TY - JOUR
T1 - Rapid homogeneous immunoassay to quantify gemcitabine in plasma for therapeutic drug monitoring
AU - Kozo, Daniel
AU - Ross, Matt W.
AU - Jarrah, Justin
AU - Barrett, Michael
AU - Harney, Rebecca L.
AU - Courtney, Jodi B.
AU - Baburina, Irina
AU - Holleran, Julianne L.
AU - Beumer, Jan H.
AU - Peters, Godefridus J.
AU - Honeywell, Richard J.
AU - Salamone, Salvatore J.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Background: Gemcitabine (20,20-difluoro-20-deoxycytidine) is a nucleoside analog used as a single agent and in combination regimens for the treatment of a variety of solid tumors. Several studies have shown a relationship between gemcitabine peak plasma concentration (Cmax) and hematological toxicity. An immunoassay for gemcitabine in plasma was developed and validated to facilitate therapeutic drug monitoring (TDM) by providing an economical, robust method for automated chemistry analyzers. Methods: A monoclonal antibody was coated on nanoparticles to develop a homogenous agglutination inhibition assay. To prevent ex vivo degradation of gemcitabine in blood, tetrahydrouridine was used as a sample stabilizer. Validation was conducted for precision, recovery, cross-reactivity, and linearity on a Beckman Coulter AU480. Verification was performed on an AU5800 in a hospital laboratory. A method comparison was performed with (LC-MS/MS) liquid chromatography tandem mass spectrometry using clinical samples. Selectivity was demonstrated by testing cross-reactivity of the major metabolite, 20,20-difluorodeoxyuridine. Results: Coefficients of variation for repeatability and withinlaboratory precision were ,8%. The deviation between measured and assigned values was ,3%. Linear range was from 0.40 to 33.02 m/mL (1.5-125.5 mM). Correlation with validated LC-MS/ MS methods was R2 = 0.977. The assay was specific for gemcitabine: there was no cross-reactivity to 20,20-difluorodeoxyuridine, chemotherapeutics, concomitant, or common medications tested. Tetrahydrouridine was packaged in single-use syringes. Gemcitabine stability in whole blood was extended to 8 hours (at room temperature) and in plasma to 8 days (2-88C). Conclusions: The assay demonstrated the selectivity, test range, precision, and linearity to perform reliable measurements of gemcitabine in plasma. The addition of stabilizer improved the sample handling. Using general clinical chemistry analyzers, gemcitabine could be measured for TDM.
AB - Background: Gemcitabine (20,20-difluoro-20-deoxycytidine) is a nucleoside analog used as a single agent and in combination regimens for the treatment of a variety of solid tumors. Several studies have shown a relationship between gemcitabine peak plasma concentration (Cmax) and hematological toxicity. An immunoassay for gemcitabine in plasma was developed and validated to facilitate therapeutic drug monitoring (TDM) by providing an economical, robust method for automated chemistry analyzers. Methods: A monoclonal antibody was coated on nanoparticles to develop a homogenous agglutination inhibition assay. To prevent ex vivo degradation of gemcitabine in blood, tetrahydrouridine was used as a sample stabilizer. Validation was conducted for precision, recovery, cross-reactivity, and linearity on a Beckman Coulter AU480. Verification was performed on an AU5800 in a hospital laboratory. A method comparison was performed with (LC-MS/MS) liquid chromatography tandem mass spectrometry using clinical samples. Selectivity was demonstrated by testing cross-reactivity of the major metabolite, 20,20-difluorodeoxyuridine. Results: Coefficients of variation for repeatability and withinlaboratory precision were ,8%. The deviation between measured and assigned values was ,3%. Linear range was from 0.40 to 33.02 m/mL (1.5-125.5 mM). Correlation with validated LC-MS/ MS methods was R2 = 0.977. The assay was specific for gemcitabine: there was no cross-reactivity to 20,20-difluorodeoxyuridine, chemotherapeutics, concomitant, or common medications tested. Tetrahydrouridine was packaged in single-use syringes. Gemcitabine stability in whole blood was extended to 8 hours (at room temperature) and in plasma to 8 days (2-88C). Conclusions: The assay demonstrated the selectivity, test range, precision, and linearity to perform reliable measurements of gemcitabine in plasma. The addition of stabilizer improved the sample handling. Using general clinical chemistry analyzers, gemcitabine could be measured for TDM.
KW - Gemcitabine
KW - Immunoassay
KW - Oncology
KW - Pharmacokineticpharmacodynamic
KW - Therapeutic drug monitoring
UR - http://www.scopus.com/inward/record.url?scp=85019746966&partnerID=8YFLogxK
U2 - https://doi.org/10.1097/FTD.0000000000000402
DO - https://doi.org/10.1097/FTD.0000000000000402
M3 - Article
C2 - 28490046
SN - 0163-4356
VL - 39
SP - 235
EP - 242
JO - Therapeutic Drug Monitoring
JF - Therapeutic Drug Monitoring
IS - 3
ER -