Publications

Abstract Introduction The monitoring of unfractionated heparin (UFH) by anti‐factor Xa activity (AXA) is commonly used to ensure effective anticoagulation and prevent bleeding risk. However, in patients previously treated with an anti‐Xa direct oral anticoagulant (DOAC) switching to UFH therapy, there is a risk of interference that may lead to inappropriate anticoagulation. The first objective of this study was to validate DOAC‐Remove to remove DOAC for measuring UFH specific AXA. The second objective was to assess the length of DOAC interference on UFH monitoring and to identify potential predictive factors. Materials and Methods This monocentric retrospective study included all patients admitted from April 2019 to April 2021 previously treated with anti‐Xa DOAC, and for whom an interference on UFH monitoring was suspected. Interference was defined as a difference in the AXA measured before and after using DOAC‐Remove >2.8‐fold standard deviation of the method. Results Removal with DOAC‐Remove was specific of DOAC (apixaban n = 42, rivaroxaban n = 41, UFH n = 20) and sufficient to avoid interference on UFH AXA measurement. The exact interference length was 6.0 days [IQR 3.0–11.0] for apixaban ( n = 26) and 4.5 days [IQR 2.0–5.8] for rivaroxaban ( n = 20). Among the 89 patients sorted based on an interference length ≤ or >3 days, 74 (83.1%) presented an interference greater than 3 days. Correlations were observed with age for apixaban and creatinine for rivaroxaban. Conclusions Our results suggest that DOAC‐Remove could be of high interest in patients receiving UFH previously treated with an anti‐Xa DOAC even if DOAC was stopped for more than 3 days.

TRIAL REGISTRATION: NCT04420468. OBJECTIVES: Severe acute respiratory syndrome coronavirus 2–related multisystem inflammatory syndrome in children is frequently associated with shock; endothelial involvement may be one of the underlying mechanisms. We sought to describe endothelial dysfunction during multisystem inflammatory syndrome in children with shock and then assess the relationship between the degree of endothelial involvement and the severity of shock. DESIGN: Observational study. SETTING: A PICU in a tertiary hospital. PATIENTS: Patients aged under 18 ( n = 28) with severe acute respiratory syndrome coronavirus 2–related multisystem inflammatory syndrome in children and shock, according to the Centers for Disease Control and Prevention criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Correlations between endothelial marker levels and shock severity were assessed using Spearman coefficient. The median (interquartile range) age was 9 years (7.5–11.2 yr). Sixteen children presented with cardiogenic and distributive shock, 10 presented with cardiogenic shock only, and two presented with distributive shock only. The median left ventricular ejection fraction, troponin level, and lactate level were, respectively, 40% (35–45%), 261 ng/mL (131–390 ng/mL), and 3.2 mmol/L (2–4.2 mmol/L). Twenty-five children received inotropes and/or vasopressors; the median Vasoactive and Inotropic Score was 8 (5–28). Plasma levels of angiopoietin-2 (6,426 pg/mL [2,814–11,836 pg/mL]), sE-selectin (130,405 pg/mL [92,987–192,499 pg/mL]), von Willebrand factor antigen (344% [288–378%]), and the angiopoietin-2/angiopoietin-1 ratio (1.111 [0.472–1.524]) were elevated and significantly correlated with the Vasoactive and Inotropic Score ( r = 0.45, p = 0.016; r = 0.53, p = 0.04; r = 0.46, p = 0.013; and r = 0.46, p = 0.012, respectively). CONCLUSIONS: Endothelial dysfunction is associated with severe acute respiratory syndrome coronavirus 2–related multisystem inflammatory syndrome in children with shock and may constitute one of the underlying mechanisms.

As compared with controls, ECFC-ECs from individuals with VTD have higher oxidative stress, proliferation stress, cellular senescence, and low proliferative potential. These findings suggest that patients with a history of VTD are ECFC-ECs dysfunctional that could be associated to permanent risk for new thrombotic events.

