BACKGROUND: Several studies have demonstrated the occurrence of secondary tumors as a rare but significant complication of chimeric antigen receptor T (CAR-T) cell therapy, underscoring the need for a detailed investigation. Given the limited variety of secondary tumor types reported to date, a comprehensive characterization of the various secondary tumors arising after CAR-T therapy is essential to understand the associated risks and to define the role of the immune microenvironment in malignant transformation. This study aims to characterize the immune microenvironment of a newly identified secondary tumor post-CAR-T therapy, to clarify its pathogenesis and potential therapeutic targets. METHODS: In this study, the bone marrow (BM) samples were collected by aspiration from the primary and secondary tumors before and after CD19 CAR-T treatment. The CD45 + BM cells were enriched with human CD45 microbeads. The CD45 + cells were then sent for 10× genomics single-cell RNA sequencing (scRNA-seq) to identify cell populations. The Cell Ranger pipeline and CellChat were used for detailed analysis. RESULTS: In this study, a rare type of secondary chronic myelomonocytic leukemia (CMML) were reported in a patient with diffuse large B-cell lymphoma (DLBCL) who had previously received CD19 CAR-T therapy. The scRNA-seq analysis revealed increased inflammatory cytokines, chemokines, and an immunosuppressive state of monocytes/macrophages, which may impair cytotoxic activity in both T and natural killer (NK) cells in secondary CMML before treatment. In contrast, their cytotoxicity was restored in secondary CMML after treatment. CONCLUSIONS This finding delineates a previously unrecognized type of secondary tumor, CMML, after CAR-T therapy and provide a framework for defining the immune microenvironment of secondary tumor occurrence after CAR-T therapy. In addition, the results provide a rationale for targeting macrophages to improve treatment strategies for CMML treatment.
Humans ; Lymphoma, Large B-Cell, Diffuse/therapy* ; Tumor Microenvironment/genetics* ; Antigens, CD19/metabolism* ; Leukemia, Myelomonocytic, Chronic/genetics* ; Immunotherapy, Adoptive/adverse effects* ; Male ; Single-Cell Analysis/methods* ; Female ; Sequence Analysis, RNA/methods* ; Receptors, Chimeric Antigen ; Middle Aged

Objective To investigate the differences of type 2 innate lymphocytes (ILC2) and interlukin 9 (IL-9) between chronic lymphocytic leukemia (CLL) patients and healthy controls, and to understand the effects of ILC2 on the function of regulatory T cells (Tregs), CD8⁺ T cells and CLL cells through IL-9. Methods Flow cytometry was used to detect the levels of ILC2 and Tregs in the peripheral blood of 45 newly diagnosed CLL patients and 24 healthy controls, and the expressions of granzyme B and perforin in CD8⁺ T cells in the peripheral blood of 28 patients and 15 healthy controls; ELISA was used to detect the level of IL-9 in the serum. ILC2 of patients and healthy controls was sorted by immunomagnetic beads and cultured separately, and the level of IL-9 in the culture supernatant was measured by ELISA. ILC2 sorted from CLL patients and healthy control-derived peripheral blood mononuclear cells(PBMCs) were co-cultured with the B cell leukemia MEC-1 cells, one group was supplemented with IL-9 antibody and the other group was not. After 72 hours of culture, the ratio of Tregs, programmed death 1 (PD-1), T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), cytotoxic T lymphocyte antigen 4 (CTLA-4) on Tregs, granzyme B and perforin in CD8⁺ T cells were measured by flow cytometry, IL-9 level of the culture supernatant was measured by ELISA, the apoptosis of MEC-1 cells was measured by Annexin V-PI. Results Compared with the healthy control group, the levels of ILC2, Tregs and IL-9 in the CLL group increased significantly. The levels of granzyme B and perforin in CD8⁺ T cells were positively correlated in the peripheral blood of CLL patients. Compared with the healthy control group, IL-9 levels in the supernatant of sorted ILC2 from CLL patients increased. In the anti-IL9 antibody group, the level of PD-1 and TIGIT on Tregs decreased, and the level of granzyme B in CD8⁺ T cells increased significantly. The level of IL-9 in the anti-IL9 antibody group decreased statistically. And MEC-1 cells showed increased early apoptotic rate in the anti-IL9 antibody group statistically. Conclusion In CLL, ILC2 affects CD8⁺ T cells and Tregs through IL-9, which weakens the anti-tumor effect of CD8⁺ T cells, enhances the immunosuppressive effect of Tregs, and plays a role in the occurrence and development of CLL disease.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; T-Lymphocytes, Regulatory/immunology* ; Middle Aged ; Male ; Female ; Interleukin-9/blood* ; Aged ; Granzymes/metabolism* ; Perforin/metabolism* ; Immunity, Innate ; Adult ; Lymphocytes/immunology*

