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Neurol Neuroimmunol Neuroinflamm. 2025 May;12(3):e200384. doi: 10.1212/NXI.0000000000200384. Epub 2025 Mar 21.

ABSTRACT

BACKGROUND AND OBJECTIVES: Myasthenia gravis (MG) is an autoimmune disease most frequently caused by autoantibodies (auto-Abs) against the acetylcholine receptor (AChR) located at the neuromuscular junction. Thymic follicular hyperplasia is present in most of the patients with early-onset AChR-Ab+ MG (EOMG), but its cellular and molecular drivers and development remain poorly understood.

METHODS: We constructed a single cell-based transcriptional profile of lymphoid cell types in thymi from 11 immunotherapy-naïve patients with EOMG. Multiplex histology and ELISA were used to determine migration inhibitory factor (MIF) levels.

RESULTS: Within EOMG thymi, we consistently observed 6 distinct clusters of B-cell populations maturing toward germinal center (GC)-associated and Ab-secreting cells, featuring prominent GC activity, as indicated by substantial clonal expansions and cycling B-cell subsets. Cell-cell interactome predictions identified strong interactions between T cells and GC-associated and memory B cells, dominated by B-cell prosurvival signaling through the MIF-CD74 axis. Multiplex histology confirmed abundant expression of CD74 in MG thymic B cells. Circulating MIF levels in EOMG correlated with higher disease severity as assessed by Myasthenia Gravis Foundation of America status.

DISCUSSION: Our data not only illustrate and define hyperplastic thymic niches in MG as favorable environments for pathogenic B-cell proliferation, maturation, and persistence but also suggest that the MIF-CD74 axis should be investigated for potential novel therapeutic targeting in EOMG.

PMID:40117520 | DOI:10.1212/NXI.0000000000200384


Source: https://pubmed.ncbi.nlm.nih.gov/4011752 ... t9+e462414