CD44: a cancer stem cell marker and therapeutic target in leukemia treatment.

CD44 is a ubiquitous leukocyte adhesion molecule involved in cell-cell interaction, cell adhesion, migration, homing and differentiation. CD44 can mediate the interaction between leukemic stem cells and the surrounding extracellular matrix, thereby inducing a cascade of signaling pathways to regulate their various behaviors. In this review, we focus on the impact of CD44s/CD44v as biomarkers in leukemia development and discuss the current research and prospects for CD44-related interventions in clinical application.

The predictive value of T-cell chimerism for disease relapse after allogeneic hematopoietic stem cell transplantation.

Introduction: Chimerism is closely correlated with disease relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, chimerism rate is dynamic changes, and the sensitivity of different chimerism requires further research. Methods: To investigate the predictive value of distinct chimerism for relapse, we measured bone marrow (BM), peripheral blood (PB), and T-cell (isolated from BM) chimerism in 178 patients after allo-HSCT. Results: Receiver operating characteristic (ROC) curve showed that T-cell chimerism was more suitable to predict relapse after allo-HSCT compared with PB and BM chimerism. The cutoff value of T-cell chimerism for predicting relapse was 99.45%. Leukemia and myelodysplastic syndrome (MDS) relapse patients' T-cell chimerism was a gradual decline from 2 months to 9 months after allo-HSCT. Higher risk of relapse and death within 1 year after allo-HSCT. The T-cell chimerism rates in remission and relapse patients were 99.43% and 94.28% at 3 months after allo-HSCT (P = 0.009), 99.31% and 95.27% at 6 months after allo-HSCT (P = 0.013), and 99.26% and 91.32% at 9 months after allo-HSCT (P = 0.024), respectively. There was a significant difference (P = 0.036) for T-cell chimerism between early relapse (relapse within 9 months after allo-HSCT) and late relapse (relapse after 9 months after allo-HSCT) at 2 months after allo-HSCT. Every 1% increase in T-cell chimerism, the hazard ratio for disease relapse was 0.967 (95% CI: 0.948-0.987, P<0.001). Discussion: We recommend constant monitoring T-cell chimerism at 2, 3, 6, and 9 months after allo-HSCT to predict relapse.

True Donor Cell Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation: Diagnostic and Therapeutic Considerations-Brief Report.

Donor cell leukemia (DCL) is a rare complication after allogeneic hematopoietic stem cell transplantation (HSCT) accounting for 0.1% of relapses and presenting as secondary leukemia of donor origin. Distinct in phenotype and cytogenetics from the original leukemia, DCL's clinical challenge lies in its late onset. Its origin is affected by donor cell anomalies, transplant environment, and additional mutations. A 43-year-old woman, treated for early stage triple-negative breast cancer, developed mixed-phenotype acute leukemia (MPAL), 12 years later. Following induction chemotherapy, myeloablative conditioning, and allo-HSCT from her fully HLA-matched brother, she exhibited multiple cutaneous relapses of the original leukemia, subsequently evolving into DCL of the bone marrow. Cytogenetic analysis revealed a complex male karyotype in 20 out of 21 metaphases, however, still showing the MPAL phenotype. DCL diagnosis was confirmed by 90.5% XY in FISH analysis and the male karyotype. Declining further intensive chemotherapy including a second allo-HSCT, she was subsequently treated with repeated radiotherapy, palliative systemic therapies, and finally venetoclax and navitoclax but died seven months post-DCL diagnosis. This case underlines DCL's complexity, characterized by unique genetics, further complicating diagnosis. It highlights the need for advanced diagnostic techniques for DCL identification and underscores the urgency for early detection and better prevention and treatment strategies.

Sequential CD7 CAR T-Cell Therapy and Allogeneic HSCT without GVHD Prophylaxis.

