B-cell Acute Lymphoblastic Leukemia Research Articles

Successful allogeneic CD34+ hematopoietic stem cell boost for prolonged cytopenias following CAR T-cell therapy in B-cell acute lymphoblastic leukemia. On behalf of the Spanish Group for Hematopoietic Transplantation and Cellular Therapy (GETH-TC)

Successful allogeneic CD34+ hematopoietic stem cell boost for prolonged cytopenias following CAR T-cell therapy in B-cell acute lymphoblastic leukemia. On behalf of the Spanish Group for Hematopoietic Transplantation and Cellular Therapy (GETH-TC)

CD40 agonist on patient-derived xenograft mice for the treatment of B-cell acute lymphoblastic leukemia.

Cluster of differentiation 40 (CD40) is expressed on B-cell acute lymphoblastic leukemia (B-ALL) cases. However, the effect of CD40 activation on B-ALL cells has never been tested in vivo. The aim of our preclinical study was to investigate the therapeutic potential of a CD40 agonist in the treatment of B-ALL using patient-derived xenograft (PDX) mouse models. Intravenous administration of the CD40 agonist significantly impeded B-ALL cell proliferation and growth in vivo, accompanied by rapid activation of the extracellular signal-regulated kinase (ERK) pathway, leading to the induction of apoptosis and disruption of cell cycle progression. Co-treatment with a specific inhibitor of ERK further demonstrated that CD40 stimulation induced the pro-apoptosis of B-ALL cells in an ERK-dependent manner. Proteomic analysis revealed alterations in key signaling pathways associated with B-ALL expansion and maintenance. Moreover, the CD40 agonist markedly reduced the frequency of leukemia-initiating cells and leukemia development in PDX mice. Our study showed that the CD40 agonist can be associated with chemotherapeutic agents such as vincristine and dexamethasone, and this combination showed improved effectiveness. Additionally, the CD40 agonist was more effective on pre-B-ALL (EGIL B-III) that expressed CD40, than on common B-ALL (EGIL B-II) that lacked CD40 expression. These findings suggest that CD40 agonists are promising immunotherapeutic candidates for pediatric B-ALL, warranting further clinical investigations to improve patient outcomes in CD40-expressing B-ALL.

NCMP-05. CLINICAL AND RADIOGRAPHIC IMPROVEMENT WITH REPLACEMENT OF FOLATE METABOLITES IN A PATIENT WITH INTRATHECAL METHOTREXATE-INDUCED MYELOPATHY

Abstract Methotrexate (MTX)-induced myelopathy is a rare but serious adverse effect of intrathecal (IT) MTX, which may mimic subacute combined degeneration (SCD). MTX disrupts the normal synthesis of methionine, which plays an important role in maintaining myelin sheath integrity, resulting in degeneration of the dorsal columns. This degeneration does not respond to classic treatment with vitamin B12 and folate supplementation, unlike SCD. Here, we describe a case of a 45-year-old woman with Philadelphia-positive B-cell acute lymphoblastic leukemia treated with hyperCVAD regimen with ponatinib, who after 14 doses of prophylactic IT MTX, developed progressive lower extremity weakness, paresthesias, gait instability, saddle anesthesia, and bowel/bladder dysfunction. Her neurologic exam was also notable for diffuse hyporeflexia. The onset of symptoms followed a diarrheal infection, and an initial MRI spine showed no evidence of abnormal enhancement. She was initially treated with intravenous immunoglobulins for presumed acute inflammatory demyelinating polyneuropathy. She then re-presented one week later with progressively worsening symptoms. A repeat MRI spine revealed a new longitudinally extensive T2 hyperintense signal within the dorsal columns from T7 to T12. CSF results were notable for mild pleocytosis and increased myelin basic protein; the latter of which is often seen in MTX-induced myelopathy. The patient received high-dose administration of key metabolites of the methyl-transfer pathway including S-adenosylmethionine (PO 400mg three times daily), folinate (IV 20mg four times daily), cyanocobalamin (PO 1000mcg once daily) and methionine (PO 5mg once daily) for 7 days. This treatment regimen resulted in both clinical and radiographic improvement. Subsequent MRI spine demonstrated complete resolution of the abnormal signal in the thoracic cord. This case highlights (1) the diagnostic complexity of IT MTX-induced myelopathy (2) the role response to treatment plays in uncovering this diagnosis, and (3) how the replacement of folate metabolites facilitates both radiographic and clinical improvement in IT MTX-induced myelopathy.

