The impact of Trifolium pratense extract on apoptosis and autophagy in NALM-6 cells: implications for B-ALL intervention.

B-cell acute lymphoblastic leukemia (B-ALL), a prevalent malignancy predominantly affecting children, poses challenges such as drug resistance and cytotoxicity despite available treatment methods. The persistence of these challenges underscores the necessity for innovative therapeutic approaches to enhance efficacy. Natural compounds derived from plants, recognized for their potential to inhibit cancer cell growth, have drawn attention. Trifolium pratense extract, known for its significant anticancer properties in previous studies, was the focus of this investigation. This experimental study aimed to explore the impact of T. pratense extract on apoptosis and autophagy in NALM-6 cells. The cells were exposed to varying concentrations of the extract at specific time intervals, with viability and metabolic activity assessed using Trypan blue exclusion and MTT assays. Flow cytometry was employed to evaluate apoptosis using Annexin V/PI staining and ROS production using DCFH-DA staining. Real-time PCR was used to quantify gene expression related to apoptosis, autophagy, and oxidative stress, with data analysis performed using GraphPad PRISM software. Trifolium pratense extract demonstrated the capacity to induce apoptosis, autophagy, and significantly increase ROS production in NALM-6 cells. These effects were facilitated by the upregulation of corresponding genes. The MTT assay revealed an IC50 of 231 µg/mL at 48 h, and Flow cytometry analysis showed a 51.8% increase in apoptosis in this cell line. Overall, this study emphasizes the effectiveness of T. pratense extract in inducing autophagy and apoptosis pathways in NALM-6 cells derived from B-cell acute lymphoblastic leukemia, suggesting its potential as a candidate for further investigation as a supplement in ALL treatment.

[Progress in therapy with L-asparaginase].

L-asparaginase is a key drug in the treatment of acute lymphocytic leukemia/lymphoblastic lymphoma and is currently used in treatment regimens for a wide range of age groups, including children, adolescents, young adults, and older adults. Discontinuation of L-asparaginase leads to worse survival outcomes. Strategies such as appropriate prevention and management of asparaginase-specific adverse events such as hypersensitivity reactions and optimizing administration by therapeutic drug monitoring are important to ensure completion of all asparaginase doses planned in each regimen. Two new L-asparaginase preparations with different properties are now available in Japan, and attempts to leverage these properties for more effective and safe administration are attracting attention. This article reviews previous advances in therapy with L-asparaginase and outlines current and future challenges for maximizing the therapeutic efficacy of L-asparaginase.

Psychiatric disorders among survivors of childhood acute lymphoblastic leukemia in Denmark and Sweden.

BACKGROUND: The diagnosis and treatment of childhood acute lymphoblastic leukemia (ALL) may impact mental health. We investigated the long-term risk of psychiatric disorders among survivors of ALL in a population-based cohort study. METHODS: We identified patients diagnosed with ALL in Denmark and Sweden before age 20 during 1982-2008. Survivors of ALL (n = 2026), their siblings (n = 3027), and population comparison subjects (n = 9713) were followed for hospital contacts for psychiatric disorders from 5 years after ALL diagnosis (or corresponding index date) until 2017. RESULTS: By age 30, the absolute risk of psychiatric hospital contacts was 19.9% (95% confidence interval [CI]: 17.9-22.1) for ALL survivors, 18.5% (95% CI: 16.9-20.2) for siblings, and 18.3% (95% CI: 17.3-19.2) for population comparison subjects. Overall, survivors were at higher risk of any psychiatric disorders than siblings (hazard ratio [HR] = 1.25; 95% CI: 1.04-1.50), and population comparison subjects (HR = 1.20; 95% CI: 1.06-1.35). The subgroup of survivors (n = 332) who received a hematopoietic stem cell transplantation (HSCT) and/or had a relapse were at highest risk of psychiatric disorders (HR = 2.07; 95% CI: 1.26-3.41 compared to siblings; HR = 1.67; 95% CI: 1.25-2.23 compared to population comparison subjects). CONCLUSIONS: The overall absolute risk of psychiatric hospital contacts among ALL survivors was close to that in siblings and population comparison subjects. The modestly increased relative risk was mainly driven by the subgroup of survivors who received HSCT and/or had a relapse. Our findings are reassuring for the large subgroup of ALL survivors without HSCT or relapse, and provide novel insight on both absolute and relative risk of hospital contacts for psychiatric disorders.

Fusion of Color Correction and HSV Segmentation Techniques for Automated Segmentation of Acute Lymphoblastic Leukemia.

This article presents an enhanced segmentation methodology for the accurate detection of acute lymphoblastic leukemia (ALL) in blood smear images. The proposed approach integrates color correction techniques with HSV color space segmentation to improve white blood cell analysis. Our method addresses common challenges in microscopic image processing, including sensor nonlinearity, uneven illumination, and color distortions. The key objectives of this study are to develop a robust preprocessing pipeline that normalizes blood smear images for consistent analysis, implement an HSV-based segmentation technique optimized for leukocyte detection, and validate the method's effectiveness across various ALL subtypes using clinical samples. The proposed technique was evaluated using real-world blood smear samples from ALL patients. Quantitative analysis demonstrates significant improvements in segmentation accuracy compared to traditional methods. Our approach shows strong capability in reliably detecting and segmenting ALL subtypes, offering the potential for enhanced diagnostic support in clinical settings.

