Search

Patients who develop chimeric antigen receptor (CAR) T-cell-related immune effector cell-associated neurotoxicity syndrome (ICANS) frequently undergo evaluation with electroencephalography (EEG). We hypothesize that EEG features and Synek scale score, a measure of degree of EEG abnormality, are associated with ICANS severity. Here, we performed a retrospective review of 125 adult patients at Memorial Sloan Kettering Cancer Center (MSKCC) who received CAR-T cell therapy from 2010 to 2019, including 53 patients with B-acute lymphoblastic leukemia treated with 1928z CAR T cells (NCT01044069) and 72 patients with large B-cell lymphoma (LBCL) treated with the commercial CAR T products axicabtagene ciloleucel or tisagenlecleucel. We collected video EEG monitoring (27 with B-ALL and 20 with LBCL) and recorded daily EEG features, Synek scores, and ICANS grade for 47 eligible patients. Synek scale and ICANS grade were positively correlated (correlation coefficient 0.47, 95% CI: 0.31-0.60). This was further corroborated in the univariable model associating high Synek scale (3 or 4) with high ICANS grade (OR = 15.2; 95%CI:7.8-29.7, p < 0.0001). EEG features such as discontinuity, absence of posterior dominant rhythm, and presence of generalized sharp waves were statistically significantly associated with higher ICANS grade in univariable models. In the multivariable model, discontinuity (OR = 4.2 (95%CI:1.3-13.8, p = 0.02) and absence of posterior dominant rhythm (OR = 10.5 (95%CI:4.6-23.9, p < 0.0001) were statistically associated with higher ICANS grade. Overall, EEG discontinuity and absence of posterior dominant rhythm were independently associated with higher severity of neurotoxicity. Further, our data suggest that Synek Scale, may be a severity marker for neurotoxicity., Competing Interests: Declarations. Competing interests: Dr. Perales reports honoraria from Adicet, Allovir, Caribou Biosciences, Celgene, Bristol-Myers Squibb, Equilium, Exevir, Incyte, Karyopharm, Kite/Gilead, Merck, Miltenyi Biotec, MorphoSys, Nektar Therapeutics, Novartis, Omeros, OrcaBio, Syncopation, VectivBio AG, and Vor Biopharma. He serves on DSMBs for Cidara Therapeutics, Medigene, and Sellas Life Sciences, and the scientific advisory board of NexImmune. He has ownership interests in NexImmune, Omeros and OrcaBio. He has received institutional research support for clinical trials from Incyte, Kite/Gilead, Miltenyi Biotec, Nektar Therapeutics, and Novartis., (© 2024. The Author(s).)

Research has demonstrated the high mortality and morbidity associated with B-Acute lymphoblastic lymphoma (B-ALL). Researchers have developed several therapeutic approaches to combat the disorder. Recently, researchers developed chimeric antigen receptors (CARs)-T cells, which recognize antigens independently of major histocompatibility complexes (MHCs) and activate at a higher level with additional persistence. However, relapsing B-ALL has been reported in several cases. This review article was aimed to collecting recent information regarding the mechanisms used by B-ALL-related lymphocytes to escape from CAR-T cells and the plausible resolution projects., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Aim: This study was to explore role of immune landscape and the immune cells in acute lymphoblastic leukemia (ALL) progression., Background: The most prevalent genetic alteration in childhood ALL is the ETV6-RUNX1 fusion. The increased proliferation of B progenitor cells could expedite the disease's progression due to irregularities in the cell cycle. Nevertheless, the mechanisms by which particular cell clusters influence the cell cycle and promote the advancement of ALL are still not well understood., Objective: This study was to explore role of immune landscape and the immune cells in ALL progression., Methods: Single-cell RNA sequencing (scRNA-seq) data of ETV6-RUNX1 and healthy pediatric samples obtained from GSE132509 were clustered and annotated using the Seurat package, and differentially highly expressed genes identified in each cluster were analyzed using DAVID for pathway annotation. Chromosome amplification and deletion were analyzed using the inferCNV package. SCENIC evaluated the regulation of transcription factors and target gene formation in cells. cellphoneDB and CellChat were served to infer ligand-receptor pairs that mediate interactions between subpopulations. The role of the target gene in regulating ALL progression was assessed using RT-qPCR, Transwell and scratch healing assays., Results: The bone marrow mononuclear cells (BMMCs) from ETV6-RUNX1 and healthy pediatric samples in GSE132509 were divided into 11 clusters, and B cell cluster 1 was identified as B progenitor cell, which was amplified on chromosome 6p. B progenitor cells were divided into seven clusters. Expression levels of amplified genes in chromosome 6p of B progenitor cell cluster 5 were the highest, and its specific highly expressed genes were annotated to pathways promoting cell cycle progression. Regulons formed in B progenitor cell cluster 5 were all involved in promoting cell cycle progression, so it was regarded as the B progenitor cell cluster that drives cell cycle progression. The key regulator of the B progenitor cell is E2F1, which promotes the migration and invasion ability of the cell line HAP1. The major ligand-receptor pairs that mediate the communication of B progenitor cell cluster 5 with cytotoxic NK/T cells or naive T cells included FAM3C-CLEC2D, CD47-SIRPG, HLAE-KLRC2, and CD47-KLRC2. HLAE-KLRC1 and TGFB1-(TGFBR1+TGFBR2)., Conclusion: This study outlined the immune cell landscape of ETV6-RUNX1 ALL and identified chromosome 6p amplification in B progenitor cells, described the major B progenitor cell cluster driving cell cycle progression and its potential regulatory mechanisms on NK cells and T cells, providing cellular and molecular insights into ETV6-RUNX1 ALL., Competing Interests: The authors declare that they have no competing interests., (© 2024 Qu et al.)

To study the changes of lymphocyte subsets in children with acute lymphoblastic leukemia (ALL) at initial diagnosis and compare them with those of healthy children and patients who have achieved complete remission (CR). Furthermore, we aim to analyze the prognostic significance of lymphocyte subsets in these patients. From May 2011 to December 2015, 405 children with ALL were enrolled in this study. Peripheral blood was collected at the time of diagnosis, and lymphocyte subsets were detected by flow cytometry. Then, the percentages of lymphocyte subsets in each group were compared. In addition, survival and prognostic factor analyses were performed to determine the prognostic value of lymphocyte subsets. Lymphocyte subsets in children with ALL were dramatically different from those in healthy children and patients achieving CR. Additionally, lymphocyte subsets were correlated with different minimal residual disease and risk parameters. Furthermore, percentages of CD3+ T cells and CD4+ T cells and the ratio of CD4/CD8 were associated with different clinical outcomes. Multivariate analysis demonstrated the percentage of CD4+ T cell as an independent predictor for clinical prognosis. Lymphocyte subsets in pediatric ALL undergo dramatic changes and were related to prognosis, especially CD4+ T cells., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose of Review: The use of immunotherapy in recent years has changed the paradigm of treatment in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL), improving outcomes in the relapsed/refractory setting. New strategies are incorporating immunotherapy into front-line regimens to reduce the toxicity of chemotherapy, prolong survival and increase the possibility of treating older patients. The aim of this review was to describe the new strategies, which have incorporated these drugs into front-line regimens for BCP-ALL patients., Recent Findings: Recent studies have demonstrated that immunotherapy can be included in front-line induction, consolidation and/or maintenance regimens for the treatment of BCP-ALL patients by its addition to chemotherapy, by substituting some chemotherapy cycles or even including immunotherapy in chemotherapy-free strategies., Summary: The implications of these relevant findings will allow treating older patients, reducing the toxicity of chemotherapy and increasing patient outcomes. In addition, these findings have raised the possibility of avoiding the need for hematologic stem cell transplant in some selected patients., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Childhood acute lymphoblastic leukemia (ALL) is a common pediatric cancer. The heterogeneous characterization of B cells in ALL progression poses new challenges to researchers. We used single-cell sequencing to explore the critical role of B cells in regulating the ALL immune microenvironment., Method: We collected the single cell (sc) RNA-seq data of ALL and health sample from the gene expression omnibus (GEO) database, the "Seurat" and "harmony" R package was used for quality control and scRNA-seq analysis, in which the CellMarker2.0 database was used for cell type annotation. Subsequently, the FindAllMarkers function was used to identify the differentially expressed genes (DEGs) among various cell types and the DAVID database was applied for the biological process of DEGs. Then, the "inferCNV" package was used for copy number variation, regulons and cell communication were performed by SCENIC tool and CellChat package. The role of the target gene in regulating ALL progression was assessed using RT-qPCR, Transwell and scratch healing assays., Results: We identified nine mainly cell clusters after scRNA-seq analysis, in which the B cells had higher infiltration proportion in the ALL samples and were sub-clustered into five cell sub-groups. The B cells 1 is closely associated with cell proliferation and stemness (TNFAIP3 and KDM5B), and the significant CNV of amplification occurred on chr6 and chr21 that supported stemness of B cells1. RXRB is a key transcription factor mediated the proliferation of B cells 1, which in turn suppressed hematopoietic stem cells (HSCs) proliferation and promoted cytotoxic NK/T cells activation through diverse cell communication ways. One of the key regulators of B cells is MYC, which promotes the migration and invasive ability of cell line leukemia cell lines., Conclusion: This study reveals the stemness characteristics of B cells and their critical role in ALL progression, a finding that provides new potential directions for the development of targeted therapies against ALL., Competing Interests: The authors declare that they have no competing interests., (© 2024 Wang et al.)

