Association of interleukin-6 levels with morbidity and mortality in patients with coronavirus disease 2019 (COVID-19)

Abstract

The prognostic value of interleukin-6 (IL-6) in coronavirus disease 2019 (COVID-19) needs to be clarified. In this retrospective study, COVID-19 patients treated at Renmin Hospital of Wuhan University from January 7 to February 8, 2020 with measurements of serum IL-6 levels within 1 week after admission were included. Data regarding demographics, clinical characteristics, laboratory tests, complications, and outcomes were collected and analyzed. Sixty-six patients diagnosed with COVID-19 were included in this study (31 patients were females). They were divided into a normal group (serum IL-6 <10 pg/mL, n = 35) and an abnormal group (serum IL-6 <10 pg/mL, n = 31). Compared with the normal group, the incidence of critical cases (P <0.001), acute respiratory distress syndrome (ARDS) (P = 0.001), acute cardiac injury (P = 0.002), cardiac insufficiency (P = 0.039), mechanical ventilation rate (P = 0.002), and mortality (P = 0.021) was significantly increased in the abnormal group. Serum IL-6 concentration was an independent predictor of fatal outcome (P = 0.04). The optimal cutoff value of serum IL-6 concentration for predicting fatal outcomes was 26.09 pg/ mL (P <0.001). In COVID-19, elevated serum IL-6 levels were associated with critical illness, use of mechanical ventilation, and complications, including heart injury and ARDS, and could predict a fatal outcome. Early detection of serum IL-6 levels after admission should be necessary in COVID-19 patients.