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

PCT and IL-6 levels increased progressively across risk strata and correlated positively with SOFA score (both p < 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.