Background: In acute leukemia, many associations have been identified between prognosis and some factors, such as individual antigen expression, cytogenetics, gender, age, high leukocyte level (WBC), platelet count (PLT), and lactate dehydrogenase (LDH), but few are consistent. In this study, we aimed to investigate the cell surface markers and other clinical pathological features for prognosis determination in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients in our population., Methods: This cross-sectional study was performed from January 2017 to December 2023 in İstanbul Training and Research Hospital and included 113 patients (86 AML and 27 ALL) newly diagnosed with AML (non-APL) and ALL. The following tests were fulfilled for the included patients: complete blood count (CBC), LDH, and flow cytometric analysis using a blood sample or bone marrow aspirate. The effects of surface markers, gender, age, WBC, PLT, and LDH on 24-month survival were evaluated retrospectively., Results: Among the investigated parameters, lack of CD13 expression and positive CD10, cTdT expressions were associated with poor prognosis in AML patients (p = 0.01, p = 0.04, and p = 0.04, respectively). We have found no association between the surface markers and other parameters with prognosis in ALL patients. Age > 65 years was associated with poor prognosis in both AML and ALL patients (p < 0.001)., Conclusions: CD10, cTdT positivity, and CD13 negativity may predict poor prognosis for AML and can be considered as prognostic biomarkers for AML patients.

Despite a high response rate in chimeric antigen receptor (CAR) T cell therapy for acute lymphocytic leukaemia (ALL) 1-3 , approximately 50% of patients relapse within the first year 4-6 , representing an urgent question to address in the next stage of cellular immunotherapy. Here, to investigate the molecular determinants of ultralong CAR T cell persistence, we obtained a single-cell multi-omics atlas from 695,819 pre-infusion CAR T cells at the basal level or after CAR-specific stimulation from 82 paediatric patients with ALL enrolled in the first two CAR T ALL clinical trials and 6 healthy donors. We identified that elevated type 2 functionality in CAR T infusion products is significantly associated with patients maintaining a median B cell aplasia duration of 8.4 years. Analysis of ligand-receptor interactions revealed that type 2 cells regulate a dysfunctional subset to maintain whole-population homeostasis, and the addition of IL-4 during antigen-specific activation alleviates CAR T cell dysfunction while enhancing fitness at both transcriptomic and epigenomic levels. Serial proteomic profiling of sera after treatment revealed a higher level of circulating type 2 cytokines in 5-year or 8-year relapse-free responders. In a leukaemic mouse model, type 2 high CAR T cell products demonstrated superior expansion and antitumour activity, particularly after leukaemia rechallenge. Restoring antitumour efficacy in type 2 low CAR T cells was attainable by enhancing their type 2 functionality, either through incorporating IL-4 into the manufacturing process or by priming manufactured CAR T products with IL-4 before infusion. Our findings provide insights into the mediators of durable CAR T therapy response and suggest potential therapeutic strategies to sustain long-term remission by boosting type 2 functionality in CAR T cells., (© 2024. The Author(s).)

Purpose: Leukaemia remains a major contributor to global mortality, representing a significant health risk for a substantial number of cancer patients. Despite notable advancements in the field, existing treatments frequently exhibit limited efficacy or recurrence. Here, we explored the potential of abolishing HVEM (herpes virus entry mediator, TNFRSF14) expression in tumours as an effective approach to treat acute lymphoblastic leukaemia (ALL) and prevent its recurrence., Methods: The clinical correlations between HVEM and leukaemia were revealed by public data analysis. HVEM knockout (KO) murine T cell lymphoblastic leukaemia cell line EL4 were generated using CRISPR-Cas9 technology, and syngeneic subcutaneous tumour models were established to investigate the in vivo function of HVEM. Immunohistochemistry (IHC), RNA-seq and flow cytometry were used to analyse the tumour immune microenvironment (TIME) and tumour draining lymph nodes (dLNs). Immune functions were investigated by depletion of immune subsets in vivo and T cell functional assays in vitro. The HVEM mutant EL4 cell lines were constructed to investigate the functional domain responsible for immune escape., Results: According to public databases, HVEM is highly expressed in patients with ALL and acute myeloid leukemia (AML) and is negatively correlated with patient prognosis. Genetic deletion of HVEM in EL4 cells markedly inhibited tumour progression and prolonged the survival of tumour-bearing mice. Our experiments proved that HVEM exerted its immunosuppressive effect by inhibiting antitumour function of CD8 + T cell through CRD1 domain both in vivo and in vitro. Additionally, we identified a combination therapy capable of completely eradicating ALL tumours, which induces immune memory toward tumour protection., Conclusions: Our study reveals the potential mechanisms by which HVEM facilitates ALL progression, and highlights HVEM as a promising target for clinical applications in relapsed ALL therapy., (© 2024. Springer Nature Switzerland AG.)

Chimeric antigen receptor cell therapy is a successful immunotherapy for the treatment of blood cancers. However, hurdles in their manufacturing remain including efficient isolation and purification of the T-cell starting material. Herein, we describe a one-step separation based on inertial spiral microfluidics for efficient enrichment of T-cells in B-cell acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia patient's samples. In healthy donors used to optimize the process, the lymphocyte purity was enriched from 65% (SD ± 0.2) to 91% (SD ± 0.06) and T-cell purity was enriched from 45% (SD ± 0.1) to 73% (SD ± 0.02). Leukemic samples had higher starting B-cells compared to the healthy donor samples. Efficient enrichment and recovery of lymphocytes and T-cells were achieved in ALL samples with B-cells, monocytes and leukemic blasts depleted by 80% (SD ± 0.09), 89% (SD ± 0.1) and 74% (SD ± 0.09), respectively, and a 70% (SD ± 0.1) T-cell recovery. Chronic lymphocytic leukemia samples had lower T-cell numbers, and the separation process was less efficient compared to the ALL. This study demonstrates the use of inertial microfluidics for T-cell enrichment and depletion of B-cell blasts in ALL, suggesting its potential to address a key bottleneck of the chimeric antigen receptor-T manufacturing workflow., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Invasive aspergillosis (IA) is a potentially life-threatening complication of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). We conducted a systematic review and meta-analyses of studies on acute leukemia in children aged 0-17 years since 2000. Findings were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We included 24 studies with 3661 ALL patients and 1728 AML patients. IA cumulative incidence varied (0%-10% for ALL and 0%-18% for AML) across the studies. Pooled cumulative IA incidences were estimated at 3.2% (95% CI: 1.8%-5.8%) in ALL and 5.2% (95% CI: 3.1%-8.6%) in AML, with corresponding case fatality rates of 13.3% (95% CI: 6.3%-25.9%), and 7.8% (95% CI: 0.7%-51.2%), respectively. Our analysis highlights the impact of IA in childhood leukemia, underscoring the need to address strategies for prevention, early detection, and treatment of IA in pediatric leukemia., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: We employed Mendelian randomization (MR) to investigate the causal relationship between the gut microbiota and lymphoid leukemia, further exploring the causal relationships among immune cells, lymphoid leukemia, and potential metabolic mediators., Methods: We utilized data from the largest genome-wide association studies to date, encompassing 418 species of gut microbiota, 713 types of immune cells, and 1,400 serum metabolites as exposures. Summary statistics for lymphoid leukemia, acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL) were obtained from the FinnGen database. We performed bidirectional Mendelian analyses to explore the causal relationships among the gut microbiota, immune cells, serum metabolites, and lymphoid leukemia. Additionally, we conducted a two-step mediation analysis to identify potential intermediary metabolites between immune cells and lymphoid leukemia., Results: Several gut microbiota were found to have causal relationships with lymphoid leukemia, ALL, and CLL, particularly within the Firmicutes and Bacteroidetes phyla . In the two-step MR analysis, various steroid hormone metabolites (such as DHEAS, pregnenolone sulfateprogestogen derivatives, and androstenediol-related compounds) were identified as potential intermediary metabolites between lymphoid leukemia and immune cells. In ALL, the causal relationship between 1-palmitoyl-2-docosahexaenoyl-GPE (16:0/22:6) and ALL was mediated by CD62L-plasmacytoid DC%DC (mediated proportion=-2.84%, P =0.020). In CLL, the causal relationship between N6,n6,n6-trimethyllysine and CLL was mediated by HLA DR+ CD8br AC (mediated proportion=4.07%, P =0.021)., Conclusion: This MR study provides evidence supporting specific causal relationships between the gut microbiota and lymphoid leukemia, as well as between certain immune cells and lymphoid leukemia with potential intermediary metabolites., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhuang, Yin, Yang, Man, Wang, Geng and Shi.)

