1. Evaluation of a fluorescent polarization immunoassay for whole blood everolimus determination using samples from renal transplant recipients
- Author
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Peter Marbach, Jared Boyd, Paul Salm, Paul J. Taylor, Christopher Warnholtz, and Lili Arabshahi
- Subjects
medicine.medical_specialty ,Fluorescent polarization ,Clinical Biochemistry ,Urology ,Cross Reactions ,Deming regression ,Fluorescence Polarization Immunoassay ,medicine ,Humans ,Everolimus ,Longitudinal Studies ,Kidney transplantation ,Chromatography, High Pressure Liquid ,Whole blood ,Sirolimus ,Chromatography ,medicine.diagnostic_test ,Chemistry ,General Medicine ,medicine.disease ,Kidney Transplantation ,Therapeutic drug monitoring ,Immunoassay ,Immunosuppressive Agents ,medicine.drug - Abstract
Objectives: This study compared the performance of a fluorescent polarization immunoassay (FPIA) against HPLC-tandem mass spectrometry (HPLC-MS) for the measurement of everolimus in renal transplant recipients. Design and methods: A total of 333 pre-dose samples from 45 renal transplant patients were analyzed by FPIA and HPLC-MS. Results: The inter-batch inaccuracy and precision of the FPIA for control samples were ≤6% and ≤13.0%, respectively ( n = 17). The comparison of patient results yielded the Deming regression equation FPIA = 1.19 × HPLC-MS + 0.51. The mean bias was 24.4% (95% CI: −3.0 to 54.2%, range: −30.1% to 79.4%). Conclusions: The FPIA had acceptable analytical performance during the study but compared to HPLC-MS overestimated everolimus in patient samples. This overestimation is probably due to calibration differences between the methods and cross-reactivity of the FPIA antibody with everolimus metabolites. The clinical importance of the observed overestimation by FPIA requires further investigation.
- Published
- 2005