NEUT-SFL in Patients with COVID-ARDS: A Novel Biomarker for Thrombotic Events?

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped RNA virus first identified in December 2019 in Wuhan, China, and responsible for coronavirus disease 2019 (COVID-19). The ongoing COVID-19 pandemic is impacting healthcare worldwide. Patients who develop coagulopathy have worse outcomes. The pathophysiology of COVID-19 suggests a strong interplay between hemostasis and immune cells, especially neutrophils. Our purpose was to assess neutrophil fluorescence as a potential biomarker of deep vein thrombosis (DVT) in patients with COVID-acute respiratory distress syndrome (COVID-ARDS). Sixty-one patients with COVID-ARDS admitted to the four intensive care units (ICUs) of a French general hospital were included in this prospective study. Neutrophil activation was assessed by measuring neutrophil fluorescence (NEUT-Side Fluorescence Light, NEUT-SFL) with a specific fluorescent dye staining analyzed by a routine automated flow cytometer Sysmex XN-3000™ (Sysmex, Kobe, Japan). DVT was diagnosed by complete duplex ultrasound (CDU). We found that NEUT-SFL was elevated on admission in patients with COVID-ARDS (49.76 AU, reference value 46.40 AU, p < 0.001), but did not differ between patients with DVT (49.99 AU) and those without (49.52 AU, p = 0.555). NEUT-SFL is elevated in patients with COVID-ARDS, reflecting neutrophil activation, but cannot be used as a marker of thrombosis. Because neutrophils are at interface between immune response and hemostasis through release of neutrophil extracellular traps, monitoring their activation could be an interesting approach to improve our management of coagulopathy during COVID-ARDS. Further research is needed to better understand the pathophysiology of COVID-19 and identify high-performance biomarkers.

Characterization of pulmonary impairment associated with COVID-19 in patients requiring mechanical ventilation. / Caracterização do comprometimento pulmonar associado à COVID-19 em pacientes com necessidade de ventilação mecânica.

OBJECTIVE: To detect early respiratory and hemodynamic instability to characterize pulmonary impairment in patients with severe COVID-19. METHODS: We retrospectively analyzed data collected from COVID-19 patients suffering from acute respiratory failure requiring intubation and mechanical ventilation. We used transpulmonary thermodilution assessment with a PiCCO™ device. We collected demographic, respiratory, hemodynamic and echocardiographic data within the first 48 hours after admission. Descriptive statistics were used to summarize the data. RESULTS: Fifty-three patients with severe COVID-19 were admitted between March 22nd and April 7th. Twelve of them (22.6%) were monitored with a PiCCO™ device. Upon admission, the global-end diastolic volume indexed was normal (mean 738.8mL ± 209.2) and moderately increased at H48 (879mL ± 179), and the cardiac index was subnormal (2.84 ± 0.65). All patients showed extravascular lung water over 8mL/kg on admission (17.9 ± 8.9). We did not identify any argument for cardiogenic failure. CONCLUSION: In the case of severe COVID-19 pneumonia, hemodynamic and respiratory presentation is consistent with pulmonary edema without evidence of cardiogenic origin, favoring the diagnosis of acute respiratory distress syndrome.

OBJETIVO: Detectar precocemente a instabilidade respiratória e hemodinâmica para caracterizar o comprometimento pulmonar em pacientes com COVID-19 grave. MÉTODOS: Analisamos retrospectivamente os dados colhidos de pacientes com COVID-19 que apresentaram insuficiência respiratória aguda com necessidade de intubação e ventilação mecânica. Utilizamos a avaliação da termodiluição transpulmonar por meio do dispositivo PiCCO™. Foram coletados os dados demográficos, respiratórios, hemodinâmicos e ecocardiográficos dentro das primeiras 48 horas após a admissão. Para resumir os dados, utilizamos estatística descritiva. RESULTADOS: Entre 22 de março e 7 de abril de 2020, foram admitidos 23 pacientes com COVID-19 grave. Foram monitorados com o dispositivo PiCCO™ 12 (22,6%) deles. Quando da admissão, o volume diastólico final global indexado era normal (média de 738,8mL ± 209,2) e, na hora 48, encontrava-se moderadamente aumentado (879mL ± 179), enquanto o índice cardíaco se achava abaixo do normal (2,84 ± 0,65). Todos os pacientes revelaram a presença de água extravascular pulmonar acima de 8mL/kg na admissão (17,9 ± 8,9). Não identificamos qualquer evidência de origem cardiogênica. CONCLUSÃO: No caso de pneumonia grave por COVID-19, o quadro hemodinâmico e respiratório é compatível com edema pulmonar sem evidência de origem cardiogênica, o que favorece o diagnóstico de síndrome do desconforto respiratório agudo.

Clinical characteristics and risk factors associated with severe COVID-19: prospective analysis of 1,045 hospitalised cases in North-Eastern France, March 2020.

BackgroundIn March 2020, the COVID-19 outbreak was declared a pandemic by the World Health Organization.AimOur objective was to identify risk factors predictive of severe disease and death in France.MethodsIn this prospective cohort study, we included patients ≥ 18 years old with confirmed COVID-19, hospitalised in Strasbourg and Mulhouse hospitals (France), in March 2020. We respectively compared patients who developed severe disease (admission to an intensive care unit (ICU) or death) and patients who died, to those who did not, by day 7 after hospitalisation.ResultsAmong 1,045 patients, 424 (41%) had severe disease, including 335 (32%) who were admitted to ICU, and 115 (11%) who died. Mean age was 66 years (range: 20-100), and 612 (59%) were men. Almost 75% of patients with body mass index (BMI) data (n = 897) had a BMI ≥ 25 kg/m2 (n = 661). Independent risk factors associated with severe disease were advanced age (odds ratio (OR): 1.1 per 10-year increase; 95% CrI (credible interval): 1.0-1.2), male sex (OR: 2.1; 95% CrI: 1.5-2.8), BMI of 25-29.9 kg/m2 (OR: 1.8; 95% CrI: 1.2-2.7) or ≥ 30 (OR: 2.2; 95% CrI: 1.5-3.3), dyspnoea (OR: 2.5; 95% CrI: 1.8-3.4) and inflammatory parameters (elevated C-reactive protein and neutrophil count, low lymphocyte count). Risk factors associated with death were advanced age (OR: 2.7 per 10-year increase; 95% CrI: 2.1-3.4), male sex (OR: 1.7; 95% CrI: 1.1-2.7), immunosuppression (OR: 3.8; 95% CrI: 1.6-7.7), diabetes (OR: 1.7; 95% CrI: 1.0-2.7), chronic kidney disease (OR: 2.3; 95% CrI: 1.3-3.9), dyspnoea (OR: 2.1; 95% CrI: 1.2-3.4) and inflammatory parameters.ConclusionsOverweightedness, obesity, advanced age, male sex, comorbidities, dyspnoea and inflammation are risk factors for severe COVID-19 or death in hospitalised patients. Identifying these features among patients in routine clinical practice might improve COVID-19 management.

Macrophage Activation in COVID-19 Patients in Intensive Care Unit.

We report six cases of patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, admitted to intensive care unit (ICU), for whom bone marrow aspirate revealed hemophagocytosis. We compared their clinical presentation and laboratory findings to those that can be encountered during a hemophagocytic lymphohistiocytosis. These observations might evoke a macrophage activation mechanism different from the one encountered in the hemophagocytic lymphohistiocytosis (HLH).