Eosinophil-independent IL-5 levels are increased in critically ill COVID-19 patients who survive

The alarmin IL-33 exacerbates pulmonary inflammation and immune dysfunction in SARS-CoV-2 infection

“…In contrast, the alteration of type II cytokines (IL-4, IL-13, and IL-10) was relatively mild ( Figure 1 ). Increased levels of serum IL-5 have been reported in critically ill COVID-19 patients, 30 and we also observed a strong increase in serum IL-5 at day 2 in mice. Next, we explored the role of IL-33 in animal models using two strategies that included an IL-33 knockout (endogenous) and treatment with recombinant IL-33 (exogenous) ( Figures 2 and 3 ).…”

The Impact of Cytokines on Coagulation Profile in COVID-19 Patients: Controlled for Socio-Demographic, Clinical, and Laboratory Parameters

“…In our study, we observed an association of higher IL-5 values with prolonged bleeding time. More recent studies have shown that high levels of IL-5 are associated with better survival in critical patients with COVID-19 [ 42 ]. IL-5- and eosinophil-mediated inflammation regulates the expression of genes involved in cell proliferation, survival, and maturation, as well as effector functions of B cells and eosinophils [ 43 ].…”

“…Because of their prepared granules, which include cytotoxic proteins such as eosinophil peroxidase, major basic protein, eosinophil neurotoxin, and eosinophil cationic protein, as well as reactive nitrogen species, eosinophils are crucial in the host’s defense against viral infections [ 44 ]. It is unlikely that eosinophils directly contributed to the favorable outcomes, but activated CD8 T-cells mediate antiviral responses leading to improved survival [ 42 , 44 ]. We also found associations between lower values of IL-17F and IFN-γ and prolonged coagulation time as measured by INR, aPTT, and prothrombin time.…”