ABSTRACT
Inflammatory cytokines and chemokines (CC) drive COVID-19 pathology. Yet, patients with similar circulating CC levels present with different disease severity. Here, we determined 171 microRNAomes from 58 hospitalised COVID-19 patients (Cohort 1) and levels of 25 cytokines and chemokines (CC) in the same samples. Combining microRNA (miRNA) and CC measurements allowed for discrimination of severe cases with greater accuracy than using miRNA or CC levels alone. Severity group-specific associations between miRNAs and COVID-19-associated CC (e.g. IL6, CCL20) or clinical hallmarks of COVID-19 (e.g. neutrophilia, hypoalbuminemia) separated patients with similar CC levels but different disease severity. Critically, analysis of an independent cohort of 108 patients from a different centre (Cohort 2) demonstrated feasibility of CC/miRNA profiling in leftover blood samples with similar severe disease CC and miRNA profiles, and revealed CCL20, IL6, IL10, and miR-451a as key correlates of fatal COVID-19. These findings highlight that systemic miRNA/CC networks underpin severe COVID-19.Funding: The study was funded by the UKRI MRC/NIHR award to the UK Coronavirus Immunology Consortium (UK-CIC, MR/V028448/1). Sample collection at Manchester NHS Trusts was supported by the NIHR Manchester Biomedical Research Centre (TH and AS) and 3M Global Giving award (JRG and TH). Sample collection at York and Scarborough NHS Trust was supported by the Wellcome Trust (ISSF grant WT204829 through the Centre for Future Health at the University of York) and the Hull York Medical School. JRG is supported by a senior fellowship by The Kennedy Trust for Rheumatology Research. This report contains independent research supported by the North West Lung Centre Charity and the NIHR Manchester Clinical Research Facility at Wythenshawe Hospital.Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: For the cohort 1, ethics approval was obtained from the North West-Haydock Research Ethics Committee for ManARTS (reference 15/NW/0409) and from the Wales Research Ethics Committee 4 for NCARC (reference 18/WA/0368). For the cohort 2, ethics approval was obtained from Yorkshire & The Humber - Leeds West Research Ethics Committee (REC reference 19/YH/0394 with approved 26 SA002 amendment of IRAS project 269597).
Subject(s)
Hypoalbuminemia , COVID-19ABSTRACT
Background: Early clinical reports have suggested that the prevalence of thrombotic complications in the pathogenesis of COVID-19 may be as high as 30% in intensive care unit (ICU)-admitted patients and could be a major factor contributing to mortality. However, mechanisms underlying COVID-19-associated thrombo-coagulopathy, and its impact on patient morbidity and mortality, are still poorly understood. Methods: We performed a comprehensive analysis of coagulation and thromboinflammatory factors in plasma from COVID-19 patients with varying degrees of disease severity. Furthermore, we assessed the functional impact of these factors on clot formation and clot lysis. Results: Across all COVID-19 disease severities (mild, moderate and severe) we observed a significant increase (6-fold) in the concentration of ultra-large von Willebrand factor (UL-VWF) multimers compared to healthy controls. This is likely the result of an interleukin (IL)-6 driven imbalance of VWF and the regulatory protease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13). Upregulation of this key pro-coagulant pathway may also be influenced by the observed increase (~6-fold) in plasma -defensins, a consequence of increased numbers of neutrophils and neutrophil activation. Markers of endothelial, platelet and leukocyte activation were accompanied by increased plasma concentrations of Factor XIII (FXIII) and plasminogen activator inhibitor (PAI)-1. In patients with high FXIII we observed alteration of the fibrin network structure in in vitro assays of clot formation, which coupled with increased PAI-1, prolonged the time to clot lysis by the t-PA/plasmin fibrinolytic pathway by 52% across all COVID-19 patients (n=23). Conclusions: We show that an imbalance in the VWF/ADAMTS13 axis causing increased VWF reactivity may contribute to the formation of platelet-rich thrombi in the pulmonary vasculature of COVID-19 patients. Through immune and inflammatory responses, COVID-19 also alters the balance of factors involved in fibrin generation and fibrinolysis which accounts for the persistent fibrin deposition previously observed in post-mortem lung tissue.