中性粒细胞与淋巴细胞比值对成人重症破伤风的预测价值

Predictive value of neutrophil-to-lymphocyte ratio in adult severe tetanus

目的通过比较重症和轻症破伤风患者的中性粒细胞与淋巴细胞比值(neutrophil-to-lymphocyte ratio,NLR),探讨NLR对成人重症破伤风的预测价值。方法纳入2009年1月至2020年12月临沂市中心医院收治的65例破伤风患者。按照Ablett分级,分成轻症组和重症组。比较两组患者的一般情况、实验室检查结果、NLR等。统计学方法采用独立样本t检验。采用多因素logistic回归分析探寻重症破伤风的潜在风险因素。采用Spearman等级相关分析风险因素与患者Ablett分级之间的相关性。通过受试者操作特征曲线评估风险因素对重症破伤风的预测能力。结果65例破伤风患者中,轻症34例,重症31例。重症组的潜伏期为(7.00±3.19)d,短于轻症组的(9.18±2.59)d,差异有统计学意义(t=3.03,P=0.004)。重症组NLR为4.251±1.936,高于轻症组的2.533±1.026,差异有统计学意义(t=4.41,P<0.001)。多因素logisitic回归分析显示,NLR和潜伏期是破伤风重症化的独立相关因素[比值比(odds ratio,OR)=2.359,95%可信区间(confidence interval,CI)1.415~3.934,P=0.001;OR=0.748,95%CI 0.599~0.936,P=0.011]。破伤风患者NLR与其Ablett分级呈正相关(r=0.644,P<0.001)。受试者操作特征曲线分析显示,NLR为2.471时,对重症破伤风具有较高的预测价值,曲线下面积为0.787,灵敏度和特异度分别为87.1%和61.8%;NLR联合潜伏期(临界值为7.5 d)能提高预测价值(Z=3.43,P<0.001),曲线下面积为0.832,灵敏度为87.1%,特异度为67.6%。结论NLR对破伤风患者是否发展为重症破伤风具有较好的预测价值,联合潜伏期能提高其预测效能。

Objective To evaluate the predictive value of neutrophil-to-lymphocyte ratio(NLR)for adult severe tetanus by comparing the NLR in patients with severe and mild tetanus.Methods A total of 65 adult tetanus patients from the Linyi Central Hospital from January 2009 to December 2020 were enrolled.The patients were divided into two groups including mild group and severe group according to the Ablett classification.The general conditions,laboratory data,and NLR of patients in two group were retrospectively compared using independent samples t test.Multivariate logistic regression analysis was used for the analysis of risk factors for severe tetanus.Spearman correlation method was used for the analysis of the correlation between risk factors and Ablett grades.Receiver operator characteristic(ROC)curve was used for the evaluation of the predictive value.Results Among the 65 tetanus cases,34 was in mild group and 31 in severe group.The latency period of patients in severe group was(7.00±3.19)d,which was shorter than that in mild group((9.18±2.59)d),and the difference was statistically significant(t=3.03,P=0.004).The NLR of patients in severe group was 4.251±1.936,which was higher than that of mild group(2.533±1.026),and the difference was statistically significant(t=4.41,P<0.001).Multivariate logistic regression analysis showed that NLR and latency period were independent risk factors for tetanus severity(odds ratio(OR)=2.359,95%confidence interval(CI)1.415 to 3.934,P=0.001 and OR=0.748,95%CI 0.599 to 0.936,P=0.011,respectively).In tetanus patients,the NLR level was positively correlated with Ablett grade(r=0.644,P<0.001).The ROC curve showed that NLR had good predictive value for adult severe tetanus at a cut-off value of 2.471(area under the curve(AUC)=0.787),with the sensitivity and specificity of 87.1%and 61.8%,respectively.When combining NLR with latency period(cut-off value of 7.5 d),predictive efficiency was further improved(AUC=0.832)with the sensitivity of 87.1%and specificity of 67.6%(Z=3.43,P<0.001).Conclusions NLR has a good predictive value for adult severe tetanus,and the predictive efficiency is further improved when combined with latency period.