Genomic profiling of circulating tumor DNA for childhood cancers.

The utility of circulating tumor DNA (ctDNA) analysis has not been well-established for disease detection and monitoring of childhood cancers, especially leukemias. We developed PeCan-Seq, a deep sequencing method targeting diverse somatic genomic variants in cell-free samples in childhood cancer. Plasma samples were collected at diagnosis from 233 children with hematologic, solid and brain tumors. All children with hematologic malignancy (n = 177) had detectable ctDNA at diagnosis. The median ctDNA fraction was 0.77, and 97% of 789 expected tumor variants were identified, including sequence mutations, copy number variations, and structural variations responsible for oncogenic fusions. In contrast, ctDNA was detected in 19 of 38 solid tumor patients and 1 of 18 brain tumor patients. Somatic variants from ctDNA were correlated with minimal residual disease levels as determined by flow cytometry in serial plasma samples from patients with B-cell acute lymphoblastic leukemia (B-ALL). We showcase multi-tumor detection by ctDNA analysis for a patient with concurrent B-ALL and neuroblastoma. In conclusion, PeCan-seq sensitively identified heterogeneous ctDNA alterations from 1 mL plasma for childhood hematologic malignancies and a subset of solid tumors. PeCan-seq provides a robust, non-invasive approach to augment comprehensive genomic profiling at diagnosis and mutation-specific detection during disease monitoring.

FISH combined with RT-PCR facilitates classification of Chinese adult patients with B-other ALL through improved identification of ZNF384 rearrangement

ZNF384 gene rearrangements are a distinct subtype of adult B cell acute lymphoblastic leukemia (B-ALL). We screened 46 B-other ALL patients for ZNF384 fusions using fluorescent in situ hybridization (FISH) and reverse transcription-polymerase chain reaction (RT-PCR). Clinical data, treatment response, and minimal residual disease (MRD) status were analyzed. Ten (21.7%) patients were ZNF384-r positive (nine by FISH, nine by RT-PCR, eight by both). FISH showed atypical signals, including 3’ signal gain and 5’ signal deletion. EP300 was the main fusion partner (n = 5). TAF15::ZNF384, SYNRG::ZNF384, CREBBP::ZNF384, and TCF3::ZNF384 fusions were found in one patient each; one case’s partner gene is unknown. One patient was MRD-negative at the end of the first induction, lower than in patients without ZNF384-r. ZNF384-r incidence matched B-other ALL incidence in Chinese patients. Combined FISH and RT-PCR improved detection. ALL with ZNF384-r has unique features, and lower MRD-negative response may indicate a negative impact on traditional treatments.

The mechanisms of B-cell acute lymphoblastic leukemia relapsing following chimeric antigen receptor-T cell therapy; the plausible future strategies.

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.

Isolated peripheral neuroleukemiosis mimicking Guillain‐Barré syndrome in an adolescent with relapsed B‐lymphoblastic leukemia

