Publications by authors named "Annabelle Dupont"

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: Several cohort studies have investigated the molecular basis of von Willebrand disease (VWD); very few have focused on the Afro-Caribbean population.

Objectives: To determine the genotypic and phenotypic characterization of VWD in a large cohort of Afro-Caribbean patients living in Martinique.

Materials And Methods: A total of 31 families comprising 63 Afro-Caribbean patients with VWD were enrolled.

View Article and Find Full Text PDF

Heparin-induced thrombocytopenia (HIT) is a severe complication of heparin therapy, frequently associated with thrombosis. Immunoglobulin G (IgG) antibodies to heparin-platelet factor 4 (PF4/H) complexes play a central role in HIT by activating platelets and leukocytes via Fc gamma Receptor IIa (FcγRIIA). However, some patients also develop IgG against unmodified PF4 (anti-PF4), but their implication in the pathophysiology of HIT is unclear.

View Article and Find Full Text PDF

Background: To date, the only effective treatment of severe aortic stenosis is valve replacement. With the introduction of transcatheter aortic valve replacement and extending indications to younger patients, the use of bioprosthetic valves (BPVs) has considerably increased. The main inconvenience of BPVs is their limited durability because of mechanisms similar as the fibro-calcifying processes observed in native aortic stenosis.

View Article and Find Full Text PDF
Article Synopsis
  • Type 2 Normandy von Willebrand disease (VWD2N) is generally seen as a mild bleeding disorder treatable with desmopressin (DDAVP), but the genetic variations among patients, especially the common variant p.Arg854Gln (R854Q), can significantly influence disease severity and treatment response.
  • A study involving 123 VWD2N patients analyzed their phenotype and DDAVP response based on genotype, revealing that those with R854Q alleles exhibited different clinical outcomes and bleeding symptoms compared to those without.
  • The findings indicate that genetic factors, particularly the presence of the R854Q variant, affect factor VIII levels and the efficacy of DDAVP, highlighting the importance of tailored treatment approaches for V
View Article and Find Full Text PDF

In France, both students from medicine and pharmacy background can have access to the residency in laboratory medicine (LM). The current curriculum of LM residency includes an early choice of option after the first two years of residency, which subsequently guides the rest of the training. This study aimed to analyze these choice and motivational factors, since its implementation in 2017.

View Article and Find Full Text PDF

The recreational use of nitrous oxide (N2O) is an emerging public health issue. Chronic N2O abuse may result in various clinical symptoms, encompassing neurological, psychiatric and cardiovascular outcomes. Despite the difficulties for the laboratory investigation of N2O intoxication, there is currently no guidelines in France to help both clinicians and biologists use appropriate biomarkers for the diagnosis and monitoring of patients with clinical symptoms potentially related to N2O intoxication.

View Article and Find Full Text PDF

Clonal hematopoiesis of indeterminate potential (CHIP) is considered as being a novel age-related risk factor for cardiovascular diseases. By capture-sequencing of a 67-gene panel, we established a large spectrum of CHIP in 258 patients with aortic valve stenosis undergoing transcatheter aortic valve replacement (TAVR) and assessed their association with long-term survival after TAVR. One or several CHIP variants in 35 genes were identified in 68% of the cohort, and being the 2 most frequently mutated genes.

View Article and Find Full Text PDF

Background: Thrombocytopenia has been consistently described in patients with extracorporeal membrane oxygenation (ECMO) and associated with poor outcome. However, the prevalence and underlying mechanisms remain largely unknown, and a device-related role of ECMO in thrombocytopenia has been hypothesized. This study aims to investigate the mechanisms underlying thrombocytopenia in ECMO patients.

View Article and Find Full Text PDF

Severe COVID-19 infections are at high risk of causing thromboembolic events (TEEs). However, the usual exams may be unavailable or unreliable in predicting the risk of TEEs at admission or during hospitalization. We performed a retrospective analysis of two centers (n = 124 patients) including severe COVID-19 patients to determine the specific risk factors of TEEs in SARS-CoV-2 infection at admission and during stays at the intensive care unit (ICU).

View Article and Find Full Text PDF

The association between endometriosis and autoimmune diseases is well known, however no acquired platelet function defect has been described so far. We describe the case of two patients with endometriosis associated with an antiplatelet glycoprotein VI (anti-GPVI) antibody. The two women with deep pelvic endometriosis associated with secondary infertility presented a mild bleeding tendency, a deficient platelet aggregation response to collagen, convulxin or CRP and a severe GPVI deficiency.

