基质效应对荧光偏振免疫测定技术和酶放大免疫测定方法检测环孢素A结果的影响

Influence of matrix effect upon cyclosporine A test by fluorescence polarization immunoassay and enzyme-multiplied immunoassay technique methods

目的通过荧光偏振免疫测定（fluorescence polarization immunoassay，FPIA）和酶放大免疫测定技术（enzyme-multiplied immunoassay technique，EMIT）测定环孢素A（cyclosporine，CsA），了解基质效应对检测结果的影响，解释在CsA室间质评结果中两方法的检测结果的差别，并找到纠正方法。方法选择不同浓度的临床全血标本100份，用FPIA和EMIT技术进行检测，对比检测结果；通过添加Cu2＋，Zn2＋评估离子残留对免疫反应的影响；用添加等体积血红蛋白富集液后再次抽提的方法，评价非全血基质对质控品和CsA标准品抽提率的影响。结果检测临床全血标本FPIA（X）和EMIT（Y）检测结果具有良好的相关性（Y=0．9268X-8．115，R2=0．9969）；金属离子残留对FPIA法和EMIT法均不产生干扰（P〉0．05）；非全血基质样本会降低两方法的抽提率；样本中血红蛋白含量≥30g／L就可纠正非全血基质对抽提率的影响。结论下发质控品的非全血基质是导致CsA室间质评结果中两系统的检测结果不一致的主要原因，可通过添加血红蛋白富集液进行纠正；遇器官移植受者有极低血红蛋白（〈30g／L）时，要充分考虑低血红蛋白对CsA检测结果的影响。

Objective To explore the matrix effect on cyclosporine A （CsA） test by fluorescence polarization immunoassay （ FPIA ） and enzyme-multiplied immunoassay technique （ EMIT ）, explain the discrepancy of external quality control results between these two methods and find the corrective action. Methods One hundred whole blood samples with various concentrations were adopted and CsA levels were detected by FPIA and EMIT. The results were compared with each other. Moreover, the influence of residual metal ions upon immunoreactions was assessed by adding Cu2＋ and Zn2＋. The effect of non-whole blood matrix on extraction efficiency for quality control materials and CsA calibrator was evaluated by adding identical volume of Hb-rich reagents followed with re-extraction. Results There is good correlation between results measured with FPIA （X） and EMIT （Y） methods （ Y = 0. 926 8X - 8.115, R2 = 0. 996 9 ）. Neither FPIA nor EMIT was affected by residual metal ions （ P 〉 0.05 ）. Non-whole blood matrix decreased the extraction efficiency of two methods, but it could be corrected by supplementation of the Hb-rich reagents （≥30 g/L）. Conclusions Nan-whole blood matrix may be the main reason for the inconsistent results measured by FPIA and EMIT methods. It could be corrected by using Hb-rich reagents. In addition,we should consider the influence of low Hb on CsA test,especially for organ transplant patients with lower Hb （ 〈30 g/L）.