Dysregulated primary hemostasis in critically ill COVID-19 patients (preprint)

Background: Microvascular thrombosis, as well as arterial and venous thrombotic events, have been largely described during severe Coronavirus disease 19 (COVID-19). Therapeutic anticoagulation has been proposed in critical patients, 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 of 150 NC (normalized concentration) 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. Next, an unbiased gene set enrichment analysis revealed that critically ill patients had increased expression of genes related to primary hemostasis. Hierarchical clustering identified ITG2AB, GP1BB, PPBP and SELPLG to be upregulated in a grade-dependent manner. ROC curve analysis for the prediction of mechanical ventilation was significant for SELPLG and PPBP (AUC = 0.8, p = 0.046 for both markers). An optimal cutoff value for PBPP was predictive of mechanical ventilation with 100% NPV and 45% PPV, and for SELPLG was predictive of mechanical ventilation with 100% NPV and 50% PPV.Conclusion: We provide evidence that platelets contribute to disease severity with the identification of sP-selectin as a biomarker for poor outcome. Transcriptional analysis identified PPBP and SELPLG RNA count as biomarkers for mechanical ventilation. These findings provide rationale for novel therapeutic approaches with antiplatelet agents.

D-dimers at hospital admission for COVID-19 are associated with in hospital mortality independently of venous thromboembolism: Insight from a French multicenter cohort study (preprint)

Background: Coronavirus disease 2019 (COVID-19) has been associated with coagulation disorders, in particular high levels of D-dimers, and increased frequency of venous thromboembolism (VTE). We explore the association between D-dimers at admission and in-hospital mortality in hospitalized COVID-19 patients with or without symptomatic VTE.Methods: From February 26 to April 20, 2020, D-dimer level at admission and outcomes of patients hospitalized for COVID-19 in medical wards (in-hospital mortality or VTE) were retrospectively analyzed in a multicenter study in 24 French hospitals.Results: Among 2878 patients enrolled in the study, 1154 (40.9%) patients had D-dimer measurement at admission. A receiver operating characteristic (ROC) curve analysis identified D-dimer level above 1128 ng/mL as the optimum cutoff value to predict in-hospital mortality (Area Under the Curve of 64.9% (95% CI 0.60–0.69) with a sensitivity of 71.1% (95% CI 0.62–0.78) and a specificity of 55.6% (95% CI 0.52–0.58) that not differ in the subgroup of patients with VTE during hospitalization. Among 609 (52.8%) patients with D-dimers level < 1128 ng/mL at admission, only 35 (5.7%) deaths occurred during hospitalization. After adjustment, in a cox proportional hazard and logistic regression models, D-dimers above 1128 ng/mL at admission were also associated to a worth prognosis with a OR of 3.07 (95% CI 2.05–4.69, p < 0.001) and an unadjusted hazard ratio of 2.11 (95%CI 1.31–3.4, p < 0.01).Conclusions: D-dimer level over 1128 ng/mL is a relevant predictive factor for in-hospital mortality in COVID-19 hospitalized patients in medical ward, regardless the occurrence of VTE during hospitalization.