Clinical data of 1 494 patients with hematological diseases who were scheduled to receive allogeneic hematopoietic stem cell transplantation and received the anti-human-leukocyte-antigen (HLA) antibody test for the first time at the First Affiliated Hospital of Soochow University from 2016 to 2018 was collected to analyze the positive rates and distribution characteristics of different types of pre-existing anti-HLA antibodies in patients with different hematological diseases. Among 1 494 patients with hematological diseases, there were 849 males and 645 females, aged [31 (17, 45)] years, and included 577 cases of acute myeloid leukemia (AML), 373 cases of acute lymphocytic leukemia (ALL), 234 cases of aplastic anemia (AA), 175 cases of myelodysplastic syndrome (MDS), and 135 cases of other diseases. The total positive rate of pre-existing anti-HLA antibodies was 25.1% (375/1 494), among which the positive rates of anti-HLA class Ⅰ, anti-HLA class Ⅱ, and anti-HLA class Ⅰ+Ⅱ antibodies were 11.2% (168/1 494), 4.9% (73/1 494), and 9.0% (134/1 494), respectively.The total positive rates of pre-existing anti-HLA antibodies in patients with MDS、AA、AML、ALL and other diseases were 40.6% (71/175), 30.8% (72/234), 26.2% (151/577), 12.3% (46/373), and 25.9% (35/135), respectively, with statistically significant difference ( P <0.001). The positive rates of anti-HLA class Ⅰ, anti-HLA class Ⅱ, and anti-HLA class Ⅰ+Ⅱ antibodies in patients with different hematological diseases showed statistically significant differences (all P <0.001). Given the varying positive rates and distribution characteristics of pre-existing anti-HLA antibodies among patients with different hematological diseases, anti-HLA antibody test should be performed before receiving hematopoietic stem cell transplantation.

Background: Auer rods (AuRs) are prominent intracellular structures found almost exclusively in myeloid cell malignancies, such as acute myeloid leukemia (AML), chronic and juvenile myelomonocytic leukemia and myelodysplastic syndrome. Extremely rare AuRs have been reported in patients with acute lymphoblastic leukemia (ALL) or among ambiguous lineage leukemia patients with a dominantly lymphoblastic immunophenotype., Procedure: We report diagnostic and follow-up data of an international cohort of 11 children suffering from leukemias with AuRs and with significant presence of T and myeloid markers, majority of whom categorized as early T-cell precursor (ETP, n = 7); or T-ALL (ETP status unknown, n = 2), ALAL (acute leukemia of ambiguous lineage, n = 1), and AML reclassified from ALAL (n = 1). We described other diagnostic details and treatment types and responses. Moreover, we summarize previously published data., Results: Among the four patients who started and remained on ALL-type therapy, all were in the first complete remission, whereas both patients who started and remained on AML-type therapy relapsed and died. Of the patients who followed either a combined ALL/AML protocol (Interfant 06) or who switched from one of the two types of therapy to the other, one patient died, and the remaining four were in first complete remission at the most recent follow-up. We also searched for similar cases in the literature and found only three additional children with nonmyeloid leukemia and AuRs and 10 adults with this type of leukemia., Conclusions: Briefly, ALL- or combined ALL/AML-type therapy may be effective for treating AuR-positive leukemia patients with a lymphoid immunophenotype., (© 2024 The Author(s). Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

Little is known about the efficacy of COVID-19 vaccines during acute lymphoblastic leukemia therapy (ALL); data for COVID-19 vaccine immune responses in pediatric leukemia remain sparse. We conducted a single center study of patients aged 5-25 years undergoing ALL chemotherapy who received COVID-19 vaccination. Twenty-one patients were enrolled; efficacy was evaluable in 20. Twenty were vaccinated while receiving chemotherapy. Twenty received the BNT162b2 mRNA vaccine. Spike reactive antibodies (S-IgG) and/or T-cells (SRT) were detected in 16 of 20 (80%) vaccinated patients; 13 (65%) and 9 (45%) were positive for S-IgG and SRT, respectively. Six (30%) showed both spike reactive B and T-cell responses. Eleven of the 13 with S-IgG positivity were negative for anti-Nucleocapsid IgG, an antibody profile consistent with a vaccine induced immune response. All 13S-IgG+ patients showed neutralizing antibodies. SRT included CD4+ (7) and CD8+ (6) T-cells; both CD4+ and CD8+ SRT were seen in 4. SRT were multifunctional (producing multiple cytokines) in most patients (8 of 9); 4 showed SRT with triple cytokine and B-cell co-stimulatory responses, indicating a multimodal adaptive immune response. Immune responses were seen among patients vaccinated in the settings of lymphopenia (6 of 12) intensive chemotherapy (3 of 4), and Peg allergy (6 of 8). Sequencing revealed public CD4+ and CD8+ TCR sequences reactive to epitopes across the spike protein. In conclusion, COVID-19 vaccination induced B and/or T-cell responses in a majority of children and young adults undergoing ALL chemotherapy., (© 2024 UICC.)

Objectives: The aim of this retrospective study was to investigate the influence of chemotherapy on the immune status of individual patients diagnosed with acute lymphoblastic leukemia (ALL) and to elucidate the clinical characteristics of immune reconstitution in ALL patients following chemotherapy., Methods: Clinical data of children with ALL were gathered, including information on the number of lymphocyte subsets prior to chemotherapy, at the end of therapy, six months, and one year after the end of the treatment., Results: A total of 146 children with ALL were included, and T cells, B cells, and NK cells all decreased to various degrees prior to treatment. The abnormal CD3 + T cell numbers group experienced a considerably higher mortality (21.9% vs. 6.1%) and recurrence rate (31.3% vs. 11.4%) compared to the normal group (P < 0.05). T cells, B cells, and NK cells were all significantly compromised at the end of therapy compared to the beginning of chemotherapy, with B cells being more severely compromised (P < 0.001). At the end of treatment, levels of B cells, CD4 + T cells, CD4/CD8, IgG and IgM in low risk (LR) group were significantly higher than those in intermediate risk (IR) group (P < 0.01), and levels of NK cells in LR group were evidently lower than those in IR group (P < 0.001). Six months after the end of therapy, all the above indicators recovered (P < 0.001) except CD4/CD8 ratio (P = 0.451)., Conclusions: The immune systems of the ALL patients were severely compromised upon therapy withdrawal, particularly the B cells. At six months after the therapy ended, the B cells were basically restored to normal level, while the T-cell compartment was not. The impaired numbers of CD3 + T cell may contribute to a weakened anti-tumor response, potentially leading to a poorer prognosis., (© 2024. The Author(s).)

