Study of Association of Infection-related Biomarkers and Inflammatory Cytokines with the Severity of Coronavirus Disease 2019: A Prospective Observational Study

Sepsis-linked biomarkers and inflammatory cytokines are markedly associated with potential risks of progression to severity in coronavirus disease 2019 (COVID-19). Clinical studies that find a plausible association between sepsis biomarkers and the inflammatory cytokine response in the Indian community need to be studied with clarity. To study the relationship between sepsis-linked biomarkers and inflammatory cytokines interleukin-6 (IL-6), C-reactive protein (CRP), ferritin, and D-dimer linked to clinical severity resulting from COVID-19 infection. The present prospective observational cohort study was conducted between March and December 2021 in the Department of Critical Care Medicine at a tertiary care hospital in Pune, Maharashtra, India, on COVID-19 patients. Upon patient admission, inflammatory biomarkers such as IL-6, CRP, ferritin, and D-dimer were recorded. Oxygen requirements during hospitalization, invasive mechanical ventilation (IMV), high-flow nasal cannula (HFNC), noninvasive mechanical ventilation (NIV), duration of ventilator use, intensive care unit (ICU) stay, and mortality were documented. The average levels of IL-6, CRP, D-dimer, and serum ferritin protein recorded at the time of patient arrival were notably higher in the severe (S) group compared to the nonsevere (NS) group. The average duration of ventilator use, ICU stay, and hospital stay was significantly longer in the S group than in the NS group. The percentage of patients who required HFNC, NIV, IMV, and mortality was significantly higher in the S group compared to the NS group. Sepsis-linked biomarkers and inflammatory cytokines such as IL-6, CRP, D-dimer, and serum ferritin levels at the time of admission were markedly associated with severity outcomes in COVID-19 infection.