Publications

Abstract Background Approximately 15–30% of hospitalized coronavirus disease 2019 (COVID-19) patients develop acute respiratory distress syndrome, systemic tissue injury, and/or multi-organ failure leading to death in around 45% of cases. There is a clear need for biomarkers that quantify tissue injury, predict clinical outcomes, and guide the clinical management of hospitalized COVID-19 patients. Methods We herein report the quantification by droplet-based digital polymerase chain reaction (ddPCR) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNAemia and the plasmatic release of a ubiquitous human intracellular marker, the ribonuclease P (RNase P) in order to evaluate tissue injury and cell lysis in the plasma of 139 COVID-19 hospitalized patients at admission. Results We confirmed that SARS-CoV-2 RNAemia was associated with clinical severity of COVID-19 patients. In addition, we showed that plasmatic RNase P RNAemia at admission was also highly correlated with disease severity (P < .001) and invasive mechanical ventilation status (P < .001) but not with pulmonary severity. Altogether, these results indicate a consequent cell lysis process in severe and critical patients but not systematically due to lung cell death. Finally, the plasmatic RNase P RNA value was also significantly associated with overall survival. Conclusions Viral and ubiquitous blood biomarkers monitored by ddPCR could be useful for the clinical monitoring and the management of hospitalized COVID-19 patients. Moreover, these results could pave the way for new and more personalized circulating biomarkers in COVID-19, and more generally in infectious diseases, specific from each patient organ injury profile.

Abstract Objective: Very small embryonic-like stem cells (VSELs) are multipotent stem cells localized in adult bone marrow (BM) that may be mobilized into peripheral blood (PB) in response to tissue injury. We aimed to quantify VSELs in BM and PB of patients with critical limb ischemia (CLI) and to test their angiogenic potential in vitro as well as their therapeutic capacity in mouse model of CLI. Approach and Results: We isolated BM VSELs from patients with CLI and studied their potential to differentiate into vascular lineages. Flow and imaging cytometry showed that VSEL counts were lower in BM (p<0.001) and higher (p<0.001) in PB from CLI patients compared to healthy controls, suggesting that ischemia may trigger VSELs mobilization in this patient population. Sorted BM-VSELs cultured in angiogenic media acquired a mesenchymal phenotype (CD90+, Thy-1 gene positive expression). VSEL-derived cells had a pattern of secretion similar to that of endothelial progenitor cells, as they released low levels of VEGF-A and inflammatory cytokines. Noteworthy, VSELs triggered post-ischemic revascularization in immunodeficient mice (p<0.05 vs PBS treatment), and acquired an endothelial phenotype either in vitro when cultured in the presence of VEGF-B (Cdh-5 gene positive expression), or in vivo in Matrigel implants (human CD31+ staining in neo-vessels from plug sections). Conclusions: VSELs are a potential new source of therapeutic cells that may give rise to cells of the endothelial lineage in humans. Disclosures No relevant conflicts of interest to declare.

Background: Carmat bioprosthetic total artificial heart (Aeson; A-TAH) is a pulsatile and autoregulated device. The aim of this study is to evaluate level of hemolysis potential acquired von Willebrand syndrome after A-TAH implantation. Methods: We examined the presence of hemolysis and acquired von Willebrand syndrome in adult patients receiving A-TAH support (n=10) during their whole clinical follow-up in comparison with control subjects and adult patients receiving Heartmate II or Heartmate III support. We also performed a fluid structure interaction model coupled with computational fluid dynamics simulation to evaluate the A-TAH resulting shear stress and its distribution in the blood volume. Results: The cumulative duration of A-TAH support was 2087 days. A-TAH implantation did not affect plasma free hemoglobin over time, and there was no association between plasma free hemoglobin and cardiac output or beat rate. For VWF (von Willebrand factor) evaluation, A-TAH implantation did not modify multimers profile of VWF in contrast to Heartmate II and Heartmate III. Furthermore, fluid structure interaction coupled with computational fluid dynamics showed a gradually increase of blood damage according to increase of cardiac output ( P <0.01), however, the blood volume fraction that endured significant shear stresses was always inferior to 0.03% of the volume for both ventricles in all regimens tested. An inverse association between cardiac output, beat rate, and high-molecular weight multimers ratio was found. Conclusions: We demonstrated that A-TAH does not cause hemolysis or AWVS. However, relationship between HMWM and cardiac output depending flow confirms relevance of VWF as a biological sensor of blood flow, even in normal range.