BACKGROUND: Patients with relapsed or refractory hematologic cancers have a poor prognosis. Chimeric antigen receptor (CAR) T-cell therapy as a bridge to allogeneic hematopoietic stem-cell transplantation (HSCT) has the potential for long-term tumor elimination. However, pre-HSCT myeloablation and graft-versus-host disease (GVHD) prophylaxis agents have toxic effects and could eradicate residual CAR T cells and compromise antitumor effects. Whether the integration of CAR T-cell therapy and allogeneic HSCT can preserve CAR T-cell function and improve tumor control is unclear. METHODS: We tested a novel "all-in-one" strategy consisting of sequential CD7 CAR T-cell therapy and haploidentical HSCT in 10 patients with relapsed or refractory CD7-positive leukemia or lymphoma. After CAR T-cell therapy led to complete remission with incomplete hematologic recovery, patients received haploidentical HSCT without pharmacologic myeloablation or GVHD prophylaxis drugs. Toxic effects and efficacy were closely monitored. RESULTS: After CAR T-cell therapy, all 10 patients had complete remission with incomplete hematologic recovery and grade 4 pancytopenia. After haploidentical HSCT, 1 patient died on day 13 of septic shock and encephalitis, 8 patients had full donor chimerism, and 1 patient had autologous hematopoiesis. Three patients had grade 2 HSCT-associated acute GVHD. The median follow-up was 15.1 months (range, 3.1 to 24.0) after CAR T-cell therapy. Six patients remained in minimal residual disease-negative complete remission, 2 had a relapse of CD7-negative leukemia, and 1 died of septic shock at 3.7 months. The estimated 1-year overall survival was 68% (95% confidence interval [CI], 43 to 100), and the estimated 1-year disease-free survival was 54% (95% CI, 29 to 100). CONCLUSIONS: Our findings suggest that sequential CD7 CAR T-cell therapy and haploidentical HSCT is safe and effective, with remission and serious but reversible adverse events. This strategy offers a feasible approach for patients with CD7-positive tumors who are ineligible for conventional allogeneic HSCT. (Funded by the National Natural Science Foundation of China and the Key Project of Science and Technology Department of Zhejiang Province; ClinicalTrials.gov numbers, NCT04599556 and NCT04538599.).

Music Nursing as Complementary Therapy Improves Anxiety, Fatigue, and Quality of Life in Children with Acute Leukaemia: A Retrospective Study.

OBJECTIVE: To explore the effects of music nursing as a complementary therapy on anxiety, fatigue, and quality of life in children with acute leukemia (AL). METHODS: This study included 150 children with AL admitted to our hospital from August 2021 to August 2023 and divided them into two groups based on treatment: the control (n = 76, received routine nursing) and observation (n = 74, received music nursing on the basis of routine nursing) groups. Comparison of groups was performed in terms of general information, anxiety, fatigue, and quality of life at admission (T0) and 1 month after admission (T1). RESULTS: No significant differences were observed in the general data between the two groups (P > 0.05). Anxiety, fatigue, and quality of life of the two groups also showed no significant differences at T0 (P > 0.05). The observation group showed significantly lower anxiety than the control group at T1 (P < 0.05). At T1, the observation group exhibited a lower fatigue degree compared with the control group (P < 0.05). At T1, the observation group attained higher scores on physiological and emotional dimensions of the quality of life compared with the control group, and the differences were statistically significant (P < 0.05). CONCLUSION: Music nursing for AL children, which has a certain clinical application value, can effectively reduce their anxiety and fatigue and improve their quality of life.

The graft versus leukemia effect: donor lymphocyte infusions and cellular therapy.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for many hematologic malignancies as well as non-malignant conditions. Part of the curative basis underlying HSCT for hematologic malignancies relies upon induction of the graft versus leukemia (GVL) effect in which donor immune cells recognize and eliminate residual malignant cells within the recipient, thereby maintaining remission. GVL is a clinically evident phenomenon; however, specific cell types responsible for inducing this effect and molecular mechanisms involved remain largely undefined. One of the best examples of GVL is observed after donor lymphocyte infusions (DLI), an established therapy for relapsed disease or incipient/anticipated relapse. DLI involves infusion of peripheral blood lymphocytes from the original HSCT donor into the recipient. Sustained remission can be observed in 20-80% of patients treated with DLI depending upon the underlying disease and the intrinsic burden of targeted cells. In this review, we will discuss current knowledge about mechanisms of GVL after DLI, experimental strategies for augmenting GVL by manipulation of DLI (e.g. neoantigen vaccination, specific cell type selection/depletion) and research outlook for improving DLI and cellular immunotherapies for hematologic malignancies through better molecular definition of the GVL effect.

