Dexamethasone Modulates the Cytokine Response but Not COVID-19-Induced Coagulopathy in Critically Ill.

Severe forms of coronavirus 2019 (COVID-19) disease are caused by an exaggerated systemic inflammatory response and subsequent inflammation-related coagulopathy. Anti-inflammatory treatment with low dose dexamethasone has been shown to reduce mortality in COVID-19 patients requiring oxygen therapy. However, the mechanisms of action of corticosteroids have not been extensively studied in critically ill patients in the context of COVID-19. Plasma biomarkers of inflammatory and immune responses, endothelial and platelet activation, neutrophil extracellular trap formation, and coagulopathy were compared between patients treated or not by systemic dexamethasone for severe forms of COVID-19. Dexamethasone treatment significantly reduced the inflammatory and lymphoid immune response in critical COVID-19 patients but had little effect on the myeloid immune response and no effect on endothelial activation, platelet activation, neutrophil extracellular trap formation, and coagulopathy. The benefits of low dose dexamethasone on outcome in critical COVID-19 can be partially explained by a modulation of the inflammatory response but not by reduction of coagulopathy. Future studies should explore the impact of combining dexamethasone with other immunomodulatory or anticoagulant drugs in severe COVID-19.

Analytical performance evaluation of bioactive adrenomedullin on point-of-care platform

For matrix comparison, EDTA whole blood samples (freshly collected and stored at 2-8 °C until the testing) from ten healthy donors were spiked with synthetic bio-ADM to achieve two bio-ADM levels per donor spanning the measuring range. The analytical performance evaluation was mainly conducted using frozen and contrived plasma samples and to validate bio-ADM measurements with IB10 sphingotest SP ® sp bio-ADM SP ® sp . Keywords: acute care;bioactive adrenomedullin;critical care biomarker;endothelial function;Nexus IB10;point-of-care platform EN acute care bioactive adrenomedullin critical care biomarker endothelial function Nexus IB10 point-of-care platform e13 e16 4 11/28/22 20230101 NES 230101 To the Editor, Biologically active adrenomedullin (bio-ADM) is a peptide hormone that regulates the endothelial barrier function [[1]], [[2]], [[3]]. [Extracted from the article]

Inflammation-Induced Coagulopathy Substantially Differs Between COVID-19 and Septic Shock: A Prospective Observational Study.

Critical COVID-19, like septic shock, is related to a dysregulated systemic inflammatory reaction and is associated with a high incidence of thrombosis and microthrombosis. Improving the understanding of the underlying pathophysiology of critical COVID-19 could help in finding new therapeutic targets already explored in the treatment of septic shock. The current study prospectively compared 48 patients with septic shock and 22 patients with critical COVID-19 regarding their clinical characteristics and outcomes, as well as key plasmatic soluble biomarkers of inflammation, coagulation, endothelial activation, platelet activation, and NETosis. Forty-eight patients with matched age, gender, and co-morbidities were used as controls. Critical COVID-19 patients exhibited less organ failure but a prolonged ICU length-of-stay due to a prolonged respiratory failure. Inflammatory reaction of critical COVID-19 was distinguished by very high levels of interleukin (IL)-1ß and T lymphocyte activation (including IL-7 and CD40L), whereas septic shock displays higher levels of IL-6, IL-8, and a more significant elevation of myeloid response biomarkers, including Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) and IL-1ra. Subsequent inflammation-induced coagulopathy of COVID-19 also differed from sepsis-induced coagulopathy (SIC) and was characterized by a marked increase in soluble tissue factor (TF) but less platelets, antithrombin, and fibrinogen consumption, and less fibrinolysis alteration. In conclusion, COVID-19 inflammation-induced coagulopathy substantially differs from SIC. Modulating TF release and activity should be evaluated in critical COVID-19 patients.

Development of SARS-CoV2 humoral response including neutralizing antibodies is not sufficient to protect patients against fatal infection.