AbstractBackgroundNeuroleukemiosis, leukemic infiltration of the peripheral nervous system (PNS), is rare. Very few cases of isolated neuroleukemiosis, PNS leukemic infiltration without leukemia blasts in the blood or bone marrow, have been reported in pediatrics. Most cases have occurred in adults with acute myelogenous leukemia (AML) in remission who presented with peripheral neuropathy. We describe a pediatric patient presenting with isolated neuroleukemiosis mimicking Guillain‐Barré syndrome.Patient descriptionA 15‐year‐old boy presented 1 month after IVIG treatment for Guillain‐Barre syndrome with worsening ataxia and weakness. He had a past medical history of B‐cell acute lymphoblastic leukemia (B‐ALL) in remission for 8 years. Examination revealed distal greater than proximal weakness of the bilateral lower extremities, areflexia at the Achilles tendon, and 1+ patellar and upper extremity reflexes. Initial magnetic resonance imaging (MRI) of the brain and spine were normal, and lumbar puncture revealed increased protein with uninterpretable white count due to excessive red blood cells. Repeat MRI brain and spinal cord showed extensive enlargement of all nerve roots and enhancement of the cauda equina and portions of cranial nerve VII bilaterally. Repeat lumbar puncture with cytology revealed leukemic blast cells. Blasts were not detected in peripheral blood smear or by flow cytometry. Bone marrow biopsy was also free of blast cells, confirming the diagnosis of relapsed B‐ALL restricted to the nervous system.ConclusionsNeuroleukemiosis is a rare entity with typical clinical features of mono‐ or polyneuropathy. It most often occurs in adults in remission from AML. However, neuroleukemiosis should also be on the differential for pediatric patients in remission from ALL presenting with neuropathy.

Venetoclax in combination with a pediatric-inspired regimen for the treatment of newly diagnosed adults with Philadelphia chromosome-negative acute lymphoblastic leukemia.

BCL-2 protein overexpression, common in B-cell acute lymphoblastic leukemia (B-ALL), including the Philadelphia (Ph)-like subtype, mediates leukemic cell survival. We treated 24 patients with 14 days of BCL-2 inhibitor, venetoclax, 400 mg daily (dose level 1) during induction and consolidation cycles combined with the CALGB 10403 regimen in newly diagnosed adults with Ph-negative B-ALL. Median age was 31 (range: 18-53) years, 92% were Hispanic, and 12 (50%) patients had Ph-like ALL. No dose limiting toxicity occurred in the phase 1 part. Median times to neutrophil and platelet count recovery were 20 and 21 days from start of induction, respectively. The most common grade ≥3 treatment-related adverse events were leukopenia (96%), neutropenia (83%), anemia (83%), thrombocytopenia (79%), lymphopenia (71%), hyperbilirubinemia (38%), and elevated ALT (33%). One patient with non-Ph-like ALL died from asparaginase-associated pancreatitis, and 23 (96%) patients achieved complete remission (CR) or CR with incomplete count recovery (CRi) following induction with or without extended induction phase. Of 22 patients who started consolidation, 20 (91%) achieved negative minimal residual disease status (MRD-) (.

YTHDC1 is a therapeutic target for B-cell acute lymphoblastic leukemia by attenuating DNA damage response through the KMT2C-H3K4me1/me3 epigenetic axis.

B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive malignancy characterized by the aberrant accumulation of immature and dysfunctional B cells in bone marrow (BM). Although chemotherapy and other therapies have been widely applied, some patients such as relapsed ordrug-refractory (R/R) B-ALL patients exhibit limited response. YT521-B homologous domain-containing protein 1 (YTHDC1) is a nuclear reader of N6-methyladenosine (m6A) RNA modification, which has been implicated in different malignancies including leukemia. In the current study, we show that YTHDC1 is highly expressed in B-ALL cells. YTHDC1 knockdown attenuated B-ALL cell proliferation and cell cycle progression in vitro, and prolonged survival of mice in the human B-ALL xenograft model in vivo attributable to compromised leukemogenesis. Mechanistically, YTHDC1 knockdown significantly increased the accumulation of endogenous and chemotherapeutic agents-induced DNA damage in B-ALL cells. Furthermore, we identified that YTHDC1 binds to and stabilizes m6A-modified KMT2C mRNA. KMT2C is a key enzyme catalyzing histone H3K4 methylation required for the expression of DNA damage response (DDR)-related genes, implying that YTHDC1 inhibitors might improve chemotherapy by attenuating DDR via reducing KMT2C. Indeed, with molecular docking and biochemical experiments, we identified EPZ-5676 as a YTHDC1 inhibitor, and combination of EPZ-5676 with Cytarabine (Ara-c) significantly improved the efficacy of chemotherapy in B-ALL mouse models using YTHDC1high primary and lined B-ALL cells. Collectively, YTHDC1 is required for DDR in B-ALL cells by upregulating DDR-related gene expression via stabilizing m6A-modified KMT2C mRNA, thereby leading to increased histone H3K4 methylation, and targeted inhibition of YTHDC1 is a potentially new therapeutic strategy against B-ALL, especially YTHDC1high B-ALL.

