血清肌酐两种测定方法偏倚的比较

摘要

Objective To analyze the bias between sarcosine oxidase and Jaffe's methods for measuring the ser-um creatinine (Cre) .Methods According to the procedure described by the NCCLS approved guideline ,40 patients samples were analyzed in 5 operating days ,each sample was analyzed in duplicate by both enzymatic assay and Jaffe's kinetic assay .The duplicates were assessed for each method within the same run .The coefficient of correlation was calculated and the bias between two methods was calculated accordingly .Results The bias between the enzymatic as-say and Jaffe's kinetic assay were 1 .5% at 100 μmol/L ,6 .4% at 300 μmol/L and 7 .9% at 500 μmol/L for creati-nine .Conclusion The bias between two methods could be increased as the concentration of the serum creatinine in-creases .New reference range for creatinine should be established when new instrument or new reagent is applied .%　　目的分析肌氨酸氧化酶法（简称酶法）和苦味酸速率法（Jaffe′s法）测定血清肌酐结果的偏倚。方法依据美国国家临床实验室标准协会EP9-A文件，每天取临床样本8份，分别用两种方法测定血清Cre含量，共测定5d，记录结果，去除离群点，计算线性回归方程和相关系数，进行偏倚估计。结果在测定患者新鲜血清样本Cre时，酶法和Jaffe′s法测定结果的预期相对偏倚在Cre浓度小于100μmol/L时，两种方法的预期偏倚不超过-1．5％，酶法的测定结果低于Jaffe′s法；当Cre浓度大于300μmol/L时，两种方法的预期偏倚不低于6．4％，酶法的测定结果高于Jaffe′s法；当Cre浓度大于500μmol/L时，两种方法的预期偏倚不低于7．9％。结论预期偏倚在中低浓度时随肌酐浓度增高而降低，高浓度时则随浓度增高而增大，但Jaffe′s法测定结果较酶法低。临床实验室在换用不同仪器或试剂时必须对肌酐测定的不同方法建立不同的参考值范围。