OBJECTIVES:Identifying robust biomarkers reflecting thromboinflammation, endothelial injury, angiogenesis, and fibrosis that predict clinical recovery remains challenging. Although several biomarkers are associated with disease severity, the added value of their longitudinal dynamics beyond established markers is unclear. We assessed the association between biomarker trajectories and time to hospital discharge in hospitalized patients with COVID-19. METHODS:We analyzed hospitalized adults with PCR-confirmed SARS-CoV-2 infection enrolled in the DisCoVeRy randomized trial. Blood samples were collected at baseline and days 3, 5, 8, and 11 to measure D-dimer and 12 biomarkers. The primary outcome was time to hospital discharge by day 29, with death as a competing risk. Bayesian joint models combining linear mixed-effects models for biomarker trajectories and cause-specific Cox models were adjusted for baseline severity, ISARIC 4C score, and treatment arm. Models included D-dimer alone and each biomarker added individually. Results are reported as adjusted hazard ratios (aHR) with 95% credibility intervals (CrI). RESULTS:Of the 603 participants randomized, 492 had at least one sample measured, 32% (155/492) had a severe disease, and 5.5% (27/492) died before day 29. Of all biomarkers, only soluble ST2 (sST2) was still associated with time-to-discharge in multivariate analysis after adjusting baseline covariates (aHR: 0.26, 95% CrI: [0.17-0.41], P<10-4). A level of sST2 twice as high leads to a 33% (95% CrI: [24%;41%]) lower instantaneous probability of discharge. D-dimer was significantly associated with time-to-discharge in the null model (0.37 [0.23-0.58], P<10-4), but not when including sST2 (0.68 [0.42-1.07], P=0.09). CONCLUSION:Longitudinal sST2 dynamics were associated with delayed hospital discharge before day 29 and provided better prognostic information than D-dimer. By integrating signals of inflammation, endothelial injury, and tissue remodeling, sST2 may serve as a biomarker of impaired recovery and a potential tool for risk stratification and clinical decision support. External validation by prospective studies is needed to confirm our findings.

BACKGROUND:Soluble ST2 (sST2), the circulating decoy receptor of interleukin-33 (IL-33), has been validated as a prognostic biomarker of disease severity and vascular injury during acute COVID-19. However, its relevance in the context of post-acute sequelae of SARS-CoV-2 infection (PASC or long COVID) remains unclear. METHODS:We analyzed the association between plasma sST2 concentrations and clinical or vascular features in a prospective cohort of 137 long COVID patients (median age: 55 years; 49.6% male), encompassing 194 follow-up visits conducted 3 to 24 months after infection. Fatigue and dyspnea were systematically assessed, alongside full pulmonary function testing (PFTs), including diffusing capacity of the lung for carbon monoxide (DLCO). Plasma concentrations of sST2, VEGF-A, von Willebrand factor antigen (VWF: Ag) and circulating endothelial cells (CECs) were measured. RESULTS:sST2 concentrations were significantly elevated in hospitalized patients during the acute phase of COVID-19 compared to healthy controls (P<0.001), but returned to baseline concentrations during the post-acute phase and remained stable across follow-up timepoints (3, 6, 12, and 24 months; P=0.11). sST2 was not associated with initial COVID-19 severity (P=0.13), nor with persistent symptoms including fatigue (P=0.11) or dyspnea (P=0.49), or with reduced DLCO (P=0.32) or abnormal PFTs (P=0.55). No correlation was found with VEGF-A, CECs, VWF: Ag, or D-dimers. CONCLUSION:Although sST2 is a robust biomarker of acute COVID-19 severity, it does not reflect persistent endothelial dysfunction or symptom burden in long COVID. These findings suggest IL-33/sST2-independent mechanisms may underlie chronic vascular injury in PASC.

