B-162 Direct Quantitation of Five Immunosuppressant Drugs in Dried Whole Blood Spots by a Fully Automated DSM-LC-MS System

Abstract

Abstract Background Liquid chromatography-mass spectrometry (LC-MS) is increasingly used in clinical research to quantify immunosuppressant drugs in whole blood as it can offer higher sensitivity and selectivity than other analytical techniques. LC-MS systems may be coupled with upstream dried matrix spot modules within one high-throughput, integrated and online workflow, allowing the extraction of matrices such as whole blood from pre-collected sample cards collected in a quick and minimally invasive manner. In this poster, such a workflow will be utilized to demonstrate the quantitation of five commonly monitored therapeutic immunosuppressants; cyclosporin A, everolimus, mycophenolic acid, sirolimus and tacrolimus. Methods Calibration and QC samples were prepared in whole blood. 10 μL of each calibrant was then spotted in triplicate on DBS cards. Immunosuppressants and standards were extracted using a Thermo Scientifc™ Transcend™ DSX-1 Systems via flow-through desorption with a heated clamp. TurboFlow allowed interference removal in the extracted samples prior to analytical separation. An integrated software, Aria MX, controlled each step of sample desorption and separation. Analyte quantitation was performed by a TSQ Altis™ mass spectrometer, and the data was analyzed using TraceFinder™ 5.1 General Quan software. Results Five commonly therapeutically monitored immunosuppressant drugs were quantified from blood spotted onto DBS cards using a fully automated workflow, resulting in a highly sensitive 5-minute method. Calibration curves were fitted using a weighting factor of 1/x with requirements of R2 > 0.98, RSD/CV < 15%. The calibrants were used to determine the limits of detection (LODs) and quantitation (LOQs) shown in the below table. Conclusion A complete, integrated and fully automated workflow has been developed to rapidly and robustly quantify immunosuppressant drugs from dried blood spots. Quick and reproducible extraction of each target analyte and efficient chromatographic separation facilitated a 5-minute method for the quantitation of five of the most commonly therapeutically monitored immunosuppressant drugs.