In vitro anti-leukemic effect of Wharton's jelly derived mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) have the ability to self-renew and are multi-potent. They are a primary candidate for cell-based therapy due to their potential anti-cancer effects. The aim of this study was to evaluate the in vitro anti-leukemic effect of Wharton's Jelly-derived MSC (WJ-MSC) on the leukemic cell lines K562 and HL-60. METHODS: In this present study, WJ-MSCs were isolated from human umbilical cord. The cells were incubated according to the standard culture conditions and characterized by flow cytometry. For experiments, WJ-MSC and leukemic cells were incubated in the direct co-culture at a ratio of 1:5 (leukemia cells: WJ-MSC). HUVEC cells were used as a non-cancerous cell line model. The apoptotic effect of WJ-MSCs on the cell lines was analyzed using Annexin V/PI apoptosis assay. RESULTS: After the direct co-culture of WJ-MSCs on leukemic cell lines, we observed anti-leukemic effects by inducing apoptosis. We had two groups of determination apoptosis with and without WJ-MSCs for all cell lines. Increased apoptosis rates were observed in K562 and HL-60 cell lines, whereas the apoptosis rates in HUVEC cells were low. CONCLUSIONS: MSCs are known to inhibit the growth of tumors of both hematopoietic and non-hematopoietic origin in vitro. In our study, WJ-MSC treatment strongly inhibited the viability of HL-60 and K562 and induced apoptosis. Our results also provided new insights into the inhibition of tumor growth by WJ-MSCs in vitro. In the future, WJ-MSCs could be used to inhibit cancer cells in clinical applications.

The role of immune reconstitution in relapse after allogeneic hematopoietic stem cell transplantation.

INTRODUCTION: Leukemia relapse following stem cell transplantation remains a significant barrier to long-term remission. Timely and balanced immune recovery after transplantation is crucial for preventing leukemia relapse. AREAS COVERED: After an extensive literature search of PubMed and Web of Science through October 2023, we provide an overview of the dynamics of immune reconstitution and its role in controlling leukemia relapse. We also discuss strategies to promote immune reconstitution and reduce disease recurrence following allogeneic hematopoietic stem cell transplantation. EXPERT OPINION: Immune reconstitution after transplantation has substantial potential to prevent relapse and might predict disease recurrence and prognosis. High dimensional cytometry, multi-omics, and T cell repertoire analysis allow for a more comprehensive and detailed understanding of the immune system's dynamics post-transplantation, and contribute to the identification of rare immune cell subsets or potential biomarkers associated with successful immune reconstitution or increased risk of complications. Strategies to enhance the immune system, such as adoptive immunotherapy and cytokine-based therapy, have great potential for reducing leukemia relapse after transplantation. Future research directions should focus on refining patient selection for these therapies, implementing appropriate and timely treatment, investigating combination approaches to maximize therapeutic outcomes, and achieving a robust graft-versus-leukemia (GVL) effect while minimizing graft-versus-host disease (GVHD) for optimal results.

Leukemia cancer cells and immune cells derived-exosomes: Possible roles in leukemia progression and therapy.

Exosomes have a significant impact on tumor survival, proliferation, metastasis, and recurrence. They also open up new therapeutic options and aid in the pathological identification and diagnosis of cancers. Exosomes have been shown in numerous studies to be essential for facilitating cell-to-cell communication. In B-cell hematological malignancies, the proteins and RNAs that are encased by circulating exosomes are thought to represent prospective sources for therapeutic drugs as well as biomarkers for diagnosis and prognosis. Additionally, exosomes can offer a "snapshot" of the tumor and the metastatic environment at any given point in time. In this review study, we concluded that leukemia-derived exosomes could be utilized as prognostic, diagnostic, and therapeutic biomarkers for individuals suffering from leukemia. Moreover, clinical studies have demonstrated that immune cells like dendritic cells create exosomes, which have the ability to activate the immune system against leukemia.

Single nucleotide polymorphisms conferring susceptibility to leukemia and oral mucositis: a multi-center pilot study of patients prior to conditioning therapy for hematopoietic cell transplant.