More than a year after the start of the pandemic, COVID-19 remains a global health emergency. Although the immune response against SARS-CoV-2 has been extensively studied, some points remain controversial. One is the role of antibodies in viral clearance and modulation of disease severity. While passive transfer of neutralizing antibodies protects against SARS-CoV-2 infection in animal models, titers of anti-SARS-CoV-2 antibodies have been reported to be higher in patients suffering from more severe forms of the disease. A second key question for pandemic management and vaccine design is the persistence of the humoral response. Here, we characterized the antibody response in 187 COVID-19 patients, ranging from asymptomatic individuals to patients who died from COVID-19, and including patients who recovered. We developed in-house ELISAs to measure titers of IgG, IgM and IgA directed against the RBD or N regions in patient serum or plasma, and a spike-pseudotyped neutralization assay to analyse seroneutralization. Higher titers of virus-specific antibodies were detected in patients with severe COVID-19, including deceased patients, compared to asymptomatic patients. This demonstrates that fatal infection is not associated with defective humoral response. Finally, most of recovered patients still had anti-SARS-CoV-2 IgG more than 3 months after infection.

Oxidative stress-induced endothelial dysfunction and decreased vascular nitric oxide in COVID-19 patients.

BACKGROUND: SARS-CoV-2 targets endothelial cells through the angiotensin-converting enzyme 2 receptor. The resulting endothelial injury induces widespread thrombosis and microangiopathy. Nevertheless, early specific markers of endothelial dysfunction and vascular redox status in COVID-19 patients are currently missing. METHODS: Observational study including ICU and non-ICU adult COVID-19 patients admitted in hospital for acute respiratory failure, compared with control subjects matched for cardiovascular risk factors similar to ICU COVID-19 patients, and ICU septic shock patients unrelated to COVID-19. FINDINGS: Early SARS-CoV-2 infection was associated with an imbalance between an exacerbated oxidative stress (plasma peroxides levels in ICU patients vs. controls: 1456.0 ± 400.2 vs 436 ± 272.1 mmol/L; P < 0.05) and a reduced nitric oxide bioavailability proportional to disease severity (5-α-nitrosyl-hemoglobin, HbNO in ICU patients vs. controls: 116.1 ± 62.1 vs. 163.3 ± 46.7 nmol/L; P < 0.05). HbNO levels correlated with oxygenation parameters (PaO2/FiO2 ratio) in COVID-19 patients (R2 = 0.13; P < 0.05). Plasma levels of angiotensin II, aldosterone, renin or serum level of TREM-1 ruled out any hyper-activation of the renin-angiotensin-aldosterone system or leucocyte respiratory burst in ICU COVID-19 patients, contrary to septic patients. INTERPRETATION: Endothelial oxidative stress with ensuing decreased NO bioavailability appears as a likely pathogenic factor of endothelial dysfunction in ICU COVID-19 patients. A correlation between NO bioavailability and oxygenation parameters is observed in hospitalized COVID-19 patients. These results highlight an urgent need for oriented research leading to a better understanding of the specific endothelial oxidative stress that occurs during SARS-CoV-2. FUNDING: Stated in the acknowledgments section.

Inflammation-Induced Coagulopathy Substantially Differs Between COVID-19 and Septic Shock: A Prospective Observational Study

Critical COVID-19, like septic shock, is related to a dysregulated systemic inflammatory reaction and is associated with a high incidence of thrombosis and microthrombosis. Improving the understanding of the underlying pathophysiology of critical COVID-19 could help in finding new therapeutic targets already explored in the treatment of septic shock. The current study prospectively compared 48 patients with septic shock and 22 patients with critical COVID-19 regarding their clinical characteristics and outcomes, as well as key plasmatic soluble biomarkers of inflammation, coagulation, endothelial activation, platelet activation, and NETosis. Forty-eight patients with matched age, gender, and co-morbidities were used as controls. Critical COVID-19 patients exhibited less organ failure but a prolonged ICU length-of-stay due to a prolonged respiratory failure. Inflammatory reaction of critical COVID-19 was distinguished by very high levels of interleukin (IL)-1β and T lymphocyte activation (including IL-7 and CD40L), whereas septic shock displays higher levels of IL-6, IL-8, and a more significant elevation of myeloid response biomarkers, including Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) and IL-1ra. Subsequent inflammation-induced coagulopathy of COVID-19 also differed from sepsis-induced coagulopathy (SIC) and was characterized by a marked increase in soluble tissue factor (TF) but less platelets, antithrombin, and fibrinogen consumption, and less fibrinolysis alteration. In conclusion, COVID-19 inflammation-induced coagulopathy substantially differs from SIC. Modulating TF release and activity should be evaluated in critical COVID-19 patients.

Seroprevalence of SARS-CoV-2 infection in health care workers of a teaching hospital in Belgium: self-reported occupational and household risk factors for seropositivity.

