Explore solutions to the "grey zone" of activated partial thromboplastin time mixing study
10.3760/cma.j.cn114452-20220330-00190
- VernacularTitle:活化部分凝血活酶时间延长混合血浆纠正试验“灰区”解决方案探究
- Author:
Chaonan LIU
1
;
Liqin LING
;
Xunbei HUANG
;
Jian MI
;
Juan LIAO
;
Jin JIA
;
Jing ZHOU
Author Information
1. 四川大学华西医院实验医学科，成都610000
- Keywords:
Activated clotting time live enzymes;
Correct test;
Grey area;
Rosner index;
After incubation extended time percentage
- From:
Chinese Journal of Laboratory Medicine
2022;45(10):1056-1062
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore solutions to the "grey zone" of activated partial thromboplastin time (APTT) mixing study, and establish the clinical application pathway of it.Methods:Patients treated in West China Hospital of Sichuan University from January 1, 2018, to December 31, 2019, with a prolonged APTT were included in this study. The ROC curve was used to analyze the"cut-off"of different methods and explore solutions to the "grey zone" by combination of the 1∶1 and 4∶1 mixing study. Similar samples from January 1, 2020 to December 31, 2020 were included to verify the diagnostic efficiency of the clinical application pathway.Results:The traditional Rosner index criterion had a low diagnostic accuracy in differentiating factor deficiencies from inhibitors. A total of 49 cases (15%) in the establishment group and validation group were located in the "grey zone". The optimal cut-off value of the Rosner index in our 1∶1 mixing study for determining factor deficiency was 5.0%, and inhibitor was 9.1%. The sample between 5.0% and 9.0% needed 4∶1 mixing studies, which could significantly improve the detection sensitivity of inhibitors. The percentage of extended time after incubation-P (1∶1 mixing>10.8% and 4∶1 mixing>13.5%) was better than the traditional criterion mentioned by"consensus"in determining whether the inhibitor was time-dependent. The sensitivity, specificity, positive predictive value and negative predictive value of combined the 1∶1 and 4∶1 mixing study in differentiating factor deficiencies from inhibitors all attained more than 90%. Only 7% (3/43)of inhibitors were incorrectly classified into the factor deficiency group by the combination, which was 20.9% (9/43) by traditional criterion. The specificity for detecting time-dependent inhibitor was increased from 54.2% to 100%, and accuracy was increased from 63.3% to 97.4%.Conclusions:The combination of 1∶1 and 4∶1 mixing study can better resolve the "grey zone". The established clinical application pathway is beneficial for the further promotion and clinical application of APTT mixing study.