PURPOSE: Leukemias have been associated with oral manifestations, reflecting susceptibility to cancer therapy-induced oral mucositis. We sought to identify SNPs associated with both leukemia and oral mucositis (OM). METHODS: Whole exome sequencing was performed on leukemia and non-cancer blood disorder (ncBD) patients' saliva samples (N = 50) prior to conditioning therapy. WHO OM grading scores were determined: moderate to severe (OM2-4) vs. none to mild (OM0-1). Reads were processed using Trim Galorev0.6.7, Bowtie2v2.4.1, Samtoolsv1.10, Genome Analysis Toolkit (GATK)v4.2.6.1, and DeepVariantv1.4.0. We utilized the following pipelines: P1 analysis with PLINK2v3.7, SNP2GENEv1.4.1 and MAGMAv1.07b, and P2 [leukemia (N = 42) vs. ncBDs (N = 8)] and P3 [leukemia + OM2-4 (N = 18) vs. leukemia + OM0-1 (N = 24)] with Z-tests of genotypes and protein-protein interaction determination. GeneCardsSuitev5.14 was used to identify phenotypes (P1 and P2, leukemia; P3, oral mucositis) and average disease-causing likelihood and DGIdb for drug interactions. P1 and P2 genes were analyzed with CytoScape plugin BiNGOv3.0.3 to retrieve overrepresented Gene Ontology (GO) terms and Ensembl's VEP for SNP outcomes. RESULTS: In P1, 457 candidate SNPs (28 genes) were identified and 21,604 SNPs (1016 genes) by MAGMAv1.07b. Eighteen genes were associated with "leukemia" per VarElectv5.14 analysis and predicted to be deleterious. In P2 and P3, 353 and 174 SNPs were significant, respectively. STRINGv12.0 returned 77 and 32 genes (C.L. = 0.7) for P2 and P3, respectively. VarElectv5.14 determined 60 genes from P2 associated with "leukemia" and 11 with "oral mucositis" from P3. Overrepresented GO terms included "cellular process," "signaling," "hemopoiesis," and "regulation of immune response." CONCLUSIONS: We identified candidate SNPs possibly conferring susceptibility to develop leukemia and oral mucositis.

HLA peptide-binding pocket diversity modulates immunological complications after cord blood transplant in acute leukaemia.

Pocket motifs and their amino acid positions of HLA molecules are known to govern antigen presentation to effector cells. Our objective was to analyse their influence on the risk of graft-versus-host disease (GVHD) and relapse after umbilical cord blood transplant (UCBT). The transplant characteristics of 849 patients with acute leukaemia were obtained from the Eurocord/EBMT database. Higher acute (a) GVHD was associated with homozygosity of UCB HLA-C amino acid positions 77 and 80 (NN/KK) (p = 0.008). Severe aGVHD was associated with HLA-A pocket B YSAVMENVHY motif (p = 0.002) and NN and RR genotypes of the HLA-C amino acid positions 77 and 156 (p = 0.006 and p = 0.002). Such risk was also increased in case of recipient and UCB mismatches in P4 (p < 0.0001) and P9 (p = 0.003) pockets of HLA-DQB1 alleles. For chronic GVHD, the pocket B YYAVMEISNY motif of the HLA-B*15:01 allele and the absence of mismatch between recipient and UCB in the P6 pocket of HLA-DRB1 were associated with a lower risk (p = 0.0007 and p = 0.0004). In relapse, both UCB pocket B YFAVMENVHY belonging to HLA-A*32:01 and recipient pocket B YDSVGENYQY motif of the HLA-C*07:01 allele were associated with higher risk (p = 0.0026 and p = 0.015). We provide clues on HLA-mediated cellular interactions and their role in the development of GVHD and relapse.

Successful treatment of a B/T MPAL patient by chemo-free treatment with venetoclax, azacitidine, and blinatumomab.

B/T mixed phenotype acute leukemia (MPAL), which represents only 2-3% of all MPAL cases, is classified as a high-risk leukemia subtype. Adults diagnosed with B/T MPAL have a notably low 3-year survival rate, estimated at 20-40%. The rarity and undercharacterization of B/T MPAL present substantial challenges in identifying an optimal treatment protocol. This report aims to shed light on this issue by presenting a case in which a patient with a complex karyotype was treated using a combination of venetoclax, azacitidine, and blinatumomab. This novel, chemo-free regimen resulted in the patient achieving both hematologic and molecular complete remission, with no severe organ or hematological toxicity observed. Notably, the patient continued to maintain molecular remission for 1 year following the transplantation. Based on these findings, the combination of venetoclax, azacitidine, and blinatumomab could be considered a potential therapeutic approach for B/T MPAL patients, meriting further investigation.

Fever at Time of Leukemia Diagnosis in Children: Predictor of Bloodstream Infection or Catheter Removal?

