Will Mass Spectrometry Replace Current Techniques for Both Routine Monitoring and MRD Detection in Multiple Myeloma?

Katie L Thoren

doi:10.3390/hemato2040052

Abstract

In recent years, mass spectrometry has been increasingly used for the detection of monoclonal proteins in serum. Mass spectrometry is more analytically sensitive than serum protein electrophoresis and immunofixation, can help distinguish therapeutic monoclonal antibodies from M-proteins, and can detect the presence of post-translational modifications. Mass spectrometry also shows promise as a less-invasive, peripheral-blood-based test for detecting minimal residual disease in multiple myeloma. Studies comparing the clinical utility of mass spectrometry to current blood- and bone-marrow-based techniques have been conducted. Although still primarily limited to research settings, clinical laboratories are starting to adopt this technique for patient care. This review will discuss the current status of mass spectrometry testing for multiple myeloma, the benefits and challenges of this technique, and how it may be incorporated into clinical practice in the future.

Highlights

Treatments for multiple myeloma have greatly improved over the last decade and new diagnostic methods are being developed to detect lower levels of disease
Comparisons to progression free survival (PFS) suggest that this confounding factor can be overcome and that mass spectrometry may be more sensitive than bone-marrow-based minimal residual disease (MRD) tests
Mass spectrometry will likely become a valuable technique for MRD monitoring and detecting early relapse, since it is well-suited for serial sampling

Summary

Introduction

Treatments for multiple myeloma have greatly improved over the last decade and new diagnostic methods are being developed to detect lower levels of disease. Mass spectrometrybased methods that detect the monoclonal immunoglobulin (M-protein) have been developed and offer several analytical advantages over electrophoretic techniques [1,2,3,4] They are more analytically sensitive and specific than serum protein electrophoresis (SPEP) and immunofixation (IF). They provide additional information about the protein (i.e., light chain glycosylation) that is not available by SPEP and IF. Because these techniques are still relatively new, the field is trying to determine how (and if) these analytical advantages will improve patient care and where these assays fit into clinical practice. We discuss the different mass spectrometry methods, our current understanding of their clinical utility, and whether they may overtake current techniques for both routine monitoring and MRD detection in multiple myeloma

Mass Spectrometry Methods

Clinical Utility

High Levels of Disease

Findings

Conclusions