Single-Cell Analysis Highlights Pivotal Role of Eosinophil-Basophil Mast Cell Progenitor-Related Mechanism in Primary Immune Thrombocytopenia.

Immune thrombocytopenia (ITP) is an autoimmune disease. Megakaryocyte dysfunction caused by autoimmune response can lead to thrombocytopenia, and the underlying mechanism is still unclear. Single-cell sequencing analysis revealed the heterogeneity of CD34 + HSPCs in bone marrow between ITP patients and healthy groups. Pre-B cell population 1 (pre-B1) showed a significantly lower percentage contribution in ITP groups, and the underlying mechanism involves cell cycle-, cell apoptosis- and cell death-related pathways. The number of eosinophil-basophil mast cell progenitors (EBMPs) is significantly increased in ITP patients and the DEGs of the EBMPs in ITP patients were significantly enriched in immune-related pathways. Further, immunofluorescent staining and Western blot assay highlight C-X-C Motif Chemokine Ligand 8 (CXCL8) and Interferon Regulatory Factor 1 (IRF1) expression were significantly increased in the EBMPs of ITP patients. Furthermore, cell-cell communication analysis identified an impaired LGALS9-CD44 axis between EBMP cells and MkP1 cells in ITP patients, suggesting that targeting the LGALS9-CD44 interaction might hold promise as a therapeutic approach for ITP. Our observations indicate that ITP patients exhibit an elevated proportion of EBMP cells alongside a reduced proportion of pre-B1 cells. CXCL8 and IRF1 are potentially associated with EBMP cell dysfunction and the ITP disease process. Furthermore, the diminished LGALS9-CD44 axis between EBMP and MkP1 cells may contribute to ITP progression, suggesting a direction for future therapeutic investigation.