Platelets and monocytes: A dynamic duo aiding in the prediction of the clinical response to thrombopoietin receptor agonists in immune thrombocytopenia?

Patients with immune thrombocytopenia (ITP) suffer from an autoimmune bleeding disorder with an isolated low number of platelets. Platelets and megakaryocytes are targeted by the immune system, due to a loss of immune tolerance, via the action of platelet-autoantibodies and/or cytotoxic T cells. ITP is a highly variable disorder regarding the underlying biological mechanisms, disease trajectories and treatment responses. Predictive indicators are therefore strongly warranted. To analyze the predictive response to the thrombopoietin receptor agonist eltrombopag, in this issue of the British Journal of Haematology, Osuna-Gomez and co-workers research platelet-leukocyte complexes in 38 ITP patients upon treatment with eltrombopag. Elevated platelet counts upon treatment with eltrombopag were associated with increased complexes of platelets bound to leucocytes. A higher percentage of monocytes bound to platelets, with an increased IL-10 production in monocytes, was found to be associated to a favorable clinical response to treatment with eltrombopag. Further validation is required but these findings reveal the potential of analyzing platelet-monocyte complexes as a predictive indicator for the clinical response to eltrombopag in patients with ITP. Commentary on: Osuna-Gómez et al. Interplay of leucocyte-platelet complexes and clinical response to eltrombopag in immune thrombocytopenia patients. Br J Haematol 2025 (Online ahead of print). doi: 10.1111/bjh.19779.