儿童外周末梢全血与静脉血清降钙素原检测的多中心平行对照研究

Consistency of peripheral whole blood and venous serum procalcitonin in children: a multicenter parallel controlled study

目的了解外周末梢全血与血清降钙素原(PCT)水平的相关性和一致性,探讨末梢全血PCT检测在儿科感染领域中的应用价值。方法横断面研究,对2018年3月至2019年2月在11所儿童专科医院出生28 d以上的1898例患儿同时采集的末梢全血和静脉血清,分别检测PCT水平,根据文献资料和临床对静脉血清PCT正常参考值及其临床意义分组。采用χ2检验和方差分析进行组间比较,定量数值Pearson相关分析法进行相关性分析,转换成等级资料在不同的临床界限区间采用Spearman检验作分层相关性分析,转换成二分类资料进行一致性评价并初步探索末梢血PCT水平的最佳切点。结果共纳入有效样本1898例(男1098例、女800例),年龄27.4(12.2,56.7)个月。末梢全血和静脉血清PCT之间有良好相关性(r=0.97,P<0.01),直线回归方程式为PCT_(静脉血清)=0.135+0.929×PCT_(末梢全血)。检测绝对值两者间的一致性欠佳,差异有统计学意义(r=0.51~0.92,P<0.01),但等级资料分层分析提示两者实测值在各界限区的符合率为84.9%~97.1%。二分类资料显示两种检测法一致性佳(符合率96.8%~99.3%,Youden指数0.82~0.89)。从病情轻重设定的4个PCT区间(<0.5、0.5~<2.0、2.0~<10.0、≥10.0μg/L)内,末梢全血PCT预判临床的效果良好(曲线下面积为0.9912~0.9979)。不同静脉血清PCT切点值0.5、1.0、2.0、10.0μg/L对应的末梢全血PCT的最佳切点值分别为0.395、0.595、1.175、3.545μg/L。结论末梢全血PCT与静脉血清PCT之间相关性良好,利用末梢全血PCT检测可以辅助判断临床病情的性质和轻重,而采血简便、快速报告并易重复检测的特点为其提供了临床应用的前景。

Objective To explore the consistency of peripheral whole blood and venous serum procalcitonin(PCT)levels,and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection.Methods This multicenter cross-sectional parallel control study was conducted in 11 children′s hospital.All the 1898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment,reagent and method.According to the venous serum PCT level,the patients were stratified to subgroups.Analysis of variance and chi-square test were used to compare the demographic characteristics among groups.And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman′s rank correlation test.Furthermore,the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection.Results A total of 1898 valid samples were included(1098 males,800 females),age 27.4(12.2,56.7)months.There was a good correlation between PCT values of peripheral whole blood and venous serum(r=0.97,P<0.01).The linear regression equation was PCT_(venous serum)=0.135+0.929×PCT_(peripheral) whole blood.However,when stratified to 5 levels,PCT results showed diverse and unsatisfied consistency between the two sampling methods(r=0.51-0.92,all P<0.01).But after PCT was converted to ordinal categorical variables,the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%.The dichotomous variables also showed a good consistency(coincidence rate 96.8%-99.3%,Youden index 0.82-0.89).According to the severity of disease,the serum PCT value was classified into 4 intervals(<0.5、0.5-<2.0、2.0-<10.0、≥10.0μg/L),and the peripheral blood PCT value also showed a good predictive value(AUC value was 0.9912-0.9979).The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0μg/L corresponding to venous serum PCT values were 0.395,0.595,1.175 and 3.545μg/L,respectively.Conclusions There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value,which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity.Besides,the sampling of peripheral whole blood is simple and easy to repeat.