Acute pancreatitis following asparaginase treatment in pediatric acute lymphoblastic leukemia with a heterozygous SPINK1 c.194 + 2T>C intronic variant: a case report

BackgroundAsparaginase is a critical component of chemotherapy for pediatric acute lymphoblastic leukemia (ALL), but its use is often complicated by asparaginase-associated pancreatitis (AAP). Genetic predispositions, such as variants in the SPINK1 gene, have been linked to an increased risk of pancreatitis. However, the role of genetic factors in relation to asparaginase treatment remains incompletely understood, partly because mutations in pancreatitis-causing genes are rarely found in pediatric ALL.Case descriptionA four-year and three-month-old Chinese girl was admitted to our hospital due to fever for half a day, with no history of significant prior medical history. Initial blood tests revealed hematological abnormalities, including leukopenia, anemia, and thrombocytosis. Bone marrow aspiration identified 81.5% blast cells with B-lymphocyte morphology and immunophenotype, leading to a diagnosis of B-cell acute lymphoblastic leukemia (B-ALL). The patient began treatment under the CCCG-ALL-2015 protocol, which included PEG-asparaginase (PEG-asp). On day 10 of induction, she developed AAP, which was primarily characterized by severe epigastric pain and elevated serum amylase. Despite effective symptom management with analgesics and anti-inflammatory therapy, AAP recurred following administration of L-asparaginase (L-asp). Genetic analysis revealed a heterozygous SPINK1 c.194 + 2T>C variant (rs148954387), a well-known pathogenic variant associated with increased susceptibility to pancreatitis. Sanger sequencing confirmed that the SPINK1 variant was inherited from her asymptomatic mother. The patient's AAP was managed conservatively, and an asparaginase-free regimen ultimately achieved complete remission without recurrence of pancreatitis.ConclusionsThe identification of the SPINK1 c.194 + 2T>C variant, which is recognized as pathogenic, provides valuable information for understanding the heightened risk of AAP in our pediatric ALL patient. Our case underscores the potential role of genetic predisposition in the development of AAP and highlights the importance of considering genetic screening prior to asparaginase therapy in pediatric ALL patients to identify those at increased risk.

Clonal evolution from B-cell acute lymphoblastic leukemia with BCR::ABL1 multilineage involvement to acute myeloid leukemia after multiple anti-CD19 chimeric antigen receptor T-cell therapy.

Not available.

Outcomes of children and young adults with B-cell acute lymphoblastic leukemia given blinatumomab as last consolidation treatment before allogeneic hematopoietic stem cell transplantation.

Blinatumomab has remarkable efficacy in patients with relapsed/refractory (r/r) or measurable residual disease (MRD)-positive B-cell acute lymphoblastic leukemia (B-ALL). In many patients, blinatumomab treatment is followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, the influence of blinatumomab on HSCT outcomes in children and young adults (YA) remains to be fully elucidated. We conducted a single-center, retrospective analysis on patients given blinatumomab as last treatment before HSCT. Seventy-eight pediatric and YA patients were evaluated. With a median follow-up of 23.23 months, the 2-year disease-free (DFS) and overall survival (OS) probability were 72.2% and 89.2%, respectively, with a 2-year cumulative incidence (CI) of non-relapse mortality (NRM) of 2.6%. A trend toward improved 2-year DFS, but not OS, was noted in patients transplanted in first complete remission (CR1) (92.9%) compared to those in second or greater remission (CR2/3) (68.5%, p=0.18) due to a lower CI of relapse (0% vs. 29.9%, p=0.05). Among CR2/3 patients, those receiving the sequential combination of inotuzumab and blinatumomab had a significantly lower CI of relapse as compared to those who did not receive inotuzumab (9.5% vs. 40.4%, p=0.023). Relapse after HSCT occurred in 16 patients, all exhibiting CD19-positive blasts; 10 of them received anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy and 2 inotuzumab as salvage therapy, leading to a 2-year post-relapse OS of 52.7%. Our results indicate that HSCT following blinatumomab in children and YA with B-ALL is highly effective, being associated with low NRM and not affecting the efficacy of subsequent salvage immunotherapies, including CAR-T cells.