This study aims to evaluate SARS-CoV-2 seroprevalence among health care workers (HCWs) and to assess self-reported risk factors for seropositivity. A total of 3255 HCWs were included and the overall seroprevalence was 7.8%. The likelihood of seropositivity was higher in participants reporting any COVID-19 symptoms within the last 4 months (OR 8.32, 95% CI 5.83-11.88, P < 0.001). Being a female HCW (OR 1.32, 95% CI 1.11-2.32, P < 0.01), having a cohabitant who was infected with SARS-CoV-2 (OR 2.55, 95% CI 1.78-3.66 P < 0.001) or a cohabitant who was a nursing home caregiver (OR 3.71, 95% CI 1.59-8.65, P = 0.002) were independently associated with an increased risk of seropositivity. Working in a COVID-19 unit (OR 1.64, 95% CI 1.21-2.23, P < 0.001) and being exposed to a SARS-CoV-2 infected co-worker (OR 1.30,95% CI 0.97-1.74, P = 0.016) resulted in higher seropositivity rate. Even if in-hospital exposure may play a significant role, increased infection risk is most likely attributable to household contact.

Clinical usefulness of fully automated chemiluminescent immunoassay for quantitative antibody measurements in COVID-19 patients.

Since December 2019, we have been in the battlefield with a new threat to the humanity, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), characterized by viral pneumonia. It may be asymptomatic or cause various symptoms, ranging from flu-like symptoms to acute respiratory distress syndrome and eventually death. At present, the only reliable test for COVID-19 diagnosis is quantitative reverse transcriptase-polymerase chain reaction. Assessing the immune response against SARS-CoV-2 could increase the detection sensitivity of infected population. Hereby, we report the performances of a fully automated chemiluminescent immunoassay (CLIA) on 276 serum samples. One hundred samples obtained from COVID-19 negative subjects (COVID-19 free) were analyzed to evaluate the diagnostic specificity of antibody (Ab) detection. Thereafter, 176 samples obtained from 125 patients with confirmed COVID-19 (COVID-19 patients) were selected to assess the diagnostic sensitivity of the CLIA. All samples were analyzed on MAGLUMI 800 platform. All COVID-19 free samples had Ab levels below the cutoff values. Hence, the diagnostic specificity was estimated at 100% (95% confidence interval [CI] = 96.3-100.0; positive predictive value = 100%). By the 18th day from the onset of symptoms, we reached an optimal diagnostic sensitivity (more than 95.0%) In fact, the diagnostic sensitivity increased over time and between 15 and 25 days after symptoms onset, reached 95.5% (95% CI = 84.9-99.2). The new automated CLIA analyzer appeared to be a robust and reliable method to measure specific Ab against COVID-19 at high throughput. Our data suggest that combining Ab and nucleic acid detection could increase diagnostic sensitivity.

Organisation and quality monitoring for point-of-care testing (POCT) in Belgium: proposal for an expansion of the legal framework for POCT into primary health care.

BACKGROUND: There is a trend towards decentralisation of laboratory tests by means of Point-of-Care testing (POCT). Within hospitals, Belgian law requires a POCT policy, coordinated by the clinical laboratory. There is however no legal framework for POCT performed outside the hospital: no reimbursement, no compulsory quality monitoring and no limits nor control on the prices charged to the patient. Uncontrolled use of POCT can have negative consequences for individual and public health. PROPOSAL: We propose that POCT outside hospitals would only be reimbursed for tests carried out within a legal framework, requiring evidence-based testing and collaboration with a clinical laboratory, because clinical laboratories have procedures for test validation and quality monitoring, are equipped for electronic data transfer, are familiar with logistical processes, can provide support when technical issues arise and can organise and certify training. Under these conditions the government investment will be offset by health benefits, e.g. fall in antibiotic consumption with POCT for CRP in primary care, quick response to SARS-CoV2-positive cases in COVID-19 triage centres. PRIORITIES: 1° extension of the Belgian decree on certification of clinical laboratories to decentralised tests in primary care; 2° introduction of a separate reimbursement category for POCT; 3° introduction of reimbursement for a limited number of specified POCT; 4° setup of a Multidisciplinary POCT Advisory Council, the purpose of which is to draw up a model for reimbursement of POCT, to select tests eligible for reimbursement and to make proposals to the National Institute for Health and Disability Insurance (RIZIV/INAMI).

