VTE, and slightly higher in patients with pulmonary embolism (adjusted odds ratio 3.19 [95%CI:1.68-6.09]) than in those with deep vein thrombosis alone (2.29 [95%CI:1.22-4.30]). No interaction between high RDW and thrombophilia abnormalities on the risk of VTE was observed. Conclusion Our findings confirm RDW as an independent and easily available marker for stratification of the risk of VTE.

Background Sudden sensorineural hearing loss (ISSHL) is idiopathic in 85% of cases and cochlear micro-thrombosis has been hypothesized as pathogenic mechanism. The role of thrombophilia and cardiovascular risk factors in ISSHL is controversial and whether these risk factors influence the clinical outcome of ISSHL is unknown. Methods and patients To investigate the role of thrombophilia and cardiovascular risk factors in ISSHL and to evaluate their influence on clinical outcome of the disease, 118 patients with a first episode of ISSHL and 415 healthy controls were investigated. Thrombophilia screening included measurements of antithrombin, protein C, protein S, factor V Leiden, prothrombin G20210A, antiphospholipid antibodies, fibrinogen, factor VIII and homocysteine. Results Deficiencies of antithrombin, protein C or S taken together, high factor VIII and hyperhomocysteinemia were significantly associated with ISSHL (OR [95%CI]: 7.55 [1.05-54.47], 2.91 [1.31-6.44] and 2.69 [1.09-6.62], respectively), whereas no association was found with the remaining thrombophilia markers. A 2-fold increased risk of poor clinical outcome was observed for every 5 μmol/L increase of fasting homocysteine levels (adjusted OR [95%CI]) 2.13 [1.02-4.44]) until levels of approximately 15 μmol/L, then the risk increased slowly. Cardiovascular risk factors (arterial hypertension, hyperlipidemia, diabetes and smoking) were associated with an increased risk of ISSHL (OR [95%CI] 1.88 [1.17-3.03]) and with a poor clinical outcome (OR [95%CI] 2.22 [0.93-5.26]). Conclusions Hyperhomocysteinemia, high factor VIII and, with more uncertainty, deficiencies of antithrombin, protein C or S and cardiovascular risk factors increase the risk of ISSHL. Hyperhomocysteinemia and cardiovascular risk factors are associated with a poor clinical outcome of ISSHL.

Summary Background In individuals with borderline von Willebrand factor (VWF) plasma levels, second-level tests are required to confirm or exclude von Willebrand disease (VWD). These tests are time-consuming and expensive. Objective To assess which parameters can predict VWD diagnosis in individuals with borderline VWF levels (30–60 IU dL−1). Methods Nine hundred and fifty individuals with bleeding episodes or abnormal coagulation test results were investigated with first-level tests (blood count, prothrombin time, activated partial thromboplastin time, blood clotting factor VIII, VWF ristocetin cofactor activity [VWF:RCo], and VWF antigen), and 93 (62 females and 31 males; median age, 28 years; interquartile range 15–44) had borderline VWF:RCo levels. All underwent second-level investigations to confirm or exclude VWD. A multivariable logistic regression model was fitted with sex, age, bleeding score, family history, VWF:RCo and ABO blood group as predictors, and used to predict VWD diagnosis. Results Forty-five of the 93 individuals (48%) had VWD (84% type 1). A negative linear relationship between VWF:RCo levels and risk of VWD diagnosis was present, and was particularly evident with blood group non-O [adjusted odds ratio 7.00 (95% confidence interval [CI] 1.48–33.11) for every 5 IU dL−1 decrease in VWF:RCo]. The other variable clearly associated with VWD diagnosis was female sex (adjusted odds ratio 5.76 [95% CI 1.47–22.53]). The area under the receiver operating characteristic curve of the full logistic model was 0.89 (95% CI 0.82–0.95). Conclusions In individuals with borderline VWF, the two strongest predictors of VWD diagnosis are low VWF:RCo levels (particularly in those with blood group non-O) and female sex. This predictive model has a promising discriminative ability to identify patients with borderline VWF levels who are likely to have VWD.

