Modified pentamer formation assay for measurement of tacrolimus and its active metabolites: comparison with liquid chromatography-tandem mass spectrometry and microparticle enzyme-linked immunoassay (MEIA-II)
| Autor: | Qingling Zhang, Victor W. Armstrong, Christa Scholz, Michael Oellerich, Hoda Aboleneen, Maria Shipkova, Ekkehard Schuetz, Stephan Groothuisen |
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| Rok vydání: | 1998 |
| Předmět: |
Metabolite
Clinical Biochemistry Enzyme-Linked Immunosorbent Assay Microparticle Enzyme Immunoassay 030226 pharmacology & pharmacy 01 natural sciences High-performance liquid chromatography Tacrolimus 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Liquid chromatography–mass spectrometry medicine Humans Active metabolite Chromatography High Pressure Liquid Detection limit Chromatography medicine.diagnostic_test Chemistry 010401 analytical chemistry Biochemistry (medical) Kidney Transplantation 0104 chemical sciences Liver Transplantation Immunoassay Regression Analysis Quantitative analysis (chemistry) Immunosuppressive Agents Chromatography Liquid |
| Zdroj: | Clinical chemistry. 44(12) |
| ISSN: | 0009-9147 |
| Popis: | 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 μg/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 μg/L (range, −0.08 to 5.17 μg/L) higher than LC/MS/MS, whereas PFA results were only 1.07 μg/L (range, −2.62 to 5.33 μg/L) higher. Of 104 specimens tested, 25 displayed differences ≥3 μg/L between MEIA-II and PFA: median difference, 4.65 μg/L (range, 3.01–8.79 μg/L). The corresponding median difference between PFA and LC/MS/MS was −0.91 μg/L (range, −4.11 to 0.85 μg/L), and the difference between MEIA-II and LC/MS/MS was 3.67 μg/L (range, 1.88–6.34 μg/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 μg/L (range, −0.45 to 4.11 μg/L); PFA minus LC/MS/MS, 1.90 μg/L (range, −1.70 to 5.50 μg/L). Active tacrolimus metabolites may have contributed to the higher apparent tacrolimus concentrations in these specimens. |
| Databáze: | OpenAIRE |
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