COVID-19 pandemic has significantly impacted global health, particularly evident in the detection of lung lesions via chest computed tomography scans. This study investigates the role of biomarkers in lung injury among COVID-19 patients and patients with idiopathic pulmonary fibrosis (IPF). This single-center prospective study included 154 hospitalized and 10 outpatient COVID-19 patients, 62 IPF patients, and 40 healthy volunteers, and evaluated biomarkers of alveolar epithelial cell dysfunction, extracellular matrix (ECM) and fibroblast dysfunction, and macrophage/monocyte activation (Galectin-3, CXCL13). Findings were further validated in an independant confirmation cohort (DisCoVeRy trial). COVID-19 patients had higher levels of biomarkers compared to healthy controls, except for SP-D. Compared to IPF patients, COVID-19 patients had significantly higher plasma levels of OPN, Galectin-3 and CXCL13 at admission. Elevated CXCL13 and Galectin-3 levels in COVID-19 were associated with greater lung injury. Multivariate logistic regression and Kaplan Meier analysis confirmed the role of CXCL13 in predicting severe lung injury (odd ratio 3.17, 95% CI 1.03-9.76) and in-hospital mortality (p = 0.04), with consistent results observed in the confirmation cohort. COVID-19 is characterized by increased ECM and macrophage activation biomarkers compared with IPF. CXCL13 may serve as a relevant biomarker for assessing lung injury and improving risk stratification at hospital admission.

Platelet activation is crucial for hemostasis and thrombosis, particularly in patients on antiplatelet therapy. Managing bleeding risk during cardiac surgery requires understanding platelet dynamics, especially when antiplatelet agents are maintained until the coronary artery bypass surgery (CABG). to explore the relevance of plasma levels of sCD40L, sP-Selectin, PF4, and NAP-2 in predicting bleeding events during CABG in patients under dual antiplatelet therapy (clopidogrel+aspirin, DAPT) or aspirin. Platelet reactivity before CABG was assessed in 143 patients by plasma levels of sCD40L, sP-Selectin, PF4, and NAP-2 as well as platelet aggregation tests and platelet membrane expression of P-Selectin. Postoperative bleeding was monitored at 24 h with the chest tube blood output. Patients receiving DAPT demonstrated markedly reduced plasma levels of PF4 and NAP-2 compared to patients on aspirin alone (PF4: 676 vs. 992 ng/ml, p < 0.001; NAP-2: 167 vs. 281 ng/ml, p < 0.001). PF4 and NAP-2 levels correlated with 10 and 20 µM ADP-induced and collagen-induced platelet aggregation (p = 0.01) but not with arachidonic acid or PAR1ap as agonists. Platelet membrane P-Selectin expression before CABG was significantly correlated with PF4 and NAP-2 levels (r = 0.26, p < 0.001 for PF4, r = 0.23, p = 0.01 for NAP-2), confirming its role in reflecting basal platelet activation. sP-Selectin and sCD40L showed no significant correlation with any clinical outcomes, treatment group or platelet activation test whereas PF4 and NAP-2 were independently correlated with increased 24-hour bleeding volume (PF4: r =-0.19 p = 0.03; NAP-2: r=-0.17 p = 0.04). PF4 is the most platelet-specific biomarker for predicting platelet reactivity and bleeding in patients receiving DAPT until the CABG. Plasma PF4 quantification could provide a simpler alternative to aggregation tests for predicting platelet reactivity, postoperative bleeding and could guide perioperative antiplatelet management.

This study explores the concentration, size, and epitope profiles of extracellular vesicles (EVs) as biomarkers for COVID-19 outcomes. CD86 stood out as a key predictor of mortality, suggesting that EV profiling could help assess disease severity and guide treatment decisions.BackgroundSARS-CoV-2 infection triggers a complex array of immune and vascular responses. Extracellular vesicles (EVs) have emerged as critical players in the disease’s progression and potential biomarkers for assessing severity.AimTo explore the concentration, size, and epitope profiles of EVs in COVID-19 patients and correlate these findings with clinical outcomes.MethodsWe analyzed EVs from 80 COVID-19 patients (critical or non-critical). EV concentration and size were measured using Nanoparticle Tracking Analysis (NTA) and Videodrop, while antigen expression was assessed via a 37-marker MACSPlex bead assay.ResultsOur findings reveal a significant elevation in circulating EV concentration in critical COVID-19 patients as measured by Videodrop (p = 0.007), though not by NTA (p = 0.063), highlighting method-specific sensitivities. Key EV surface markers, including CD86, CD8, CD326, CD209, and CD9, were significantly higher in critical patients, while CD19 was reduced. Kaplan-Meier survival analysis showed that higher expression levels of several EV markers, including CD86, were associated with decreased survival. Among these, CD86 emerged as the most potent independent predictor of in-hospital mortality, regardless of inflammatory status.ConclusionThis study highlights the importance of CD86-expressing EVs as biomarkers for COVID-19 severity and mortality, suggesting that EV profiling could inform personalized therapies for severe cases.