Characteristics and outcomes of therapy-related acute leukemia following autologous transplant (Auto-HCT) for multiple myeloma.

With a prolonging duration of survivorship, patients with multiple myeloma (MM) who receive high-dose chemotherapy and autologous hematopoietic stem cell transplantation (auto-HCT) have an increased risk of secondary malignancy, most concerning acute leukemia. We retrospectively reviewed the records of all patients with MM who underwent auto-HCT between January 1, 2010, and January 1, 2023, who later developed therapy-related acute leukemia (t-AL). Of 1770 patients with MM who underwent auto-HCT, 18 (1.01%) developed t-AL at a mean interval of 60.0 ± 41.3 months after auto-HCT. The patients with t-AL consisted of 9 (50%) with B-cell acute lymphoblastic leukemia (B-ALL), 8 (44.4%) with acute myeloid leukemia (AML), and 1 (5.6%) with acute promyelocytic leukemia (APML). All patients had received an alkylating agent as part of induction, and the majority received lenalidomide as maintenance therapy. Genetic abnormalities of t-AL were consistent with prior reports. Median overall survival from diagnosis of t-AL was 19.5 months. In patients with t-AL who entered CR, long term survival was common. Further research on predisposing conditions to developing t-AL in patients with MM undergoing auto-HCT is warranted.

FLAER Revealed Normally Expected Non-PNH FLAER-Dim Immature Myeloid Cells (CD117+/CD34-) In Bone Marrow Aspirates and Could Be Utilized as a Marker of Hierarchical Hematopoiesis.

Fluorescently labeled aerolysin (FLAER) is widely used for the identification of paroxysmal nocturnal hemoglobinuria (PNH) clones in peripheral blood (PB) samples. However, there are only a few reports on the differential fluorescent intensity of FLAER in normal bone marrow (BM) cell subpopulations. The purpose of this study was to evaluate FLAER expression during normal and pathological hematopoiesis, to map the critical existence of non-PNH FLAER-dim cells. A total of 54 BM aspirates were prospectively analyzed with FLAER-based flow cytometric (FC) protocols, during their routine work-up. These were obtained from patients with the following diagnoses: PNH (3), infections/reactive (5), myelodysplastic syndromes (MDS) (7), myelodysplastic/myeloproliferative neoplasms (MDS/MPN) (4), chronic myelogenous leukemia (CML) (3), acute myelogenous leukemia (AML) at diagnosis (20), AML in measurable residual disease (MRD) assessment (7), and B-cell acute lymphoblastic leukemia (B-ALL) in MRD assessment (5). The applied protocols consisted of FLAER, HLA-DR, CD14, CD33, CD34, CD66b, CD38, CD117, CD64, CD45, and FLAER, CD66c, CD14, CD33, CD34, CD66b, CD123, CD16, CD64, and CD45, respectively. FLAER expression was assessed in CD34++/CD38- and CD34+/CD38+ stem cells, CD34-/CD117+/HLA-DR+/CD33+ myeloid precursors, and CD64+/CD14-/HLA-DR+ monocyte precursors but also in mature myeloid cells. All patients revealed an intermediate FLAER intensity in CD34++/CD38- stem cells, with a discrete FLAER-negative subpopulation observed only in maturing CD34+/CD38+ stem cells of patients with PNH. The lowest FLAER intensity was noticed in CD34-/CD117+/HLA-DR+/CD33+ myeloid precursors, not only in patients with PNH but also in PNH-negative BM aspirates. An ascending FLAER intensity was further observed during monocytic and granulocytic maturation, with a discrete FLAER-negative population in CD64+/CD14-/HLA-DR+ monocyte precursors and maturing neutrophils and monocytes of patients with PNH only. The maturation pattern of FLAER expression was further confirmed in a patient with acute promyelocytic leukemia treated with all-trans retinoic acid (ATRA), where FLAER was concurrently upregulated with CD66b in a consecutive series of PB samples tested over a 20-day-period after diagnosis. The application of FLAER in PNH-positive and PNH-negative reactive or malignant BM aspirates identified normally expected non-PNH FLAER-dim CD34-/CD117+/HLA-DR+/CD33+ myeloid precursors in all samples. A specific FLAER-associated maturation pattern was observed, which is proposed for further study within MRD and diagnostic protocols.

