AIM: The severity of COVID-19 is influenced by uncontrolled hyper-inflammatory response with excessive release of many cytokines and chemokines. The understanding of the temporal change in the cytokine levels that underlies the diverse clinical presentations of COVID-19 can help in the prediction of the disease outcome and in the design of proper treatment strategies. METHOD: Data were collected from children (<
18 years old) hospitalised with severe COVID-19 or severe MIS-C who were compared to a group of healthy control children. Patient demographics, clinical, laboratory data and cytokines profiles were evaluated. Blood samples were collected within 24 h of admission for all enrolled children and on Day 14. RESULTS: Twenty-five children with severe COVID-19 and 23 cases with severe MIS-C were included in the study. The biochemical and inflammatory markers tend to be elevated in MIS-C group. There was a significant difference between studied cases and the control group in the following cytokines: G-CSF, IL-10, HMGB1, TNF-α, IL-6, IL-8 and INF-gamma (P <
0.05). While there was a significant difference between severe COVID-19 and MIS-C groups in the following cytokines at Day 1 of admission
IL-10, IL-6, IL-8 and INF-gamma
while at Day 14, there was a significant difference only for G-CSF, IL-10 and IL-6, all other cytokines were comparable. CONCLUSION: Our study underpinned patterns of cytokine response in severe COVID-19 and MIS-C. There is a significant upregulation in pro-inflammatory cytokines (mainly G-CSF, IL-10, HMGB1, TNF-α, IL-6, IL-8 and INF-gamma). These biomarkers that could imply on the severity rating and treatment strategies, should be preferentially assessed in SARS-CoV-2 associated immunological events.