The state of complement in COVID-19

Hyperactivation of the complement and coagulation systems is recognized as part of the clinical syndrome of COVID-19. Here we review systemic complement activation and local complement activation in response to the causative virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and their currently known relationships to hyperinflammation and thrombosis. We also provide an update on early clinical findings and emerging clinical trial evidence that suggest potential therapeutic benefit of complement inhibition in severe COVID-19. Hyperactivation of the complement system has been implicated in the pathology of COVID-19. Here the authors bring together the latest information on the role of complement in COVID-19 and progress in targeting complement components for treatment of severe disease.Hyperactivation of the complement and coagulation systems is recognized as part of the clinical syndrome of COVID-19. Here we review systemic complement activation and local complement activation in response to the causative virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and their currently known relationships to hyperinflammation and thrombosis. We also provide an update on early clinical findings and emerging clinical trial evidence that suggest potential therapeutic benefit of complement inhibition in severe COVID-19. Hyperactivation of the complement system has been implicated in the pathology of COVID-19. Here the authors bring together the latest information on the role of complement in COVID-19 and progress in targeting complement components for treatment of severe disease.A