Early Cytokine Profiles in Critically Ill Patients with COVID-19 and Their Association with Mortality

BACKGROUND/OBJECTIVES: The purpose of this study was to (i) determine the levels of interleukins in patients with COVID-19 admitted to the Intensive Care Unit (ICU) and (ii) evaluate their early dynamics, as well as (iii) assess their relationships with morbidity and mortality. METHODS: This was a prospective analytical study of critically ill patients with COVID-19 who were monitored from admission to three days of stay in the ICU. Circulating levels of IL-1β, IL-2, IL-6, IL-7, IL-8, IL-10, and tumour necrosis factor-alpha (TNF-α) were measured. Cytokine levels were analysed in relation to clinical severity parameters and 28-day mortality. RESULTS: A dynamic cytokine response was observed during the first 72 h, with a significant increase in TNF-α levels and a decrease in IL-10 and IL-1β. Non-survivors showed higher TNF-α levels than survivors. In the multivariable analysis adjusted for clinical severity, TNF-α remained independently associated with 28-day mortality, whereas other cytokines did not retain statistical significance. The overall predictive performance of cytokines was moderate. CONCLUSIONS: Early cytokine dynamics reflect the evolving inflammatory response in critically ill COVID-19 patients. TNF-α emerges as an independent predictor of mortality, supporting its role as a relevant biomarker of adverse outcomes. Although its predictive capacity is moderate, TNF-α may provide clinically meaningful information for risk stratification when integrated with established clinical and laboratory parameters.