Early prognostic value of combined procalcitonin and interleukin-6 in sepsis: a retrospective cohort study

AIMS: To investigate the value of combined procalcitonin (PCT) and interleukin-6 (IL-6) assessment for early risk stratification in sepsis. PATIENTS AND METHODS: This retrospective cohort study enrolled 375 patients with sepsis stratified by the first Sequential Organ Failure Assessment (SOFA) score within 24 h of admission. Serum PCT and IL-6 levels were collected. Multivariable logistic regression, receiver operating characteristic analysis, internal validation, decision curve analysis, and dynamic biomarker analyses were performed. RESULTS: < 0.001). PCT remained independently associated with septic shock, whereas C-reactive protein remained independently associated with 28-d mortality. Combined PCT and IL-6 assessment showed improved predictive performance compared with either biomarker alone. Dynamic analyses further demonstrated significant differences in ΔPCT and ΔIL-6 among risk groups during d 1-7 of anti-infective therapy. CONCLUSION: Early PCT and IL-6 levels were associated with sepsis severity and adverse outcomes. Combined biomarker assessment may provide adjunctive value for early sepsis risk stratification when interpreted together with established clinical indicators.