Objective: To investigate the characteristics of the essential thrombocythemia (ET) cases transformed to the acute myeloid leukemia (AML) and the role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of this disease. Methods: The clinical and laboratory characteristics of 3 ET cases before and after transformation and after allo-HSCT were retrospectively analyzed, meanwhile the related literatures were reviewed and discussed. Results: Case 1 was a male patient of 44 years old, whose PLT was 500×10⁹/L when firstly diagnosed ET. After 3 years the disease progressed into myelodysplastic syndrome (MDS) while WT1 expression increased from 77 (first visit) to 13 171 copies/10 000 ABL copies, at the same time chromosome changed dramatically. During the period of decitabine treatment the disease processed into AML. Case 2 was a male of 58 years old whose PLT was 2 100×10⁹/L when firstly diagnosed ET. The disease progressed to AML after 9 years, whose WT1 expression increased from 130 (first visit) to 3 222 copies/10 000 ABL copies, and he relapsed shortly after intensive chemotherapy. Case 3 was a male of 60 years old whose PLT was 900×10⁹/L when firstly diagnosed ET. The disease progressed to AML after 5 years, whose WT1 increased from 56 (first visit) to3 696 copies/10 000 ABL copies. Moreover leukemia spread to central nervous system (CNS) during chemotherapy. Before allo-HSCT, cases 1 did not achieve remission; case 2 relapsed after a short time of remission and case 3 transferred to CNS leukemia. All of the 3 cases underwent allo-HSCT successfully, and they all achieved completely remission, whose chromosome and gene mutation recovered negative. At the same time, CNS leukemia of case 3 disappeared. The median WT1 decreased to 50 copies/10 000 ABL copies. There was no severe complication during the median time of 5 months after allo-HSCT. Conclusions The patients transformed to AML had poor prognosis, allo-HSCT was the only method that can cure the disease now.

Objective:To investigate the effect of autologous hematopoietic stem cell transplantation (auto-HSCT) bridging to chimeric antigen receptor T cell (CAR-T) immunotherapy for follicular lymphoma (FL) transformed to B-lymphoblastic leukemia/lymphoma (B-LBL).Methods:The diagnosis and treatment of 1 patient with FL transformed to B-LBL admitted to the First Hospital of Soochow University in August 2020 were retrospectively analyzed and the literature was reviewed.Results:The male patient was 65 years old, and was diagnosed as FL (stage Ⅳ group A, FL international prognostic index -1 score 3 points, high-risk group) in August 2020. And then he was given 6 courses of RB (rituximab combined with bendamustine) regimen, with complete remission (CR) at mid-term and end-stage PET-CT, followed by regular maintenance therapy with rituximab every 2 months, and disease progressed after 4 courses of maintenance therapy. According to the results of histopathology and bone marrow aspiration in December 2021, he was diagnosed B-LBL involving the bone marrow. Partial remission was achieved after induction therapy with zanubnulindb combined with hyper CVAD (cyclophosphamide + doxorubicin + vindesine + dexamethasone) regimen, followed by auto-HSCT bridging to CAR-T treatment targeting CD19 and CD22, which proceeded smoothly with cytokine release syndrome grade 0, immune effector cell-associated neurotoxicity syndrome grade 0. The patient successfully underwent hematopoietic reconstruction and orally taken ibrutinib after discharge. PET-CT indicated CR 2 months after transplantation and he was still in disease-free survival state.Conclusions:The prognosis of FL transformed to B-LBL is poor, and auto-HSCT bridging to CAR-T can improve the prognosis and prolong the survival time of patients who cannot undergo allogeneic hematopoietic stem cell transplantation.