C1-INH and the contact system in COVID-19

Coronavirus disease 2019 (COVID‐19) is frequently associated with severe systemic consequences, including vasculitis, a hyperinflammatory state and hypercoagulation. The mechanisms leading to these life‐threatening abnormalities are multifactorial. Based on the analysis of publicly available interactomes, we propose that severe acute respiratory syndrome coronavirus‐2 infection directly causes a deficiency in C1 esterase inhibitor, a pathogen‐specific mechanism that may help explain significant systemic abnormalities in patients with COVID‐19.This study was supported by grant COVID‐006 from the Spanish Science Council (CSIC) (to T.M.T.). Research by R.P. is funded by the Spanish Ministry of Science and Innovation (RTI 2018‐096055‐B‐100).Peer reviewe