Multicenter Evaluation of a Novel Nanoparticle Immunoassay for 5-Fluorouracil on the Olympus AU400 Analyzer

• DOI: 10.1097/ftd.0b013e3181b9b8c0
• Publication Date: 2017-10-13T16:41:58Z
• Authors: Jan H Beumer; M Boisdron-Celle; William Clarke; Jodi B Courtney; Merrill J Egorin; Erick Gamelin; Rebecca L Harney; Catherine Hammett...; Sandy Lepp; Yunying Li; Gregory D Lundell; Gwen McMillin; Gerard Milano; Salvatore J Salamone
• Keywords: Immunoassay; Time Factors; Antibodies, Monoclonal; Reproducibility of Results; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Limit of Detection; Nephelometry and Turbidimetry; Calibration; Humans; Nanoparticles; Fluorouracil; Drug Monitoring

5-Fluorouracil (5-FU) is the most widely used chemotherapy drug, primarily against gastrointestinal, head and neck, and breast cancers. 5-FU has large pharmacokinetic variability resulting in unexpected toxicity or ineffective treatment. Therapeutic drug management of 5-FU minimizes toxicity and improves outcome. A nanoparticle-based immunoassay was developed to provide oncologists with a rapid, cost-effective tool for determining 5-FU plasma concentrations.Monoclonal antibodies, bound to nanoparticles, were used to develop an immunoassay for the Olympus AU400. Assay precision, linearity, calibration stability, and limit of detection were run at multiple centers; interference, cross-reactivity, lower limit of quantitation and recovery at 1 center. Clinical samples collected from 4 cancer centers were analyzed for 5-FU concentrations by liquid chromatography-tandem mass spectrometry and compared with the immunoassay results.With calibrators from 0 to 1800 ng/mL 5-FU and autodilution, concentrations up to 9000 ng/mL could be determined. Time to first result was 10 minutes, and 400 samples per hour could be quantitated from a standard curve stored for >30 days. Imprecision across all laboratories was <5%, and the assay was linear upon dilution over the entire range. Cross-reactivities for dihydro-5-FU, uracil, capecitabine, and tegafur were <1%, 9.9%, 0.05%, and 0.23%, respectively. The limit of detection was 52 ng/mL with a lower limit of quantitation of 86 ng/mL. Assay results of clinical samples (93-1774 ng/mL) correlated with liquid chromatography-tandem mass spectrometry results: (R = 0.9860, slope 1.035, intercept 10.87 ng/mL).This novel immunoassay is suitable for quantitating 5-FU plasma concentrations with advantages of speed, small sample size, minimal sample pretreatment, and application on automated instrumentation. These advantages enable efficient therapeutic drug management of 5-FU in clinical practice.