BRAF V600E-Mutant Acute Myeloid Leukemia: A Case Series and Literature Review of a Rare Entity

Background: Although BRAF V600E mutations are common in solid tumors and select hematologic neoplasms, they are reported less frequently in myeloid malignancies. Of the cases of BRAF V600E-mutant acute myeloid leukemia (AML) that have been described, most display monocytic morphology and concurrent KMT2A rearrangement. Strikingly, all cases have been associated with poor survival. Case Presentation: Here, we report two cases of AML, one diagnosed in an elderly male with metastatic lung adenocarcinoma and hepatocellular carcinoma and the other diagnosed in a young boy previously treated for B-cell acute lymphoblastic leukemia. Peripheral blood NGS revealed oncogenic mutations in BRAF p.V600E (VAF = 33%), TET2 p.M508Cfs*25 (VAF = 48%), TET2 p.C211* (VAF = 49%), ZRSR2 p.R295* (VAF = 71%), BRAF p.N581S (VAF = 6%), and EZH2 c.118-2A>G, p.? (VAF = 4%) in case 1 and BRAF p.V600E (VAF = 1%) and KRAS p.G12A (VAF = 28%) in case 2. Cytogenetic workup revealed a complex karyotype in case 1 and an abnormal karyotype with non-clonal aberrations and KMT2A (MLL) rearrangement in case 2. Morphologically, both patients were found to have AML with monocytic features. The post-mortem examination of case 2 also revealed extensive solid organ infiltration, consistent with a monocytic leukemia. Both patients died within days of diagnosis, demonstrating the lethality of this molecular subgroup of AML. Conclusions: Our cases add to the literature, highlighting the poor prognosis of patients diagnosed with BRAF-mutant AML. Although it is uncertain whether the complex karyotype and somatic mutations observed in case 1 and KMT2A rearrangement and variants identified in case 2 may have either independently or cooperatively conferred a poor prognosis, we contend that additional comprehensive studies are needed to further understand the pathophysiology and prognosis of BRAF mutations in AML. We further posit whether patients with BRAF V600E-mutant AML may benefit from the combined use of BRAF inhibitors and/or RAS-pathway-targeting regimens, which are currently FDA-approved for the treatment of BRAF V600-mutant solid tumors and BRAF-mutant histiocytic neoplasms.

Distinct Immunophenotypes in the DNA Index-Based Stratification of Pediatric B-Cell Acute Lymphoblastic Leukemia.

B-cell acute lymphoblastic leukemia (B-ALL) presents a challenge in hematological malignancies due to its heterogeneity, which impacts treatment outcomes. Stratification based on the DNA index (DNAi) categorizes patients into favorable prognosis (hyperploid), standard prognosis (normoploid), and uncertain or poor prognosis (hypoploid) groups. In this study, we explored whether specific immunophenotypic markers are associated with each DNAi-based group and their potential connection to prognostic categories, aiming to provide new insights that may contribute to a better understanding of prognosis in B-ALL. In this study, we utilized flow cytometry to analyze immunophenotypic markers and combined this with DNA index (DNAi) measurements to stratify pediatric B-ALL patients into distinct risk categories. Our methodology focused on accurately classifying patients into hyperploid, normoploid, and hypoploid groups based on their DNA content, facilitating a comparative analysis of immunophenotypic characteristics across these groups. Our analysis revealed that hypoploid B-ALL patients displayed a significantly lower percentage of cells in the S phase of the cell cycle compared to normoploid and hyperploid groups. Additionally, distinct immunophenotypic profiles were observed in hypoploid patients, characterized by higher expression levels of HLA-DR and a notable co-expression of CD34 and CD22. This study found that hypoploid B-ALL patients have distinct characteristics, such as lower S-phase cell percentages and specific immunophenotypic profiles, including higher HLA-DR expression and CD34/CD22 co-expression. These differences across DNA index-based prognostic categories warrant further research to explore their potential prognostic significance.

