The diagnostic and prognostic value of sTM, t-PAIC, and NLRP3 in ICU patients with sepsis

BACKGROUND: This study aimed to evaluate the diagnostic and prognostic values of soluble thrombomodulin (sTM), tissue-type plasminogen activator-inhibitor 1 complex (t-PAIC), and NLRP3 in sepsis patients admitted to the intensive care unit (ICU). METHODS: This retrospective study enrolled 206 patients with sepsis or septic shock. Baseline characteristics and inflammatory markers were compared among sepsis, septic shock, and ICU control groups, as well as between survivors and non-survivors. Serum levels of sTM, t-PAIC, and NLRP3 were measured. ROC curves were used to evaluate diagnostic performance, while univariate and multivariate analyses identified significant prognostic predictors. RESULTS: Significant differences were observed in BMI, heart disease, lung disease, APACHE II scores, mechanical ventilation, vasopressor use, CRRT, and 28-day mortality across the three groups (all p < 0.05). Compared to ICU controls, the sepsis group showed significant differences in WBC and sTM levels, while the septic shock group exhibited variations in ten biomarkers, including WBC, neutrophil count, AST, BUN, Cr, CRP, IL-6, Lac, D-dimer, and sTM. Distinct biomarker profiles differentiated sepsis from septic shock (NLR, AST, CRP, IL-6, Lac). PCT, t-PAIC, and NLRP3 levels differed significantly across all group comparisons (all p < 0.05). Age, APACHE II score, neutrophil count, PLT, NLR, AST, BUN, Na+, PCT, P/F ratio, Lac, sTM, and t-PAIC were significantly different between survivors and non-survivors (all p < 0.05). Among individual indicators, NLRP3 showed the highest diagnostic accuracy (AUC = 0.992). However, the diagnostic performance of the sTM and NLRP3 combination (AUC = 0.802), the t-PAIC and NLRP3 combination (AUC = 0.805), and the three-biomarker panel (AUC = 0.822) for septic shock was lower than that of NLRP3 alone. Prognostic stratification using APACHE II, IL-6, PCT, Lac, sTM, t-PAIC, and NLRP3 revealed significant differences in survival outcomes. APACHE II score, PCT, sTM, and t-PAIC were identified as independent prognostic factors. CONCLUSIONS: sTM, t-PAIC, and NLRP3 demonstrate measurable utility in differentiating sepsis from general ICU controls, with sTM and t-PAIC showing a modest association with survival outcomes. NLRP3 exhibits a relatively stronger signal in identifying septic shock, while sTM and t-PAIC may serve as independent prognostic indicators.