Analysis of the Value of IL-6 and PCT in the Assessment of Disease Severity and Prognosis of Patients with Severe Community Acquired Pneumonia

LIU Fei; JIANG Chen; HONG Yuze; HE Hantao; WANG Xiaoyao

doi:10.3639/j.issn.2095-3097.2025.04.008

Abstract：Objective To investigate the value of interleukin-6(IL-6)and procalcitonin(PCT)levels in the assessment of disease severity and prognosis in patients with severe community-acquired pneumonia(SCAP).Methods A total of 130 patients with community-acquired pneumonia diagnosed at Huangshan Shoukang Hospital from October 2020 to March 2024 were enrolled.Patients were divided into a severe group(n=68)and a mild group(n=62)based on pneumonia severity index(PSI)and CURB-65 scores.The severe group was further categorized into a good prognosis group(n=50)and a poor prognosis group(n=18)according to 28-day outcomes.IL-6 levels were measured via chemiluminescence immunoassay(Roche Cobas e801 analyzer);PCT levels were determined using electrochemilumi-nescence(BRAHMS PCT-sensitive KRYPTOR system).Group differences were compared,and independent risk factors for disease severity and prognosis were identified through multivariate logistic regression.Receiver operating character-istic(ROC)curves were generated to evaluate the predictive value of IL-6,PCT,and their combination.Results Serum IL-6 and PCT levels were significantly elevated in the severe group compared with the mild group(both P＜0.05),and markedly reduced in the good prognosis group versus the poor prognosis group(both P＜0.05).Multifactorial logistic re-gression analysis identified IL-6 and PCT as independent risk factors for both SCAP severity and poor prognosis(both P＜0.05).ROC curve analysis showed that the combination of IL-6/PCT model(AUC=0.851,95％CI:0.744-0.926)outperformed individual markers(IL-6 AUC=0.668;PCT AUC=0.658),with sensitivity of 86.00％and specificity of 77.78％.Conclusion IL-6 and PCT levels correlate with disease severity and prognosis in SCAP.Combined measure-ment enhances prediction accuracy,providing a basis for early clinical intervention.