Clinical effect of prophylactic pegfilgrastim in patients with newly diagnosed acute lymphoblastic leukemia who receive intensive chemotherapy.

BACKGROUND: Using granulocyte colony-stimulating factor (G-CSF) after completing chemotherapy reduces the duration of neutropenia and infections. However, the efficacy and safety of prophylactic pegfilgrastim in acute lymphoblastic leukemia (ALL) patients have not yet been evaluated after intensive cytotoxic chemotherapy compared to the daily G-CSF. This study aimed to evaluate the efficacy of pegfilgrastim for ALL patients who received intensive chemotherapy compared with a short-acting G-CSF. PATIENTS AND METHODS: Clinical data of 145 patients treated with hyper-CVAD, modified VPDL/VPD, or KALLA 1406/1407 regimen were retrospectively evaluated. Pegfilgrastim or the short-acting G-CSF was selected according to the clinician's discretion. Patients not receiving pegfilgrastim were treated with the short-acting G-CSF. RESULTS: The median age of enrolled patients was 45 years. Sixty newly diagnosed ALL patients were treated with hyper-CVAD regimen, while KALLA and VPDL regimens were administered to 39 and 46 patients, respectively. Among the 60 patients treated with hyper-CVAD, 20 patients received pegfilgrastim. Patients who received pegfilgrastim had a significantly shorter duration of neutropenia and hospitalization and reduced incidence of severe infections compared to patients receiving the short-acting G-CSF. Consistent results were also confirmed in an analysis targeting only patients who achieved remission during hyper-CVAD induction therapy. There was no significant difference in neutrophil recovery ability and hospitalization duration when the daily short-acting G-CSF was used prophylactically after completing hyper-CVAD, KALLA, and VPDL regimens as induction therapy. CONCLUSION: Using pegfilgrastim after hyper-CVAD therapy was more effective than the short-acting G-CSF in terms of infection, neutropenia recovery, and hospitalization in patients with newly diagnosed ALL.

Impact of pre-infusion disease burden on outcomes in pediatric relapsed/refractory B-cell lymphoblastic leukemia following anti-CD19 CAR T-cell therapy.

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapies have demonstrated high efficacy in pediatric patients with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Despite this success, the challenge of post-infusion relapse persists. In our study, we evaluate 116 children with R/R B-ALL who received anti-CD19 CAR T-cell therapy at our center. All patients were included in the response analysis and assessed for survival and toxicity. The CR rate was 98.3%, with 90.5% achieving minimal residual disease negative (MRD)- CR by day 28 (d28). The overall survival (OS) and event-free survival (EFS) were 69.3%±4.5% and 59.0%±4.6%, respectively, with a median follow-up duration of 47.9 months. The patients with pre-infusion MRD ≥ 1% was associated with lower 4-year OS (p = 0.006) and EFS (p = 0.027) comparing to those with MRD < 1%. The incidences of grade ≥ 3 cytokine release syndrome (CRS) and neurotoxicity were21.6 and 5.0%, respectively. Therefore, pre-infusion disease burden is a predictor of long-term outcome following anti-CD19 CAR T-cell therapy for pediatric R/R B-ALL.

Teenager with persistent facial edema and induration.

INTRODUCTION: Acute lymphoblastic leukemia (ALL) is the most common oncological disease in the pediatric population; however, skin infiltration occurs only in 1-3% of the patients and almost always manifests after the diagnosis is made. CLINICAL CASE: A male teenage patient who presented with facial edema and infiltration, associated with systemic symptoms such as asthenia and adynamia. On physical examination, the patient presented facial edema and indurated plaques, as well as cervical, inguinal, and axillary adenopathy. Complete blood count showed pancytopenia and a chest X-ray revealed a mediastinal mass. Due to a high suspicion of malignancy a bone marrow and skin biopsy was taken, both with pre-B ALL. Chemotherapy was started and the patient is now in maintenance phase. CONCLUSIONS: Leukemia cutis manifestations are heterogenous, from a small papule to a big nodule. It is more common in patients with acute myeloid leukemia and it is rare in patients with pre-B ALL, specially in the pediatric population. The diagnosis should be done with a biopsy and the treatment is with systemic chemotherapy. The diagnosis should always be considered in patients with unexplained edematous or indurated lesions, especially in the context of systemic symptoms.

