Anti-RNApol3-Associated myocarditis: an emerging disease linking autoimmunity and infection.

Background: Fulminant myocarditis (FM) is a severe condition primarily triggered by viruses. Anti-RNA polymerase III autoantibodies (RNApol3) which are typically found in patients with severe systemic sclerosis, have been reported in patients with influenza-related FM. Our objective is to provide additional insight into RNApol3-associated FM.

Lower disease activity but higher risk of severe COVID-19 and herpes zoster in patients with systemic lupus erythematosus with pre-existing autoantibodies neutralising IFN-α.

Objectives: Type-I interferons (IFNs-I) have potent antiviral effects. IFNs-I are also overproduced in patients with systemic lupus erythematosus (SLE). Autoantibodies (AAbs) neutralising IFN-α, IFN-β and/or IFN-ω subtypes are strong determinants of hypoxemic COVID-19 pneumonia, but their impact on inflammation remains unknown.

Intravenous Immunoglobulins Tapering and Withdrawal in Systemic Capillary Leak Syndrome (Clarkson Disease).

Background: The systemic capillary leak syndrome (SCLS), also known as Clarkson disease, is a very rare condition characterized by recurrent life-threatening episodes of vascular hyperpermeability in the presence of a monoclonal gammopathy. Extended intravenous immunoglobulin (IVIG) treatment is associated with fewer recurrences and improved survival, but the optimal treatment dosage and duration remain unknown.

Objective: We aim to evaluate the safety of IVIG tapering and withdrawal in patients with SCLS.

In-ICU-acquired infections in flare-up systemic rheumatic disease patients receiving immunosuppressant.

Objectives: Systemic rheumatic diseases (SRDs) are a group of inflammatory disorders that can need intensive care unit (ICU) admission during a flare-up, requiring administration of immunosuppressants. We undertook this study to determine the frequency, outcome, and occurrence associated factors of infections in flare-up SRD patients receiving immunosuppressant.

Methods: Monocenter, a retrospective study including SRD patients admitted to ICU for a flare-up requiring immunosuppressant from 2004 to 2019.

Memory CD4+ T-Cell Lymphocytic Angiopathy in Fatal Forms of COVID-19 Pulmonary Infection.

The immunopathological pulmonary mechanisms leading to Coronavirus Disease (COVID-19)-related death in adults remain poorly understood. Bronchoalveolar lavage (BAL) and peripheral blood sampling were performed in 74 steroid and non-steroid-treated intensive care unit (ICU) patients (23-75 years; 44 survivors). Peripheral effector SARS-CoV-2-specific T cells were detected in 34/58 cases, mainly directed against the S1 portion of the spike protein.

Pre-COVID-19 Immunity to Common Cold Human Coronaviruses Induces a Recall-Type IgG Response to SARS-CoV-2 Antigens Without Cross-Neutralisation.

The capacity of pre-existing immunity to human common coronaviruses (HCoV) to cross-protect against COVID-19is yet unknown. In this work, we studied the sera of 175 COVID-19 patients, 76 healthy donors and 3 intravenous immunoglobulins (IVIG) batches. We found that most COVID-19 patients developed anti-SARS-CoV-2 IgG antibodies before IgM.

LOX-1-Expressing Immature Neutrophils Identify Critically-Ill COVID-19 Patients at Risk of Thrombotic Complications.

Background: Lymphopenia and the neutrophil/lymphocyte ratio may have prognostic value in COVID-19 severity.

Objective: We investigated neutrophil subsets and functions in blood and bronchoalveolar lavage (BAL) of COVID-19 patients on the basis of patients' clinical characteristics.

Methods: We used a multiparametric cytometry profiling based to mature and immature neutrophil markers in 146 critical or severe COVID-19 patients.

CD8+PD-L1+CXCR3+ polyfunctional T cell abundances are associated with survival in critical SARS-CoV-2-infected patients.

The importance of the adaptive T cell response in the control and resolution of viral infection has been well established. However, the nature of T cell-mediated viral control mechanisms in life-threatening stages of COVID-19 has yet to be determined. The aim of the present study was to determine the function and phenotype of T cell populations associated with survival or death of patients with COVID-19 in intensive care as a result of phenotypic and functional profiling by mass cytometry.

Distinct cytokine profiles associated with COVID-19 severity and mortality.

Background: Markedly elevated levels of proinflammatory cytokines and defective type-I interferon responses were reported in patients with coronavirus disease 2019 (COVID-19).

Objective: We sought to determine whether particular cytokine profiles are associated with COVID-19 severity and mortality.

Methods: Cytokine concentrations and severe acute respiratory syndrome coronavirus 2 antigen were measured at hospital admission in serum of symptomatic patients with COVID-19 (N = 115), classified at hospitalization into 3 respiratory severity groups: no need for mechanical ventilatory support (No-MVS), intermediate severity requiring mechanical ventilatory support (MVS), and critical severity requiring extracorporeal membrane oxygenation (ECMO).

IgA dominates the early neutralizing antibody response to SARS-CoV-2.

Humoral immune responses are typically characterized by primary IgM antibody responses followed by secondary antibody responses associated with immune memory and composed of IgG, IgA, and IgE. Here, we measured acute humoral responses to SARS-CoV-2, including the frequency of antibody-secreting cells and the presence of SARS-CoV-2-specific neutralizing antibodies in the serum, saliva, and bronchoalveolar fluid of 159 patients with COVID-19. Early SARS-CoV-2-specific humoral responses were dominated by IgA antibodies.