High platelet to lymphocyte ratio (PLR) and neutrophil to lymphocyte ratio (NLR) are associated with an increased risk of arterial thrombosis, but their role in venous thromboembolism (VTE) has not been fully investigated. A case–control study, of 486 patients with VTE, 100 with cerebral vein thrombosis (CVT), and 299 healthy individuals, was carried out to investigate whether high PLR or NLR values are associated with an increased risk of VTE. Patients with high PLR or NLR did not have an increased risk of VTE (odds ratio [OR] 0.89, 95% confidence interval [CI]: 0.46-1.76; OR: 0.69, 95% CI: 0.34-1.39, respectively) or CVT (OR: 1.65, 95% CI: 0.68-4.00; OR: 0.39, 95% CI: 0.09-1.72, respectively). Subgroups analysis showed that high PLR values were associated with the risk of provoked CVT (OR: 2.65, 95% CI: 1.02-6.92), and there was an interaction with thrombophilia abnormalities (OR: 7.67, 95% CI: 1.67-35.27) in patients with CVT. In conclusion, high PLR and NLR values are not associated with an overall increased risk of VTE or CVT. High PLR values increase the risk of provoked CVT and interact with thrombophilia abnormalities in patients with CVT.

Background The role of thrombophilic and cardiovascular risk factors in different manifestations of retinal vein occlusion (RVO), i.e., central or branch RVO, and at different ages is still debated. Aims To evaluate the association between thrombophilic and cardiovascular risk factors and the risk of RVO (overall, separately for central and branch RVO, and at different ages). Methods Case-control study on 313 patients with a first objectively-confirmed RVO (216 central and 97 branch RVO) and 415 healthy individuals. Results Antithrombin, protein C or protein S deficiency (adjusted odds ratio [95%CI]: 15.60 [2.01–121]; p = 0.009), hyperhomocysteinemia (HHCy; 3.22 [1.38–7.49]; p = 0.007), high factor VIII (FVIII) levels (3.08 [1.20–7.89]; p = 0.019), factor V Leiden (2.93 [0.97–8.86]; p = 0.058) and the presence of at least one cardiovascular risk factor (1.79 [1.00–3.23]; p = 0.050) were associated with an increased risk of branch RVO. The association was weaker for central RVO, and limited to HHCy (2.15 [1.09–4.24]; p = 0.027) and high FVIII (1.99 [0.90–4.42]; p = 0.091). For HHCy, high FVIII and cardiovascular risk factors the association with the risk of RVO was stronger at an age > 50 years (3.41[1.29–8.99], p = 0.013; 2.57[1.00–6.68], p = 0.050; and 2.03[1.16–3.56], p = 0.013, respectively) than ≤ 50 years (1.93[0.85–4.36], p = 0.114; 1.67[0.54–5.12], p = 0.371; and 1.22[0.73–2.03], p = 0.454, respectively), whereas classic inherited thrombophilia (antithrombin, protein C or protein S deficiencies, factor V Leiden and prothrombin G20210A mutation) was slightly more prevalent at an age ≤ 50 years (1.62 [0.76–3.45], p = 0.210) than > 50 years (1.11[0.44–2.79], p = 0.833). Conclusions Thrombophilic and cardiovascular risk factors are associated with RVO, particularly branch RVO. The risk of RVO associated with HHCy, high FVIII and cardiovascular risk factors is higher at an older age.

