Search

MIS-C is a novel immunodysregulation syndrome in children with a history of SARS-CoV-2 infection. This study employs a multi-omics approach to explore its immunopathogenesis. The authors show that IFNγ-mediated interactions between T cells, monocytes, and NK cells reside at the heart of the disease., In rare instances, pediatric SARS-CoV-2 infection results in a novel immunodysregulation syndrome termed multisystem inflammatory syndrome in children (MIS-C). We compared MIS-C immunopathology with severe COVID-19 in adults. MIS-C does not result in pneumocyte damage but is associated with vascular endotheliitis and gastrointestinal epithelial injury. In MIS-C, the cytokine release syndrome is characterized by IFNγ and not type I interferon. Persistence of patrolling monocytes differentiates MIS-C from severe COVID-19, which is dominated by HLA-DRlo classical monocytes. IFNγ levels correlate with granzyme B production in CD16+ NK cells and TIM3 expression on CD38+/HLA-DR+ T cells. Single-cell TCR profiling reveals a skewed TCRβ repertoire enriched for TRBV11-2 and a superantigenic signature in TIM3+/CD38+/HLA-DR+ T cells. Using NicheNet, we confirm IFNγ as a central cytokine in the communication between TIM3+/CD38+/HLA-DR+ T cells, CD16+ NK cells, and patrolling monocytes. Normalization of IFNγ, loss of TIM3, quiescence of CD16+ NK cells, and contraction of patrolling monocytes upon clinical resolution highlight their potential role in MIS-C immunopathogenesis., Graphical Abstract

Middle East respiratory syndrome coronavirus (MERS-CoV) causes pneumonia with a relatively high case fatality rate in humans. Smokers and chronic obstructive pulmonary disease (COPD) patients have been reported to be more susceptible to MERS-CoV infection. Here, we determined the expression of MERS-CoV receptor, dipeptidyl peptidase IV (DPP4), in lung tissues of smokers without airflow limitation and COPD patients in comparison to non-smoking individuals (never-smokers). ispartof: Clinical Infectious Diseases vol:66 issue:1 pages:45-53 ispartof: location:United States status: published

Background Infections with SARS-CoV-2 continue to cause significant morbidity and mortality. Interleukin (IL)-1 and IL-6 blockade have been proposed as therapeutic strategies in COVID-19, but study outcomes have been conflicting. We sought to study whether blockade of the IL-6 or IL-1 pathway shortened the time to clinical improvement in patients with COVID-19, hypoxic respiratory failure, and signs of systemic cytokine release syndrome. Methods We did a prospective, multicentre, open-label, randomised, controlled trial, in hospitalised patients with COVID-19, hypoxia, and signs of a cytokine release syndrome across 16 hospitals in Belgium. Eligible patients had a proven diagnosis of COVID-19 with symptoms between 6 and 16 days, a ratio of the partial pressure of oxygen to the fraction of inspired oxygen (PaO2:FiO(2)) of less than 350 mm Hg on room air or less than 280 mm Hg on supplemental oxygen, and signs of a cytokine release syndrome in their serum (either a single ferritin measurement of more than 2000 mu g/L and immediately requiring high flow oxygen or mechanical ventilation, or a ferritin concentration of more than 1000 mu g/L, which had been increasing over the previous 24 h, or lyrnphopenia below 800/mL with two of the following criteria: an increasing ferritin concentration of more than 700 mu g/L, an increasing lactate dehydrogenase concentration of more than 300 international units per L, an increasing C-reactive protein concentration of more than 70 mg/L, or an increasing D-dimers concentration of more than 1000 ng/mL). The COV-AID trial has a 2 x 2 factorial design to evaluate IL-1 blockade versus no IL-1 blockade and IL-6 blockade versus no IL-6 blockade. Patients were randomly assigned by means of permuted block randomisation with varying block size and stratification by centre. In a first randomisation, patients were assigned to receive subcutaneous anakinra once daily (100 mg) for 28 days or until discharge, or to receive no IL-1 blockade (1:2). In a second randomisation step, patients were allocated to receive a single dose of siltuximab (11 mg/kg) intravenously, or a single dose of tocilizumab (8 mg/kg) intravenously, or to receive no IL-6 blockade (1:1:1). The primary outcome was the time to clinical improvement, defined as time from randomisation to an increase of at least two points on a 6-category ordinal scale or to discharge from hospital alive. The primary and supportive efficacy endpoints were assessed in the intention-to-treat population. Safety was assessed in the safety population. This study is registered online with ClinicalTrials.gov (NCT04330638) and EudraCT (2020-001500-41) and is complete. Findings Between April 4, and Dec 6,2020,342 patients were randomly assigned to IL-1 blockade n=112) or no IL-1 blockade (n=230) and simultaneously randomly assigned to IL-6 blockade (n=227; 114 for tocilizumab and 113 for siltuximab) or no IL-6 blockade (n=115). Most patients were male (265 [77%] of 342), median age was 65 years (IQR 54-73), and median Systematic Organ Failure Assessment (SOFA) score at randomisation was 3 (2-4). All 342 patients were included in the primary intention-to-treat analysis. The estimated median time to clinical improvement was 12 days (95% CI 10-16) in the IL-1 blockade group versus 12 days (10-15) in the no IL-1 blockade group (hazard ratio [HR] 0.94 [95% CI 0.73-1.21]). For the IL-6 blockade group, the estimated median time to clinical improvement was 11 days (95% CI 10-16) versus 12 days (11-16) in the no IL-6 blockade group (HR 1.00[0-78-1-29]). 55 patients died during the study, but no evidence for differences in mortality between treatment groups was found. The incidence of serious adverse events and serious infections was similar across study groups. Interpretation Drugs targeting IL-1 or IL-6 did not shorten the time to clinical improvement in this sample of patients with COVID-19, hypoxic respiratory failure, low SOFA score, and low baseline mortality risk. Copyright (C) 2021 Elsevier Ltd. All rights reserved. Belgian Health Care Knowledge Center; VIB Grand Challenges program The authors acknowledge professional support and committed efforts from various organisations and individuals involved in this trial and thank all trial participants and clinicians involved in patient recruitment at the different participating sites. This study was funded by KCE, and KCE was involved in various aspects of the study design, management, and execution (Nelle Stocquart, Jillian Harrison). The VIB Grand Challenges Program (Sofie Bekaert) funded measurements of cytokines and the Ghent University Special Research Fund (BOF) supported the clinical follow-up of patients at Ghent University Hospital (UZ Ghent). The clinical trial team of the Department of Respiratory Medicine at UZ Ghent (Stefanie Vermeersch, Benedicte Demeyere, Anja Delporte) were involved in protocol development, amendment filing, and eCRF construction. The Health Innovation and Research Institute of UZ Ghent was involved in eCRF design, protocol design, ethical committee reporting, drug dispensing, trial monitoring, data cleaning, and sponsor site management (Charlotte Clauwaert, Dries Loncke, Hanife Kokur, Lieselot Van Landuyt, Joke Tommelein, Hélène De Naeyer). The hospital pharmacy of UZ Ghent dispensed drugs to all study sites (Els Kestens). Team members of the Primary Immune Deficiency laboratory (Karlien Claes, Veronique Debacker, Lisa Roels, Zara Declercq) handled samples from all study sites. The authors acknowledge the insights of the data safety monitoring board (Drs Renaat Peleman, Geert Leroux-Roels, Steven Callens, Frank Vermassen, Piet Hoebeke, Karim Vermaelen, A Dupont, Tomasz Burzykowski, and Marnik Vuylsteke under the chairmanship of SR).