CYP3A5 基因检测质控品制备及其应用研究

目的通过构建体外质粒DNA作为质控样品开展他克莫司代谢基因——细胞色素P450 3A5(CYP3A5)基因检测室间质量评价计划(简称室间质评),评估参评实验室检测能力及存在的问题,提高临床实验室CYP3A5基因的检测质量。方法利用基因工程技术体外构建含CYP3A5*3(rs776746)位点上、下游序列的重组质粒,筛选CYP3A5*3 AA和GG基因型分别作为野生型和突变型样品,两者等比例混合后作为杂合突变型样品,并制备质控样品盘开展室间质量评价。依据回报结果计算各实验室成绩,汇总不同样品的总体符合率,并分析不同检测方法的符合率和检测错误类型。结果体外构建的重组质粒经Sanger测序验证分别含CYP3A5*3位点野生型和突变型序列。2017年两次室间质评中成绩满分的实验室分别为93.33%(14/15)和100%(17/17)。两次室间质评中,样品检测的总体符合率分别为96%(72/75)和100%(85/85)。荧光分子杂交法检测的样品符合率均为100%; Sanger测序法检测样品符合率为90%(27/30)和100%(40/40)。结论制备的质控样品能够有效监测试剂检测性能,具有良好的适用性。各实验室在CYP3A5*3基因位点检测总体准确率较高,但个别实验室检测能力有待提高。室间质评计划能帮助实验室发现检测中存在的问题,提高检测质量。

Development and applications of quality control materials for detection of [STBX][STHZ]CYP3A5 [STBZ]genotypes

Abstract: Objective: To evaluate the external quality assessment (EQA) program for genotyping results of tacrolimus metabolism-related cytochrome P450 family 3 subfamily A member 5 ( CYP3A5 )using plasmid DNA constructed in vitro as quality control samples, discuss the problems in clinical laboratories enrolled in the program and improve the detection quality of CYP3A5 gene. Methods: Recombinant plasmid carrying CYP3A5 *3 (rs776746) AA locus sequence was constructed as wild type sample and plasmid with CYP3A5 *3 GG mutation as mutant type sample. Heterozygous mutant samples were obtained by mixing the two plasmids with equal proportion. Recombinant plasmids DNA were used as the sample panel for EQA scheme. Participating laboratories were asked to test the samples using their routine methods and report the results before deadlines. The scores of each laboratory were calculated based on their results and the overall coincidence of different samples as well as the sensitivity and specificity of different methods. Results: CYP3A5 *3 locus genotypes of the constructed plasmid were verified by Sanger sequencing. The results of 15 and 17 valid laboratories were received respectively in the two EQA programs. The total percentage of 93.33% (14/15) and 100% (17/17) of the laboratories submitted correct results for all the samples. The overall coincidence rates were 96% (72/75) and 100% (85/85) respectively. All the laboratories using digital FISH got full marks in two EQA schemes, while the coincidence rates were 90% (27/30) and 100% (40/40) for Sanger sequencing. Conclusion: The recombinant plasmid DNA constructed in this study could effectively detect the performance of reagents with good clinical applicability. The results of EQA programs suggested that the overall accuracy rate of enrolled laboratories was high enough, while the performances in some laboratories still need to be improved. Quality controls in clinical laboratories were essential to assure the accuracy of results.