Table 1.
Influenza infection | COVID-19 | SARS | MERS | [Ref.] | |
---|---|---|---|---|---|
Hyperinflammation | |||||
Hypercytokinemia associated with poor prognosis | + | + | + | + | [34,78,80,119,120] |
Increased CRP levels associated with poor prognosis | + | + | + | + | [27,29,30,41,121,122] |
Hyperferritinemia associated with poor prognosis | + | + | + | NS | [28,31,123] |
Immunosuppression | |||||
Lymphopenia associated with the severe disease | + | + | + | NS1 | [40,41] |
Reduction of NK cell counts in the blood and/or NK cell dysfunction associated with the severe disease | + | + | + | NS | [41,124] |
Reduction of both CD4 and CD8 T cell counts in the blood associated with severe disease | + | + | + | NS | [41,52] |
Lymphopenia is commonly observed in patients with MERS, however, its association with the disease severity has not been studied.