PLG and COVID-19: In the present study, in an aged population of patients with diagnosis of COVID-19 and with high rate of comorbidity, we demonstrated that low levels of plasminogen were significantly associated with several prognostic parameters of complications, such as inflammatory markers (CRP, PCT, and IL-6), markers of coagulation (D-dimer, INR, and APTT), and markers of organ dysfunctions (FBG and GFR).