The role of Erythroid cells in immune regulation and immunosuppression is one of the emerging topics in modern immunology that still requires further clarification as Erythroid cells from different tissues and different species express different immunoregulatory molecules. In this study, we performed a thorough investigation of human bone marrow Erythroid cells from adult healthy donors and adult acute lymphoblastic leukemia patients using the state-of-the-art single-cell targeted proteomics and transcriptomics via BD Rhapsody and cancer-related gene copy number variation analysis via NanoString Sprint Profiler. We found that human bone marrow Erythroid cells express the ARG1, LGALS1, LGALS3, LGALS9 , and C10orf54 (VISTA) immunosuppressive genes, CXCL5, CXCL8 , and VEGFA cytokine genes, as well as the genes involved in antimicrobial immunity and MHC Class II antigen presentation. We also found that ARG1 gene expression was restricted to the single erythroid cell cluster that we termed ARG1-positive Orthochromatic erythroblasts and that late Erythroid cells lose S100A9 and gain MZB1 gene expression in case of acute lymphoblastic leukemia. These findings show that steady-state erythropoiesis bone marrow Erythroid cells express myeloid signature genes even without any transdifferentiating stimulus like cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Perik-Zavodskii, Perik-Zavodskaia, Alrhmoun, Volynets, Shevchenko, Nazarov, Denisova and Sennikov.)

Objective: The survival rates of children with acute lymphoblastic leukemia (ALL) have improved over the years, but infections remain a significant cause of morbidity and mortality. Chemotherapy has a range of harmful side effects including the loss of protective antibodies against vaccine-preventable diseases. The objective of this study was to evaluate the serological status of pediatric ALL cases before and after intensive chemotherapy., Materials and Methods: Children treated and followed for ALL at Dokuz Eylül University were included in this retrospective cross-sectional study. Antibody levels against hepatitis A, hepatitis B, and rubella were routinely assessed at both the time of diagnosis and 6 months after completion of chemotherapy. Measles, mumps, and varicella antibody levels were evaluated at only 6 months after treatment., Results: Seventy-eight children who completed chemotherapy for ALL were enrolled in the study. All participants had non-protective antibody levels for at least one of the diseases. The highest seropositivity rate was found for hepatitis A (55.1%) and the lowest for measles (17.9%) after chemotherapy. Overall, 50.7%, 30.6%, and 45.7% of the patients significantly lost their humoral immunity against hepatitis B, hepatitis A, and rubella, respectively. Patients in the higher-risk group for ALL had lower seropositivity rates than patients of the other risk groups. There were statistically significant relationships between the protective antibody rates for hepatitis A and varicella and the ages of the patients. Except for hepatitis A vaccination, pre-chemotherapy vaccination did not affect post-chemotherapy serology. On the other hand, all children with a history of varicella before diagnosis showed immunity after chemotherapy., Conclusion: Patients with ALL, including those previously fully vaccinated, are at great risk of infection due to the decrease in protective antibody levels after chemotherapy. There is a need for routine post-chemotherapy serological testing and re-vaccination based on the results obtained., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors., (©Copyright 2024 by Turkish Society of Hematology Turkish Journal of Hematology, Published by Galenos Publishing House.)

Introduction: The human leukocyte antigen (HLA) evolutionary divergence (HED) reflects immunopeptidome diversity and has been shown to predict the response of tumors to immunotherapy. Its impact on allogeneic hematopoietic stem cell transplantation (HSCT) is controversial in different studies., Methods: In this study, we retrospectively analyzed the clinical impact of class I and II HED in 225 acute lymphoblastic leukemia patients undergoing HSCT from related haploidentical donors. The HED for recipient, donor, and donor-recipient pair was calculated based on Grantham distance, which accounts for variations in the composition, polarity, and volume of each amino acid within the peptide-binding groove of two HLA alleles. The median value of HED scores was used as a cut-off to stratify patients with high or low HED., Results: The class I HED for recipient (R&#95;HED class I ) showed the strongest association with cumulative incidence of relapse (12.2 vs. 25.0%, P = 0.00814) but not with acute graft-versus-host disease. The patients with high class II HED for donor-recipient (D/R&#95;HED class II ) showed a significantly higher cumulative incidence of severe aGVHD than those with low D/R&#95;HED class II (24.0% vs. 6.1%, P = 0.0027). Multivariate analysis indicated that a high D/R&#95;HED class II was an independent risk factor for the development of severe aGVHD (P = 0.007), and a high R&#95;HED class I had a more than two-fold reduced risk of relapse (P = 0.028). However, there was no discernible difference in overall survival (OS) or disease-free survival (DFS) for patients with high or low HED, which was inconsistent with the previous investigation., Discussion: While the observation are limited by the presented single center retrospective cohort, the results show that HED has poor prognostic value in OS or DFS, as well as the associations with relapse and aGVHD. In haploidentical setting, class II HED for donor-recipient pair (D/R&#95;HED class II ) is an independent and novel risk factor for finding the best haploidentical donor, which could potentially influence clinical practice if verified in larger cohorts., Competing Interests: Author H-FZ, X-JL and X-BL are employed by Beijing BFR Gene Diagnostics Co., Ltd. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Cao, Zhou, Liu and Li.)

Chimeric antigen receptor (CAR) T cell therapy is a promising treatment for pediatric patients with relapsed or refractory B cell acute lymphoblastic leukemia (R/R B ALL). Cytokine release syndrome (CRS) is a common toxicity after CAR T cell therapy and fever is often the first symptom. Differentiating CRS from infection after CAR T cell therapy can be challenging. Plasma microbial cell free DNA (mcfDNA) is a novel diagnostic tool which allows for qualitative and quantitative assessment of over 1000 organisms. This pilot study sought to characterize mcfDNA results in pediatric patients with R/R B ALL in the first 2 months after CAR T cell therapy., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Parasites have been associated with possible anticancer activity, including Trypanosoma cruzi , which has been linked to inhibiting the growth of solid tumors. To better understand this antitumor effect, we investigated the association of anti- T. cruzi antibodies with B cells of the acute lymphoblastic leukemia (ALL) SUPB15 cell line. The antibodies were generated in rabbits. IgGs were purified by affinity chromatography. Two procedures (flow cytometry (CF) and Western blot(WB)) were employed to recognize anti- T. cruzi antibodies on SUPB15 cells. We also used CF to determine whether the anti- T. cruzi antibodies could suppress SUPB15 cells. The anti- T. cruzi antibodies recognized 35.5% of the surface antigens of SUPB15. The complement-dependent cytotoxicity (CDC) results demonstrate the cross-suppression of anti- T. cruzi antibodies on up to 8.4% of SUPB15 cells. For the WB analysis, a band at 100 kDa with high intensity was sequenced using mass spectrometry, identifying the protein as nucleolin. This protein may play a role in the antitumor effect on T. cruzi . The anti- T. cruzi antibodies represent promising polyclonal antibodies that have the effect of tumor-suppressive cross-linking on cancer cells, which should be further investigated.

Acute lymphoblastic leukemia (ALL) is one of the most common acute leukemias, with rapid onset and progression. The standardized application of chemotherapy and transplantation have improved the prognosis of patients, while the unmet therapeutic needs still exist. Recently novel immunotherapies including Bispecific T cell Engager develop rapidly, offering more options for ALL treatment and also demanding higher requirements for clinical diagnosis and treatment management. Based on the evidence of domestic and international medical evidence and clinical experience, the expert panel updated Chinese consensus for the Bispeific T cell Engager in the treatment of B-cell acute lymphoblastic leukemia (2022) and formulated this edition of the Chinese expert consensus.

