Pathological evidence of pulmonary thrombotic phenomena in severe COVID-19

Abstract Between February and March 2020, the Journal of Thrombosis and Hemosthasis has published four papers addressing the intricate, complex and still little understood relation between COVID-19 and thrombogenesis (1-4). ARS-Cov-2 induces in severe cases a cytokine storm that ultimately leads to the activation of the coagulation cascade, causing thrombotic phenomena (5). There is a further strong link between abnormal coagulation parameters (D-dimer and fibrin degradation products) and mortality. Tang et al. described that 71.4% of nonsurvivors and 0.6% of survivors showed evidence of disseminated intravascular coagulation (DIC), suggesting that DIC is a frequent occurrence in severe COVID-19 (4). The frequency of DIC in these patients is much higher than that reported for severe SARS (6).