Objective To explore the value of neutrophil to lymphocyte ratio (NLR) combined with human neutrophil lipocalin (HNL) in evaluating the severity and prognosis of sepsis patients.

Methods A total of 70 patients with sepsis were selected and divided into mild sepsis group (n = 36), severe sepsis group (n = 25), and sepsis shock group (n = 9) according to the severity of disease. The patients were further divided into death group (n = 16) and survival group (n = 54) based on their clinical outcomes within 28 days after admission. Pearson method was used to analyze the correlation between NLR and HNL levels in sepsis patients; logistic regression analysis was applied to evaluate the relevant factors affecting the prognosis of sepsis patients; ROC curve analysis was employed to analyze the predictive efficacy of NLR and HNL for the prognosis of sepsis patients.

Results The NLR of patients in the sepsis shock group was higher than that in the mild sepsis group (P ＜ 0.05); the HNL levels of patients in the severe sepsis group and sepsis shock group were higher than those in the mild sepsis group (P ＜ 0.05), and the HNL levels of patients in the sepsis shock group were higher than those in the severe sepsis group (P ＜ 0.05). The NLR and HNL levels of patients in the death group were higher than those in the survival group (P ＜ 0.05 and P ＜ 0.01), and the differences of red blood cell distribution width, platelet distribution width, and platelet count between the two groups were statistically significant (P ＜ 0.01). The results of Pearson correlation analysis showed that NLR was positively correlated with HNL levels in sepsis patients (r = 0.708, P ＜ 0.05). The results of multivariate logistic regression analysis indicated that red blood cell distribution width ≥16%, platelet distribution width ≥22 fl, and elevated NLR and HNL levels were all risk factors for death in sepsis patients (P ＜ 0.05 to P ＜ 0.01), while platelet count ≥150 × 10⁹/L was the protective factor (P ＜ 0.05). The results of ROC curve analysis found that the AUC of NLR and HNL independently predicting prognosis and death of sepsis patients were 0.642 and 0.769, respectively, and the AUC predicted by the combination of the two was 0.887, which was better than that predicted by NLR and HNL independently (Z = 2.47, 1.98, P ＜ 0.05).

Conclusions The increase of NLR and HNL levels can promote the development of sepsis, and the combined detection of NLR and HNL has high predictive value for the prognosis of sepsis patients.