MSACL 2024 Abstract

INTRODUCTION:
The barrier to adopting mass spectrometry for the majority of laboratories has been well documented, yet the desire to generate higher quality results remains. High-Resolution Ion Mobility (HRIM) offers a glimpse into another dimension that can make ‘mass spectrometry for all’ a reality, where knowledge of how it works is not necessary for the everyday user.

Urine toxicology is an example of a well-established offering of most laboratories. It is a vital component to numerous patient management scenarios from emergency room visits to recovery programs and even drug screening for transplant recipients. The variability in menu design and widespread use of immunoassays in many labs has represented a challenge for physicians, laboratorians, and patients in obtaining reliable results in a timely manner. Further, the ‘screen with reflex to confirmation’ workflow is a mainstay of urine toxicology testing due to ease of use and automated workflows available with immunoassays; however, this two stage workflow is unnecessarily costly, often lacks sufficient specificity for the screening results to be reliably actionable, and relies on laboratories to adopt relatively complex mass spectrometry workflows or requires a costly sendout testing process with a delay in results based on reference laboratory performance. Using urine toxicology as one of numerous examples, we aim to demonstrate how high-resolution ion mobility is poised to put a mass spectrometer in every laboratory without anyone realizing it is there.

OBJECTIVES:
The primary objective of this study was to illustrate the various benefits of using a simplified urine toxicology, mass spectrometry-based workflow relying on a combination of Collision Cross Section and High-Resolution Mass Spectrometry in the absence of chromatographic retention time for identification. A secondary objective is to illustrate the potential power of embedding untargeted analyses into routine testing workflows in the hopes of turning the 'unused' data into gold.

METHODS:
A qualitative, urine toxicology workflow was developed using a modular, automated tip-based extraction for removal of matrix. A High-Resolution Ion Mobility-High Resolution Mass Spectrometry prototype system was used with a less than 2.5-minute injection-to-injection cycle. 62 targeted drugs were identified using an automated detection algorithm based on CCS, with helium as the drift gas, in combination with m/z. A CLIA validation protocol was followed to assess precision, accuracy, carryover, analytical sensitivity, and analytical specificity. An internally developed liquid chromatography-tandem mass spectrometry method was used to confirm all results in addition to external comparisons for the majority of included drug targets.

RESULTS:
Instrument Detection Limits were calculated to assess overall sensitivity of the prototype system, with sufficient sensitivity achieved for all included drug targets. Imprecision and accuracy were within acceptable limits and analytical sensitivity and specificity were greater than 90% when compared to internally and externally derived results using orthogonal technology. Patient comparison results (n > 120) demonstrated acceptable agreement with the prototype system detecting additional compounds not included in all externally derived results due to known variability with drug panel inclusion and established cutoffs. Additional detected features were extracted from authentic sample data files highlighting the epidemiological value and potential biomarker discovery at scale with targeted and untargeted workflows in use for routine clinical testing.

CONCLUSION:
Eliminating the dependence on chromatography for compound identification is critical to reducing barriers for mass spectrometry adoption in the field. Moreover, laboratories that have integrated mass spectrometry into their workflows need a strategy to delegate routine assays. This shift will enable them to concentrate on developing next-generation biomarkers without compromising the established performance or becoming constrained by rigid systems. Additionally, to prevent the stagnation of promising biomarker translation due to inefficient affinity-based methods, it's imperative to develop a platform that is capable of performing these novel assays without the complexity of existing mass spectrometry workflows. This will maximize the potential of innovation in health equity for precision medicine. Ultimately, enhancing patient outcomes begins with a paradigm shift from a technology-centric approach to one that prioritizes addressing patient needs.