常规法测定不同GGT催化活性的不确定度评定

Estimation of measurement uncertainty of γ-glutamyl transferase with different concentrations

目的评定常规方法测定不同γ-谷氨酰基转移酶(GGT)活性的不确定度。方法用实验室常规方法和IFCC推荐的参考方法分别检测混合血清,以参考方法为依据评定常规方法测定GGT活性的不确定度,并绘制GGT活性测定的不确定度特征曲线,建立不确定度与酶活性水平间的函数关系。结果运用不确定度特征曲线分析,当GGT活性较低时,应使用不确定度的绝对形式表示;当GGT活性较高时,应用相对不确定度表示。建立了GGT活性(x)与不确定度(u)之间的近似关系:u(x)≈2.42+0.033x。结论绘制不确定度特征曲线或建立不确定度与活性水平之间的函数关系可以方便地指导临床实验室评定测量不确定度。

Objective To evaluate the measurement uncertainty of γ-glutamyl transferase（GGT） activity with different concentrations. Methods The pooled serum was measured simultaneously by both routine laboratory method and the reference method recommended by IFCC. The measurement uncertainty of the routine method was evaluated based on the reference method, and the curve of uncertainty profile of GGT active concentration was plotted. The functional relation between concentrations and the uncertainty was established. Results For the uncertainty profile of the assay, the uncertainty was often denoted as absolute value at low concentrations, whereas it was commonly expressed as relative value at high concentrations. The functional relation between concentrations and the measurement uncertainty was established by the equation u（x）≈2.42 ＋ 0. 033x. Conclusions In clinical laboratories, plotting the curve of uncertainty profile or establishing functional relation between concentrations and measurement uncertainty may be more convenient for the e- valuation of uncertainty.