Treatment protocol and outcome
All patients received background corticosteroid therapy with 80 mg/day methylprednisolone (or its equivalent) and enoxaparin 0.4 mg/day at the admission and continued consecutive days (SoC). Anakinra was added to the background treatment in patients who did not respond to initial treatment at least two days or concomitantly with steroids in patients with higher risk and/or critical illness at admission and continued until discharge or death. Average starting dose of anakinra was 400 mg/day intravenously and increased gradually to maximum 1600 mg/day if necessary (10 mg/kg/day). Anakinra dose adjustment was performed by the same experienced physician in COVID-19 (MB) according to daily clinical (respiratory symptoms, degree of oxygen supply, presence of fever) and laboratory findings.
Diagnosis of PTE was confirmed by thorax CT-angiography in patients with prominent d-dimer increase despite decrease in acute phase reactants (APR) such as CRP and ferritin and/or increase in need of oxygen therapy and respiratory distress despite the decrease in levels of APRs. Diagnosis of MI was made according to the Thygesen et al. study (Thygesen et al., 2018). Severe infection was defined as development of opportunistic infection, need of intravenous antibiotics, sepsis, or requirement of intensive care unit (ICU) admission or development of death due to secondary infection.