TA-TMA occurring after sequential CD7 CAR-T cell therapy and allogeneic hematopoietic stem cell transplantation: a case report.

Currently, CAR-T cell therapy bridging to allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a pivotal therapeutic strategy for refractory/relapsed hematologic malignancies. Sequential therapy with CD7 chimeric antigen receptor T (CAR-T) cells combined with allo-HSCT provides a novel therapeutic approach for T-lymphoid malignancies, CD7-highly expressed acute myeloid leukemia (AML), and mixed phenotype acute leukemia (MPAL). This strategy circumvents the toxicities of conventional myeloablative conditioning chemotherapy and immunosuppressive agents, while achieving tumor eradication, hematopoietic reconstitution, and prevention of graft-versus-host disease (GVHD). Transplant-associated thrombotic microangiopathy (TA-TMA) is a rare but life-threatening complication following allo-HSCT, associated with elevated non-relapse mortality (NRM). This article reports a case of early-onset TA-TMA in a patient with MPAL after CD7 CAR-T bridging to allo-HSCT. This study aims to enhance clinicians' awareness of the diagnosis and management of TA-TMA following CAR-T bridging to allo-HSCT, provide a reference for early identification and timely intervention, and further improve patient outcomes.