肝素对亮氨酸氨基肽酶测定的干扰评价

目的依据美国临床实验室标准化协会（CLSI）EP7-A2文件评价肝素对速率法测定亮氨酸氨基肽酶（LAP）的干扰,明确干扰物质带来的结果差异,确保分析方法性能符合临床要求。方法首先,使用2个不同厂家北京利德曼生化股份有限公司（简称利德曼）、日本第一化学药品株氏会社（简称日本一化）]的试剂同时测定40例患者不抗凝血样本和肝素锂抗凝血样本的LAP,对2种样本的LAP结果进行分析,对有差异的结果进行干扰筛选分析。然后,分别进行＂配对差异＂试验和＂剂量效应＂试验以及肝素干扰LAP测定的浓度范围的评价。结果利德曼试剂测定2种样本LAP的结果有差异（P〈0.05）,日本一化试剂结果无差异（P〉0.05）。＂配对差异＂试验显示肝素对利德曼试剂测定低浓度LAP时存在干扰,而高浓度LAP不存在干扰。＂剂量效应＂试验结果显示肝素在不同浓度对LAP测定的干扰为非线性函数。初步判定LAP≤97 U/L时,肝素对利德曼试剂产生干扰;在LAP≥149 U/L时,其干扰效应不明显。结论当样本LAP≤97 U/L时,用利德曼试剂测定肝素锂抗凝样本LAP时会对检测结果产生正干扰。为保证LAP检测结果的准确性,如果继续使用利德曼LAP试剂,则需换用无抗凝的干燥管采集样本;如果继续使用肝素锂抗凝管采集样本,可换用日本一化LAP试剂。

Evaluation on the interference of heparin in the determination of leucine aminopeptidase

Objective To investigate on the interference and its results＇ difference of heparin in the determination of leucine aminopeptidase（LAP） by rate method according to EP7-A2 document from Clinical Laboratory of Standards Institute（CLSI）,and ensure that the analysis performance meets the clinical requirements.Methods The LAP of the 40 blood specimens were divided each in 2 tubes：one without anticoagulant and another with heparin lithium-anticoagulant,which were measured for LAP by 2 manufacturers＇ LAP reagents（Beijing Leadman Biochemistry Co.,Ltd and Daiichi Pure Chemicals Co.,Ltd） respectively.The results of LAP were analyzed.The interference screening test based on the difference of results.The ＂paired difference＂ experiment and ＂dose-response＂ experiment were determined.LAP concentration range of heparin interference was evaluated.Results There was difference in the LAP determination result with Beijing Leadman reagents（P0.05）,while there was no difference with Daiichi Pure Chemicals reagents（P0.05）.In ＂paired difference＂ experiment,heparin interfered the determination of LAP in low to middle concentration range and not in high concentration,when using Beijing Leadman reagents.The ＂dose-response＂ experiment showed that non-linear function existed between the different concentrations of heparin in the interference of LAP determination.Assessment test preliminarily decided that heparin interfered LAP test using Beijing Leadman reagents,when the concentration range was LAP≤97 U/L.When LAP≥149 U/L,the interference was not obvious.Conclusions If the LAP concentration is ≤97 U/L,the test results will be interfered when the heparin anticoagulant specimens are tested by LAP reagents of Beijing Leadman.In order to ensure the accuracy of LAP detection,if the LAP reagents of Beijing Leadman are used,we should use dry tube without anticoagulant to collect specimens.If continuing to use heparin lithium-anticoagulant tubes,we should use LAP reagents of Daiichi Pure Chemicals.