A biological profile for diagnosis and outcome of COVID-19 patients.

Objectives As severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) pandemic is increasing its victims on a global scale with recurring outbreaks, it remains of outmost importance to rapidly identify people requiring an intensive care unit (ICU) hospitalization. The aim of this study was to identify Coronavirus Disease 2019 (COVID-19) biomarkers, to investigate their correlation with disease severity and to evaluate their usefulness for follow-up. Methods Fifty patients diagnosed with SARS-Cov-2 were included in March 2020. Clinical and biological data were collected at admission, during hospitalization and one month after discharge. Patients were divided into two severity groups: non-ICU (28) and ICU and/or death (22) to stratify the risk. Results Blood parameters in COVID-19 patients at admission showed increased C-reactive protein (CRP) (100%), ferritin (92%), lactate dehydrogenase (LDH) (80%), white blood cell (WBC) count (26%) with lymphopenia (52%) and eosinopenia (98%). There were significant differences in levels of CRP, ferritin, D-dimers, fibrinogen, lymphocyte count, neutrophil count and neutrophil-to-lymphocyte ratio (NLR) among the two severity groups. Mapping of biomarker's kinetics distinguished early and late parameters. CRP, ferritin, LDH, lymphopenia and eosinopenia were present upon admission with a peak at the first week. Late biomarkers such as anemia, neutrophilia and elevated liver biomarkers appeared after one week with a peak at three weeks of hospitalization. Conclusions We confirmed that high-values of CRP, NLR, D-dimers, ferritin as well as lymphopenia and eosinopenia were consistently found and are good markers for risk stratification. Kinetics of these biomarkers correlate well with COVID-19 severity. Close monitoring of early and late biomarkers is crucial in the management of critical patients to avoid preventable deaths.

[Management of a global health crisis: first COVID-19 disease feedback from Overseas and French-speaking countries medical biologists]. / Gestion d'une crise sanitaire mondiale : premiers retours d'expérience de biologistes médicaux d'Outre-mer et de francophonie face au COVID-19.

The French society of clinical biology "Biochemical markers of COVID-19" has set up a working group with the primary aim of reviewing, analyzing and monitoring the evolution of biological prescriptions according to the patient's care path and to look for markers of progression and severity of the disease. This study covers all public and private sectors of medical biology located in metropolitan and overseas France and also extends to the French-speaking world. This article presents the testimonies and data obtained for the "Overseas and French-speaking countries" sub-working group made up of 45 volunteer correspondents, located in 20 regions of the world. In view of the delayed spread of the SARS-CoV-2 virus, the overseas regions and the French-speaking regions have benefited from feedback from the first territories confronted with COVID-19. Thus, the entry of the virus or its spread in epidemic form could be avoided, thanks to the rapid closure of borders. The overseas territories depend very strongly on air and/or sea links with the metropolis or with the neighboring continent. The isolation of these countries is responsible for reagent supply difficulties and has necessitated emergency orders and the establishment of stocks lasting several months, in order to avoid shortages and maintain adequate patient care. In addition, in countries located in tropical or intertropical zones, the diagnosis of COVID-19 is complicated by the presence of various zoonoses (dengue, Zika, malaria, leptospirosis, etc.).

High clinical performance and quantitative assessment of antibody kinetics using a dual recognition assay for the detection of SARS-CoV-2 IgM and IgG antibodies.

OBJECTIVES: Several serological SARS-CoV-2 immunoassays have been developed recently but require external validation before widespread use. This study aims at assessing the analytical and clinical performance of the iFlash® anti-SARS-CoV-2 chemiluminescence assay for the detection of both IgM and IgG antibodies. The kinetics of the antibody response was also evaluated. DESIGN & METHODS: The precision, carry-over, linearity, limit of blank, detection and quantification were assessed. Sensitivity analysis was performed by using 178 sera collected from 154 RT-PCR confirmed COVID-19 patients. The specificity analysis was performed from 75 selected non-SARS-CoV-2 sera with a potential cross-reaction to the SARS-CoV-2 immunoassay. RESULTS: This iFlash® SARS-CoV-2 assay showed excellent analytical performance. After 2 weeks since symptom onset, the sensitivities for IgM and IgG were 62.2% (95% CI: 52.3-71.2%) and 92.9%% (95% CI: 85.7-96.7%), respectively by using the cut-off provided by the manufacturer. After cut-off optimization (i.e. >2.81 for IgM and >4.86 for IgG), the sensitivity for IgM and IgG were 81.6 (95% CI: 72.7-88.1%) and 95.9% (95% CI: 89.4-98.7%), respectively. Optimized cut-off for IgG improved the sensitivity to reach 100% (95%CI: 87.6-100) from 28 days since symptom onset. CONCLUSIONS: This study shows that the iFlash® SARS-CoV-2 assay from YHLO biotechnology, has satisfactory analytical performance. Nevertheless, the sensitivity of the IgM is limited for a proper clinical use compared to IgG. The determination of anti-SARS-CoV-2 IgG antibodies from 28 days since symptom onset was associated with high sensitivity, especially using optimized cut-offs (i.e. 100%).

