Systemic Immune-Inflammatory Index predicts prognosis of patients with COVID-19: a retrospective study

Abstract

Background Our study aimed to investigate the prognostic value of a novel inflammatory index, systemic immune-inflammation index (SII), with the clinical outcomes of patients infected with coronavirus disease 2019 (COVID-19).Methods We evaluated a cohort study of COVID-19 patients (18–95 years old) in Tongji Hospital of Huazhong University of Science and Technology from January 28th 2020 to February 29th 2020. The enrolled patients were divided into two groups (including low-SII group and high-SII group) according to the cut-off point which is analyzed by receiver operating characteristic (ROC) curve. Univariate and multivariate COX regression analysis were performed to identify the factors associated with the outcomes of patients with COVID-19 infection. The primary and secondary outcome were in-hospital mortality and the development of acute respiratory distress syndrome (ARDS), respectively.Results A number of 326 adult patients (43.87% males, 61.22 ± 0.86 years) were enrolled in the final analyses. There were 147 cases (45.09%) died in hospital and 116 patients (35.58%) developed ARDS. ROC curve analysis indicated that the SII had a greater prediction accuracy in predicting the in-hospital mortality (area under the curve [AUC] = 0.789, sensitivity = 69.90%, specificity = 70.80%) and the development of ARDS (AUC = 0.736, sensitivity = 67.80%, specificity = 71.10%). Kaplan-Meier analysis revealed that patients in high-SII group had a greater risk of adverse clinical outcomes (all P < 0.001). The multivariate Cox regression analysis indicated that elevated SII was found as the risk predictor of in-hospital mortality (hazard ratio [HR] = 2.839, 95% confidence interval [CI] = 1.116–7.222, P = 0.028) and the developed ARDS (HR = 6.832, 95%CI = 2.583–18.074, P < 0.001). Additional significant independent predictor for adverse outcomes was the lymphocyte proportion. What’s more, it suggests that the invasive mechanical ventilation performed in the early stage of the disease progression may be beneficial for patients.Conclusion SII, a novel biomarker, might be a remarkable prognostic indicator to assess the in-hospital mortality and the development of ARDS in patients with COVID-19 and help for clinical risk assessment.

Can prognostic nutritional index and systemic immune‐inflammatory index predict disease severity in COVID‐19?

“…16,17 However, there are a few studies investigating the predictive role of SII in the prognosis of COVID-19. 20,33 In those studies, the SII levels were high in patients who died at the hospital and who developed ARDS. In our study, SII was significantly specificity for prediction of the disease severity in COVID-19.…”

“… 16 , 17 , 18 , 19 However, there are only a very few studies investigating the role of SII in reflecting the inflammatory status and prediction of prognosis in COVID‐19 patients. 20 PNI and SII markers are helpful predictors for COVID‐19 patients.…”

Combined Blood Indexes of Systemic Inflammation as a Mirror to Admission to Intensive Care Unit in COVID-19 Patients: A Multicentric Study

“…SII, which depends on the number of lymphocytes, neutrophils, and platelets, is an indicator associated with inflammation and can reflect the immune and inflammatory state [12]. Some studies have identified a clear correlation between SII and prognosis in malignancy and inflammatory conditions [13,14]. However, there are limited data about the benefit of SII in assessing the prognosis in COVID-19 patients.…”

Quantitative Evaluation of COVID-19 Pneumonia Lung Extension by Specific Software and Correlation with Patient Clinical Outcome

“…In particular, we dichotomized the continuous variables above/below the median and summed for each patient the single variables in order to have a score that could assume values from 0 (low risk) to 10 (high risk) (CLINICAL). To this, we added as variable for multivariate analysis the Total affected lung V% (VOLUME) and Systemic Inflammatory response Index as a surrogate of all laboratory test included in the manuscript (calculated by: platelet counts × neutrophil counts/lymphocyte counts) (INFLA) as suggested by recent publications to be a remarkable prognostic indicator to assess the in-hospital mortality and the development of respiratory complications in patients with COVID-19 [ 11 , 12 ]. The performance of the predictive models, singles and composite (MODEL 1 including all clinical, laboratory and CT variables) were assessed using receiver operating characteristic analysis (ROC), and the area under the curve (AUC) values were compared using the DeLong test.…”