Clinical implications of miRNAs in erythropoiesis, anemia, and other hematological disorders.

Erythropoiesis is regulated by the differential expression of many genes. Besides being transcriptionally regulated, these genes are also with the oath of epigenetic regulation by the microRNAs (miRNAs), in particular. Various miRNAs appear to be very important for the normal process of erythropoiesis and various hematological abnormalities in humans. Therefore, the review aims to summarize the significance of miRNAs in erythropoiesis and different hematological diseases with clinical importance. Our analysis indicates that specific miRNAs regulate erythropoiesis in a stage-specific manner from hematopoietic stem cells to differentiated erythrocytes. Further, many miRNAs have been reported to be linked with various hematological diseases. The importance of miRNAs as biomarkers or therapeutic drug targets for various hematological disorders like anemia, β-thalassemia, and leukemia has been revealed through various clinical studies and clinical trials. The miR-34a mimic and miR-155 inhibitor demonstrate promising therapeutic effects in various hematological malignancies. Additionally, miR-34a, miR-538e, miR-193e, and miR-198 exhibit diagnostic potential in acute myeloid leukemia, while miR-451, miR-151-5p, and miR-1290 show diagnostic potential in B-cell acute lymphoblastic leukemia. Thus, this review encompasses the latest observations and implications of specific miRNAs in erythropoiesis and various hematological disorders. However, challenges persist in developing safe and efficient delivery strategies to target miRNAs specifically, minimizing off-target effects and enhancing therapeutic outcomes. Future mechanistic pre-clinical and clinical research would contribute to overcoming these challenges.

T-Cell Immunoglobulin and Mucin Domain 3 (TIM-3) Gene Expression as a Negative Biomarker of B-Cell Acute Lymphoblastic Leukemia.

B-cell acute lymphoblastic leukemia (B-ALL) accounts for 85% of all childhood ALL. Malignancies exhaust T and B cells, resulting in an increased expression of immune checkpoint receptors (ICRs), such as T-cell immunoglobulin and mucin domain 3 (TIM-3). TIM-3 has been found to be dysregulated in different types of cancer. However, there is a lack of rigorous studies on the TIM-3 expression in B-ALL. The current study aimed to measure the expression of TIM-3 at the gene and protein levels and evaluate the potential of TIM-3 as a biomarker in B-ALL. A total of 28 subjects were recruited between 2021 and 2023, comprising 18 subjects diagnosed with B-ALL and 10 non-malignant healthy controls. The B-ALL patients were divided into three groups: newly diagnosed (four patients), in remission (nine patients), and relapse/refractory (five patients). The expression levels of TIM-3 were evaluated using the real-time qPCR and ELISA techniques. The results revealed that the TIM-3 expression was significantly downregulated in the malignant B-ALL patients compared to the non-malignant healthy controls in the mRNA (FC = -1.058 ± 0.3548, p = 0.0061) and protein blood serum (p = 0.0498) levels. A significant TIM-3 gene reduction was observed in the relapse/refractory cases (FC = -1.355 ± 0.4686, p = 0.0327). TIM-3 gene expression allowed for significant differentiation between patients with malignant B-ALL and non-malignant healthy controls, with an area under the curve (AUC) of 0.706. The current study addressed the potential of reduced levels of TIM-3 as a negative biomarker for B-ALL patients.

Outcomes After Brexucabtagene Autoleucel Administered as a Standard Therapy for Adults With Relapsed/Refractory B-Cell ALL.

