Soluble IL-2R Levels Predict in-Hospital Mortality in COVID-19 Patients with Respiratory Failure

Abstract Acute respiratory distress syndrome is the primary cause of death in patients with coronavirus disease 2019 (COVID-19) pneumonia. Our study aims to determine the association between serum markers and mortality in COVID-19 patients with respiratory failure. This retrospective study was conducted in a tertiary care hospital in South Korea. Forty-three patients with COVID-19, who required high flow nasal cannulation or mechanical ventilation from Feb 2020-Jan 2021, were included. Demographic and laboratory data were analyzed at baseline and on Day 7 of admission. Older age was associated with mortality. Serum creatinine, troponin, procalcitonin, and soluble interleukin-2 receptor (sIL-2R) at baseline were more elevated in the non-survivor group; however, were not associated with mechanical ventilator use on Day 7 PaO2/FiO2 ratio, lymphocyte and platelet counts, lactate dehydrogenase, IL-6, c-reactive protein, and sIL-2R on Day 7 were significantly associated with mortality. Delta sIL-2R (Day 7-Day 0) per standard deviation was significantly higher in the non-survivor group (adjusted hazard ratio 3.225, 95% CI 1.151-9.037, p=0.026). sIL-2R could predict mortality in COVID-19 patients with respiratory failure, not mechanical ventilator use. Its sustained elevation suggests a hyper-inflammatory state, and mirrors the severity of COVID-19 in patients with respiratory failure; therefore, warrants further attention.