The Value of Interleukin-6 among Several Inflammatory Markers as a Predictor of Respiratory Failure in COVID-19 Patients

Abstract

Patients with coronavirus disease 2019 (COVID-19) develop severe respiratory failure within a short period during the clinical course. It is essential to predict respiratory deterioration in the short term. We investigated the use of inflammatory markers to predict respiratory distress within three days from their analysis in COVID-19 patients. This retrospective observational study included 81 patients admitted with COVID-19. Patients were divided into two groups according to whether the maximum fraction of inspired oxygen (FiO2) for three days from the blood marker measurements was ≥0.4 (high FiO2 group; HFG) or <0.4 (low FiO2 group; LFG). Interleukin-6 (IL-6), C-reactive protein (CRP), lactate dehydrogenase (LDH), white blood cell, D-dimer, and creatinine levels were compared between the two groups. The levels of all markers were significantly higher in HFG patients. Areas under the receiver operating characteristic curve of IL-6, CRP, and LDH had high values of 0.85, 0.82, and 0.81, respectively. The odds ratio of IL-6 which was crude and adjusted for dexamethasone administration initiated before laboratory measurement, showed the high value of 29.1 (5.6–295.6) and 53.9 (4.5–3242.8), respectively. IL-6 can be used as a reliable marker for predicting respiratory illness within three days after assessment.

Identification of IL-6 Signalling Components as Predictors of Severity and Outcome in COVID-19

“…Most investigations regarding IL-6 in SARS-CoV-2 infection have demonstrated that IL-6 increases prior to ARDS in critical COVID-19 patients (35) and that elevated IL-6 levels were predictors of the need for mechanical ventilation (40). Our results are in line with those studies in the context of severity of the disease.…”

“…Our cohort was initially classified into moderate and severe patients, distinguishing two groups in the latter category, severe survivors and severe non-survivors. Similar to recent studies, our data showed that IL-6 was significantly increased in severe groups (35). However, the levels of IL-6 were lower compared to those observed in sepsis (983 pg/mL), in non-COVID ARDS (460 pg/mL), and in CAR-T CRS (3110 pg/mL) (36), suggesting that the systemic inflammation during COVID-19 is less robust (37)(38)(39).…”

Interaction of ACEI antihypertensive agent's administration with the inflammatory status at admission concerning COVID-19 clinical stay outcomes

“…Clinical and phenotypical characteristics of COVID-19 patients were compared by categorical variables or by the median values of continuous variables. For this last purpose, the reference values of IL-6 and LDH considered in our design are compatible with previous reports exploring laboratory predictors and prognostic factors of severe COVID-19 disease concerning respiratory functions [ 10 , 11 ] as well as pharmacological prescription making decision criteria [ 12 ]. Moreover, Chi-square and unpaired Student's t -tests were applied for the univariate analysis.…”

Roles of Interleukin-6-mediated immunometabolic reprogramming in COVID-19 and other viral infection-associated diseases

“…The level of CRS-related cytokine IL-6 in COVID-19 patients is gradually increased with the increasing severity ranging from asymptomatic cases to mild and severe cases [76] , [92] . Similarly, the correlation between the IL-6 level and metabolites increases with the increasing disease severity.…”

“…4 ). Thus, IL-6 acts as a pivotal inflammatory factor triggering CRS in COVID-19 patients, which can be used to effectively assess the disease severity and predict prognosis of COVID-19 patients [90] , [91] , [92] . Recent clinical trials have shown that tocilizumab could suppress hyperactive immune response, improving the inflammatory symptoms of patients with or without mild organ damage at the early stage of COVID-19 [86] , [88] , [93] .…”