TY - JOUR T1 - Mass spectrometry quantitation of immunosuppressive drugs in clinical specimens using online solid-phase extraction and accurate-mass full scan-single ion monitoring. AU - Yeung,Priscilla S-W, AU - Miller,Paige, AU - Lai-Nyugen,Tran Bao, AU - Cheng,Phil, AU - Ibrahim,Amira, AU - Shi,Run-Zhang, AU - Bowen,Raffick A R, AU - Luo,Ruben Yiqi, Y1 - 2023/03/07/ PY - 2023/2/10/received PY - 2023/3/3/revised PY - 2023/3/5/accepted PY - 2023/3/20/entrez PY - 2023/3/21/pubmed PY - 2023/3/21/medline KW - Accurate-mass KW - CAP, College of American Pathologists KW - CLSI, Clinical & Laboratory Standards Institute KW - CV, coefficient of variation KW - ESI, electrospray ionization KW - FS-SIM, full scan-single ion monitoring KW - Full scan single-ion monitoring KW - HCD, high-energy C-trap dissociation KW - IRB, Institutional Review Board KW - Immunosuppressive drugs KW - LC-MS, liquid chromatography-mass spectrometry KW - LDT, laboratory developed test KW - MRM, multiple reaction monitoring KW - Mass spectrometry KW - Online solid-phase extraction KW - SD, standard deviation KW - SPE, solid-phase extraction KW - TDM, therapeutic drug monitoring KW - Therapeutic drug monitoring SP - 99 EP - 104 JF - Journal of mass spectrometry and advances in the clinical lab JO - J Mass Spectrom Adv Clin Lab VL - 28 N2 - INTRODUCTION: Therapeutic drug monitoring (TDM) of immunosuppressants is essential for optimal care of transplant patients. Immunoassays and liquid chromatography-mass spectrometry (LC-MS) are the most commonly used methods for TDM. However, immunoassays can suffer from interference from heterophile antibodies and structurally similar drugs and metabolites. Additionally, nominal-mass LC-MS assays can be difficult to optimize and are limited in the number of detectable compounds. OBJECTIVES: The aim of this study was to implement a mass spectrometry-based test for immunosuppressant TDM using online solid-phase extraction (SPE) and accurate-mass full scan-single ion monitoring (FS-SIM) data acquisition mode. METHODS: LC-MS analysis was performed on a TLX-2 multi-channel HPLC with a Q-Exactive Plus mass spectrometer. TurboFlow online SPE was used for sample clean up. The accurate-mass MS was set to positive electrospray ionization mode with FS-SIM for quantitation of tacrolimus, sirolimus, everolimus, and cyclosporine A. MS2 fragmentation pattern was used for compound confirmation. RESULTS: The method was validated in terms of precision, analytical bias, limit of quantitation, linearity, carryover, sample stability, and interference. Quantitation of tacrolimus, sirolimus, everolimus, and cyclosporine A correlated well with results from an independent reference laboratory (r = 0.926-0.984). CONCLUSIONS: Accurate-mass FS-SIM can be successfully utilized for immunosuppressant TDM with good correlation with results generated by standard methods. TurboFlow online SPE allows for a simple "protein crash and shoot" sample preparation protocol. Compared to traditional MRM, analyte quantitation by FS-SIM facilitates a streamlined assay optimization process. SN - 2667-145X UR - https://www.unboundmedicine.com/medline/citation/36937810/Mass_spectrometry_quantitation_of_immunosuppressive_drugs_in_clinical_specimens_using_online_solid_phase_extraction_and_accurate_mass_full_scan_single_ion_monitoring_ DB - PRIME DP - Unbound Medicine ER -