Background: The increased interest in anti-platelet factor 4 (PF4)-heparin complex (anti-PF4/H) antibodies following the COVID-19 pandemic has established them as crucial players in immunothrombosis. Objectives: We aimed to investigate the involvement of anti-PF4/H antibodies during COVID-19 and after vaccination, particularly in patients with systemic inflammatory disease (SID). Methods: This retrospective study analyzed the presence of anti-PF4/H antibodies and their ability to induce platelet activation in COVID-19 patients with and without suspected heparin-induced thrombocytopenia (HIT), vaccine-induced immune thrombotic thrombocytopenia (VITT) patients, and in controls and SID patients following COVID-19 vaccination. Results: No significant increase in anti-PF4/H antibody levels was observed during COVID-19 regardless of disease severity. Despite a 2-fold increase in HIT suspicion observed during the pandemic, there was no corresponding increase in HIT diagnoses. Additionally, no significant increase in anti-PF4/H levels was noted after vaccination, even in SID patients. None of the positive anti-PF4/H antibodies detected in COVID-19 or vaccination cohorts induced platelet activation, measured by soluble P-selectin levels and flow cytometry-based on platelet microvesicle generation. Finally, in VITT patients, unlike in HIT patients, anti-PF4/H levels were strongly associated with platelet microvesicle assay and moderately with soluble P-selectin levels. Conclusion: Our study found no significant increase in anti-PF4/H antibodies in COVID-19 or after vaccination, including in SID patients. However, in VITT patients, but not in HIT patients, these antibodies were correlated with platelet activation. This finding suggests that anti-PF4/H antibodies play a different role in the pathophysiology of VITT but that their interest is limited outside clear contexts of HIT/ VITT suspicion.

Valve interstitial cells (VICs) play a critical role in aortic valve calcification and angiogenic processes associated with calcific aortic valve stenosis (CAVS). Within the same valve, VICs from differently calcified regions can exhibit diverse phenotypic and functional properties. We hypothesised that VICs isolated from noncalcified (NC-VICs) and calcified (C-VICs) areas of human aortic valves possess distinct angiogenic characteristics. In this study, we isolated C-VICs and NC-VICs from 23 valves obtained after aortic valve replacement due to CAVS. Both VIC types exhibited similar phenotypes in culture, characterised by morphology, expression of mesenchymal/fibroblastic markers, proliferation and osteogenic differentiation. No significant differences were observed in the secretion of angiogenic factors, including VEGF-A, Ang-1, Ang-2, PlGF, bFGF between NC-VICs and C-VICs. However, when co-injected with endothelial colony-forming cells (ECFCs) into Matrigel implants in vivo in mice, implants containing NC-VICs showed significantly higher microvessel density compared to those with C-VICs (p < 0.001). Additionally, NC-VICs co-cultured with ECFCs expressed significantly higher levels of the perivascular markers αSMA and calponin compared to C-VICs (p < 0.001 and p < 0.05, respectively). In conclusion, our study reveals the heterogeneity in VIC plasticity within the aortic valve during CAVS. The diminished capacity of VICs from calcified areas to differentiate into perivascular cells suggests a loss of function as valve disease progresses. Furthermore, the ability of VICs to undergo perivascular differentiation may provide insights into valve homeostasis, angiogenesis and the exacerbation of calcification.

Pulmonary embolism (PE) is a life-threatening condition with long-term complications, including residual pulmonary vascular obstruction (RPVO). RPVO is associated with an increased risk of venous thromboembolism recurrence, chronic symptoms, and reduced quality of life. We hypothesize that an endothelial activation and vascular injury play a central role in the pathophysiology of RPVO. This prospective monocentric study investigates the potential of circulating biomarkers, including CD34⁺ cells, circulating endothelial cells (CECs), and platelet-derived growth factor BB (PDGF-BB), as indicators of vascular sequelae and predictors of RPVO. We included 56 patients with a first episode of PE. Biomarker levels were measured at PE diagnosis and six months later, coinciding with RPVO assessment using ventilation-perfusion lung scans. This defined groups of patients with (RPVO ≥ 10

