A Secondary Retrospective Analysis of the Predictive Value of Activated Neutrophils (NEUT-RI) in Septic and Non-septic Patients in Intensive Care

Background: Effective identification and management in the early stages of sepsis are critical for achieving positive outcomes. In this context, neutrophil activation status (NEUT-RI) emerges as a promising and easily interpretable parameter. This study aimed to assess the predictive value of NEUT-RI in diagnosing sepsis and to evaluate its prognostic significance in distinguishing 28-day mortality outcomes. Materials: The study is a secondary retrospective observational analysis. Clinical data upon ICU admission were collected. A control group of critically ill patients without sepsis criteria was included. Patients were divided into subgroups based on renal function for biomarker evaluation, with 28-day outcomes reported for septic and non-septic patients. Results: 200 patients were included in the study. A significant difference between the "septic" and "non-septic" groups was detected in the NEUT-RI plasma concentration (53.80 [49.65–59.05] vs. 48.00 [46.00–49.90], p< 0.001, respectively). NEUT-RI and PCT distinguished between not complicated sepsis and septic shock (PCT 1.71 [0.42 - 12.09] vs 32.59 [8.83 - 100.00], < 0.001 and NEUT-RI 51.50 [47.80 - 56.30] vs 56.20 [52.30 - 61.92], p=0.005). NEUT-RI, PCT and CRP values were significantly different in patients with “renal failure”. NEUT-RI and PCT at admission in ICU in septic group were higher in patients who died (58.80 [53.85-73.10] vs 53.05 [48.90-57.22], p=0.005 and 39.56 [17.39-83.72] vs 3.22 [0.59-32.32], p=0.002, respectively). Both NEUT-RI and PCT showed high negative predictive value and low positive predictive value. Conclusions: The inflammatory biomarkers assessed in this study offer valuable support in the early diagnosis of sepsis. NEUT-RI elevation appears particularly promising for early sepsis detection and severity discrimination upon admission