CRP and COVID-19: In a retrospective study of consecutive patients with acute PE that included COVID-19 positive and COVID-19 negative patients, although inflammatory (CRP) and prothrombotic markers ( APTT, Fibrinogen) were significantly elevated in the COVID-19 PE positive cohort, the D-dimer level was lower in the COVID-19 positive cohort compared to the negative cohort suggesting non-thrombotic mechanisms for D-dimer elevation [26].