血液筛查核酸检测内标在系统评价的应用分析

Application of internal control in nucleic acid amplification technology in blood screening on system evaluation

目的分析COBAS s201核酸血筛系统内标(internal control,IC)检测结果差异的影响因素,探讨利用IC的Ct值评价检测系统的稳定性。方法随机抽取本室2015年1-10月共131批次的核酸检测的IC结果,按不同仪器(A、B仪器)、试剂批号(批号1、批号2和批号3)和标本类型(MPC、HIV-1O、HIV-2、NC和献血者标本)分别分成3组,分析各组间及组内各IC的Ct均值的差异。结果本室测定IC的Ct均值的95%参考范围为35.18-37.34;95%置信区间为[36.21,36.30];A、B仪器间以及3个试剂批号间的IC结果差异均有统计学意义(P<0.05),其中A仪器IC均值小于B仪器(P<0.05),批号2 IC的Ct均值分别小于批号1和批号3(P<0.05);不同试剂批号间IC结果差异(F=94.487,P<0.05)明显高于不同仪器检测的IC结果差异(F=16.609,P<0.05);此外,5种不同标本类型的IC也存在显著差异(P<0.05),其中标本组和NC组IC的Ct值分别大于MPC组、HIV-1O组和HIV-2组(P<0.05),MPC组、HIV-1O组和HIV-2组间的IC差异无统计学意义(P>0.05),NC组和标本组的IC值差异不显著(P>0.05)。结论不同试剂批号和仪器能引起IC值检测差异,做好试剂使用前性能确认和仪器定期维护校准是保障核酸检测结果准确稳定的有效方法;监测IC变化可作为实验室内部质量控制的评价指标。

Objective To analyse the factors influencing the differences of the internal control （IC） test results in the COBAS s201 blood screening of nucleic acid amplification technology （ NAT）, and to discuss the usages of IC values for sta- bility of detection system. Methods according to different instruments （A and B instrument）, different reagent lots （ Lotl, Lot2 and Lot3） and different specimen types （MPV, tiIV-10, HIV-2, NC and donor samples）, the IC values of the results from 131 batches of NAT selected randomly in the lab from Jan, 2015 to Oct, 2015 were divided into three groups. The differences of the CT mean values of the IC between the groups and within each group were analysed, respectively. Results in the lab, the 95% reference range of the CT mean values of the IC tested were 35.18 to 37.34, and the 95% confidence interval of IC mean values were 36. 21 to 36. 3. The differences of the IC results between A and B instrument and among the three reagent lots were statistically significant （P 〈 0. 05）. The CT mean values of the IC in the A instrument was less than it in the B instrument （P 〈 0. 05 ）. The the CT mean values of the IC in the Lot2 was less than it in the Lotl and Lot3, re- spectively （P 〈 0. 05）. The differences of IC results in the different reagent lots （F = 94. 487, P 〈 0. 05） were significantly higher than them in the different instruments （ F = 16. 609, P 〈 0. 05 ）, In addition, there were significant differences among the five different specimen types （P 〈 0. 05）. The the CT values of the IC in the samples and NC groups were higher than them in the MPC, HIV-10 and HIV-2 groups （ P 〈 0. 05 ）. There were no statistieal significance in the differenees of IC val- ues among the MPC, HIV-10 and HIV-2 groups （P 〉0.05）, and the differences of IC values between the NC and samples groups was not signifieant （ P 〉 0. 05 ）. Conclusion the differences of IC values tested were induced by different reagent lots and instrument. The effective ways to guarantee the aceuraey and stability of the results in NAT are good reagents eonfir- marion before using and regular maintenance and calibration of the instruments. Monitoring the variation of the IC can be used as an index to evaluate internal quality control in lab.