Objective  To analyze the correlations between levels of antibacterial peptide LL-37 as well as procalcitonin (PCT) and disease condition as well as short-term prognosis in patients with septic shock.

  Methods  A total of 90 patients with systemic inflammatory response syndrome (SIRS) were collected as study objects, and were divided into septic shock group (44 cases) and sepsis group (46 cases) according to severity of the sepsis. Another 50 patients with mild infection were chosen as control group. The serum levels of antibacterial peptide LL-37, PCT, hypersensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6) and the scores of APACHE Ⅱ as well as Sequential Organ Failure Assessment (SOFA) score were detected and compared between two groups. The correlations of serum levels of antibacterial peptide LL-37, PCT and APACHE Ⅱ as well as SOFA scores were confirmed by Pearson linear correlation analysis. Follow-up 28 days, the patients with septic shock were divided into survival group and death group according to the prognosis, and levels of antibacterial peptide LL-37 and PCT were compared. The risk factors of survival prognosis were confirmed by multivariate Logistic analysis. The diagnostic value of the serum levels of antibacterial peptide LL-37 and PCT to the prognosis of the patients with septic shock were analyzed by receiver operating characteristic curves (ROC).

  Results  The levels of antibacterial peptide LL-37, PCT, hs-CRP, IL-6, APACHE Ⅱ scores and SOFA scores in the septic shock group were higher than that of the sepsis group, and the above indexes in the sepsis group were higher than that in the control group (P < 0.05). The antibacterial peptide LL-37 and PCT were positively correlated with SOFA scores (r=0.803, P=0.024; r=0.826, P=0.019) and APACHE Ⅱ scores (r=0.784, P=0.029; r=0.811, P=0.022). Serum levels of antibacterial peptide LL-37 and PCT in the death group were significantly higher than those in the survival group (P < 0.05). Serum antibacterial peptide LL-37, PCT and SOFA score were all influencing factors for the prognosis of patients with septic shock (OR=2.913, 2.887, 2.457, P=0.029, 0.036, 0.045). The ROC curve showed that the area under the curve (AUC) of serum antibacterial peptide LL-37 combined with PCT in predicting the death of patients with septic shock after 28 days follow-up was 0.806, the sensitivity was 89.6% and specificity was 82.4%.

  Conclusion  The combination of the serum levels of antibacterial peptide LL-37 and PCT can effectively assess the ill-condition and short-term prognosis of patients with septic shock.