Essentials Predicting recurrences may guide therapy after unprovoked venous thromboembolism (VTE). We evaluated the DASH score in 827 patients with unprovoked VTE to verify prediction accuracy. A DASH score ≤ 1 had a cumulative recurrence risk at 1 year of 3.6%, as predicted by the model. The DASH score performed better in younger (< 65 years old) subjects. Summary: Background The DASH prediction model has been proposed as a guide to identify patients at low risk of recurrence of venous thromboembolism (VTE), but has never been validated in an independent cohort. Aims To validate the calibration and discrimination of the DASH prediction model, and to evaluate the DASH score in a predefined patient subgroup aged > 65 years. Methods Patients with a proximal unprovoked deep vein thrombosis (DVT) or pulmonary embolism (PE) who received a full course of vitamin K antagonist or direct oral anticoagulant (> 3 months) and had D-dimer measured after treatment withdrawal were eligible. The DASH score was computed on the basis of the D-dimer level after therapy withdrawal and personal characteristics at the time of the event. Recurrent VTE events were symptomatic proximal or distal DVT/PE, and were analyzed with a time-dependent analysis. Observed 12-month and 24-month recurrence rates were compared with recurrence rates predicted by the DASH model. Results We analyzed a total of 827 patients, of whom 100 (12.1%) had an objectively documented recurrence. As compared with the original DASH cohort, there was a greater proportion of subjects with a ‘low-risk’ (≤ 1) DASH score (66.3% versus 51.6%, P < 0.001). The slope of the observed versus expected cumulative incidence at 2 years was 0.71 (95% confidence interval 0.51–1.45). The c-statistic was lower for subjects aged > 65 years (0.54) than for younger subjects (0.72). Conclusions These results confirm the validity of DASH prediction model, particularly in young subjects. The recurrence risk in elderly patients (> 65 years) was, however, > 5% even in those with the lowest DASH scores.

The influence of thrombosis on the prognosis of patients with hepatocellular carcinoma (HCC) after liver transplantation (LT) and the role of the commonest inherited thrombophilia abnormalities factor V Leiden and prothrombin G20210A in the development of thrombosis are unknown. We investigated a cohort of patients who underwent LT for HCC with the aim to estimate the incidence rate (IR) of thrombosis, its influence on mortality and re-transplantation rates and, in the frame of a nested case-control study, the role of thrombophilia in donors and recipients for the development of thrombosis. Four-hundred and thirty patients underwent LT and were followed for a median of 7.2 years. Twenty-six recipients (6%) developed thrombosis (IR 1.06 [95%CI: 0.71-1.53] per 100 pts-yr). Mortality rate after LT was 3.95 (95%CI: 3.22-4.79) per 100 pts-yr and was not influenced by thrombosis. Re-transplantation was planned for 33 patients and was more common in patients with thrombosis than in those without (HR 2.50 [95%CI: 0.87-7.17]). The risk of thrombosis was 4 times higher in recipients with thrombophilia than in those without (OR 4.23 [95%CI: 0.99-18.04]) and 6 times higher when the analysis was restricted to venous thrombosis (OR 6.26 [95%CI: 1.19-32.85]). The presence of inherited thrombophilia in the donors did not increase the risk of thrombosis of the recipient. In conclusion, thrombosis is a complication of 6% of patients transplanted for HCC and increases the risk of re-transplantation but not of mortality. The risk of thrombosis, particularly venous, is increased in the presence of thrombophilia abnormalities in the recipients.

Analyses of the bleeding tendency by means of the bleeding score (BS) have been proposed until now to confirm diagnosis but not to predict clinical outcomes in patients with inherited von Willebrand disease (VWD). We prospectively followed up, for 1 year, 796 Italian patients with different types of VWD to determine whether the previous BS of European VWD1 is useful to predict the occurrence of spontaneous bleeds severe enough to require replacement therapy with desmopressin (DDAVP) and/or von Willebrand factor (VWF)/factor VIII concentrates. Among the 796 patients included, 75 (9.4%) needed treatment of 232 spontaneous bleeding events. BS10 and VWF:ristocetin cofactor activity10 U/dL were associated with the risk of bleeding, but only a BS10 remained highly associated in a multivariable Cox proportional hazard model (adjusted hazard ratio: 7.27 [95% confidence interval, 3.83-13.83]). Although the bleeding event-free survival was different in VWD types, only a BS10 could predict for each type which patient had bleeding events severe enough to require treatment with DDAVP and/or concentrates. Therefore, BS can be considered a simple predictor of clinical outcomes of VWD and may identify patients needing intensive therapeutic regimens.