View Article and Find Full Text PDF

von Willebrand factor (VWF) is a multimeric protein, the size of which is regulated via ADAMTS13-mediated proteolysis within the A2 domain. We aimed to isolate nanobodies distinguishing between proteolyzed and non-proteolyzed VWF, leading to the identification of a nanobody (designated KB-VWF-D3.1) targeting the A3 domain, the epitope of which overlaps the collagen-binding site.

View Article and Find Full Text PDF
Article Synopsis
  • Two patients with relapsed WM and acquired von Willebrand syndrome (AVWS) were treated with ibrutinib, showing rapid effectiveness and safety without any bleeding issues.
  • The treatment normalized von Willebrand factor clearance, suggesting that ibrutinib is a promising option for WM patients with AVWS, indicating a need for further research on its long-term efficacy and safety.
View Article and Find Full Text PDF

Background: Aortic valve stenosis involves inflammation, excess deposition of a collagen-rich extracellular matrix, and calcification. Recent studies have shown that M1 or inflammatory macrophages derived from infiltrating monocytes promote calcification of valvular interstitial cells, the most prevalent cell type of the aortic valve. We hypothesized that valvular interstitial cells could modulate inflammatory macrophages phenotype.

View Article and Find Full Text PDF

Objectives: Intra-device thrombosis remains one of the most common complications during extracorporeal membrane oxygenation (ECMO). Despite anticoagulation, approximately 35% of patients develop thrombi in the membrane oxygenator, pump heads, or tubing. The aim of this study was to describe the molecular and cellular features of ECMO thrombi and to study the main drivers of thrombus formation at different sites in the ECMO circuits.

View Article and Find Full Text PDF

Transcatheter aortic valve replacement (TAVR), as an alternative to open heart surgery, has revolutionized the treatment of severe aortic valve stenosis (AVS), the most common valvular disorder in the elderly. AVS is now considered a form of atherosclerosis and, like the latter, partly of inflammatory origin. Patients with high-grade AVS have a highly disturbed blood flow associated with high levels of shear stress.

View Article and Find Full Text PDF

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection fatality rate (IFR) doubles with every 5 y of age from childhood onward. Circulating autoantibodies neutralizing IFN-α, IFN-ω, and/or IFN-β are found in ∼20% of deceased patients across age groups, and in ∼1% of individuals aged <70 y and in >4% of those >70 y old in the general population. With a sample of 1,261 unvaccinated deceased patients and 34,159 individuals of the general population sampled before the pandemic, we estimated both IFR and relative risk of death (RRD) across age groups for individuals carrying autoantibodies neutralizing type I IFNs, relative to noncarriers.

View Article and Find Full Text PDF

Predictive scores assessing the risk of respiratory failure in COVID-19 mostly focused on the prediction of early intubation. A combined assessment of clinical parameters and biomarkers of endotheliopathy could allow to predict late worsening of acute respiratory failure (ARF), subsequently warranting intubation in COVID-19. Retrospective single-center derivation ( = 92 subjects) and validation cohorts ( = 59 subjects), including severe COVID-19 patients with non-invasive respiratory support, were assessed for at least 48 h following intensive care unit (ICU) admission.

View Article and Find Full Text PDF

Introduction: Coronavirus disease 2019 (COVID-19) can cause life-threatening acute respiratory distress syndrome (ARDS). Recent data suggest a role for neutrophil extracellular traps (NETs) in COVID-19-related lung damage partly due to microthrombus formation. Besides, pulmonary embolism (PE) is frequent in severe COVID-19 patients, suggesting that immunothrombosis could also be responsible for increased PE occurrence in these patients.

View Article and Find Full Text PDF

SARS-CoV-2 infection fatality rate (IFR) doubles with every five years of age from childhood onward. Circulating autoantibodies neutralizing IFN-α, IFN-ω, and/or IFN-β are found in ~20% of deceased patients across age groups. In the general population, they are found in ~1% of individuals aged 20-70 years and in >4% of those >70 years old.

View Article and Find Full Text PDF

Potentially toxic plasticizers are commonly added to polyvinyl chloride medical devices for transfusion in order to improve their flexibility and workability. As the plasticizers are not chemically bonded to the PVC, they can be released into labile blood products (LBPs) during storage. Ideally, LBPs would be used in laboratory studies of plasticizer migration from the medical device.

View Article and Find Full Text PDF