Natural killer (NK) cells play a crucial role in innate immunity, particularly in combating infections and tumors. However, in hematological cancers, NK cells often exhibit impaired functions. Therefore, it is very important to activate its endosomal Toll-like receptors (TLRs) as a potential strategy to restore its antitumor activity. We stimulated NK cells from the peripheral blood mononuclear cells from children with acute lymphoblastic leukemia and NK cells isolated, and the NK cells were stimulated with specific TLR ligands (Poly I:C, Imiquimod, R848, and ODN2006) and we evaluated changes in IFN-γ, CD107a, NKG2D, NKp44 expression, Granzyme B secretion, cytokine/chemokine release, and cytotoxic activity. Results revealed that Poly I:C and Imiquimod enhanced the activation of both immunoregulatory and cytotoxic NK cells, increasing IFN-γ, CD107a, NKG2D, and NKp44 expression. R848 activated immunoregulatory NK cells, while ODN2006 boosted CD107a, NKp44, NKG2D, and IFN-γ secretion in cytotoxic NK cells. R848 also increased the secretion of seven cytokines/chemokines. Importantly, R848 and ODN 2006 significantly improved cytotoxicity against leukemic cells. Overall, TLR stimulation enhances NK cell activation, suggesting TLR8 (R848) and TLR9 (ODN 2006) ligands as promising candidates for antitumor immunotherapy.

Natural killer (NK) cells have high intrinsic cytotoxic capacity, and clinical trials have demonstrated their safety and efficacy for adoptive cancer therapy. Expression of chimeric antigen receptors (CARs) enhances NK cell target specificity, with these cells applicable as off-the-shelf products generated from allogeneic donors. Here, we present for the first time an innovative approach for CAR NK cell engineering employing a non-viral Sleeping Beauty (SB) transposon/transposase-based system and minimized DNA vectors termed minicircles. SB-modified peripheral blood-derived primary NK cells displayed high and stable CAR expression and more frequent vector integration into genomic safe harbors than lentiviral vectors. Importantly, SB-generated CAR NK cells demonstrated enhanced cytotoxicity compared with non-transfected NK cells. A strong antileukemic potential was confirmed using established acute lymphocytic leukemia cells and patient-derived primary acute B cell leukemia and lymphoma samples as targets in vitro and in vivo in a xenograft leukemia mouse model. Our data suggest that the SB-transposon system is an efficient, safe, and cost-effective approach to non-viral engineering of highly functional CAR NK cells, which may be suitable for cancer immunotherapy of leukemia as well as many other malignancies., Competing Interests: Declaration of interests E.U. is an Advisory Board member for Phialogics and has sponsored research projects with Gilead and BMS. Z.I. is an inventor on patents related to Sleeping Beauty and MC technology. M.H. is listed as inventor on patent applications and granted patents related to CAR technologies and transposon-based gene transfer that are, in part licensed to industry. M.H. is a co-founder and equity owner of T-CURX GmbH, Würzburg, Germany. M.H. and E.U. are inventors on patents related to CAR and MC technology. T.B., P.W., W.S.W., and E.U. are inventors on patents related to optimized CAR designs. T.B., P.W., and E.U. are inventors on non-viral gene-editing technologies of NK cells., (Copyright © 2024. Published by Elsevier Inc.)

Abstract: Acute lymphoblastic leukemia (ALL) arises from the uncontrolled proliferation of B-cell precursors (BCP-ALL) or T cells (T-ALL). Current treatment protocols obtain high cure rates in children but are based on toxic polychemotherapy. Novel therapies are urgently needed, especially in relapsed/refractory (R/R) disease, high-risk (HR) leukemias and T-ALL, in which immunotherapy approaches remain scarce. Although the interleukin-7 receptor (IL-7R) plays a pivotal role in ALL development, no IL-7R-targeting immunotherapy has yet reached clinical application in ALL. The IL-7Rα chain (CD127)-targeting IgG4 antibody lusvertikimab (LUSV; formerly OSE-127) is a full antagonist of the IL-7R pathway, showing a good safety profile in healthy volunteers. Here, we show that ∼85% of ALL cases express surface CD127. We demonstrate significant in vivo efficacy of LUSV immunotherapy in a heterogeneous cohort of BCP- and T-ALL patient-derived xenografts (PDX) in minimal residual disease (MRD) and overt leukemia models, including R/R and HR leukemias. Importantly, LUSV was particularly effective when combined with polychemotherapy in a phase 2-like PDX study with CD127high samples leading to MRD-negativity in >50% of mice treated with combination therapy. Mechanistically, LUSV targeted ALL cells via a dual mode of action comprising direct IL-7R antagonistic activity and induction of macrophage-mediated antibody-dependent cellular phagocytosis (ADCP). LUSV-mediated in vitro ADCP levels significantly correlated with CD127 expression levels and the reduction of leukemia burden upon treatment of PDX animals in vivo. Altogether, through its dual mode of action and good safety profile, LUSV may represent a novel immunotherapy option for any CD127+ ALL, particularly in combination with standard-of-care polychemotherapy., (© 2024 American Society of Hematology. Published by Elsevier Inc. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Childhood acute lymphoblastic leukemia (cALL) survivors suffer early-onset chronic diseases classically associated with aging. Normal aging is accompanied by organ dysfunctions, including immunological ones. We hypothesize that thymic immunosenescence occurs in cALL survivors and that its severity may correlate with early-onset chronic diseases. The PETALE study is a cALL survivor cohort with an extensive cardiovascular and metabolic evaluation. The thymic immunosenescence biomarker, signal joint T-cell receptor excision circles (TREC), was evaluated and was highly correlated with age in healthy participants (n = 281) and cALL survivors (n = 248). We observed a systematic thymic immunoage accentuation in each cALL survivor compared to controls ranging from 5.9 to 88.3 years. The immunoage gain was independent of age at diagnosis and treatment modalities and was more severe for females. Thymic aging was associated with several pathophysiological parameters, was greater in survivors suffering from metabolic syndrome, but there was no significant association with global physical condition. The decrease in TREC was independent from blood cell counts, which were normal, suggesting a segmental aging of the thymic compartment. Indeed, increased plasmatic T cell regulatory cytokines IL-6, IL-7 and GM-CSF accompanied high immunoage gain. Our data reveal that cALL or its treatment trigger a rapid immunoage gain followed by further gradual thymic immunosenescence, similar to normal aging. This leads to an enduring shift in accentuated immunoage compared to chronological age. Thus, accentuated thymic immunosenescence is a hallmark of cALL survivorship and TREC levels could be useful immunosenescence biomarkers to help monitoring the health of cancer survivors., (© 2024. The Author(s).)

In their paper, the authors present their experience with the use of chimeric antigen receptor T cells targeting CD7 as a bridge to allogeneic haematopoietic cell transplantation in patients with relapsed/refractory T-cell acute lymphoblastic leukaemia/lymphoblastic lymphoma. Commentary on: Cao et al. A safety and efficacy study of allogeneic haematopoietic stem cell transplantation for refractory and relapsed T-cell acute lymphoblastic leukaemia/lymphoblastic lymphoma patients who achieved complete remission after autologous CD7 chimeric antigen receptor T-cell therapy. Br J Haematol 2024;204:2351-2364., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

The treatment of childhood acute lymphoblastic leukemia (ALL) has reached overall survival rates exceeding 90%. The present and future challenges are to cure the remainder of patients still dying from disease, and to reduce morbidity and mortality in those who can be cured with standard-of-care chemotherapy by replacing toxic chemotherapy elements while retaining cure rates. With the novel therapeutic options introduced in the last years, including immunotherapies and targeted antibodies, the treatment of ALL is undergoing major changes. For B-cell precursor ALL, blinatumomab, an anti-CD19 bispecific antibody, has established its role in the consolidation treatment for both high- and standard-risk first relapse of ALL, in the presence of bone marrow involvement, and may also have an impact on the outcome of high-risk subsets such as infant ALL and Philadelphia chromosome-positive ALL. Inotuzumab ozogamicin, an anti-CD22 drug conjugated antibody, has demonstrated high efficacy in inducing complete remission in relapsed ALL, even in the presence of high tumor burden, but randomized phase III trials are still ongoing. For T-ALL the role of CD38-directed treatment, such as daratumumab, is gaining interest, but randomized data are needed to assess its specific benefit. These antibodies are currently being tested in patients with newly diagnosed ALL and may lead to major changes in the present paradigm of treatment of pediatric ALL. Unlike the past, lessons may be learned from innovations in adult ALL, in which more drastic changes are piloted that may need to be translated to pediatrics.