Copy number alteration (CNA) is a significant genetic change in pediatric B-cell acute lymphoblastic leukemia (B-ALL), with CDKN2A/B deletions, PAX5 deletions, and IKZF1 deletions being the most common. Recent studies have increasingly highlighted the potential prognostic significance of these gene deletions and multiple co-deletions in pediatric B-ALL. This paper reviews the main detection methods for CNA, as well as the prognostic characteristics and treatment approaches for common CNA in pediatric B-ALL.
Humans ; DNA Copy Number Variations ; Child ; PAX5 Transcription Factor/genetics* ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Cyclin-Dependent Kinase Inhibitor p15/genetics* ; Ikaros Transcription Factor/genetics* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Gene Deletion ; Cyclin-Dependent Kinase Inhibitor p16/genetics* ; Prognosis

OBJECTIVE: To investigate the expression of co-inhibitory molecules TIGIT/CD155 and PD-1 on CD4⁺T cells and Treg cells in peripheral blood of patients with chronic lymphocytic leukemia (CLL) and analyze their clinical significance. METHODS: The expression of PD-1 and TIGIT on CD4⁺T cells and Treg cells was detected by flow cytometry in 40 CLL patients and 20 healthy controls. Additionally, the expression of CD155 on peripheral blood B cells and DC cells of the enrolled subjects was detected. RESULTS: The proportions of PD-1⁺TIGIT⁺CD4⁺T cells, PD-1⁺TIGIT⁺Treg cells and CD155⁺DC cells in peripheral blood of CLL patients were significantly higher than those of healthy controls ( P < 0.05). The proportions of PD-1⁺TIGIT⁺CD4⁺T cells and PD-1⁺TIGIT⁺Treg cells in CLL patients were significantly higher than those of PD-1⁺TIGIT^-CD4⁺T cells and PD-1⁺TIGIT^-Treg cells, respectively ( P < 0.05). Both PD-1⁺TIGIT⁺CD4⁺T cells and PD-1⁺TIGIT⁺Treg cells were positively correlated with the level of CD155⁺DC cells (r =0.742, r =0.766). With the progression of Binet stage, the proportions of PD-1⁺TIGIT⁺CD4⁺T cells, PD-1⁺TIGIT⁺Treg cells, and CD155⁺DC cells gradually increased ( P < 0.05), and the aforementioned three types cells were all increased in patients with CD38≥30%, IGVH unmutated, or poor prognosis due to chromosomal abnormalities ( P < 0.05). CONCLUSION Co-inhibitory molecules PD-1 and TIGIT may be involved in immunodepletion in patients with advanced CLL, which has clinical prognostic value. Dual inhibitor molecular targeted therapy provides a new direction for the individualized treatment of CLL.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; Receptors, Immunologic/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; T-Lymphocytes, Regulatory/metabolism* ; Receptors, Virus/metabolism* ; CD4-Positive T-Lymphocytes/metabolism* ; Male ; Female ; Middle Aged ; Flow Cytometry ; Clinical Relevance

OBJECTIVE: To retrospectively analyze the clinical characteristics of 15 children with B-cell acute lymphoblastic leukemia (B-ALL) treated with blinatumomab, and summarize the efficacy and safety of blinatumomab in the treatment of pediatric B-ALL. METHODS: Fifteen children who received treatment with blinatumomab from February 2022 to January 2023 were enrolled in this study. One course (28 days) of blinatumomab concurrent with intrathecal chemotherapy was given according to the standard regimen, except for 2 cases who had shortened course of treatment due to hematopoietic stem cell transplantation (HSCT) and did not receive combined intrathecal chemotherapy, and 1 case had a shortened course of treatment due to economic problems. The efficacy and safety of the treatment were evaluated. RESULTS: In terms of efficacy, for the children who had achieved complete molecular remission (CMR) before treatment, blinatumomab treatment could effectively maintain CMR status; For the children who did not achieve CMR, the CMR rate after one standard course of treatment with blinatumomab reached 66.7%(4/6); For the children with relapsed/refractory ALL (R/R ALL) who had minimal residual disease (MRD), the MRD clearance rate reached 75.0%(3/4). The statistical results of the incidence of adverse events showed that 13.3%(2/15) of the children did not experience any adverse events. The most common adverse events were cytokine release syndrome (CRS) (73.3%, 11/15) and transaminase elevation (26.7%, 4/15); 33.3%(5/15) of the children experienced grade 3 or higher adverse events. All the adverse events were resolved after symptomatic treatment.The level of IgG decreased significantly after 4-7 weeks of treatment with blinatumomab, and gradually recovered after 8 weeks of treatment. CONCLUSION Blinatumomab can be used as a safe and effective treatment for inducing deep remission in pediatric R/R-ALL patients and as a bridge therapy for the pediatric ALL patients who are intolerant to chemotherapy.
Humans ; Antibodies, Bispecific/therapeutic use* ; Child ; Retrospective Studies ; Female ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Remission Induction ; Treatment Outcome ; Child, Preschool ; Adolescent ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy*