On the basis of the results of the ZUMA-3 trial, brexucabtagene autoleucel (brexu-cel), a CD19-directed chimeric antigen receptor T-cell therapy, gained US Food and Drug Administration approval in October 2021 for adults with relapsed/refractory (R/R) B-cell ALL (B-ALL). We report outcomes of patients treated with brexu-cel as a standard therapy. We developed a collaboration across 31 US centers to study adults with B-ALL who received brexu-cel outside the context of a clinical trial. Data were collected retrospectively from October 2021 to October 2023. Toxicities were graded per American Society for Transplantation and Cellular Therapy guidelines for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). At the time of data lock, 204 patients had undergone apheresis and 189 were infused. Median follow-up time was 11.4 months. Forty-two percent of patients received brexu-cel in morphologic remission and would have been ineligible for participation in ZUMA-3. After brexu-cel, 151 achieved complete remission (CR), of which 79% were measurable residual disease (MRD) negative remissions. Median progression-free survival (PFS) was 9.5 months and median overall survival was not reached. Grade 3-4 CRS or ICANS occurred in 11% and 31%, respectively. In multivariable analysis, patients receiving consolidative hematopoietic cell transplantation (HCT; hazard ratio, 0.34 [95% CI, 0.14 to 0.85]) after brexu-cel had superior PFS compared with those who did not receive any consolidation or maintenance therapy. Similar to ZUMA-3, high rates of MRD-negative CR were observed after brexu-cel treatment for R/R B-ALL. The use of HCT as consolidation after brexu-cel resulted in improved PFS.

Development of an 18-color flow cytometry panel for B-lymphoblastic leukemia minimal residual disease detection

Abstract B-cell acute lymphoblastic leukemia (B-ALL) is characterized by a neoplastic proliferation of precursor B cells that have blast cytomorphology and immature immunophenotype. Following treatment of B-ALL, flow cytometry is utilized to detect minimal residual disease (MRD), which aids in monitoring therapeutic response and informing prognosis. In our institution, the BD FACSCanto cytometer is used in conjunction with two standardized 8-antibody EuroFlow panels to detect MRD in B-ALL patients. The objective of this study was to validate a new 18-color B-ALL MRD panel for bone marrow aspirate specimens to be run on a BD LSRFortessa cytometer, with the intention of improving sensitivity and consolidating the testing into one antibody panel. The proposed panel consisted of 22 antibodies, some of which were stacked within the same fluorescence channel, in addition to a viability stain. Twelve bone marrow aspirate specimens collected in 2023 (five positive and seven negative B-ALL MRD specimens) were stained with the new antibody panel and analyzed on the Fortessa cytometer. CD45 dim, CD19-positive blasts were analyzed using BD FACSDiva Software. For the five specimens previously reported as B-ALL MRD-positive using the EuroFlow panels, we were able to detect phenotypically identical B-ALL cells with the 18-color panel. A paired t-test done on the five MRD-positive specimens showed no significant difference in the percentage of residual B-ALL cells (out of total viable cells) measured by the 18-color panel when compared to the EuroFlow panels (EuroFlow/18-color: 0.0096%/0.0097%, 0.024%/0.012%, 0.94%/0.99%, 0.85%/0.85%, 0.022%/0.017%; p=0.58). All seven specimens that were previously reported as B-ALL MRD-negative using the EuroFlow panels were also negative for residual B-ALL cells when stained with the 18-color panel and analyzed on the Fortessa cytometer. The antibody cost per test of the EuroFlow panels ($20-$25, ~$44 for both panels) and new 18-color panel ($63) were calculated based on the unit cost of each antibody aliquot and the required volume of reagent per test. In summary, the new 18-color B-ALL MRD panel run on the BD LSRFortessa cytometer appears to provide similar results as the EuroFlow panels run on the BD FACSCanto cytometer. Although compared to the two EuroFlow panels, the single 18-color panel is more expensive per test in terms of antibodies, it may be preferable when there is scant tissue (such as cerebrospinal fluid) as there may not be enough material to run both EuroFlow panels.