Fortunately, ample efforts are being made to find the best strategy to improve the anti-leukemia capacity of NK cells for treating different types of cancer. Despite the favorable ADCC capacity of functional CD16 + NK cells for immunotherapy, when NK cells face leukemia cells, the CD16 receptor is cleaved during the process mediated by a disintegrin and metalloproteinase-17(ADAM17). Reduced CD16 expression on NK cells weakens their cytotoxicity against leukemia cells. In addition, the expression of the CD47 receptor is high in acute lymphoblastic leukemia (ALL) compared to normal cells and can be correlated with poor prognosis. In the present study, ADAM17 was inhibited in cord blood-derived CD16 + NK cells, and their activity against ALL cell lines was evaluated following blockage with anti-CD47 antibody. As the results showed, the CD16 expression was reduced in the NK cells co-cultured with ALL cell lines. However, the ADAM17 inhibition increased the CD16 expression on the NK cells. This enhanced the cytotoxicity of those cells as well as cytokine production was evaluated by measuring expression of CD107-a expression, and IFN-γ production. Moreover, the presence of the ADAM17 inhibitor increased the apoptosis effect of the generated NK cells in response to ALL cells. Therefore, the inhibition of ADAM17 is useful for the activity of CD16 + NK cells against cancer cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Immune system and bone marrow stromal cells play an important role in maintaining normal hematopoiesis. Lymphoid neoplasia disturbs not only development of immune cells, but other immune response mechanisms as well. Multipotent mesenchymal stromal cells (MSCs) of the bone marrow are involved in immune response regulation through both intercellular interactions and secretion of various cytokines. In hematological malignancies, the bone marrow stromal microenvironment, including MSCs, is altered. Aim of this study was to describe the differences of MSCs' immunological function in the patients with acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). In ALL, malignant cells arise from the early precursor cells localized in bone marrow, while in DLBCL they arise from more differentiated B-cells. In this study, only the DLBCL patients without bone marrow involvement were included. Growth parameters, surface marker expression, genes of interest expression, and secretion pattern of bone marrow MSCs from the patients with ALL and DLBCL at the onset of the disease and in remission were studied. MSCs from the healthy donors of corresponding ages were used as controls. It has been shown that concentration of MSCs in the bone marrow of the patients with ALL is reduced at the onset of the disease and is restored upon reaching remission; in the patients with DLBCL this parameter does not change. Proliferative capacity of MSCs did not change in the patients with ALL; however, the cells of the DLBCL patients both at the onset and in remission proliferated significantly faster than those from the donors. Expression of the membrane surface markers and expression of the genes important for differentiation, immunological status maintenance, and cytokine secretion differed significantly in the MSCs of the patients from those of the healthy donors and depended on nosology of the disease. Secretomes of the MSCs varied greatly; a number of proteins associated with immune response regulation, differentiation, and maintenance of hematopoietic stem cells were depleted in the secretomes of the cells from the patients. Lymphoid neoplasia leads to dramatic changes in the functional immunological status of MSCs.

Several products containing chimeric antigen receptor T cells targeting CD19 (CART19) have been approved for the treatment of patients with relapsed/refractory non-Hodgkin's lymphoma (NHL) and acute lymphoblastic leukaemia (ALL). Despite very impressive response rates, a significant percentage of patients experience disease relapse and die of progressive disease. A major cause of CART19 failure is loss or downregulation of CD19 expression in tumour cells, which has prompted a myriad of novel strategies aimed at targeting more than one antigen (e.g. CD19 and CD20 or CD22). Dual targeting can the accomplished through co-administration of two separate products, co-transduction with two different vectors, bicistronic cassettes or tandem receptors. In this manuscript, we review the pros and cons of each strategy and the clinical results obtained so far., (© 2024 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Chimeric antigen receptor (CAR) T-cell therapy is a breakthrough in hematologic malignancies, such as acute B lymphoblastic leukemia (B-ALL). Monitoring this treatment is recommended, although standardized protocols have not been developed yet. This work compares two flow cytometry monitoring strategies and correlates this technique with qPCR method. CAR-T cells were detected by two different flow-cytometry protocols (A and B) in nine blood samples from one healthy donor and five B-ALL patients treated with Tisagenlecleucel (Kymriah®, USA). HIV-1 viral load allowed CAR detection by qPCR, using samples from seven healthy donors and nine B-ALL patients. CAR detection by protocol A and B did not yield statistically significant differences (1.9% vs. 11.8% CD3 + CAR+, p = 0.07). However, protocol B showed a better discrimination of the CD3 + CAR+ population. A strong correlation was observed between protocol B and qPCR (r = 0.7, p < 0.0001). CD3 + CAR+ cells were detected by flow cytometry only when HIV-1 viral load was above 10 4 copies/mL. In conclusion, protocol B was the most specific flow-cytometry procedure for the identification of CAR-T cells and showed a high correlation with qPCR. Further efforts are needed to achieve a standardized monitoring approach., (© 2024 International Society for Advancement of Cytometry.)

Killer immunoglobulin-like receptor (KIR) and KIR-ligand (KIRL) interactions play an important role in natural killer cell-mediated effects after haematopoietic stem cell transplantation (HCT). Previous work has shown that accounting for known KIR-KIRL interactions may identify donors with optimal NK cell-mediated alloreactivity in the adult transplant setting. Paediatric acute leukaemia patients were retrospectively analysed, and KIR-KIRL combinations and maximal inhibitory KIR ligand (IM-KIR) scores were determined. Clinical outcomes were examined using a series of graphs depicting clinical events and endpoints. The graph methodology demonstrated that prognostic variables significant in the occurrence of specific clinical endpoints remained significant for relevant downstream events. KIR-KIRL combinations were significantly predictive for reduced grade 3-4 aGVHD likelihood, in patients transplanted with increased inhibitory KIR gene content and IM-KIR = 5 scores. Improvements were also observed in associated outcomes for both ALL and AML patients, including relapse-free survival, GRFS and overall survival. This study demonstrates that NK cell KIR HLA interactions may be relevant to the paediatric acute leukaemia transplant setting. Reduction in aGVHD suggests KIR effects may extend beyond NK cells. Moving forward clinical trials utilizing donors with a higher iKIR should be considered for URD HCT in paediatric recipients with acute leukaemia to optimize clinical outcomes., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Herpesvirus entry mediator (HVEM) is a molecular switch that can modulate immune responses against cancer. The significance of HVEM as an immune checkpoint target and a potential prognostic biomarker in malignancies is still controversial. This study aims to determine whether HVEM is an immune checkpoint target with inhibitory effects on anti-tumor CD4 + T cell responses in vitro and whether HVEM gene expression is dysregulated in patients with acute lymphocytic leukemia (ALL). HVEM gene expression in tumor cell lines and peripheral blood mononuclear cells (PBMCs) from ALL patients and healthy controls was measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Tumor cells were left untreated (control) or were treated with an HVEM blocker before co-culturing with CD4 + T cells in vitro in a carboxyfluorescein succinimidyl ester (CFSE)-dependent proliferation assay. HVEM expression was upregulated in the chronic myelogenous leukemia cell line (K562) (FC = 376.3, p = 0.086) compared with normal embryonic kidney cells (Hek293). CD4 + T cell proliferation was significantly increased in the HVEM blocker-treated K562 cells ( p = 0.0033). Significant HVEM differences were detected in ALL PBMCs compared with the controls, and these were associated with newly diagnosed ALL ( p = 0.0011) and relapsed/refractory ( p = 0.0051) B cell ALL ( p = 0.0039) patients. A significant differentiation between malignant ALL and the controls was observed in a receiver operating characteristic (ROC) curve analysis with AUC = 0.78 ± 0.092 ( p = 0.014). These results indicate that HVEM is an inhibitory molecule that may serve as a target for immunotherapy and a potential ALL biomarker.

