Untargeted serum metabolomic profiling in patients with generalized and ocular Myasthenia Gravis

BACKGROUND: Myasthenia Gravis (MG) is divided into ocular (OMG) and generalized (GMG) subtypes. While clinical diagnosis is well-established, understanding the underlying biochemical mechanisms and metabolic shifts during disease progression remains challenging; untargeted metabolomics offers a novel perspective to explore these systemic alterations. OBJECTIVE: To characterize the serum metabolic landscape of MG patients and identify potential metabolic signatures associated with disease subtypes (OMG and GMG) via untargeted metabolomics. METHODS: 91 participants (41 GMG, 22 OMG, 28 healthy controls [HC]) were enrolled. Fasting serum samples were analyzed by LC-MS/MS. Multivariate analyses (PCA, PLS-DA/OPLS-DA), differential metabolite screening (VIP > 1.0, p < 0.05), and KEGG pathway enrichment were performed. RESULTS: HC and MG groups showed distinct metabolic profiles. MG had 515 (175 up, 340 down) and 368 (146 up, 222 down) differential metabolites in positive/negative ion modes, respectively. Key perturbed pathways included glycerophospholipid, sphingolipid metabolism, and unsaturated fatty acid biosynthesis. Ten representative metabolites (e.g., ubiquinone, cortisol) differed significantly among groups; clustering analysis revealed distinct metabolite abundance trajectories across HC, OMG, and GMG. CONCLUSION: MG is associated with notable systemic metabolic dysregulation, particularly in lipid-related pathways. Rather than serving as immediate diagnostic tools, these integrative metabolic signatures provide a crucial biochemical framework for understanding disease pathogenesis and offer valuable clues for future hypothesis-driven research and prospective validation.