ELISA-Based Analysis Reveals an Anti-SARS-CoV-2 Protein Immune Response Profile Associated with Disease Severity.

Since the start of the COVID-19 pandemic, many studies have investigated the humoral response to SARS-CoV-2 during infection. Studies with native viral proteins constitute a first-line approach to assessing the overall immune response, but small peptides are an accurate and valuable tool for the fine characterization of B-cell epitopes, despite the restriction of this approach to the determination of linear epitopes. In this study, we used ELISA and peptides covering a selection of structural and non-structural SARS-CoV-2 proteins to identify key epitopes eliciting a strong immune response that could serve as a biological signature of disease characteristics, such as severity, in particular. We used 213 plasma samples from a cohort of patients well-characterized clinically and biologically and followed for COVID-19 infection. We found that patients developing severe disease had higher titers of antibodies mapping to multiple specific epitopes than patients with mild to moderate disease. These data are potentially important as they could be used for immunological profiling to improve our knowledge of the quantitative and qualitative characteristics of the humoral response in relation to patient outcome.

Case fatality inequalities of critically ill COVID-19 patients according to patient-, hospital- and region-related factors: a French nationwide study.

BACKGROUND: The COVID-19 sanitary crisis inflicted different challenges regarding the reorganization of the human and logistic resources, particularly in intensive care unit (ICU). Interdependence between regional pandemic burden and individual outcome remains unknown. The study aimed to assess the association between ICU bed occupancy and case fatality rate of critically ill COVID-19 patients. METHODS: A cross-sectional study was performed in France, using the national hospital discharge database from March to May, 2020. All patients admitted to ICU for COVID-19 were included. Case fatality was described according to: (i) patient's characteristics (age, sex, comorbid conditions, ICU interventions); (ii) hospital's characteristics (baseline ICU experience assessed by the number of ICU stays in 2019, number of ICU physicians per bed), and (iii) the regional outbreak-related profiles (workload indicator based on ICU bed occupancy). The determinants of lethal outcome were identified using a logistic regression model. RESULTS: 14,513 COVID-19 patients were admitted to ICU; 4256 died (29.3%), with important regional inequalities in case fatality (from 17.6 to 33.5%). Older age, multimorbidity and clinical severity were associated with higher mortality, as well as a lower baseline ICU experience of the health structure. Regions with more than 10 days with ≥ 75% of ICU occupancy by COVID-19 patients experienced an excess of mortality (up to adjusted OR = 2.2 [1.9-2.6] for region with the highest occupancy rate of ICU beds). CONCLUSIONS: The regions with the highest burden of care in ICU were associated with up to 2.2-fold increase of death rate.

Follow-up of adults with noncritical COVID-19 two months after symptom onset.

OBJECTIVES: To describe the clinical evolution and predictors of symptom persistence during 2 months' follow-up in adults with noncritical coronavirus disease 2019 (COVID-19). METHODS: We performed descriptive clinical follow-up (day (D) 7, D30 and D60) of 150 patients with noncritical COVID-19 confirmed by real-time reverse transcriptase PCR at Tours University Hospital from 17 March to 3 June 2020, including demographic, clinical and laboratory data collected from the electronic medical records and by phone call. Persisting symptoms were defined by the presence at D30 or D60 of at least one of the following: weight loss ≥5%, severe dyspnoea or asthenia, chest pain, palpitations, anosmia/ageusia, headache, cutaneous signs, arthralgia, myalgia, digestive disorders, fever or sick leave. RESULTS: At D30, 68% (103/150) of patients had at least one symptom; and at D60, 66% (86/130) had symptoms, mainly anosmia/ageusia: 59% (89/150) at symptom onset, 28% (40/150) at D30 and 23% (29/130) at D60. Dyspnoea concerned 36.7% (55/150) patients at D30 and 30% (39/130) at D60. Half of the patients (74/150) at D30 and 40% (52/130) at D60 reported asthenia. Persistent symptoms at D60 were significantly associated with age 40 to 60 years old, hospital admission and abnormal auscultation at symptom onset. At D30, severe COVID-19 and/or dyspnoea at symptom onset were additional factors associated with persistent symptoms. CONCLUSIONS: Up to 2 months after symptom onset, two thirds of adults with noncritical COVID-19 had complaints, mainly anosmia/ageusia, dyspnoea or asthenia. A prolonged medical follow-up of patients with COVID-19 seems essential, whatever the initial clinical presentation.