稀释对胱抑素C标准物质ERM-DA471互换性的影响

Influence of dilution on the interchangeability of cystatin C reference material ERM-DA471

目的评价稀释对胱抑素C标准物质ERM-DA471互换性的影响。方法按照说明书将ERM-DA471溶解,得到水平为5.48 mg/L的原液,采用称重法将原液稀释为4.0、2.0、1.0、0.5 mg/L的系列水平。收集无溶血、无乳糜的血清标本42份,将5个系列水平的ERM-DA471穿插其中,选用9个市场占有率较高的检测系统,对待评价标本检测3次,结果取平均值,根据EP14-A3标准评价系列水平标准物质ERM-DA471的互换性。结果将9个检测系统两两组合,将42份血清标本的检测结果进行回归分析,回归方程对应的斜率范围为0.782~1.125,截距范围为-0.216~0.141,R^(2)范围为0.991~0.998。根据预测值的95%CI进行判断,原水平ERM-DA471的检测结果具有互换性的检测系统组合占41.7%(15/36);水平为4.0、2.0、1.0、0.5 mg/L的ERM-DA471检测结果具有互换性的检测系统组合分别占44.4%(16/36)、80.6%(29/36)、69.4%(25/36)、69.4%(25/36);稀释后互换性未发生改变的检测系统组合占16.7%(6/36)。结论经稀释后的ERM-DA471在大部分检测系统组合间的互换性发生改变,临床在使用稀释后的标准物质ERM-DA471作为校准品时,需要重新评估其互换性。

Objective To evaluate the influence of dilution on the interchangeability of cystatin C reference material ERM-DA471.Methods ERM-DA471 was dissolved according to the instructions to obtain a stock solution with a level of 5.48 mg/L,and the stock solution was diluted to a series of levels of 4.0,2.0,1.0 and 0.5 mg/L by the weighing method.Collected 42 serum specimens without hemolysis and chyle,interspersed 5 levels of ERM-DA471 among them,selected 9 detection systems with high market share,and detected the evaluation specimens 3 times,the results were averaged.The interchangeability of serial level reference material ERM-DA471 was evaluated according to EP14-A3 standard.Results The 9 detection systems were combined in pairs,and the detection results of 42 serum specimens were analyzed by regression analysis.The corresponding slopes of the regression equations ranged from 0.782 to 1.125,the intercepts ranged from-0.216 to 0.141,and the R^(2) ranged from 0.991 to 0.998.According to 95% CI of predicted value,41.7%(15/36)of detection system combinations with interchangeability were found at the detection results of original ERM-DA471 level.The interchangeable detection system combinations of the detection results of ERM-DA471 at levels of 4.0,2.0,1.0 and 0.5 mg/L accounted for 44.4%(16/36),80.6%(29/36),69.4%(25/36),69.4%(25/36)respectively.The detection system combinations whose interchangeability did not change after dilution accounted for 16.7%(6/36).Conclusion The interchangeability of diluted ERM-DA471 among most detection system combinations has changed,and when the clinical uses the diluted reference material ERM-DA471 as a calibrator needs to re-evaluate its interchangeability.