Evaluation of Chilblains as a Manifestation of the COVID-19 Pandemic.

Importance: During the coronavirus disease 2019 (COVID-19) pandemic, several cases of chilblains have been reported. Objective: To determine if chilblains are associated with COVID-19. Design, Setting, and Participants: This monocentric case series was conducted at the Department of Dermatology at Cliniques universitaires Saint-Luc, a tertiary care hospital in Brussels, Belgium, between April 10 and April 17, 2020. We evaluated a total of 31 referred patients who had recently developed chilblains. Main Outcomes and Measures: Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA on nasopharyngeal swabs for all patients and in skin biopsy specimens for 22 patients. Blood samples from all patients were tested for specific anti-SARS-CoV-2 immunoglobulin (Ig) M and IgG antibodies. All patients had extended blood analyses. Histologic (22 patients) and immunofluorescence examinations (15 patients) were performed on the skin biopsy specimens. Results: The 31 patients were generally in good health; most were teenagers or young adults, and 19 were women. Histopathologic analysis of skin biopsy specimens (22 patients) confirmed the diagnosis of chilblains and showed occasional lymphocytic or microthrombotic phenomena. Immunofluorescence analyses showed vasculitis of small-diameter vessels in 7 patients. In all patients, SARS-CoV-2 RNA remained undetected by RT-PCR on nasopharyngeal swabs and in biopsy samples of the skin lesions. The IgM and IgG antibody titers were negative for SARS-CoV-2 in all patients (<1.0 arbitrary unit/mL). No significant abnormalities in blood test results were suggestive of systemic disease. Antinuclear antibody titers were low in 7 patients and higher in 1 patient. Conclusions and Relevance: Chilblains appeared not to be directly associated with COVID-19 in this case series. Lifestyle changes associated with community containment and lockdown measures are a possible explanation for these lesions.

Evaluation of two automated and three rapid lateral flow immunoassays for the detection of anti-SARS-CoV-2 antibodies.

INTRODUCTION: Several SARS-CoV-2 immunoassays have been developed recently. The purpose of this study was to assess the performance of five immunoassays for the detection of SARS-CoV-2 antibodies. METHODS: Two quantitative automated immunoassays (Maglumi™2019-n-Cov IgG and IgM and Euroimmun Anti-SARS-CoV-2 IgG and IgA assays) and three lateral flow rapid tests were performed. This retrospective study included 200 residual sera from patients and healthy volunteers. Case serum samples (n = 128) were obtained from COVID-19 patients confirmed by RT-qPCR and CT-scan. Days since onset of symptoms was collected from their medical records. Control non-SARS-CoV-2 samples (n = 72) were obtained from anonymous stored residual serum samples. RESULTS: Maglumi™ IgG/IgM tests showed overall less sensitivity than Euroimmun IgG/IgA test (84.4 % versus 64.3 %). Both tests showed similar specificities of IgG at 99 % and 100 %, respectively. The results from the lateral flow assays were easily interpretable with unambiguous coloured reading bands. The overall sensitivity of the three tests was similar (around 70 %) without any significant differences. The sensitivity of the three lateral flow assays and also of the serological quantitative assays increased during the second week after symptom onset and all reached similar values (91 %-94 %) after 14 days. CONCLUSION: This study shows accurate and equivalent performance of the five serological antibody assays (ELISA, CLIA and three lateral flow tests) in detecting SARS-CoV-2 antibodies 14 days after the onset of COVID-19 symptoms. This is compatible with their application in specific clinical contexts and in determining epidemiological strategies for the COVID-19 pandemic.