Fig. 1

Full trial protocol and flow diagram. a Recruitment tree: 757 patients were initially considered for the study. 167 were treated at intensive care units (ICU). 47 patients were excluded—thereof 30 patients were excluded because of other than pulmonary indications for ICU admission. SARS-CoV-2 positivity was an incidental finding without any radiologic evidence of pneumonia. 15 were treated due to non-ST or ST-elevation myocardial infarction (NSTEMI/STEMI); 11 received post-operative intensive care treatment—3 patients were incidentally tested positive for SARS-CoV-2 due to ischemic or hemorrhagic stroke; 1 patient was incidentally tested positive for SARS-CoV-2 after cerebral bleeding within the work-up for organ donation, 15 patients were excluded due to insufficient follow-up data and 2 patients were excluded, because they had pulmonary co-infection with pneumocystis jirovecii (PJP). b Inclusion and exclusion criteria of the study. SARS-CoV-2 severe acute respiratory syndrome corona virus 2; PCR: polymerase chain reaction; ICU: intensive care unit; IgA: immunoglobulin A