Source : Medrxiv (PRE-PRINT)
Auteur : Takahashi and al.
Vous A growing body of evidence indicates sex differences in the clinical outcomes of coronavirus disease 2019 (COVID-19)1-4. However, whether immune responses against SARS-CoV-2 differ between sexes, and whether such differences explain male susceptibility to COVID-19, is currently unknown. In this study, we examined sex differences in viral loads, SARS-CoV-2-specific antibody titers, plasma cytokines, as well as blood cell phenotyping in COVID-19 patients. By focusing our analysis on patients with mild to moderate disease who had not received immunomodulatory medications, our results revealed that male patients had higher plasma levels of innate immune cytokines and chemokines including IL-8, IL-18, and CCL5, along with more robust induction of non-classical monocytes. In contrast, female patients mounted significantly more robust T cell activation than male patients during SARS-CoV-2 infection, which was sustained in old age. Importantly, we found that a poor T cell response negatively correlated with patients age and was predictive of worse disease outcome in male patients, but not in female patients. Conversely, higher innate immune cytokines in female patients associated with worse disease progression, but not in male patients. These findings reveal a possible explanation underlying observed sex biases in COVID-19, and provide important basis for the development of sex-based approach to the treatment and care of men and women with COVID-19.
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Source : Immunity 52, May 19, 2020
Auteur : Haley E. Randolph and Luis B. Barreiro
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated disease, COVID-19, has demonstrated the devastating impact of a novel, infectious pathogen on a susceptible population. Here, we explain the basic concepts of herd immunity and discuss its implications in the context of COVID-19.
Source : The Journal of Infectious Diseases, 30 May 2020, jiaa305, https://doi.org/10.1093/infdis/jiaa305
Auteur :
We comparatively assessed sensitivities and specificities of four commercial ELISAs and two rapid tests in 77 patients with PCR confirmed SARS-CoV-2 infection, grouped by intervals since symptom onset. While test sensitivities were low (<40%) within the first 5 days post disease onset, IgM-, IgAand total antibody-ELISAs increased in sensitivity to >80% between the 6th and 10th day post symptom onset. The evaluated tests (including IgG and rapid tests) provided positive results in all patients at or after the 11th day post onset of disease. Specificities of the ELISAs were 83% (IgA), 98% (IgG) and 97% (IgM and total antibodies).
SARS-Coronavirus 2 (SARS-CoV-2), a new Betacoronavirus, is currently causing a massive pandemic with severe consequences for the health-care systems worldwide [1, 2]. While polymerase chain reaction (PCR) based tests quickly became the cornerstone of SARS-CoV-2 diagnosis, the potential of antibody tests has not been comprehensively evaluated. Depending on respective infection stages, antibody assays could nonetheless significantly complement PCR based testing [3, 4]. Multiple commercial enzyme-linked immunoassays and rapid tests (lateral flow immunossays) have recently become available, but their diagnostic ability has to be thoroughly evaluated and compared before they can be widely used in the clinical setting [5, 6]. Here, we compared the diagnostic ability of four ELISAs, which assess SARS-CoV-2-specific antibodies of immunoglobulin classes (Euroimmun SARS-CoV-2 IgA and IgG, Wantai SARS-CoV-2 IgM and total antibodies), and two rapid tests (Wantai SARS-CoV-2 Ab Rapid Test and 2019-nCoV IgG/IgM Rapid Test) in 77 patients with symptomatic SARS-CoV-2 infection.
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Commentateur : Dr Marie Moitry.Résumé
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