T (8; 21) acute myeloid leukemia (AML) is a special type of acute leukemia, and exhibits a heterogeneous prognosis, with a long-term relapse rate of about 40%. Once t(8; 21) AML patients experience relapse, they have an extremely poor prognosis, with a 5-year overall survival rate of less than 15%. Therefore, it is crucial to develop effective strategies to improve the prognosis of relapsed/refractory (R/R) t(8; 21) AML. CD19 is a specific B-cell surface marker, but it is aberrantly expressed in 50-80 % of t(8; 21) AML patients. CAR-T cells targeting aberrant cell-surface antigens could induce the depletion of tumor cells without the destruction of hematopoiesis. Therefore, CD19 might be a promising target for CAR-T cell therapy in R/R t(8; 21) AML with aberrant CD19 expression. The present study is aimed to explore the efficacy and safety of CD19 CAR-T cell therapy in R/R t(8;21) AML with aberrant CD19 expression.
In the present study, 3 R/R t(8;21) AML patients with aberrant CD19 expression were enrolled. After lymphodepleting chemotherapy, 3 patients received autologous CAR-T cell infusion at a dose of 1.0 × 10^6 cells/kg, 2.0 × 10^6 cells/kg, and 2.0 × 10^6 cells/kg, respectively.
They all achieved CD19 negativity approximately half a month after CD19 CAR-T cell infusion. These indicate CD19 CAR-T cell therapy is effective in R/R t(8;21) AML with aberrant CD19 expression. However, patient 1 and patient 2 rapidly relapsed within 3 months after CD19 CAR-T cell therapy. Subsequently, patient 1 received allogeneic hematopoietic stem cell transplantation (allo-HSCT). Fortunately, patient 1 achieved mCR 2 months after allo-HSCT.
Considering the short-term remission of CD19 CAR-T cell therapy in R/R t(8;21) AML, allo-HSCT might be performed as soon as possible to consolidate the efficacy of CAR-T cell therapy and reduce the risk of relapse.
Copyright © 2025 Zhang, Wang, Qiao, Wang, Wang, Liu, Qin, Chen, Huang, Zheng, Peng, Mei, Wang, Yu, Li and Yu.

Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder. It is characterized by the presence of the Philadelphia (Ph) chromosome, t(9;22)(q34.1;q11.2), which carries the BCR-ABL1 fusion gene. Tyrosine kinase inhibitors (TKIs) have markedly changed the treatment approach of CML and have become the first-line agents for almost all CML patients. However, certain patients experience resistance to these medications, which occurs through several mechanisms, including the accumulation of TKI-resistant chromosomal abnormalities. The present study reports a case of a 27-year-old Saudi male with CML receiving TKI treatment, who presented with precursor B-cell lymphoblastic crisis demonstrating the presence of the novel combined chromosomal abnormalities; non-Ph der(22), i(9) and der(20), carrying the BCR-ABL1 fusion gene. This case report adds to the literature on novel TKI-resistance-conferring chromosomal abnormalities and links them to precursor B-cell lymphoblastic crisis.

Bilineage T lymphoid and myeloid (T/My) neoplasms are rare entities among the hematopoietic and lymphoid malignancies. The majority of patients present with leukemic symptoms in which blasts are observed in the peripheral blood (PB) or bone marrow (BM) at a percentage of >20% of nucleated cells. Only a minimal number of cases of T/My bilineage hematopoietic and lymphoid malignancy have been reported with extramedullary infiltration as the initial symptom. The origin of the neoplastic cells in T/My bilineage malignancy has been documented as the hematopoietic stem cells. The present study reports the case of a 31-year-old man with a T/My bilineage malignancy, which initially showed cervical lymph node enlargement beyond the diagnostic criteria of leukemia in the PB and in the BM. Two distinct malignant populations were detected in the cervical lymph node and pleural effusion, one of which was positive for MPO-staining, while the other was positive for cytoplasmic cluster of differentiation 3. Mutations in platelet-derived growth factor receptor α, platelet-derived growth factor receptor β, fibroblast growth factor receptor 1 and other chromosome abnormalities were excluded. The patient obtained complete remission after conventional chemotherapy, but relapsed with bilineage leukemia within a short period of time. Lymphoid and myeloid lineages have been reported to be differentiated from multipotent progenitors asymmetrically. However, the cellular mutation stage in T/My bilineage malignancy remains unclear. The present study also reviews the origin, development and therapeutic strategies for extramedullary T/My bilineage malignancy.

The chromosomal translocation t(7;11)(p15;p15) and the resulting nucleoporin 98-homeobox A9 (NUP98-HOXA9) gene fusion is rare but recurrent genetic abnormity in acute myeloid leukemia (AML). The present study describes a case of AML plus maturation (-M2) with multilineage dyspoiesis in a 30-year-old male in whom a 46,XY,t(7;11)(p15;p15) karyotype was detected through chromosome analysis. Subsequent molecular and sequencing analysis demonstrated a NUP98-HOXA9 fusion gene with a type I fusion between NUP98 exon 12 and HOXA9 exon 1b, and mutations in neuroblastoma V-Ras oncogene homolog and Wilms tumor 1. The patient achieved hematological complete remission (CR) following two courses of induction chemotherapy. However, the NUP98-HOXA9 fusion gene remained detectable during the hematological CR period and following intensive consolidation chemotherapy. The disease relapsed 11 months after diagnosis, and the patient became refractory, with complications from an infection causing eventual mortality. The present case and literature review suggest that patients with AML and t(7;11) may have unique biological and clinical characteristics, and a poor prognosis.

Acute myeloid leukemia (AML) is an aggressive hematological malignancy characterized by the accumulation of immature myeloid progenitor cells in the bone marrow. Studies are required to investigate the prognostic and predictive value of surrogate biomarkers. Given the importance of angiogenesis in oncology in terms of pathogenesis as well as being a target for treatment, circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) are promising candidates to serve as such markers. The aim of the present study was to quantify CECs and EPCs in patients with AML at initial diagnosis and following induction chemotherapy, and to correlate these findings with the response to treatment in AML patients. The present study included 40 patients with de novo AML and 20 age- and gender-matched healthy controls. CECs and EPCs were evaluated by flow cytometry at initial diagnosis and after induction chemotherapy (3+7 protocol for AML other than M3 and all-trans-retinoic acid plus anthracycline for M3 disease). CECs and EPCs were significantly higher in AML patients at diagnosis and after induction chemotherapy than in controls. After induction chemotherapy, CECs and EPCs were significantly decreased compared with the levels at initial diagnosis. Patients who achieved complete response (n=28) had lower initial CEC and EPC levels compared with patients who did not respond to treatment. These results suggest that CEC levels are higher in AML patients and may correlate with disease status and treatment response. Further investigations are required to better determine the predictive value and implication of these cells in AML management.