Donald (Don) Mason, MSc, is the global scientific affairs manager at Waters Corporation. He has worked with Waters for more than 20 years, where he began with developing their clinical mass spectrometry portfolio and continues to deliver solutions that benefit laboratory medicine and patients.
Q: Why is LC-MS/MS technology valuable to the clinical lab?
A: There are three primary drivers for the use of liquid chromatography with tandem mass spectrometry (LC-MS/MS) in clinical laboratories:
- The versatility to develop lab tests that best suit the needs of individual clinical labs
- Specificity, i.e., the ability to measure the target analyte without confounding substances
- The ability to measure multiple analytes in a single analysis, providing a rich dataset
Q: WHAT ARE A FEW APPLICATIONS OF LC-MS/MS IN THE CLINICAL LAB? WHICH INSTRUMENTS ARE BEST SUITED TO THESE APPLICATIONS?
A: Clinical labs largely use tandem quadrupole mass spectrometers for quantitative analyses, such that clinicians can be provided with a numerical value for a given analyte to guide their decisions for patient care.
LC-MS/MS is well established for measuring immunosuppressant drugs, like tacrolimus and cyclosporine, which are administered to prevent solid organ rejection in patients following transplantation and must be maintained within a narrow therapeutic window.
Perhaps one of the greatest success stories for LC-MS/MS in clinical testing is newborn screening, where dried blood spots collected shortly after birth can be used to screen for more than 50 metabolites, enabling the diagnosis of a wide range of inborn metabolic disorders.
Q: HOW WAS TESTING PERFORMED FOR THESE APPLICATIONS PRIOR TO LC-MS/MS, AND WHY DID THE SHIFT TO THIS TECHNOLOGY OCCUR?
A: For applications like newborn screening for metabolic disorders, there were previously no tests available. For other areas like therapeutic drug monitoring and endocrinology, immunoassay or ligand-binding techniques were used, but their specificity suffered from cross-reactivity among structurally related compounds. However, even related compounds differ in their mass, so they can be separated both chromatographically and by mass spectrometry. Thus, there has been a shift toward LC-MS/MS technology to specifically differentiate and measure analytes.
Q: How does Water’s LC-MS/MS system benefit clinical lab staff?
A: Many clinical lab professionals enjoy the opportunity to work with a new technology that they know provides the potential for better patient care. At Waters, we are also easing the adoption of this new technology into clinical labs by integrating the workflow from sample pre-treatment with automated liquid handlers to tracking samples through the LC-MS system and the hospital’s informatics ecosystem (through its LIMS). For lab staff, such integration reduces hands-on time and errors during manual data transcription.
Ultimately, introducing a LC-MS system into a clinical lab requires a partnership between the lab and the instrument vendor to ensure that the lab is physically ready, as well as to provide training, optimization, and maintenance of the instrument. The future for LC-MS/MS is quite bright, and we are excited to partner with clinical lab professionals to expand testing beyond what’s possible with existing diagnostic technologies.