BACKGROUND: A bleeding diathesis is a common feature of Noonan syndrome, and various coagulation abnormalities have been reported. Platelet function has never been carefully investigated. METHODS: The degree of bleeding diathesis in a cohort of patients with Noonan syndrome was evaluated by a validated bleeding score and investigated with coagulation and platelet function tests. If ratios of prothrombin time and/or activated partial thromboplastin time were prolonged, the activity of clotting factors was measured. Individuals with no history of bleeding formed the control group. RESULTS: The study population included 39 patients and 28 controls. Bleeding score was ≥2 (ie, suggestive of a moderate bleeding diathesis) in 15 patients (38.5%) and ≥4 (ie, suggestive of a severe bleeding diathesis) in 7 (17.9%). Abnormal coagulation and/or platelet function tests were found in 14 patients with bleeding score ≥2 (93.3%) but also in 21 (87.5%) of those with bleeding score CONCLUSIONS: Nearly 40% of patients with the Noonan syndrome had a bleeding diathesis and >90% of them had platelet function and/or coagulation abnormalities. Results of these tests should be taken into account in the management of bleeding or invasive procedures in these patients.

We report a case of a 6-year-old girl with severe protein S deficiency due to a homozygous mutation and recurrent episodes of skin necrosis. She developed purpura fulminans at birth and a catheter-related venous thrombosis complicated by massive pulmonary embolism at the sixth day of life. Long-term oral anticoagulant therapy with a vitamin K-antagonist was started with a therapeutic range of the international normalized ratio of prothrombin time between 2.0 and 3.0. Unfortunately, this common range was not sufficient because recurrent episodes of warfarin-induced skin necrosis developed if the international normalized ratio was

Summary. Background: Inherited deficiencies of antithrombin (AT), protein C (PC) and protein S (PS) are risk factors for venous thromboembolism (VTE). They are usually defined by laboratory cut-offs (in our setting 81, 70 and 63 IU dL−1, respectively), which give only a rough idea of the VTE risk associated with plasma levels of these proteins. Objectives: We investigated whether the risk of VTE associated with the plasma deficiencies of AT, PC or PS has a dose–response effect, and whether low borderline levels of these proteins are associated with an increased risk of VTE, both in the whole study population and separately in carriers of either factor V Leiden or G20210A prothrombin gene mutation. Patients/Methods: A case–control study of 1401 patients with a first objectively-documented VTE and 1847 healthy controls has been carried out. Results: A dose–response effect on the VTE risk was observed for all the three anticoagulant proteins. Compared with individuals with AT, PC or PS levels > 100 IU/dL, the adjusted odds ratio (95%CI) of VTE was 2.00 (1.44–2.78) for AT levels between 76 and 85 IUdL−1, 2.21 (1.54–3.18) and 1.84 (1.31–2.59) for PC and PS levels between 61 and 75 IUdL−1. The risk of unprovoked VTE in factor V Leiden or prothrombin G20210A carriers appears 2 to 3-fold increased when levels of AT or PS are low borderline. Conclusions: Low borderline plasma levels of AT, PC and PS are associated with a 2-fold increased risk of VTE and should be considered in the assessment of the individual VTE risk.

