IL15 and COVID-19: Baseline levels of selected parameters previously related to an inflammatory state in acute COVID-19 were evaluated and, as expected, circulating concentrations of chemokines (IL-7, IL-15, TNF-α and IFN-γ) and biochemical parameters (D-dimer, fibrinogen, ferritin, C-reactive protein [CRP] and glucose) were all significantly higher in the severe and critical groups than in the mild group (Table 1).