APTT纠正试验结果常用判定方法临界值建立及诊断效能评价

The establishment of a cutoff value and evaluation of the diagnostic efficiency of common judgment methods for activated partial thromboplastin time mixing test results

目的 建立活化部分凝血活酶时间(APTT)纠正试验常用结果判定方法临界值并评价其诊断效能。方法 回顾性分析2019年3月至2021年10月APTT不明原因延长且于我院行纠正试验的病例116例,其中,抑制物阳性71例,因子缺乏45例,通过受试者操作特征(ROC)曲线评价罗斯纳指数(RI)法、百分比纠正法、差值法和正常参考范围法对结果判断的诊断效能,通过散点图分析标本在不同结果判定方法中的具体分布情况,并对单因子缺乏标本的因子浓度水平和不同判定方法所得结果进行Pearson相关性分析。结果 ROC曲线分析RI法、百分比纠正法、差值法和正常参考范围法的曲线下面积分别为0.975 (95%CI:0.953~0.997,P <0.01)、0.935 (95%CI:0.893~0.976,P <0.01)、0.959 (95%CI:0.927~0.990,P <0.01)、0.960 (95%CI:0.929~0.991,P <0.01);RI法、百分比纠正法、差值法对应的最佳临界值分别为12.2%、62%、7.4 s。因子缺乏程度和RI结果呈中等正相关(r=0.536,P <0.01),和百分比纠正结果呈显著负相关(r=-0.710,P <0.01)。结论 RI法、百分比纠正法和差值法新建立的临界值可更好地识别因子缺乏和抑制物阳性的标本,且与其他3种方法相比,RI法具有更好的诊断效能,可作为本实验室APTT纠正试验结果首要常规判定方法。

Objective To establish a cutoff value and evaluate the diagnostic efficiency of common judgment methods for activated partial thromboplastin time(APTT) mixing test results. Methods A retrospective analysis was performed on 116 patients with unexplained prolonged APTT,who underwent an APTT mixing test in our hospital from March 2019 to October 2021. The cohort included 71 patients positive for the presence of an inhibitor and 45 patients with a clotting factor deficiency. The diagnostic efficacy of the Rosner index(RI),corrected percentage,time difference,and normal reference range methods were evaluated using a receiver operating characteristic curve(ROC). A scatter plot was used to analyze the specific distribution of the samples for the different result judgment methods. Pearson’s correlation analysis was performed on the clotting factor concentrations for patients with a single clotting factor deficiency and the results obtained with the different judgment methods. Results The areas under the ROC curves were 0.975(95%CI:0.953-0.997,P < 0.01),0.935(95%CI:0.893-0.976,P < 0.01),0.959(95%CI:0.927-0.990,P < 0.01),0.960(95%CI:0.929-0.991,P < 0.01). The optimal cutoff values for the RI,corrected percentage,and time difference methods were 12.2%,62%,and 7.4 s,respectively. There was a moderate positive correlation between clotting factor concentration and the RI results(r = 0.536,P < 0.01),and there was a strong negative correlation between clotting factor concentration and the corrected percentage results(r =-0.710,P < 0.01). Conclusion The newly established cutoff values for the RI,corrected percentage,and time difference methods may better identify clotting factor-deficient and inhibitor-positive patients. Of these three methods,the RI method showed the greatest diagnostic efficiency,and may be used as a routine primary judgment method for APTT mixing test results in our laboratory.