Summary. Background: It is currently unclear whether or not cerebral venous thrombosis, such as splanchnic venous thrombosis, can be the first manifestation of an underlying myeloproliferative neoplasm. Objective: To determine the prevalence of the JAK2 V617F mutation in patients with a first episode of cerebral venous thrombosis. Patients: In this retrospective cohort study, patients with cerebral venous thrombosis were tested for the JAK2 V617F mutation and were followed until the development of a myeloproliferative neoplasm or censored at the end of follow-up. Results: Ten of 152 patients (6.6%) carried the JAK2 V617F mutation. Three of them had known acquired risk factors for thrombosis, and five had thrombophilia. Six patients met the diagnostic criteria for myeloproliferative neoplasm at the time of cerebral venous thrombosis, and three additional patients developed the disease during the follow-up (median duration 7.8 years, range 6 months to 21.3 years), giving an annual incidence of 0.26% patient-years (95% confidence interval 0.05–0.64). The last patient has no evidence of disease after 3 years of follow-up. Patients without the JAK2 V617F mutation at the time of cerebral venous thrombosis were retested at the end of the follow-up and remained negative, with normal blood counts (log-rank test χ2: 159 [P

Introduction Postpartum hemorrhage is responsible for 25% of maternal pregnancy-related deaths and it is the first cause of maternal morbidity and mortality worldwide. Objective To define the prevalence of postpartum hemorrhage and associated risk factors after vaginal birth and to develop a risk model that improves postpartum hemorrhage prediction. Patients and methods All women who underwent a vaginal delivery at the Obstetric Unit of a large University hospital in Milan (Italy) between July 2007and September 2009 were enrolled. Postpartum hemorrhage was defined as ≥ 500 mL blood loss. A nomogram tailored to predict postpartum hemorrhage was developed, summarizing the impact of each covariate on the probability of postpartum hemorrhage. Results 6011 women were studied (24% had blood loss ≥ 500 mL and 4.8% ≥ 1000 mL). Nulliparity, episiotomy, retained placenta and high neonatal body weight were confirmed as risk factors for postpartum hemorrhage. The odds ratio of postpartum hemorrhage was 0.86 (95%CI 0.78-0.90) for each 1 gr/dL increase in ante-partum hemoglobin. An extensive internal validation of the developed nomogram demonstrated a good stability of the risk model. Conclusions Low ante-partum hemoglobin is a new potentially modifiable risk factor for postpartum hemorrhage. A nomogram to predict the probability of postpartum hemorrhage is now available for external validation.

von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by quantitative or qualitative defects of von Willebrand factor (VWF). VWF, synthesized by endothelium and megakaryocytes (MK), circulates in plasma and is present in subendothelium and platelets. Circulating endothelial cells (CEC) and progenitor endothelial cells (EPC) have been recently proposed as markers of peripheral and bone marrow-derived angiogenesis. To evaluate the association of CEC/EPC with known inherited defects of cellular and circulating VWF, we have measured the number of CEC/EPC together with cytokines involved in angiogenesis in different VWD types. A group of 74 patients was composed by the following VWD types: VWD1 (n = 22), VWD2A (n = 9), VWD2B (n = 19), VWD2M (n = 17), and VWD3 (n = 7). Healthy individuals (n = 20) were used as controls. CEC (CD146+, CD31+, and CD45−) and EPC (CD34+, CD133+, and CD45−) were evaluated by flow cytometry. Circulating serum levels of VEGF, E-selectin, P-selectin, EPO, and TPO were determined by ELISA. CEC, VEGF, E-selectin, and EPO were higher and EPC lower in VWD patients than in controls (P < 0.01). Among the five groups of VWD patients and controls, a significant difference was found for CEC (one-way ANOVA: P = 0.005), EPC (P = 0.001), E-Selectin (P < 0.0001), EPO (P = 0.021), and TPO (P = 0.004): the latter was high in VWD3 patients. In VWD1, we found an inverse relationship between CEC and VWF:Ag levels (P = 0.048; R2 = 0.19). Based on these data, CEC are increased in VWD and are associated with the high levels of cytokines involved in angiogenesis (up-regulation). EPC are decreased, suggesting down-regulation of bone marrow-derived angiogenesis in VWD. Am. J. Hematol. 2011. © 2011 Wiley-Liss, Inc.