血清游离脂肪酸酶法测定的方法学评价及生物学变异研究

目的评价血清游离脂肪酸(FFA)酶学比色法(简称酶法)的精密度和正确度,并且研究血清FFA个体间和个体内生物学变异。方法采用美国临床和实验室标准化协会(CLSI)EP5-A2和EP15-A文件评价酶法测定血清FFA的精密度和正确度。生物学变异的研究对象为13名健康志愿者,在6周时间内每2周测定1次血清FFA浓度,利用SAS9.1软件中MIXED分析过程计算个体间生物学变异和个体内生物学变异。结果精密度实验样品的血清FFA浓度总均数为0.796 mmol/L,批内、批间、日间和室内不精密度分别为2.15%、3.44%、3.67%和5.46%。测定3个室间质评样品的百分比偏差分别为24.20%、-0.90%、-1.50%。血清FFA个体间和个体内生物学变异分别为8.43%、19.36%。结论酶法测定血清FFA的精密度和正确度能满足相关实验室质量控制要求。血清FFA的个体间和个体内生物学变异可为制定实验室质量规范和临床课题的科研设计提供参考依据。

Methodology evaluation and biological variation research of enzymatic colorimetric assay for the determination of serum free fatty acid

Objective To evaluate the precision and trueness of enzymatic colorimetric assay （enzymatic assay） for the determination of serum free fatty acid （FFA）,and to study the between-subject and within-subject biological variations of serum FFA.Methods EP5-A2 and EP1 5-A were employed to evaluate the precision and trueness of serum FFA by enzymatic assay,which were published by the Clinical and Laboratory Standards Institute （CLSI）.The serum samples from 1 3 healthy subjects for biological variation were collected and determined for FFA once every 2 weeks over a period of 6 weeks.The between-subject and within-subject biological variations were calculated by MIXED analysis of SAS9.1 software.Results The overall mean of serum FFA was 0.796 mmol/L,and imprecisions of within-batch, between-batch,inter-day and intra-laboratory were 2.1 5%,3.44%,3.67%and 5.46%,respectively.The deviations for the 3 external quality assessment control samples were 24.20%,-0.90%and -1 .50%.The between-subject and within-subject biological variations were 8.43%and 1 9.36%,respectively.Conclusions The precision and trueness of serum FFA by enzymatic assay could meet the requirements of relevant laboratory quality control.The between-subject and within-subject biological variations have important significations for establishing laboratory accreditation and providing clinical research design′s reference.