BACKGROUND:Endotheliopathy and coagulopathy are known complications of COVID-19, with a significant association with mortality. Although dexamethasone is the standard of care for patients with severe COVID-19, its precise mode of action remains elusive. We aim to investigate the functional consequences of dexamethasone treatment on COVID-19-associated procoagulant endotheliopathy. METHODS:First, during the 7 days after hospitalization, we measured several endothelial and coagulopathy biomarkers in a prospective cohort of patients with COVID-19 with acute respiratory distress syndrome (ARDS) who were either treated or not with both dexamethasone and therapeutic UFH (unfractionated heparin). Second, we developed an in vitro thrombin generation assay on cultured human endothelial cells to measure the ability of stimulated endothelial colony-forming cells to activate coagulation in normal plasma, which is expressed as an endogenous thrombin potential (ETP). RESULTS:Among the cohort of 44 ARDS COVID-19 patients, 23 patients treated with dexamethasone and therapeutic UFH had significantly decreased von Willebrand Factor, Ang-2 (angiopoietin-2), soluble E-selectin, and d-dimer levels over 7 days. To differentiate the effect of UFH and dexamethasone on endotheliopathy, we used the thrombin generation assay and showed that endothelial colony-forming cell stimulation with dexamethasone but not UFH-in addition to a cocktail of proinflammatory cytokines (to mimic the cytokine storm of severe COVID-19)-significantly decreased ETP in comparison to proinflammatory cytokines only. Moreover, in another cohort of 331 patients with COVID-19 of varying severity, the endothelial colony-forming cell stimulation with the plasma of 87 ARDS patients showed significantly higher ETP (1260 nmol/L per minute [interquartile range, 1140-1260]) compared with 75 non-ARDS patients (1024 nmol/L per minute [interquartile range, 915-1200]; P<0.001). Finally, 94 dexamethasone-treated ARDS patients had significantly lower ETP (962.8 nmol/L per minute [interquartile range, 782.9-1112]) in contrast to 75 nondexamethasone-treated ARDS patients (1,260 nmol/L per minute [interquartile range, 1140-1359]; P<0.001). ETP could help predict in-hospital mortality in a Kaplan-Meier estimator analysis (P=0.0002). CONCLUSIONS:Our data suggest that dexamethasone protects against COVID-19 endothelium-induced coagulopathy. These findings are in line with the decreased prevalence of venous thrombosis among hospitalized patients with COVID-19 treated with dexamethasone.

Objective Antiphospholipid syndrome (APS) is an autoimmune disease combining the occurrence of thrombotic and/or obstetric events with the persistent presence of antiphospholipid antibodies (i.e. lupus anticoagulant (LA), anti-cardiolipin (aCL) and anti-beta-2-glycoprotein I (a beta 2GPI) antibodies). Among the autoantibodies regularly found in patients with APS, antiphosphatidylserine/prothrombin (anti-PS/PT) antibodies seem promising because of their high correlation with LA positivity. The main objective of this study was to characterise the population of anti-PS/PT and/or anti-PT- antibody-positive patients in terms of APS severity and organ damage. Methods We performed a prospective, monocentric, descriptive study of patients who had a dosage of IgG and IgG anti-PS/PT between March 2019 and May 2020. Clinical and biological data were collected from 148 patients, 128 had thrombosis including 64 with known APS according to the Sydney criteria, and 20 patients with antiphospholipid-antibody positivity (mainly LA positivity) without clinical manifestation of APS. Cases with active neoplasia including myeloproliferative disorders at the time of inclusion were excluded. Results Anti-PS/PT positive patients did not display any particular thrombotic phenotype but had significantly more renal impairment (renal failure p=0.01 and proteinuria p=0.04), migraine (p=0.03), and thrombocytopenia (p=0.001) than negative patients, notably in the associated-APS patient group. Moreover, tetra-positivity (LA+, aCL+, a2 beta GPI+, and anti-PS/PT+) was associated with more severe APS (thrombotic recurrences, thrombosis under anticoagulant treatment, and a trend of more frequent catastrophic antiphospholipid syndrome). To a lesser extent, a similar phenotype was observed with anti-PT antibody positivity, but the 58.7% agreement with anti-PS/PT antibodies, suggests the presence of common but also specific PS/PT epitopes. Conclusion The increased thrombotic risk associated with the aPS/PT antibodies would justify their testing in all APS patients in complementarity with the conventional anti-phospholipid antibodies to propose the best-adjusted treatment.

