Eltrombopag modulates the phenotypic evolution and potential immunomodulatory roles of monocytes/macrophages in immune thrombocytopenia.

What is the context? Primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease. Loss of immune tolerance plays a crucial role in the pathogenesis of ITP.Monocytes and macrophages play an indispensable role in the pathophysiology of hematopoietic malignancies and have been implicated as key players in platelet destruction.Approximately 80% of adult patients with ITP exhibit corticosteroid treatment failure or become dependent, requiring novel therapy. Thrombopoietin (TPO) receptor agonists (TPO-RAs) have been used clinically to manage ITP effectively, however, little is known about the effect of TPO-RAs on monocyte and macrophage modulation in ITP.What is new?In this study, we investigated the phenotypic evolution and potential immunomodula-tory roles of monocytes/macrophages in ITP patients receiving eltrombopag therapy.The expansion of peripheral monocytes positively correlated with IFN-γ/IL-4 ratio in ITP patients.ITP macrophages exhibited more M1-related characteristics.After eltrombopag therapy, the peripheral monocyte count and IFN-γ/IL-4 ratio significantly decreased in ITP patients.M1-related characteristics of ITP macrophages were partially reversed by eltrombopag.What is the impact?This study provides evidence that the potential vital roles of TPO-RAs in regulating the monocyte/macrophage plasticity in ITP.