Armstrong V W, Schuetz E, Zhang Q, Groothuisen S, Scholz C, Shipkova M, Aboleneen H, Oellerich M
1 Abteilung Klinische Chemie, Georg-August-Universitaet Goettingen, D-37075 Goettingen, Germany.
Clin Chem. 1998 Dec;44(12):2516-23.
A modified pentamer formation assay (PFA) for quantification of tacrolimus and active metabolites after extraction from whole blood is described. The lower limit of detection was 2 microg/L. Intraassay precision (CV) was 5.7-13.7%, and the interassay CV was 6. 1-14.9%. Tacrolimus trough concentrations in 104 whole blood specimens from liver and kidney transplant recipients were compared with results from HPLC-tandem mass spectrometry (LC/MS/MS) and microparticle enzyme immunoassay (MEIA-II). Data were analyzed by difference plots and are presented as median (95% confidence intervals) of the method differences. MEIA-II results were on average 2.00 microg/L (range, -0.08 to 5.17 microg/L) higher than LC/MS/MS, whereas PFA results were only 1.07 microg/L (range, -2.62 to 5.33 microg/L) higher. Of 104 specimens tested, 25 displayed differences >/=3 microg/L between MEIA-II and PFA: median difference, 4.65 microg/L (range, 3.01-8.79 microg/L). The corresponding median difference between PFA and LC/MS/MS was -0.91 microg/L (range, -4.11 to 0.85 microg/L), and the difference between MEIA-II and LC/MS/MS was 3.67 microg/L (range, 1.88-6.34 microg/L), suggesting the presence of inactive metabolites that caused a positive bias in the immunoassay. In contrast, similar median differences were observed for the remaining 79 specimens: MEIA-II minus LC/MS/MS, 1.78 microg/L (range, -0.45 to 4.11 microg/L); PFA minus LC/MS/MS, 1.90 microg/L (range, -1.70 to 5.50 microg/L). Active tacrolimus metabolites may have contributed to the higher apparent tacrolimus concentrations in these specimens.
本文描述了一种改良的五聚体形成分析方法（PFA），用于定量从全血中提取后的他克莫司及其活性代谢物。检测下限为2μg/L。批内精密度（CV）为5.7 - 13.7%，批间CV为6.1 - 14.9%。将104份来自肝移植和肾移植受者的全血标本中的他克莫司谷浓度与高效液相色谱 - 串联质谱法（LC/MS/MS）和微粒体酶免疫分析法（MEIA-II）的结果进行比较。数据通过差异图进行分析，并以方法差异的中位数（95%置信区间）表示。MEIA-II结果平均比LC/MS/MS高2.00μg/L（范围为 - 0.08至5.17μg/L），而PFA结果仅比LC/MS/MS高1.07μg/L（范围为 - 2.62至5.33μg/L）。在104份检测标本中，有25份显示MEIA-II和PFA之间的差异≥3μg/L：中位数差异为4.65μg/L（范围为3.01至8.79μg/L）。PFA与LC/MS/MS之间的相应中位数差异为 - 0.91μg/L（范围为 - 4.11至0.85μg/L），MEIA-II与LC/MS/MS之间的差异为3.67μg/L（范围为1.88至6.34μg/L），这表明存在导致免疫分析出现正偏差的非活性代谢物。相比之下，其余79份标本观察到类似的中位数差异：MEIA-II减去LC/MS/MS为1.78μg/L（范围为 - 0.45至4.11μg/L）；PFA减去LC/MS/MS为1.90μg/L（范围为 - 1.70至5.50μg/L）。活性他克莫司代谢物可能导致了这些标本中他克莫司表观浓度较高。