This study aimed to assess platelet activation following implantation of the Aeson bioprosthetic total artificial heart (A-TAH). We monitored plasma levels of platelet activation markers in patients receiving A-TAH support (n = 16) throughout the follow-up period. Before implantation, soluble CD40 ligand (sCD40L) levels averaged 3,909.06 pg/ml (standard deviation [SD] = 3,772.37), remaining stable postimplantation at 3,964.56 pg/ml (SD = 2,198.85) during months 1-3 and at 3,519.27 pg/ml (SD = 1,647.04) during months 3-6. Similarly, P-selectin (sP-sel) levels were 35,235.36 pg/ml (SD = 14,940.47) before implantation, stabilizing to 33,158.96 pg/ml (SD = 9,023.11) (1-3 months) and 31,022.58 pg/ml (SD = 9,249.95) (3-6 months). Preimplantation platelet factor 4 (PF4) measured 2,593.47 ng/ml (SD = 2,167.85), remaining consistent at 2,136.10 ng/ml (SD = 1,264.47) (1-3 months) and 1,991.26 ng/ml (SD = 1,234.16) (3-6 months). Levels of neutrophil-activating peptide 2 (NAP2) were also steady, measuring 785.63 ng/ml (SD = 605.26) preimplantation, 935.10 ng/ml (SD = 517.73) at 1-3 months, and 907.21 ng/ml (SD = 501.96) at 3-6 months postimplantation. Importantly, neither aspirin nor heparin treatment affected these platelet biomarker levels. No correlation was observed between platelet activation marker levels and clinical outcomes such as pericardial effusion, nor with the timing of aspirin initiation and drain removal. Our findings confirm that A-TAH does not trigger platelet activation. The lack of association between aspirin, platelet activation, and clinical outcomes suggests the possibility of discontinuing antiplatelet therapy following A-TAH implantation in the future.

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease in which the contribution of vascular alterations remains poorly understood. While most previous studies focused on epithelial and fibroblast dysfunction, recent evidence suggests that endothelial cell injury and vascular remodeling are integral to disease pathogenesis. This study aimed to longitudinally characterize the circulating endothelial compartment in IPF and explore its association with clinical outcomes. In this multicenter substudy of the COFI (COhorte FIbrose) prospective cohort, 95 patients with IPF underwent 243 serial assessments of circulating endothelial biomarkers. These included the quantification of circulating endothelial cells (CECs) using immunomagnetic isolation, and CD34⁺CD45DIM cells, total CD34⁺ cells, and the proportions of CD34⁺KDR⁺ and CD34⁺CD133⁺ subsets within the CD34⁺ population, assessed by flow cytometry. In addition, hematopoietic endothelial progenitor cells (hEPCs) and endothelial colony-forming cells (ECFCs) were measured using standardized culture-based assays. Longitudinal analysis revealed a significant increase in CD34⁺KDR⁺ progenitor cells (p = 0.04) and CECs (p = 0.03) over time. ECFCs showed no significant variation. Higher BMI was associated with lower levels of CD34⁺KDR⁺ cells (p = 0.04), CD34⁺CD133⁺ cells (p = 0.05), whereas ECFCs were undetectable in obese patients (median 0 [0–0], p = 0.063). Multivariate analysis indicated no significant associations between baseline levels of any endothelial biomarkers and progression-free survival, exacerbation, or mortality. To the best of our knowledge, this study provides the first multicenter longitudinal profiling of the circulating endothelial compartment in IPF. Our findings suggest that endothelial dysfunction reflects a chronic, possibly secondary process in IPF rather than a primary driver of fibrosis. Circulating endothelial biomarkers may offer insight into disease activity and therapeutic response.

Hydroxychloroquine (HCQ), long used for its immunomodulatory and vasculoprotective properties in autoimmune diseases such as antiphospholipid syndrome, was among the first drugs evaluated for COVID-19. Given the prominent endothelial dysfunction and coagulopathy in severe COVID-19, we investigated whether HCQ could modulate circulating biomarkers of vascular injury. A longitudinal analysis comparing standard of care (SoC; n = 148) with HCQ plus SoC (n = 145) was conducted within the phase 3, multicenter, open-label, randomized, adaptive, controlled trial DisCoVeRy in hospitalized patients with COVID-19 (NCT04315948), which primary outcome was clinical status at day 15, measured by the WHO 7-point ordinal scale. Biomarkers of endothelial activation and coagulopathy—angiopoietin-2, P-selectin, and D-dimer—were measured on days 1, 3, 5, 8, and 11. Linear mixed-effects models assessed the influence of HCQ and baseline severity on biomarker trajectories. Severe disease at baseline was associated with higher biomarker levels: angiopoietin-2 (p < 10⁻⁵), P-selectin (p < 10⁻⁶), and D-dimer (p < 10⁻⁷). HCQ had no effect on angiopoietin-2 levels over time (0.002 95

