探讨中性粒细胞/淋巴细胞比值(NLR)与急性肾损伤(AKI)重症患者90 d死亡风险之间的关系，评估NLR对此类患者预后的预测价值。

回顾性分析2015年1月至2019年12月收治于西安交通大学第一附属医院重症监护病房的802例AKI患者，根据入院初始NLR水平分为低NLR组(NLR<9)及高NLR组(NLR≥9)，比较组间基础疾病、初始序贯器官衰竭评分(SOFA)、白细胞(WBC)、中性粒细胞百分比(NEU%)、血红蛋白(Hb)、血小板(PLT)、乳酸(Lac)、pH值、血糖(Glu)、肌酸激酶(CK)、90 d全因死亡情况等变量之间的差异。运用Logistic回归模型分析AKI重症患者90 d死亡的危险因素；绘制受试者工作特征(ROC)曲线，并根据ROC曲线下面积(AUC)评估NLR对AKI重症患者住院90 d死亡风险的预测价值。

两组患者的年龄、性别、AKI分期、Glu差异均无统计学意义；高NLR组患者的SOFA评分、WBC、Neu%、Hb、PLT、BUN、SCr、Lac及CK均高于低NLR组患者，BMI及pH值低于低NLR组患者。相较于低NLR组，高NLR组的90 d死亡率明显升高(32.6% vs 16%，P<0.001)。多因素Logistic回归分析显示，即使校正了年龄、性别、BMI、基础病因素、Lac值、AKI分期以及SOFA评分后，NLR仍是AKI重症患者90 d死亡的独立预测因子(OR＝2.402，95%CI：1.633～3.533，P<0.001)。基于传统指标(年龄、性别、BMI、基础疾病、AKI分期、SOFA评分及Lac)的90 d死亡风险基础预测模型AUC为0.761(95%CI：0.730～0.790)，而基础模型联合NLR的90 d死亡风险预测模型AUC为0.783(95%CI：0.753～0.811)，二者之间的差异具有统计学意义(P＝0.0067)。

NLR对AKI重症患者90 d死亡风险具有一定的预测价值，有助于提高基础模型对AKI重症患者90 d死亡风险的预测能力。

To explore the relationship between the neutrophil-to-lymphocyte ratio (NLR) and the 90-day mortality risk in severe patients with acute kidney injury (AKI), so as to evaluate the predictive value of NLR for the prognosis.

Retrospective analysis was made in 802 AKI patients who were admitted to the intensive care unit of the First Affiliated Hospital of Xi′an Jiaotong University from January 2015 to December 2019, and divided into low-NLR group (NLR<9) and high-NLR group (NLR≥9) according to the NLR level at admission. Differences were compared between the two groups in the underlying diseases, initial sequential organ failure assessment (SOFA), white blood cells (WBC), neutrophil percentage (NEU%), hemoglobin (Hb), platelet (PLT), lactic acid (Lac), pH, blood glucose (Glu), creatine kinase (CK), 90-day all-cause-death, and other variables. Logistic regression model was used to analyze the risk factors for 90-day mortality in critically ill patients with AKI. The receiver operating characteristic (ROC) curve was drawn, and the area under the ROC curve (AUC) was calculated to evaluate the predictive value of NLR for the 90-day mortality in critically ill patients with AKI.

There was no statistically significant difference in age, gender, ill AKI staging, and Glu between the two groups. In the high-NLR group, the levels of SOFA score, WBC, Neu%, Hb, PLT, BUN, SCr, Lac, and CK were higher, while BMI and pH were lower than those in the low-NLR group. The 90-day mortality rate was significantly higher in the high-NLR group than in the low-NLR group (32.6% vs 16%, P< 0.001). Multivariate logistic regression analysis showed that even after adjustment for age, gender, BMI, underlying disease factors, Lac value, AKI staging, and SOFA score, the NLR was still an independent predictor of 90-day mortality in critically ill patients with AKI (OR=2.402, 95%CI: 1.633-3.533, P<0.001). The AUC of the 90-day mortality risk prediction model based on traditional indicators (age, gender, BMI, underlying diseases, AKI staging, SOFA score, and Lac) was 0.761 (95%CI: 0.730-0.790), while the AUC of the 90-day mortality risk prediction model based on both traditional indicators and NLR was 0.783 (95%CI: 0.753 to 0.811), and the difference between the two models was statistically significant (P=0.0067).

NLR had a certain predictive value for the 90-day mortality risk in critically ill AKI patients, and might help improve the predictive ability of the model based on the traditional indicators.