PURPOSE: To assess the incidence of fever at diagnosis in children with leukemia and determine if fever at diagnosis is a predictor of bloodstream infection (BSI) or central venous access device (CVAD) removal for infection either within the first 30 days or between 30 and 90 days after CVAD insertion. MATERIALS AND METHODS: One hundred fifty-one patients with acute leukemia (July 1, 2018, to December 31, 2020) who underwent a CVAD insertion within 2 weeks of diagnosis were included. Patient data included demographic characteristics, fever at diagnosis, CVAD type, antibiotics before and/or on the day of CVAD insertion, BSI incidence, BSI rates per 1,000 catheter days, and need for catheter removal after CVAD insertion within 30 days and between 30 and 90 days. RESULTS: Patients with fever at diagnosis had a significantly higher incidence of BSI within the first 30 days after CVAD insertion (17/23) than that among patients without fever (6/23) (P = .046) at diagnosis. No statistically significant difference was observed in the incidence of BSI between 30 and 90 days after CVAD insertion between patients with fever (5/11) and those without fever at diagnosis (6/11) (P = .519). Fever at diagnosis was not a predictor of CVAD removal within 30 days (9 patients required CVAD removal; 7/9 had fever and 2/9 had no fever) (P = .181) or between 30 and 90 days (4 patients required CVAD removal; 1/4 had fever and 3/4 had no fever at diagnosis) (P = .343) after insertion. CONCLUSIONS: Fever at diagnosis in patients with leukemia is not a predictor of CVAD removal for infection.

What Is Childhood Leukemia?

This JAMA Patient Page outlines the symptoms, diagnosis, and treatment of childhood leukemia.

Harnessing the Transcriptional Signatures of CAR-T-Cells and Leukemia/Lymphoma Using Single-Cell Sequencing Technologies.

Chimeric antigen receptor (CAR)-T-cell therapy has greatly improved outcomes for patients with relapsed or refractory hematological malignancies. However, challenges such as treatment resistance, relapse, and severe toxicity still hinder its widespread clinical application. Traditional transcriptome analysis has provided limited insights into the complex transcriptional landscape of both leukemia cells and engineered CAR-T-cells, as well as their interactions within the tumor microenvironment. However, with the advent of single-cell sequencing techniques, a paradigm shift has occurred, providing robust tools to unravel the complexities of these factors. These techniques enable an unbiased analysis of cellular heterogeneity and molecular patterns. These insights are invaluable for precise receptor design, guiding gene-based T-cell modification, and optimizing manufacturing conditions. Consequently, this review utilizes modern single-cell sequencing techniques to clarify the transcriptional intricacies of leukemia cells and CAR-Ts. The aim of this manuscript is to discuss the potential mechanisms that contribute to the clinical failures of CAR-T immunotherapy. We examine the biological characteristics of CAR-Ts, the mechanisms that govern clinical responses, and the intricacies of adverse events. By exploring these aspects, we hope to gain a deeper understanding of CAR-T therapy, which will ultimately lead to improved clinical outcomes and broader therapeutic applications.

[Research Progress of Pyroptosis in Leukemia: from Mechanism to Treatment --Review].

Pyroptosis is a programmed death mediated by activated caspase and Gasdermin family proteins, characterized by cell swelling, cytosolysis and release of inflammatory factors. Leukemia is a malignant disease characterized by abnormal differentiation and proliferation of hematopoietic stem cells, thus seriously threating human health. In recent years, it has been found that the transformation, proliferation, metastasis and treatment response of leukemia cells are closely related to pyrodeath. Pyroptosis provides a new perspective for the study of leukemia. This paper reviews the types and molecular mechanisms of pyroptosis, the role of pyroptosis in the occurrence and development of leukemia and the treatment of leukemia, so as to provide some references for further study of the relationship between pyroptosis and leukemia, in order to provide a new strategy for the treatment of leukemia.

[Suspicion of constitutional abnormality at diagnosis of childhood leukemia: Update of the leukemia committee of the French Society of Childhood Cancers]. / Suspicion d'anomalie constitutionnelle au diagnostic de leucémie chez l'enfant : mise au point du comité leucémies de la Société française des cancers de l'enfant.

The spectrum of childhood leukemia predisposition syndromes has grown significantly over last decades. These predisposition syndromes mainly involve CEBPA, ETV6, GATA2, IKZF1, PAX5, RUNX1, SAMD9/SAMD9L, TP53, RAS-MAPK pathway, DNA mismatch repair system genes, genes associated with Fanconi anemia, and trisomy 21. The clinico-biological features leading to the suspicion of a leukemia predisposition are highly heterogeneous and require varied exploration strategies. The study of the initial characteristics of childhood leukemias includes high-throughput sequencing techniques, which have increased the frequency of situations where a leukemia predisposing syndrome is suspected. Identification of a leukemia predisposition syndrome can have a major impact on the choice of chemotherapy, the indication for hematopoietic stem cell transplantation, and screening for associated malformations and pathologies. The diagnosis of a predisposition syndrome can also lead to the exploration of family members and genetic counseling. Diagnosis and management should be based on dedicated and multidisciplinary care networks.