OBJECTIVE: To analyze clinical characteristics and prognosis of B-cell acute lymphoblastic leukemia (B-ALL) patients with IKZF1 deletion. METHODS: 72 patients with B-ALL admitted to our hospital from April 2020 to January 2023 were selected, IKZF1 deletion were detected, and clinical characteristics and prognosis were analyzed. RESULTS: Among the 72 patients, a total of 32 patients (44.4%) were identified with IKZF1 deletions (IKZF1 ⁺ ). There was no statistically significant difference in basic clinical data between patients with normal IKZF1 (IKZF1 ^-) and those with IKZF1 ⁺ (P >0.05). The proportion of patients with IKZF1 ⁺ in Ph⁺ group was significantly higher than that in Ph^- group (P < 0.05). The main types of IKZF1 ⁺ were exon 1-8 deletion (34.4%) and exon 4-7 deletion (31.2%). The median OS and PFS of IKZF1 ^- patients were significantly longer than those of IKZF1 ⁺ patients (OS: 26.0 months vs 16.0 months, χ ²=23.094, P < 0.05; PFS: 26.0 months vs 16.0 months, χ ²=11.150, P < 0.05). Among IKZF1 ⁺ patients, the median OS of patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) was significantly longer than that of patients who did not receive allo-HSCT (no reached vs 15.0 months, χ ²=5.685, P < 0.05). CONCLUSION IKZF1 deletion is a risk factor affecting the prognosis of B-ALL patients.
Humans ; Ikaros Transcription Factor/genetics* ; Prognosis ; Gene Deletion ; Female ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Adult ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Adolescent ; Young Adult ; Middle Aged

OBJECTIVE: To investigate the expression of CD19/CD73 in chronic lymphocytic leukemia (CLL) and its correlation with clinical features. METHODS: The clinical data of 60 CLL patients and 40 healthy volunteers (control group) from January 2022 to November 2023 were retrospectively analyzed. The levels of CD19 and CD73 in peripheral blood of CLL patients were measured by flow cytometry. Kaplan-Meier method was used for survival analysis. RESULTS: The hemoglobin (Hb) and CD19/CD73 levels in CLL group were significantly lower than those in control group, while CD19, CD73 and β₂-MG were significantly higher (all P <0.001). According to ROC curve analysis, the AUC value of CD19/CD73 for CLL diagnosis was 0.980 (95%CI : 0.949-1.000, P <0.05), the specificity was 92.50%, and the sensitivity was 98.30%. The CD19/CD73 level of CLL patients with splenomegaly was significantly lower than those without splenomegaly (P <0.01). There was no significant correlation between CD19/CD73 and Hb in CLL patients ( r =0.056, P >0.05). CD19/CD73 was positively correlated with β₂-MG ( r =0.837, 95%CI : 0.740 2-0.899 6, P <0.01). According to the median value (12.84) of CD19/CD73, the patients were divided into high and low expression groups. Kaplan-Meier survival analysis showed that the overall survival rate and progression-free survival rate at 18^th month in the low expression group were 87.08% and 93.25%, while those in the high expression group were 96.41% and 99.90%, respectively (both P <0.05). CONCLUSION The level of CD19/CD73 is low in CLL patients, which can be used as an auxiliary index for clinical diagnosis of CLL. CD19/CD73 is closely related to splenomegaly in CLL patients. Low expression of CD19/CD73 predicts poor prognosis.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/metabolism* ; 5'-Nucleotidase/metabolism* ; Antigens, CD19/metabolism* ; Retrospective Studies ; Male ; Female ; Prognosis ; Middle Aged ; Aged ; Adult ; GPI-Linked Proteins

