摘要目的 应用血清γ-谷氨酰基转移酶(GGT)参考方法评价国产GGT试剂的溯源性.方法 按照国际临床化学与检验医学联合会(IFCC)有关GGT活性测定的要求建立参考方法;根据美国临床和实验室标准协会(CLSI)系列文件对建立的参考方法的主要性能进行评价;应用建立的参考方法评价国内不同厂家的GGT试剂在罗氏Cobas 6000和日立7170A全自动生化分析仪上测定结果的溯源性,并用经参考方法定值的新鲜人血清作为校准品实现不同检测系统检验结果的一致性和可比性.结果 GGT参考方法的批内不精密度和总不精密度均<1%,与国际参考实验室外部质量评价计划样品靶值的相对偏倚在等效限内;校准前常规检测系统与参考方法GGT检测结果在医学决定水平处的最大偏倚分别达到-47.53%、-34.11%、-30.07%,平均偏倚分别为14.53%、12.88%、12.48%;使用新鲜血清作为校准品校准后,最大偏倚分别降至-17.63%、-5.88%、-4.08%,平均偏倚降至7.50%、2.70%、1.87%.结论 GGT参考方法性能符合要求.应用参考方法赋值的新鲜人血清作为校准品进行校准是实现国内不同厂家酶学试剂检验结果一致性和可比性的有效途径.

abstractsObjective To evaluate the measurement accuracy of serum gamma-glutamyltransferase (GGT) assays manufactured in China. Methods The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference method for GGT was set up and, after verification, was used to evaluate the performance of routine assay systems made in China. The evaluation was performed twice before and after a calibration by a common serum calibrator. Results For the reference measurement, the within run and total CVs were all less than 1%. The biases with the target values of IFCC External Quality Assessment Scheme for Reference Laboratories (RELA) were all within the limit of equivalence. Before a calibration with a common calibrator, the largest biases of results of GGT of the routine tasting systems compared with reference method at three medical decide levels were -47.53%, -34.11% and -30.07% respectively, and the averaged biases were 14.53% ,12.88% and 12.48%. After calibrating by fresh serum calibrator,the largest biases were reduced to - 17.63%, -5.88% and -4.08% ,the averaged biases were reduced to 7.50%, 2.70% and 1.87%. Conclusion The performance of GGT measurements can be effectively improved by using a common fresh serum calibrator that has a value assigned with the reference method.