PT - JOURNAL ARTICLE AU - VASSILIOU, ALICE G. AU - DIMOPOULOU, IOANNA AU - JAHAJ, EDISON AU - KESKINIDOU, CHRYSI AU - MASTORA, ZAFEIRIA AU - ORFANOS, STYLIANOS E. AU - KOTANIDOU, ANASTASIA TI - Selection of the Appropriate Control Group Is Essential in Evaluating the Cytokine Storm in COVID-19 AID - 10.21873/invivo.12381 DP - 2021 Mar 01 TA - In Vivo PG - 1295--1298 VI - 35 IP - 2 4099 - http://iv.iiarjournals.org/content/35/2/1295.short 4100 - http://iv.iiarjournals.org/content/35/2/1295.full SO - In Vivo2021 Mar 01; 35 AB - Background/Aim: Lately, studies have reported contradicting results on the cytokine storm seen in critically-ill COVID-19 patients. Depending on the control group used, cytokines have been found to be higher, similar or even lower in COVID-19 compared to critical illnesses associated with elevated cytokine concentrations. However, most of these studies do not take into account critical illness severity. Hence, we decided to compare cytokine levels in critically-ill COVID-19 patients and critically-ill patients of a general intensive care unit (ICU), who did not have sepsis or septic shock, but had an equal disease severity. Patients and Methods: Interleukin (IL)-6, IL-8, IL-10 and tumour necrosis factor-α (TNF-α) were measured on ICU admission in mechanically ventilated, COVID-19 (N=36) and non-COVID-19 (N=30) patients, who had not received dexamethasone, and had equal critical illness severity. Non-COVID-19 patients did not have sepsis or septic shock. Results: In our case control study, circulating IL-6 and IL-10 were lower, while TNF-α and IL-8 levels were higher in critically-ill COVID-19 patients, compared to critically-ill non-COVID-19 patients. Conclusion: It is difficult to infer whether the cytokine storm seen in COVID-19 differs from other critical conditions. It is important to recognize that the conclusions of related studies may depend on control group selection.