IFCC参考方法评价两个常规系统血清肌酸激酶测定结果的正确度

Accuracy of serum CK measurement results in two conventional systems evaluated by IFCC reference method

目的分析两种常规测量系统与IFCC参考方法测定血清肌酸激酶(CK)结果的准确性和一致性,验证其测定结果的正确度。方法采用IFCC参考方法和两种常规测量系统(A、B)对国际参考物质ERMAD455k、40份不同浓度的新鲜单人份样本、2018年RELA样本进行测定。根据EP09-A3文件和Bland-Altman图形分析法评价A和B测量系统测定结果的正确度。结果验证发现A、B两个测量系统所得的测量结果明显不同:A方法和B方法与IFCC参考方法的回归方程分别为Y_(A)=0.9814X_(IFCC)-4.0506,R^(2)=0.9986和Y_(B)=1.0124X_(IFCC)+0.5383,R^(2)=0.9995;B法与IFCC参考方法结果较为一致,其平均偏倚范围在1.53%,而A法与IFCC参考方法结果存在明显偏差,其平均偏倚范围为-6.25%,且A法的测定结果均偏低于B法。进一步研究发现两个常规检测系统的校准品均存在基质效应,而A校准品的基质效应较明显。结论B方法测定结果准确度和一致性好,与IFCC参考方法正确度性能一致,A方法与IFCC参考方法正确度性能不一致。

Objective To analyze the accuracy and consistency of serum CK measurement results in two conventional measurement systems and IFCC reference method and evaluate the accuracy of the measurement results.Methods ERM-AD455k and 40 fresh single samples with different concentrations and RELA samples in 2018 were determined by IFCC reference method and two conventional measurement systems(A and B).According to EP09-A3 document and Bland-Altman graphic analysis method,the accuracy of results of A and B measurement systems was evaluated.Results It was discovered that the measurement results obtained by A and B were obviously different.The regression equations of method A and method B and IFCC reference method were Y_(A)=0.9814X_(IFCC)-4.0506,R^(2)=0.9986 and Y_(B)=1.0124X_(IFCC)+0.5383,R^(2)=0.9995,respectively.The results of method B were consistent with those of IFCC reference method,with an average deviation range of 1.53%.However,there was a significant deviation between the results of method A and IFCC reference method,with an average deviation of-6.25%.Meanwhile,the measurement results of method A were all lower than those of method B.Further research discovered that there were matrix effects in the calibration products of both conventional detection systems,while the matrix effect in the calibration product A was more obvious.Conclusion With good accuracy and consistency,Method B is consistent with IFCC reference method in terms of accuracy performance,while method A is inconsistent with IFCC reference method in terms of accuracy performance.