Introduction Bispecific antibodies (BsAbs) represent a novel and potentially effective approach in cancer immunotherapy. These antibodies feature two unique binding domains, enabling them to simultaneously attach to two antigens or two epitopes of a single antigen. Recently, a variety of BsAbs targeting distinct B-cell antigens and myeloid lineage-specific surface markers-such as CD19xCD3, CD38xCD3, and CD123xCD3-have demonstrated promising results in heavily pretreated relapsed/refractory acute lymphoblastic leukemia (R/R ALL) and relapsed/refractory acute myeloid leukemia (R/R AML) patients. Areas covered New trail results were reported by different research groups at the 65th annual meeting of the American Society of Hematology (ASH). We provide a summary of the latest progress in BsAbs for immunotherapy in adult acute leukemia. Expert opinion B-ALL is the most favored leukemia for treatment with BsAbs, unlike T-ALL and AML, which are limited in constructs and results. The clinical application of blinatumomab in the first-line setting, combined with other therapies, has clearly benefited these B-ALL patients, especially older adults, due to its lower toxicity. In the B-ALL relapsed/refractory setting, new combinations with blinatumomab are under investigation, such as PD-1 or CTLA-4 inhibitors. We believe that with more clinical trial results, it is possible that blinatumomab will be used in new clinical indications soon. No novel BsAbs developed for B-ALL have yielded better results.

Leukaemia is the common name for a group of malignant diseases of the haematopoietic system with complex classifications and characteristics. Remarkable progress has been made in basic research and preclinical studies for acute leukaemia compared to that of the many other types/subtypes of leukaemia, especially the exploration of the biological basis and application of immunotherapy in acute myeloid leukaemia (AML) and B-cell acute lymphoblastic leukaemia (B-ALL). In this review, we summarize the basic approaches to immunotherapy for leukaemia and focus on the research progress made in immunotherapy development for AML and ALL. Importantly, despite the advances made to date, big challenges still exist in the effectiveness of leukaemia immunotherapy, especially in AML. Therefore, we use AML as an example and summarize the mechanisms of tumour cell immune evasion, describe recently reported data and known therapeutic targets, and discuss the obstacles in finding suitable treatment targets and the results obtained in recent clinical trials for several types of single and combination immunotherapies, such as bispecific antibodies, cell therapies (CAR-T-cell treatment), and checkpoint blockade. Finally, we summarize novel immunotherapy strategies for treating lymphocytic leukaemia and clinical trial results.

Background: KMT2A -rearranged acute lymphoblastic leukemia (ALL) in infants is an aggressive disease with 3-year event-free survival below 40%. Most relapses occur during treatment, with two thirds occurring within 1 year and 90% within 2 years after diagnosis. Outcomes have not improved in recent decades despite intensification of chemotherapy., Methods: We studied the safety and efficacy of blinatumomab, a bispecific T-cell engager molecule targeting CD19, in infants with KMT2A -rearranged ALL. Thirty patients younger than 1 year of age with newly diagnosed KMT2A -rearranged ALL were given the chemotherapy used in the Interfant-06 trial with the addition of one postinduction course of blinatumomab (15 μg per square meter of body-surface area per day; 28-day continuous infusion). The primary end point was clinically relevant toxic effects, defined as any toxic effect that was possibly or definitely attributable to blinatumomab and resulted in permanent discontinuation of blinatumomab or death. Minimal residual disease (MRD) was measured by polymerase chain reaction. Data on adverse events were collected. Outcome data were compared with historical control data from the Interfant-06 trial., Results: The median follow-up was 26.3 months (range, 3.9 to 48.2). All 30 patients received the full course of blinatumomab. No toxic effects meeting the definition of the primary end point occurred. Ten serious adverse events were reported (fever [4 events], infection [4], hypertension [1], and vomiting [1]). The toxic-effects profile was consistent with that reported in older patients. A total of 28 patients (93%) either were MRD-negative (16 patients) or had low levels of MRD (<5×10 -4 [i.e., <5 leukemic cells per 10,000 normal cells], 12 patients) after the blinatumomab infusion. All the patients who continued chemotherapy became MRD-negative during further treatment. Two-year disease-free survival was 81.6% in our study (95% confidence interval [CI], 60.8 to 92.0), as compared with 49.4% (95% CI, 42.5 to 56.0) in the Interfant-06 trial; the corresponding values for overall survival were 93.3% (95% CI, 75.9 to 98.3) and 65.8% (95% CI, 58.9 to 71.8)., Conclusions: Blinatumomab added to Interfant-06 chemotherapy appeared to be safe and had a high level of efficacy in infants with newly diagnosed KMT2A -rearranged ALL as compared with historical controls from the Interfant-06 trial. (Funded by the Princess Máxima Center Foundation and others; EudraCT number, 2016-004674-17.)., (Copyright © 2023 Massachusetts Medical Society.)

Chimeric antigen receptor (CAR) T cell therapy is an innovative immunotherapy for treating cancers in both children and adults with proven utility in numerous clinical trials. Significantly, some CAR T cell therapies have now been approved by relevant national regulatory bodies across numerous countries for clinical therapeutic use outside of clinical trials. One such recently licensed product is tisagenlecleucel, a CAR T therapy approved for the treatment of B-cell acute lymphoblastic leukemia (B-ALL) using autologous T cells from the patient. The genetically engineered T cells target a protein called CD19, common to B cells, through a CAR incorporating a 4-1BB costimulatory domain to improve response. Since tisagenlecleucel is now a standard of care treatment for B-ALL, it is clinically essential to be able to accurately monitor these CAR T cells in patients. Assessment of the copy number variant (CNV) of the CAR T cell products allows this within a clinically acceptable timeframe for optimal patient benefit. However, no standardized method with high reproducibility and efficiency has been described within a routine clinical laboratory setting. Here, we demonstrated a novel digital droplet PCR (ddPCR)-based methodology for the study of CNV (ddPCR-CNV) in 4-1BB CD19-specific CAR T cells with universal applicability across clinical diagnostic laboratories.

Background: Although B-acute lymphoblastic leukemia (B-ALL) patients' survival has been improved dramatically, some cases still relapse. This study aimed to explore the prognosis-related novel differentially expressed genes (DEGs) for predicting the overall survival (OS) of children and young adults (CAYAs) with B-ALL and analyze the immune-related factors contributing to poor prognosis., Methods: GSE48558 and GSE79533 from Gene Expression Omnibus (GEO) and clinical sample information and mRNA-seq from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database were retrieved. Prognosis-related key genes were enrolled to build a Cox proportional model using multivariate Cox regression. Five-year OS of patients, clinical characteristic relevance and clinical independence were assessed based on the model. The mRNA levels of prognosis-related genes were validated in our samples and the difference of immune cells composition between high-risk and low-risk patients were compared., Results: One hundred and twelve DEGs between normal B cells and B-ALL cells were identified based on GSE datasets. They were mainly participated in protein binding and HIF-1 signaling pathway. One hundred and eighty-nine clinical samples were enrolled in the study, both Kaplan-Meier (KM) analysis and univariate Cox regression analysis showed that CYBB, BCL2A1, IFI30, and EFNB1 were associated with prognosis, CYBB, BCL2A1, and EFNB1 were used to construct prognostic risk model. Moreover, compared to clinical indicators, the three-gene signature was an independent prognostic factor for CAYAs with B-ALL. Finally, the mRNA levels of CYBB, BCL2A1, and EFNB1 were significantly lower in B-ALL group as compared to controls. The high-risk group had a significantly higher percentage of infiltrated immune cells., Conclusion: We constructed a novel three-gene signature with independent prognostic factor for predicting 5-year OS of CAYAs with B-ALL. Additionally, we discovered the difference of immune cells composition between high-risk and low-risk groups. This study may help to customize individual treatment and improve prognosis of CAYAs with B-ALL., (© 2022 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Recent studies have linked the activity of ER aminopeptidase 2 (ERAP2) to increased efficacy of immune-checkpoint inhibitor cancer immunotherapy, suggesting that pharmacological inhibition of ERAP2 could have important therapeutic implications. To explore the effects of ERAP2 inhibition on the immunopeptidome of cancer cells, we treated MOLT-4 T lymphoblast leukemia cells with a recently developed selective ERAP2 inhibitor, isolated Major Histocompatibility class I molecules (MHCI), and sequenced bound peptides by liquid chromatography tandem mass spectrometry. Inhibitor treatment induced significant shifts on the immunopeptidome so that more than 20% of detected peptides were either novel or significantly upregulated. Most of the inhibitor-induced peptides were 9mers and had sequence motifs and predicted affinity consistent with being optimal ligands for at least one of the MHCI alleles carried by MOLT-4 cells. Such inhibitor-induced peptides could serve as triggers for novel cytotoxic responses against cancer cells and synergize with the therapeutic effect of immune-checkpoint inhibitors.

