ALT正确度控制品稳定性研究及调查结果分析

Stability of alanine aminotransferase trueness control samples

目的通过对丙氨酸氨基转移酶(ALT)正确度验证计划的调查,了解上海地区ALT正确度验证的整体情况以及稳定剂甜菜碱在正确度控制品中的运用情况,从而优化正确度验证计划方案。方法经过离心过滤处理分装得到4个正确度控制品,以ALT-A、ALT-B、ALT-C、ALT-D表示,通过冷链运输发放给临床实验室,其中ALT-B和ALT-D添加了稳定剂甜菜碱,对正确度控制品连续检测3 d。同时用国际临床化学和检验医学联合会(IFCC)一级参考方法为正确度控制品赋值,得到靶值。计算单个实验室每个正确度控制品均值与靶值的相对偏移,以≤6%为允许偏移判断标准。采取同步法进行ALT正确度控制品-20?℃3 d稳定性实验,并对所有实验室4个正确度控制品连续3 d的检测结果分别进行稳定性分析。结果 ALT正确度控制品-20?℃3 d稳定性实验结果显示添加甜菜碱的ALT-B和ALT-D均很稳定(第3天的酶活性是初始值的99.1%、100.0%),未添加甜菜碱的ALT-A和ALT-C均不太稳定(第3天的酶活性是初始值的96.7%、94.9%),各临床实验室的ALT正确度控制品稳定性情况与上述变化相同。74家临床实验室的相对偏移结果显示,ALT-A、ALT-C分别只有17家(23.0%)和25家(33.8%)在允许偏移范围内,而ALT-B和ALT-D均有49家(66.2%)在允许偏移范围内。41家三级医院中,ALT-B和ALT-D分别有27家(65.8%)和26家(63.4%)在允许偏移范围内;33家二级医院中,ALT-B和ALT-D分别有22家(66.7%)和23家(69.7%)在允许偏移范围内。ALT-B和ALT-D 2个正确度控制品均在允许偏移范围内的临床实验室数为44家(59.5%),其中三级医院为25家(61.0%),二级医院为19家(57.6%)。结论所调查的三级医院与二级医院临床实验室的偏移符合率未见明显差异。不添加稳定剂的正确度控制品稳定性无法满足正确度验证的要求,而添加了稳定剂甜菜碱的控制品可以很好地满足正确度控制品的需要。

Objective To investigate the status of alanine aminotransferase(ALT)trueness verification in Shanghai and the application of stabilizer betaine in trueness control samples,so as to optimize trueness verification.Methods A total of4trueness control samples(ALT-A,ALT-B,ALT-C and ALT-D)undergoing centrifugation and filtration processing were delivered to clinical laboratories under cold chain.ALT-B and ALT-D were added stabilizer betaine,and the trueness control samples were determined for3d.The trueness control samples were assigned using the International Federation of Clinical Chemistry and Laboratory Medicine(IFCC)primary reference method,obtaining target values.The bias of each trueness control sample's mean and target value in each laboratory was calculated,and the allowable bias judgment standard was≤6%.Stability experiment for3d at-20℃of trueness control samples was performed by synchronizing method,and the stabilities of4trueness control samples in all laboratories were analyzed.Results At-20℃for3d,ALT-B and ALT-D had good stabilities(the activities at the3rd day were99.1%and100.0%of initial value).ALT-A and ALT-C were unstable(the activities at the3rd day were96.7%and94.9%of initial value),which were the same as those for trueness control samples in all laboratories.Among74laboratories,there were23.0%(17cases)of ALT-A and33.8%(25cases)of ALT-C in the range of allowable bias,while there were66.2%(49cases)of ALT-B and ALT-D in the range of allowable bias.There were65.8%(27cases)of ALT-B and63.4%(26cases)of ALT-D in the range of allowable bias in41Level3hospitals,and there were66.7%(22cases)of ALT-B and69.7%(23cases)of ALT-D in the range of allowable bias in33Level2hospitals.There were59.5%(44cases)of ALT-B and ALT-D in the range of allowable bias,of which61.0%(25cases)in Level3hospitals and57.6%(19cases)in Level2hospitals.Conclusions There is no difference for bias between Level3and Level2hospitals.ALT trueness control samples with no stabilizer can not meet the needs of trueness verification,and ALT trueness control samples adding stabilizer betaine can satisfy the needs of trueness verification.