A Differential Proteomic Analysis on Patient Sera with Neuromyelitis Spectrum Disorders (NMOSD) and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) Suggested Shared and Distinct Disease Mechanisms

Neuromyelitis optica spectrum disorders (NMOSD) and myelin
oligodendrocyte
glycoprotein antibody-associated disease (MOGAD) are two types of
autoimmune-mediated central nervous system (CNS) inflammatory demyelinating
diseases that have similar clinical manifestations but with different
pathogenesis and prognosis. Here, we reported on a differential proteomic
analysis on the patient sera with the two diseases. Serum samples
of 25 aquaporin-4 (AQP4)-IgG+ NMOSD patients, 16 MOGAD patients, and
8 healthy individuals were submitted to shotgun analysis using nano-LC-MS/MS.
Totally, 584 nonredundant proteins were identified and quantified,
among which 340 proteins were detected in at least three samples per
group. Statistical analysis revealed 40 proteins had significant difference
in at least one group-pair comparison (fold change >1.2 or <0.83
and multiple-sample test ANOVA-q < 0.05). Also, 38 proteins were
detected only in the patient groups and not in the healthy controls.
Bioinformatic analysis on these 78 proteins revealed that disturbance
of the immune system, hemostasis processes, and carbohydrate metabolism
occurred in both diseases, while the dysregulation patterns suggested
different mechanisms. We expect this work would provide useful information
to improve the understanding of the mechanisms of NMOSD and MOGAD
and suggest potential diagnostic markers and treatment targets.