心肌酶测定的方法对比和偏差评估

目的通过对同一检验科不同检测系统进行方法比对和偏差评估,探讨不同检测系统间天冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)、肌酸激酶(CK)和肌酸激酶心型同工酶(CK-MB),4种心肌酶测定结果是否具有可比性,为血清酶测定的标准化和临床实验室认可提供实验数据。方法参考NCCLS的EP9-A文件,以日立7170生化分析仪、罗氏原装试剂、c.f,a.s校准品和质控品组成的检测系统(已通过ISO/IEC 17025标准认可)为比较方法,其他不同检测系统为实验方法,检测病人新鲜血清中4种心肌酶,用配对t检验和回归统计法分析实验方法(Y)和比较方法(X)测定结果均值处的相对偏差或医学决定水平处的系统误差,以美国临床实验室修正法规(CLIA 88)规定的室间质量评价允许误差范围的1/2为标准,判断不同检测系统的临床可接受性。结果除检测系统3、4的AST结果,检测系统1、2、3的CK-MB结果与比较方法的系统误差或均值处的相对偏差不能被接受外,其余项目测定结果的偏差临床可以接受。结论当同一实验室同一检验项目存在2个以上的检测系统时,应进行方法比对和偏差评估,判断其临床可接受性,以保证检验结果的可比性。

Comparative analysis and acceptability evaluation on results of four cardiac muscle enzymes with different detection system

Objective The comparability level for the results of four cardiac muscle enzymes,including AST,LDH,CK,CK-MB,measured by different detection system in a same laboratory department was investigated through bias estimation and method comparison in order to obtain experimental data for standardization of serum enzyme mensuration and medical laboratory accreditation.Methods Referring to EP9-A file of NCCLS,the comparison methods were accredited by ISO/IEC 17025,which includes Hitachi 7170 biochemical analyzer,reagent of Roche,c.f.a.s.calibrator and controller of Roche.Other systems were used as the experimental system.Regarding half of the error range allowed by CLIA'88 as standard,after detecting bias and system error of four cardiac enzymes in fresh serum we judged clinical acceptability between experimental methods(Y) and comparison method(X)using t test and regress analysis.Results Except AST of system 4 and CK-MB of system 1,2.3,which bias were not acceptable,the rest items were clinical accepted.Conclus on If there are more than two systems for the same test are used in a laboratory,method comparison is necessary and bias estimation for judgement of clinical acceptability in order to insure the comparability of experimental results.