INTRODUCTION: Chronic lymphocytic leukaemia (CLL) has a heterogeneous disease course and a variable preva-lence across populations. Appropriate management for achieving optimal outcomes requires consideration of multiple factors, including disease-related factors like genomic alterations, patient characteristics and fitness, availability and access to treatments, and logistics/cost. This review aims to provide comprehen-sive and pragmatic recommendations for the management of treatment-naïve (TN) CLL that are relevant to Singapore's clinical context. METHOD: Clinical consensus statements were developed by an expert panel of haematologists from Singapore through a 2-round modified Delphi process. Statements were drafted using recent evidence-based guidelines and published literature. Panel members reviewed draft statements, provided anonymised feedback and proposed modifications where relevant. A physical meeting was held to facilitate discussion, voting and endorsement of the final consensus statements. RESULTS: The final consensus included 15 statements covering major TN CLL patient subsets. The recommendations highlight the importance of molecular testing for key biomarkers, where available/accessible, to guide initial therapy. Due to the superior efficacy of targeted agents (Bruton's tyrosine kinase inhibitors [BTKis] and B-cell lymphoma 2 inhibitors [BCL2is]) these are favoured over standard chemotherapy or chemotherapy-immunotherapy, especially for patients with del(17p) or TP53 mutation, and less fit patients. CONCLUSION These consensus statements provide practical recommendations for the current manage-ment of TN CLL patients in Singapore and similar healthcare systems based on up-to-date evidence. Regular updates to treatment guidelines are important to ensure responsiveness to emerging evidence and evolving clinical practices and to improve patient outcomes and quality of life.
Humans ; Consensus ; Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis* ; Singapore

This article reports two cases of children with B-cell acute lymphoblastic leukemia (B-ALL) complicated by invasive fungal disease (IFD) who received bridging treatment using blinatumomab. Case 1 was a 4-month-old female infant who experienced recurrent high fever and limb weakness during chemotherapy. Blood culture was negative, and next-generation sequencing (NGS) of peripheral blood, bronchoalveolar lavage fluid, and cerebrospinal fluid were all negative. Chest CT and cranial MRI revealed obvious infection foci. Case 2 was a 2-year-old male patient who experienced recurrent high fever with multiple inflammatory masses during chemotherapy. Candida tropicalis was detected in peripheral blood and abscess fluid using NGS, while blood culture and imaging examinations showed no obvious abnormalities. After antifungal and blinatumomab therapy, both cases showed significant improvement in symptoms, signs, and imaging, and B-ALL remained in continuous remission. The report indicates that bridging treatment with blinatumomab in children with B-ALL complicated by IFD can rebuild the immune system and control the underlying disease in the presence of immunosuppression and severe fungal infection.
Child, Preschool ; Female ; Humans ; Infant ; Male ; Antibodies, Bispecific/therapeutic use* ; Invasive Fungal Infections/drug therapy* ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Remission Induction

OBJECTIVE: To explore the consistency of flow cytometry (FCM) method and polymerase chain reaction (PCR) technique in the detection of minimal residual disease (MRD) at different treatment stages in pediatric patients with TCF3/PBX1⁺ B-cell acute lymphoblastic leukemia (B-ALL) and the correlations between the detection results and prognosis. METHODS: The clinical data of 64 newly diagnosed pediatric patients with TCF3/PBX1⁺ B-ALL admitted to the Department of Pediatrics of Peking University People's Hospital from January 2005 to December 2017 were retrospectively analyzed. FCM and PCR methods were used to monitor the MRD level in bone marrow samples from 64 children during the same period of treatment on d33 and d90 respectively, and the detection results were analyzed. RESULTS: There were 37 males and 27 females in the 64 patients, with a median age of 8 years(range 0.8 to 16 years). The complete remission (CR) rate after the first cycle of induction chemotherapy was 98.4% (62/63), with overall CR rate of 100%. 12 patients experienced recurrence, with a median recurrence time of 16.9 (5.3-46.3) months. The median follow-up time of the 64 patients was 77.2 (1.0-184.8) months , and the 5-year overall survival (OS) rate and event-free survival (EFS) rate were 82.8%±4.7% and 75.0%±5.4%, respectively. On d90, the concordance rate of the MRD results from the two methods was 98.4%, and the related kappa value was 0.792 (P < 0.001), which were significantly higher than those on d33. After induction chemotherapy (d33), the 5-year EFS rate of MRD-FCM^- group (79.3%±5.3%) was significantly better than that of MRD-FCM⁺ group (40.0%±21.9%) (P =0.028), there were no significant differences in the 5-year OS rate and EFS rate between MRD-PCR⁺ group and MRD-PCR^- group, and the 5-year EFS rate of MRD-FCM^-/PCR^- group (85.4%±5.5%) was significantly better than that of MRD-FCM⁺/PCR⁺ group (40.0 %±21.9%) (P =0.026). CONCLUSION In children with TCF3/PBX1⁺ B-ALL, the MRD results detected by FCM and PCR methods show good consistency, especially in consolidation therapy period (d90). The MRD level at the end of induction therapy (d33) is an important factor affecting the long-term prognosis, especially the MRD results detected by FCM method, which is significantly associated with prognosis.
Male ; Female ; Child ; Humans ; Infant ; Child, Preschool ; Adolescent ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Neoplasm, Residual/diagnosis* ; Clinical Relevance ; Retrospective Studies ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; Prognosis ; Burkitt Lymphoma ; Basic Helix-Loop-Helix Transcription Factors/therapeutic use*