MSACL 2026 Abstract

The Study of Serum Monoclonal Protein (M-Protein) Glycosylation Patterns for Risk Stratification in Multiple Myeloma

Priscilla S.-W. Yeung (1, 2), Chenyin Lu (1), Danya N. Ortiz (1), Ethan Boneh (1), Brian Xu (1), Yajing Liu (1), Justin Barthel (1), Farida Elgebaly (1), David J. Iberri (3), Ruben Y. Luo (1, 2)
(1) Department of Pathology, Stanford University, Stanford, CA, USA (2) Clinical Laboratories, Stanford Health Care, Palo Alto, CA, USA (3) Department of Medicine, Division of Hematology, Stanford University, Stanford, CA, USA

Priscilla Yeung, MD, PhD (Presenter) Stanford/UCSF

Presenter Bio: Priscilla Yeung is a Fellow in the Joint Stanford-UCSF Clinical Chemistry Fellowship interested in using mass spectrometry to discover improved biomarkers for clinical testing. Her current research with Dr. Ruben Luo is focused on applying top-down mass spectrometry to the diagnosis of monoclonal gammopathies. Prior to residency, she completed her MD/PhD training at Northwestern University, where she studied the biophysical mechanisms of calcium channel gating with Dr. Murali Prakriya, and her undergraduate studies at University of Pennsylvania, where she studied amyloid-beta protein misfolding with Dr. Paul Axelsen.

Relevant Financial Disclosures (within past 24 months, reported on Apr 11, 2026) No relevant financial relationship(s) to disclose.

INTRODUCTION:
Multiple myeloma (MM) is a cancer of plasma cells in the bone marrow. Before patients develop fulminant MM, many pass through precancerous states of monoclonal gammopathy of uncertain significance (MGUS) and/or smoldering myeloma (SM), in which clonal populations of plasma cells in the bone marrow can be detected but do not cause symptoms. MGUS occurs in up to 5% of people over age 50 in the United States. Each patient has a ~1% chance per year of developing cancer, but it is difficult to accurately predict which MGUS cases will evolve into MM. In addition, because MM is currently considered incurable, during their disease, patients will progress through different lines of therapy. Although there are consensus guidelines for the general framework of treatment, much of each patient’s treatment journey is determined based on their individual responses and side effects. A better understanding of which MGUS patients will progress to MM and which MM patients will benefit from specific therapies will greatly the improve patient care. In this study, we aim to apply a high-resolution mass spectrometry (HR-MS) method to determine the glycan structure types on serum monoclonal proteins (M-proteins) to improve risk stratification in patients with monoclonal gammopathies. Based on a recent seminal study showing that the presence of M-protein light chain glycosylation is associated with disease progression, we hypothesize that the specific glycosylation patterns on serum M-proteins can improve its clinical utility as a biomarker.

METHODS:
Analysis was conducted on remnant patient serum samples with corresponding serum protein gel electrophoresis results showing monoclonal IgG bands. We optimized a HR-MS method to measure the glycosylation patterns of M-proteins. Briefly, the M-protein intact immunoglobulin was reduced, producing a pair of heavy chains (HCs) and light chains (LCs). The molecules were sequentially digested by specific enzymes to remove N-glycans and/or O-glycans. The individual components were then analyzed at various stages of deglycosylation. HR-MS analysis was performed on a Vanquish Flex multi-channel HPLC coupled with a Q-Exactive Plus mass spectrometer. Proteins were separated on MAbPac reverse phase columns. Mobile phase A was 0.1% formic acid in water and mobile phase B was 0.1% formic acid in acetonitrile. After HR-MS data acquisition, the M-protein HCs and LCs were categorized based on glycosylation status: none, N-, O-, and/or enzyme-resistant (ER-) glycans.

RESULTS:
In our preliminary cross-sectional cohort of ~300 patients, the potential prognostic value of LC glycosylation was demonstrated through the differential prevalence of O- or ER-glycans between pre-cancerous (MGUS) versus cancerous entities (MM and AL amyloidosis). In contrast a previous study which proposed the prognostic value of N-glycans on LCs, we demonstrated that O- or ER-glycosylation of M-proteins may be more linked to monoclonal gammopathy progression. Furthermore, to explore the utility of HC glycosylation patterns, the all-cause mortality rate of the patients with ~150 MM and other plasma cell malignancies was studied. Across various thresholds of survival time, HC O-glycosylation on M-proteins was observed to be a significant feature to differentiate survival and non-survival groups.

CONCLUSION:
Collectively, these preliminary data show the prognostic value of M-protein glycosylation patterns for patients with monoclonal gammopathies. We plan to further expand the cohorts to have sufficient statistical power to correlate with specific patient outcomes.