目的：探讨白细胞和血小板（white blood cell/platelet, WBC/PLT）比值对脓毒症预后早期评估中的临床价值和相关影响因素。方法：前瞻性分析2018年6月至2020年6月上海交通大学医学院附属瑞金医院急诊重症监护室（emergency intensive care unit, EICU）收治的150例脓毒症患者临床资料。根据预后分为存活组和死亡组,比较2组患者发病后24 h内WBC/PLT比值及临床生化指标差异。WBC/PLT比值与脓毒症患者各危险因素的相关性采用Pearson相关分析。采用Cox风险回归模型分析患者预后的影响因素,并绘制受试者工作特征曲线（receiver operating characteristic curve,ROC曲线）评估WBC/PLT比值对死亡的预测效果。结果：150例患者中存活组126例,死亡组24例,2组脓毒症患者年龄、性别、感染类型和基础疾病构成比差异无统计学意义（均P>0.05）;死亡组脓毒症休克比例、使用血管活性药物和机械通气及血液净化比例显著高于存活组（均P<0.05）;死亡组降钙素原、尿素氮、天冬氨酸转氨酶、凝血酶原时间、纤维蛋白降解产物、D-二聚体、前脑钠肽以及序贯器官衰竭评估（sequential organ failure assessment,SOFA）评分显著高于存活组（均P<0.05）;脓毒症死亡组患者WBC/PLT比值（0.56±1.27）显著高于存活组（0.15±0.42）（P<0.05）。150例研究对象Pearson相关分析显示：WBC/PLT比值与C反应蛋白、降钙素原、尿素氮、肌酐、前脑钠肽、活化部分凝血酶原时间、纤维蛋白降解产物、D-二聚体呈正相关,随之增加而增加（P<0.05）。Cox回归模型分析显示,高WBC/PLT比值、高尿素氮水平、高SOFA评分为影响脓毒症患者预后的独立危险因素（P<0.05）,ROC曲线分析显示,WBC/PLT比值对脓毒症患者预后有预测价值,曲线下面积为0.643[95%置信区间（confidence interval,CI）：0.516~0.770,P=0.026],最佳截断值为0.186,灵敏度为37.5%,特异度为91.3%。结论：WBC/PLT比值用于脓毒症病情评估特异性较高,可以早期预估患者的预后,值得临床推广应用。

Objective To investigate the clinical value of white blood cell-to-platelet (WBC/PLT) ratio and related factors in early prognosis evaluation of sepsis. Methods The clinical data of 150 patients diagnosed with sepsis admitted to the emergency intensive care unit (EICU) in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from June 2018 to June 2020 were prospectively analyzed. According to survival or death, the patients were divided into survival group(n=126) and death group(n=24). The difference of WBC/PLT and clinical and biochemical indexes between two groups in 24 h after onset of sepsis were compared, and the Pearson correlation was used to analyze the correlation between WBC/PLT ratio and risk factors in the patients with sepsis. The Cox regression model was used to evaluate the clinical predictive value of various factors on mortality, and the receiver operating characteristic(ROC) curve was applied to analyze the predictive effect of WBC/PLT ratio on prognosis in the patients with sepsis. Result There was no significant difference in age, gender, infection type and constituent ratio of underlying diseases between the survival or death groups (P>0.05). The proportion of septic shock patients, receiving vasoactive medicines, mechanical ventilation and blood purification in the death group were significantly higher than those in the survival group(P<0.05). The levels of procalcitonin (PCT), urea nitrogen, aspartate aminotransferase (AST), prothrombin time (PT), fibrinogen degradation product （FDP）, D-dimer, pro-brain natriuretic peptide（pro-BNP）and sequential organ failure assessment(SOFA) scores in the death group were significantly higher than those in the survival group. The ratio of WBC/PLT in death group (0.56±1.27) was significantly higher than that in survival group(0.15±0.42)(P<0.05). The Pearson correlation analysis showed that the ratio of WBC/PLT was positively correlated with C-reaction protein(CRP), PCT, urea nitrogen, creatinine, pro-BNP, FDP, and D-dimer(P<0.05). The Cox regression model analysis presented that high WBC/PLT ratio, high urea nitrogen level and high SOFA score were independent risk factors for prognosis in the patients with sepsis (P<0.05). The area under ROC curve of WBC/PLT ratio was 0.643(95% CI: 0.516-0.770, P=0.026), and an optimal cut-off value was 0.186, with sensitivity of 37.5% and specificity of 91.3%. Conclusions The WBC/PLT ratio shows high specificity in the prognosis evaluation of sepsis, which can predict the prognosis of patients early, and is worth to be used in clinical practice.