ABSTRACT
BackgroundCoagulopathy and inflammation are hallmarks of Coronavirus disease 2019 (COVID-19) and are associated with increased mortality. Clinical and experimental data have revealed a role for neutrophil extracellular traps (NETs) in COVID-19 disease. The mechanisms that drive thrombo-inflammation in COVID-19 are poorly understood. MethodsWe performed proteomic analysis and immunostaining of postmortem lung tissues from COVID-19 patients and patients with other lung pathologies. We further compared coagulation factor XII (FXII) and DNase activities in plasma samples from COVID-19 patients and healthy control donors and determined NET-induced Factor XIII (FXII) activation using a chromogenic substrate assay. FindingsFXII expression and activity were increased in the lung parenchyma, within the pulmonary vasculature and in fibrin-rich alveolar spaces of postmortem lung tissues from COVID-19 patients. In agreement with this, plasma FXII activation (FXIIa) was increased in samples from COVID-19 patients. Furthermore, FXIIa colocalized with NETs in COVID-19 lung tissue indicating that NETs accumulation leads to FXII contact activation in COVID-19. We further showed that an accumulation of NETs is partially due to impaired NET clearance by extracellular DNases as DNase substitution improved NET dissolution and reduced FXII activation in vitro. InterpretationCollectively, our study supports that the NETs/FXII axis contributes to the pathogenic chain of procoagulant and proinflammatory responses in COVID-19. Targeting both, NETs and FXIIa, could provide a strategy to mitigate COVID-19-induced thrombo-inflammation. FundingThis study was supported by the European Union (840189), the Werner Otto Medical Foundation Hamburg (8/95) and the German Research Foundation (FR4239/1-1, A11/SFB877, B08/SFB841 and P06/KFO306).
ABSTRACT
Males develop more severe SARS-CoV-2 infection related disease outcome than females. Herein, sex hormones were repeatedly proposed to play an important role in Covid-19 pathophysiology and immunity. However, it is yet unclear whether sex hormones are associated with Covid-19 outcome in males and females. In this study, we analyzed sex hormones, cytokine and chemokine responses as well as performed a large profile analysis of 600 metabolites in critically-ill male and female Covid-19 patients in comparison to healthy controls and patients with coronary heart diseases as a prime Covid-19 comorbidity. We here show that dysregulated sex hormones, IFN-{gamma} levels and unique metabolic signatures are associated with critical illness in Covid-19 patients. Both, male and female Covid-19 patients, present elevated estradiol levels which positively correlates with IFN-{gamma} levels. Male Covid-19 patients additionally display severe testosterone and triglyceride deficiencies as compared to female patients and healthy controls. Our results suggest that male Covid-19 patients suffer from multiple metabolic disorders, which may lead to higher risk for fatal outcome. These findings will help to understand molecular pathways involved in Covid-19 pathophysiology.