We investigated whether baseline levels of biomarkers related to endotheliopathy, thromboinflammation, and fibrosis were associated with clinical outcomes in hospitalized COVID-19 patients. We analyzed the associations between baseline levels of 21 biomarkers and time to hospital discharge and change in NEWS-2 score in patients from DisCoVeRy trial. We fitted multivariate models adjusted for baseline ISARIC 4C score, disease severity, D-dimer values, and treatment regimen. Between March 22 and June 29, 2020, 603 participants were randomized; 454 had a sample collected at baseline and analyzed. The backward selection of multivariate models showed that higher baseline levels of soluble suppressor of tumorigenicity 2 (sST2) and nucleosomes were statistically associated with a lower chance of hospital discharge before day 29 (sST2: aHR 0.24, 95% CI [0.15-0.38], p < 10-9; nucleosomes: aHR 0.62, 95% CI [0.48-0.81], p < 10-3). Likewise, higher levels of baseline sST2 were statistically associated with lower changes in the NEWS-2 score between baseline and day 15 (adjusted beta 4.47, 95% CI [2.65-6.28], p < 10-5). Moreover, we evaluated sST2 involvement in a confirmation cohort (SARCODO study, 103 patients) and found that elevated baseline sST2 levels were significantly associated with lower rates of hospital discharge before day 29 and a higher model performance (AUC at day 29 of 92%) compared to models without sST2. sST2 emerged as an independent predictor of clinical outcomes in two large cohort of hospitalized COVID-19 patients, warranting further investigation to elucidate its role in disease progression and potential as a therapeutic target.

COVID-19 and infectious diseases have been included in strategic development goals (SDG) of United Nations (UN). The SARS-CoV-2 pandemic has unveiled complex pathophysiological mechanisms underpinning COVID-19, notably inducing a systemic acquired vascular hemopathy characterized by endothelial dysfunction and intussusceptive angiogenesis, a rapid vascular remodeling process identified as a hallmark in severe COVID-19 cases affecting pulmonary and cardiac tissues. Stem cell migration have been proposed as significant regulators of this neoangiogenic process. In a monocentric cross-sectional study, through spectral flow cytometry analysis of peripheral blood mononuclear cells, we identified a distinct stem cell subpopulation mobilized in critical COVID-19. Indeed, by an unsupervised analysis generating a UMAP representation we highlighted eleven different clusters in critical and non-critical COVID-19 patients. Only one cluster was significantly associated to critical COVID-19 compared to non-critical patients. This cluster expressed the markers: CD45dim, CD34+, CD117+, CD147+, and CD143+, and were negative for CD133. Higher level of expression of hemangioblast markers CD143 were found in critical COVID-19 patients. This population, indicative of hemangioblast-like cells, suggests a key role in COVID-19-related neoangiogenesis, potentially driving the severe vascular complications observed. Our findings underscore the need for further investigation into the contributions of adult stem cells in COVID-19 pathology, offering new insights into therapeutic targets and interventions.

The assessment of von Willebrand factor (VWF) multimer distribution, particularly following the implantation of circulatory support devices, is a crucial parameter in hemostasis. Our study aimed to evaluate the semi-automated quantification of VWF multimers using the Sebia Hydrasys analyzer. Our analysis focused on quantifying high molecular weight, intermediate weight, and low molecular weight VWF multimers. Electrophoretic migration was performed using the Hydrasys 2 scan, and interpretation was carried out using densitometric analysis with the Phoresis software. The Hydrasys scan 2 successfully separated all the expected VWF multimer profiles based on the type of von Willebrand disease. The analysis revealed that in patients with circulatory support devices, elevated levels of plasma VWF rendered multimer migration unanalyzable using the methodology recommended by the manufacturer. Therefore, adjustment to a 100 % VWF antigenic level improved gel precision. We also suggest using as a standardized control the Cryocheck™ plasma, and have established reference values. Overall, this semi-automated, standardized, and optimized VWF multimer analysis system allows for an effective assessment of the VWF multimeric profile.