Markers of inflammasome activation in Coronavirus disease 2019 (COVID-19) Egyptian patients: Impact on disease severity

There are conflicting data regarding the relationship between coronavirus disease 2019 (COVID-19) severity and Caspase-1 (Casp-1), interleukin-1ß (IL-1β), and IL-18. Our study sought to quantify the levels of IL-18, IL-1ß, and Casp-1 as indicators for inflammasome activation in COVID-19 patients at Assiut University Hospitals and to correlate their levels with parameters of disease severity in COVID-19 patients. Serum levels of Casp-1, IL-1β and IL-18 were measured in 63 COVID-19 patients and 26 normal controls by an enzyme linked immunosorbent assay (ELISA). Also, arterial blood gas analysis and laboratory parameters including hemoglobin, platelets, lymphocyte count, liver function test, kidney function test, C-reactive protein (CRP), D-dimer, ferritin and LDH were estimated. Serum levels of Casp-1, IL-1β and IL-18 were significantly higher in the COVID-19 group as compared to controls (p= 0.04, p=0.001 and p=0.03, respectively). Although the three markers were higher in the severe group, yet only IL-1ß showed a significant difference as compared to the non-severe group (p=0.04). IL-18 had significant positive correlations with CRP and ferritin (p = 0.04 and p = 0.02, respectively). IL-1β was positively correlated with alanine aminotransferase. Casp-1 had significant positive correlations with CRP and lactate dehydrogenase (p=0.045 and p=0.001, respectively). Patients showed weak positive correlations between serum level of Casp-1 and each of IL-1β and IL-18. Also, a strong positive correlation was found between IL-1β and IL-18 (p < 0.0001). In conclusion, inflammasome activation was a hallmark in COVID-19 patients. The markers of activation were positively correlated with many parameters of inflammation, may suggest their important roles in the pathophysiology of the disease and its progression. IL-1β was the only marker to be correlated with disease severity and therefore may be suggested as a potential marker for identifying severe COVID-19 patients.