Allogenic Hematopoietic Stem Cell Transplant for Refractory Immune Thrombocytopenia

Refractory immune thrombocytopenia (ITP) is a rare but severe condition in pediatric patients, characterized by poor response to standard therapies and significant morbidity. Allogeneic hematopoietic stem cell transplantation (HSCT) has rarely been employed for refractory ITP. Here, we present a case of a child with refractory ITP and life-threatening bleeding who ultimately achieved sustained remission following HSCT.

Case report.

Following initial presentation, the patient experienced a prolonged and complex disease course, including two intracranial hemorrhages and multiple mucocutaneous bleeding episodes. The patient failed numerous therapies, consisting of immunosuppressive agents, thrombopoietin receptor agonists, and splenectomy. After multidisciplinary discussion and shared decision-making, she underwent matched sibling donor HSCT using a reduced-toxicity conditioning regimen. Engraftment was achieved without major early complications, although a mixed CD3 chimerism persisted. Two years post-transplant, the patient experienced relapse of ITP in the setting of a declining CD3⁺ donor chimerism. She received a donor lymphocyte infusion (DLI) with which she achieved 100% donor chimerism and sustained platelet recovery. The DLI was complicated by Grade III acute and later chronic graft-versus-host disease (GVHD), which was successfully managed with immunosuppression. At 7 years post-HSCT and over 5 years post-DLI, she remains in remission with normal platelet counts and no active GVHD.

This case highlights that HSCT, while rarely employed for ITP, can offer long-term disease control in select patients with severe, refractory disease.