TPO and autoimmune thrombocytopenic purpura: In addition, the probability of using cortisol drugs for the first recurrence is approximately 75%, while the probability of using TPO-RA and rituximab for the second and third recurrences is increased to 57 and 52%, respectively.27When second-line drug treatment fails, the immune disorder mechanism in the patient's body becomes more complex, leading to an increased incidence of refractory ITP.