Acute Lymphocytic Leukemia (ALL) is a malignancy that originates from immature lymphoid cells and is clinically established with flow cytometry through disease-specific markers. Variation between ethnic groups is an epidemiological aspect of ALL. Higher incidence rates have been observed in Latin American patients and ALL in Latinos carries a dismal prognosis. The cell of origin in ALL is derived from immature cells of either the B or T lineage. Most reported data among Latinos either exclusively looks at B cell precursor ALL or do not distinguish between subtypes. We used the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database to delineate the differences in incidence rates of B-ALL and T-ALL across ethnic groups in the United States. Data from SEER-18 was used to compare incidence rates of T-ALL and B-ALL. Due to the utilization of cytogenetics and subsequent changes in ICD coding over the years examined the most recent data reported from 2002 to 2017. We compared rates in Non-Hispanic Whites (NHWs), Latinos, Blacks and Asian-Pacific Islanders (API). Age-adjusted incidence rates per 100,000 person-years were calculated. The incidence rate of B-ALL in the Latino population was consistently higher than other race/ethnicities throughout the years, ranging from 1.0 per 100,000 in 2002 to 2.5 per 100,000 in 2017. Blacks had the lowest age adjusted incidence rate (AAIR) of B-ALL overall, with rates approximately one third of those found in Latinos and the highest AAIR of T-ALL with an AAIR of 0.5 per 100,000., (© 2022 John Wiley & Sons Ltd.)

B cell-activating factor (BAFF) binds the three receptors BAFF-R, BCMA, and TACI, predominantly expressed on mature B cells. Almost all B cell cancers are reported to express at least one of these receptors. Here we develop a BAFF ligand-based chimeric antigen receptor (CAR) and generate BAFF CAR-T cells using a non-viral gene delivery method. We show that BAFF CAR-T cells bind specifically to each of the three BAFF receptors and are effective at killing multiple B cell cancers, including mantle cell lymphoma (MCL), multiple myeloma (MM), and acute lymphoblastic leukemia (ALL), in vitro and in vivo using different xenograft models. Co-culture of BAFF CAR-T cells with these tumor cells results in induction of activation marker CD69, degranulation marker CD107a, and multiple proinflammatory cytokines. In summary, we report a ligand-based BAFF CAR-T capable of binding three different receptors, minimizing the potential for antigen escape in the treatment of B cell cancers., (© 2022. The Author(s).)

Within the EuroClonality-NGS group, immune repertoire analysis for target identification in lymphoid malignancies was initially developed using two-stage amplicon approaches, essentially as a progressive modification of preceding methods developed for Sanger sequencing. This approach has, however, limitations with respect to sample handling, adaptation to automation, and risk of contamination by amplicon products. We therefore developed one-step PCR amplicon methods with individual barcoding for batched analysis for IGH, IGK, TRD, TRG, and TRB rearrangements, followed by Vidjil-based data analysis., (© 2022. The Author(s).)

Isolated extramedullary relapse (EMR) without bone marrow relapse (BMR) after allogeneic hematopoietic cell transplantation (allo-HCT) is a rare condition in patients with acute lymphoblastic leukemia (ALL), and the role of immunotherapeutic agents for these patients remains unclear. We analyzed treatment outcomes of blinatumomab or inotuzumab ozogamicin (INO) as first- or second-line salvage therapy in nine patients with Philadelphia chromosome-negative B-cell precursor ALL presenting with isolated EMR after previous allo-HCT. In seven patients receiving blinatumomab as first-line salvage therapy, 4 (57.1%) achieved complete remission (CR). Among the three patients without remission after blinatumomab, two switched to INO and subsequently showed responses {one CR and one partial response [PR]}, and one switched to multiagent chemotherapy that led to CR. In the two patients receiving first-line salvage therapy with INO, one showed PR and the other achieved CR. Overall, 6 (66.7%) of nine patients achieved CR, and five of them proceeded to allo-HCT in CR. The median overall survival after relapse was 27.8 months. In conclusion, both blinatumomab and INO showed good response rates and a safe bridging role to second allo-HCT in patients with isolated EMR. However, clinical differences between isolated EMR and EMR with BMR remain to be elucidated., (© 2021. Japanese Society of Hematology.)

Background: The clinical outcome of Philadelphia chromosome-negative B cell acute lymphoblastic leukemia (Ph-neg B-ALL) varies considerably from one person to another after clinical treatment due to lack of targeted therapies and leukemia's heterogeneity. Ferroptosis is a recently discovered programmed cell death strongly correlated with cancers. Nevertheless, few related studies have reported its significance in acute lymphoblastic leukemia., Methods: Herein, we collected clinical data of 80 Ph-neg B-ALL patients diagnosed in our center and performed RNA-seq with their initial bone marrow fluid samples. Throughout unsupervised machine learning K-means clustering with 24 ferroptosis related genes (FRGs), the clustered patients were parted into three variant risk groups and were performed with bioinformatics analysis., Results: As a result, we discovered significant heterogeneity of both immune microenvironment and genomic variance. Furthermore, the immune check point inhibitors response and potential implementation of Sorafenib in Ph-neg B-ALL was also analyzed in our cohort. Lastly, one prognostic model based on 8 FRGs was developed to evaluate the risk of Ph-neg B-ALL patients., Conclusion: Jointly, our study proved the crucial role of ferroptosis in Ph-neg B-ALL and Sorafenib is likely to improve the survival of high-risk Ph-neg B-ALL patients., (© 2021. The Author(s).)

Chimeric antigen receptor T-cell therapy targeting CD19 (CART19) has expanded the treatment options for patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (ALL). The approval of tisagenlecleucel for pediatric and young adult patients with r/r ALL has allowed broader access for some patients, but the treatment of older adults is available (at the time of this writing) only within a clinical trial. High remission rates have been consistently observed with varied CART19 products and treatment platforms, but durability of remissions and thus the potential role of a consolidative allogeneic stem cell transplant (SCT) is more uncertain and likely to vary by product and population treated. The immunologic characteristics of CARTs that confer high response rates also account for the life-threatening toxicities of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, the severity of which also varies by patient and disease characteristics and product. Further considerations informing a decision to treat include feasibility of leukapheresis and timeline of manufacture, alternative treatment options available, and the appropriateness of a potential consolidative allogeneic SCT. Advances in the field are under way to improve rate and duration of responses and to mitigate toxicity., (Copyright © 2021 by The American Society of Hematology.)

Chimeric antigen receptor (CAR) T cells targeting the CD19 antigen are effective in treating adults and children with B-cell malignancies. Place-of-care manufacturing may improve performance and accessibility by obviating the need to cryopreserve and transport cells to centralized facilities. Here we develop an anti-CD19 CAR (CAR19) comprised of the 4-1BB co-stimulatory and TNFRSF19 transmembrane domains, showing anti-tumor efficacy in an in vivo xenograft lymphoma model. CAR19 T cells are manufactured under current good manufacturing practices (cGMP) at two disparate clinical sites, Moscow (Russia) and Cleveland (USA). The CAR19 T-cells is used to treat patients with relapsed/refractory pediatric B-cell Acute Lymphocytic Leukemia (ALL; n = 31) or adult B-cell Lymphoma (NHL; n = 23) in two independently conducted phase I clinical trials with safety as the primary outcome (NCT03467256 and NCT03434769, respectively). Probability of measurable residual disease-negative remission was also a primary outcome in the ALL study. Secondary outcomes include complete remission (CR) rates, overall survival and median duration of response. CR rates are 89% (ALL) and 73% (NHL). After a median follow-up of 17 months, one-year survival rate of ALL complete responders is 79.2% (95%CI 64.5‒97.2%) and median duration of response is 10.2 months. For NHL complete responders one-year survival is 92.9%, and median duration of response has not been reached. Place-of-care manufacturing produces consistent CAR-T cell products at multiple sites that are effective for the treatment of patients with B-cell malignancies., (© 2021. The Author(s).)