Edoxaban is a direct oral anticoagulant available in Europe but not in France. Given the high tourist traffic in France, understanding the pharmacology of edoxaban and the availability of its laboratory testing seemed crucial in emergency situations. The aim of this work was to describe the methodology for measuring the anti-Xa activity of edoxaban, highlighting pre-analytical and analytical aspects, along with essential clinico-biological data for therapeutic guidance. The analysis was performed using the chromogenic method on the STAR-Max analyzer, with the STA®-Liquid ANTI-Xa kit (Diagnostica Stago®). Anti-Xa Edoxaban level measurement has a detection limit of 15 ng/mL, a quantification limit of 20 ng/mL and a linearity limit of 400 ng/mL. Repeatability, intermediate precision, accuracy, and measurement uncertainty studies were conducted to assess method performance, meeting quality requirements. The comparison between two STAR-Max® analyzers showed excellent results with linear regression and a low bias with good precision and no loss of dispersion regardless of edoxaban levels. In conclusion, although the measurement of edoxaban level may be rarely necessary in clinical practice, its implementation is straightforward. The availability of edoxaban in neighboring countries, underscores the importance of having its measurement available in hospital laboratories.

Abstract Background Microvascular, arterial and venous thrombotic events have been largely described during severe coronavirus disease 19 (COVID-19). However, mechanisms underlying hemostasis dysregulation remain unclear. Methods We explored two independent cross-sectional cohorts to identify soluble markers and gene-expression signatures that discriminated COVID-19 severity and outcomes. Results We found that elevated soluble (s)P-selectin at admission was associated with disease severity. Elevated sP-selectin was predictive of intubation and death (ROC AUC = 0.67, p = 0.028 and AUC = 0.74, p = 0.0047, respectively). An optimal cutoff value was predictive of intubation with 66% negative predictive value (NPV) and 61% positive predictive value (PPV), and of death with 90% NPV and 55% PPV. An unbiased gene set enrichment analysis revealed that critically ill patients had increased expression of genes related to platelet activation. Hierarchical clustering identified ITG2AB , GP1BB , PPBP and SELPLG to be upregulated in a grade-dependent manner. ROC curve analysis for the prediction of intubation was significant for SELPLG and PPBP (AUC = 0.8, p = 0.046 for both). An optimal cutoff value for PBPP was predictive of intubation with 100% NPV and 45% PPV, and for SELPLG with 100% NPV and 50% PPV. Conclusion We provide evidence that platelets contribute to COVID-19 severity. Plasma sP-selectin level was associated with severity and in-hospital mortality. Transcriptional analysis identified PPBP/CXCL7 and SELPLG as biomarkers for intubation. These findings provide additional evidence for platelet activation in driving critical COVID-19. Specific studies evaluating the performance of these biomarkers are required.

Abstract The Aeson® total artificial heart (A-TAH) has been developed as a total heart replacement for patients at risk of death from biventricular failure. We previously described endothelialization of the hybrid membrane inside A-TAH probably at the origin of acquired hemocompatibility. We aimed to quantify vasculogenic stem cells in peripheral blood of patients with long-term A-TAH implantation. Four male adult patients were included in this study. Peripheral blood mononuclear cells were collected before A-TAH implantation (T0) and after implantation at one month (T1), between two and five months (T2), and then between six and twelve months (T3). Supervised analysis of flow cytometry data confirmed the presence of the previously identified Lin − CD133 + CD45 − and Lin − CD34 + with different CD45 level intensities. Lin − CD133 + CD45 − , Lin − CD34 + CD45 − and Lin − CD34 + CD45 + were not modulated after A-TAH implantation. However, we demonstrated a significant mobilization of Lin − CD34 + CD45 dim ( p = 0.01) one month after A-TAH implantation regardless of the expression of CD133 or c-Kit. We then visualized data for the resulting clusters on a uniform manifold approximation and projection (UMAP) plot showing all single cells of the live Lin − and CD34 + events selected from down sampled files concatenated at T0 and T1. The three clusters upregulated in T1 are CD45 dim clusters, confirming our results. In conclusion, using a flow cytometry approach, we demonstrated in A-TAH-transplanted patients a significant mobilization of Lin − CD34 + CD45 dim in peripheral blood one month after A-TAH implantation.

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.