TPO and autoimmune thrombocytopenic purpura: In 2023, Arnold DM et al. proposed the following definition of refractory ITP for consideration and future evaluation: persistence of severe thrombocytopenia (platelets < 20 × 109/L) and bleeding in a patient with ITP who has received rituximab, two different TPO-RAs, and at least one immunosuppressant medication and who does not respond or only briefly responds to high-dose corticosteroids or high-dose IVIGs (less than 7 days) [117].