Predictive Value of IL-8 for Mortality Risk in elderly sepsis Patients of Emergency Department

Abstract Objectives The present study aimed to explore the mortality risk of interleukin-8 (IL-8) among elderly patients diagnosed with sepsis upon admission to the emergency department. Methods A total of 273 elderly patients with sepsis were admitted to the emergency department of Beijing Chaoyang Hospital from January 2022 to April 2023. In total, 220 patients were included in the present study. Serum samples were obtained within 1 hour of admission to assess serum IL-8, white blood cell (WBC), procalcitonin (PCT), C-reactive protein (CRP), and lactic acid (LAC) levels, along with other relevant parameters. The Sequential Organ Failure Score (SOFA) and Acute Physiological and Chronic Health Assessment II (APACHE II) were recorded. Logistic regression analysis was employed to identify independent predictors of mortality within 28 days for elderly patients diagnosed with sepsis. Further, the capacity of these factors to predict 28-day mortality within this patient cohort was evaluated using Receiver Operating Characteristic (ROC) curve analysis. Results The levels of lactic acid (LAC), interleukin-8 (IL-8), procalcitonin (PCT), as well as the severity scores of APACHE II and SOFA, and the albumin (ALB) score, demonstrated notable and statistically significant distinctions between the non-survivor and survivor cohorts (P < 0.05). Through logistic regression analysis, it was determined that the SOFA score, APACHE II score, LAC, and IL-8 were all significant independent predictors for 28-day mortality in elderly sepsis patients (P < 0.05). The AUC of the ROC curve for IL-8 was calculated to be 0.701, indicating a moderately predictive performance. Sensitivity and specificity were reported as 74.5% and 63.4%, respectively, with a cut-off value of 14.497. In comparison, the AUC for LAC was marginally higher at 0.708, accompanied by a sensitivity of 76.5% and a specificity of 56.3%, with a corresponding cut-off value of 1.15. Further, the AUC for APACHE II was 0.761, indicating good predictive performance. The sensitivity and specificity for APACHE II were found to be 55.0% and 91.5%, with a cut-off value of 21.5. Nevertheless, the results of the statistical analysis reveal no significant difference in the predictive value between IL-8 and LAC (Z = 0.134, P = 0.894). However, IL-8 demonstrated a slightly higher specificity (63.4%) compared to LAC (56.3%). Moreover, the present findings indicate that the combined assessment of IL-8 and SOFA score (AUC 0.862, sensitivity 71.1%, specificity 93.0%; Z = 3.454, P = 0.005) demonstrated superior predictive value for mortality compared to using IL-8 alone. Conclusions IL-8 LAC, APACHE II, and SOFA can be considered independent predictors factors for mortality of elderly sepsis patients. Utilizing the combination of IL-8 and SOFA demonstrates a heightened predictive capability compared to using any single index alone.