Cogan's syndrome consists of non syphilitic interstitial keratitis associated with vestibuloauditory dysfunction. This syndrome is rare and very few cases have been reported since Cogan's first characterization in 1945. We present the case of a 24-year-oldman with a history of recurrent access of arthralgia and glomerulonephritis. Bilateral corneal disease consists of peripheral whitish patchy opacities in deep stroma. The patient also shows bilateral severe deafness, fever, meningeal and tetrapyramidal syndrome. Ocular involvement responds well to corticosteroids therapy but hearing loss is severe and often irreversible.

Objective The clinical relevance of antiphospholipid antibodies (aPLs) in COVID‐19 is controversial. This study was undertaken to investigate the prevalence and prognostic value of conventional and nonconventional aPLs in patients with COVID‐19. Methods This was a multicenter, prospective observational study in a French cohort of patients hospitalized with suspected COVID‐19. Results Two hundred forty‐nine patients were hospitalized with suspected COVID‐19, in whom COVID‐19 was confirmed in 154 and not confirmed in 95. We found a significant increase in lupus anticoagulant (LAC) positivity among patients with COVID‐19 compared to patients without COVID‐19 (60.9% versus 23.7%; P < 0.001), while prevalence of conventional aPLs (IgG and IgM anti–β 2 ‐glycoprotein I and IgG and IgM anticardiolipin isotypes) and nonconventional aPLs (IgA isotype of anticardiolipin, IgA isotype of anti‐β 2 ‐glycoprotein I, IgG and IgM isotypes of anti–phosphatidylserine/prothrombin, and IgG and IgM isotypes of antiprothrombin) was low in both groups. Patients with COVID‐19 who were positive for LAC, as compared to patients with COVID‐19 who were negative for LAC, had higher levels of fibrinogen (median 6.0 gm/liter [interquartile range 5.0–7.0] versus 5.3 gm/liter [interquartile range 4.3–6.4]; P = 0.028) and C‐reactive protein (CRP) (median 115.5 mg/liter [interquartile range 66.0–204.8] versus 91.8 mg/liter [interquartile range 27.0–155.1]; P = 0.019). Univariate analysis did not show any association between LAC positivity and higher risks of venous thromboembolism (VTE) (odds ratio 1.02 [95% confidence interval 0.44–2.43], P = 0.95) or in‐hospital mortality (odds ratio 1.80 [95% confidence interval 0.70–5.05], P = 0.24). With and without adjustment for CRP level, age, and sex, Kaplan‐Meier survival curves according to LAC positivity confirmed the absence of an association with VTE or in‐hospital mortality (unadjusted P = 0.64 and P = 0.26, respectively; adjusted hazard ratio 1.13 [95% confidence interval 0.48–2.60] and 1.80 [95% confidence interval 0.67–5.01], respectively). Conclusion Patients with COVID‐19 have an increased prevalence of LAC positivity associated with biologic markers of inflammation. However, LAC positivity at the time of hospital admission is not associated with VTE risk and/or in‐hospital mortality.

Background: Pulmonary vasodilators in general and prostacyclin analogues in particular have improved the outcome of patients with pulmonary arterial hypertension (PAH).Endothelial dysfunction is a key feature of PAH and we previously described that circulating endothelial cell (CEC) level could be used as a biomarker of endothelial dysfunction in PAH.We now hypothesized that an efficient PAH-specific vasodilator therapy might decrease CEC level.Methods/Results: CECs were prospectively quantified by immunomagnetic separation with mAb CD146-coated beads in peripheral blood from children with idiopathic PAH (iPAH, n = 30) or PAH secondary to congenital heart disease (PAH-CHD, n = 30): before, after treatment and during follow up.Controls were 23 children with reversible PAH.Oral treatment with endothelin receptor antagonists (ERA) and/or phosphodiesterase 5 inhibitors (PDE5) significantly reduced CEC counts in children.In 10 children with refractory PAH despite oral combination therapy, subcutaneous (SC) treprostinil was added and we observed a significant decrease in CEC counts during the first month of such treatment.CECs were quantified during a 6 to 36 month-follow-up after initiation of SC treprostinil and we found that CEC counts changed over time, with rising counts always preceding clinical deterioration. Conclusion:CECs might be useful as a biomarker during follow-up of pediatric iPAH and PAH-CHD to assess response to treatment and to anticipate clinical worsening.