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). 1998

V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
1 Abteilung Klinische Chemie, Georg-August-Universitaet Goettingen, D-37075 Goettingen, Germany. varmstro@med.uni-goettingen.de

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.

UI MeSH Term Description Entries
D007166 Immunosuppressive Agents Agents that suppress immune function by one of several mechanisms of action. Classical cytotoxic immunosuppressants act by inhibiting DNA synthesis. Others may act through activation of T-CELLS or by inhibiting the activation of HELPER CELLS. While immunosuppression has been brought about in the past primarily to prevent rejection of transplanted organs, new applications involving mediation of the effects of INTERLEUKINS and other CYTOKINES are emerging. Immunosuppressant,Immunosuppressive Agent,Immunosuppressants,Agent, Immunosuppressive,Agents, Immunosuppressive
D012044 Regression Analysis Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable. Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D002851 Chromatography, High Pressure Liquid Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed. Chromatography, High Performance Liquid,Chromatography, High Speed Liquid,Chromatography, Liquid, High Pressure,HPLC,High Performance Liquid Chromatography,High-Performance Liquid Chromatography,UPLC,Ultra Performance Liquid Chromatography,Chromatography, High-Performance Liquid,High-Performance Liquid Chromatographies,Liquid Chromatography, High-Performance
D002853 Chromatography, Liquid Chromatographic techniques in which the mobile phase is a liquid. Liquid Chromatography
D004797 Enzyme-Linked Immunosorbent Assay An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed. ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D016030 Kidney Transplantation The transference of a kidney from one human or animal to another. Grafting, Kidney,Renal Transplantation,Transplantation, Kidney,Transplantation, Renal,Kidney Grafting,Kidney Transplantations,Renal Transplantations,Transplantations, Kidney,Transplantations, Renal
D016031 Liver Transplantation The transference of a part of or an entire liver from one human or animal to another. Grafting, Liver,Hepatic Transplantation,Liver Transplant,Transplantation, Hepatic,Transplantation, Liver,Hepatic Transplantations,Liver Grafting,Liver Transplantations,Liver Transplants,Transplant, Liver
D016559 Tacrolimus A macrolide isolated from the culture broth of a strain of Streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro. Anhydrous Tacrolimus,FK-506,FK506,FR-900506,Prograf,Prograft,Tacrolimus Anhydrous,Anhydrous, Tacrolimus,FK 506,FR 900506,FR900506,Tacrolimus, Anhydrous

Related Publications

V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
October 1995, Therapeutic drug monitoring,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
August 2006, Therapeutic drug monitoring,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
October 2007, Therapeutic drug monitoring,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
December 1996, Transplantation proceedings,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
January 2004, Drugs in R&D,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
June 2003, Therapeutic drug monitoring,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
September 1998, Clinical chemistry,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
July 2016, American journal of clinical pathology,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
March 2005, Clinical chemistry,
V W Armstrong, and E Schuetz, and Q Zhang, and S Groothuisen, and C Scholz, and M Shipkova, and H Aboleneen, and M Oellerich
November 2004, Clinical chemistry,
Copied contents to your clipboard!