INTRODUCCIÓN: La leucemia linfoblástica aguda es la enfermedad oncológica más común en la edad pediátrica; sin embargo, la infiltración a la piel solo ocurre en el 1-3% de los pacientes y se manifiesta habitualmente posterior al diagnóstico de leucemia. CASO CLÍNICO: Adolescente varón que acude a urgencias de nuestra unidad por presentar edema facial persistente, junto con astenia y adinamia. En la exploración física presenta edema facial con placas difusas induradas y adenopatía cervical, inguinal y axilar. Se decide realizar una biometría hemática, que muestra pancitopenia, y una radiografía de tórax, que revela una masa mediastinal. Por sospecha de malignidad se decide realizar una biopsia de médula ósea y de piel, dando como resultado leucemia linfoblástica pre-B en ambas. Se inició quimioterapia y actualmente se encuentra en fase de mantenimiento. CONCLUSIONES: Las manifestaciones clínicas de leucemia cutis son heterogéneas, desde una pápula pequeña hasta lesiones nodulares de diferentes tamaños. Lo más común es verlas en pacientes con leucemia mieloide aguda, y es muy raro en pacientes con leucemia linfoblástica aguda pre-B, especialmente en la edad pediátrica. El diagnóstico se realiza con una biopsia de piel y el tratamiento es con quimioterapia sistémica. Es importante tener en mente este diagnóstico en pacientes con síntomas sistémicos de leucemia.

The Road More or Less Traveled- Examining the Role of Consolidative Allogeneic Hematopoietic Stem Cell Transplantation After Chimeric Antigen Receptor T Cell Therapy in B-cell ALL.

Treatment with CD19-targeted chimeric antigen receptor T cell therapy (CD19-CART) has improved salvage rates in children and adults with relapsed and/or refractory B-cell acute lymphoblastic leukemia (ALL). However, not all patients treated with CD19-CAR T cells achieve long-term remission. The role of allogeneic hematopoietic stem cell transplantation as consolidative therapy remains undefined. We aim to review the current literature published to date regarding prognostic markers indicating durable ALL response to CD19-CART and risk factors for relapse after CD19-CART to identify patient cohorts who may benefit from consolidative hematopoietic stem cell transplantation.

Single-cell sequencing technology to characterize stem T-cell subpopulations in acute T-lymphoblastic leukemia and the role of stem T-cells in the disease process.

BACKGROUND: Precursor T-cell acute lymphoblastic leukemia (Pre-T ALL) is a malignant neoplastic disease in which T-cells proliferate in the bone marrow. Single-cell sequencing technology could identify characteristic cell types, facilitating the study of the therapeutic mechanisms in Pre-T ALL. METHODS: The single-cell sequencing data (scRNA-seq) of Pre-T ALL were obtained from public databases. Key immune cell subpopulations involved in the progression of Pre-T ALL were identified by clustering and annotating the cellular data using AUCell. Next, pseudo-temporal analysis was performed to identify the differentiation trajectories of immune cell subpopulations using Monocle. Copy number mutation landscape of cell subpopulations was characterized by inferCNV. Finally, cellphoneDB was used to analyze intercellular communication relationships. RESULTS: A total of 10 cellular subpopulations were classified, with Pre-T ALL showing a higher proportion of NK/T cells. NK/T cells were further clustered into two subpopulations. Stem T cells showed a high expression of marker genes related to hematopoietic stem cells, Naive T cells had a high expression of CCR7, CCR7, RCAN3, and NK cells high-expressed KLRD1, TRDC. The cell proliferation was reduced and the activation of T cell was increased during the differentiation of stem T cells to Naive T cells. We observed interaction between stem T cells with dendritic cells such as CD74-COPA, CD74-MIF as well as co-inhibition-related interactions such as LGALS9-HAVCR2, TGFB1-TGFBR3. CONCLUSION: Stem T cells were involved in the development of Pre-T-ALL through the regulatory effects of transcription factors (TFs) KLF2 and FOS and multiple ligand-receptor pairs.

Targeting telomerase with MST-312 leads to downregulation of CCND1, MDM2, MYC, and HSP90AA1 and induce apoptosis in Jurkat cell line.

Acute lymphoblastic leukemia is a challenging disease to treat, especially in older adults who are most commonly diagnosed and have a high risk of relapse, even with current treatment options. MST-312, targets the RNA component of telomerase, inhibiting its activity and leading to growth arrest and telomere shortening in cancer cells. This study aimed to investigate the effects of MST-312 on apoptosis rates and the expression of telomerase target genes, CCND1, MDM2, MYC, and HSP90AA1, in Jurkat cell line. Jurkat cell line was cultured and treated with various concentrations of MST-312(0 µM, 0.5 µM, 1 µM, 2 µM, and 4 µM). The optimal concentration of MST-312 was determined using MTT assay. Flow cytometry was employed to evaluate the apoptosis induced by MST-312 treatment. The expression levels of the target genes were measured using real-time polymerase chain reaction before and after the treatment with MST-312. P-value < 0.05 was considered statistically significant. The percentages of apoptotic cells after 48 h, as determined by flow cytometry analysis, were 30.32%, 52.35%, 57.60%, and 68.82%, respectively, compared to the control group which was 4.6%. The expression levels of all genes, including CCND1, MDM2, MYC, and HSP90AA1, were decreased compared to the control group. The results showed that MST-312 induced dose- and time-dependent apoptosis and downregulated the expression of CCND1, MDM2, MYC, and HSP90AA1in Jurkat cell line.

Mycovirus-Containing Aspergillus flavus Alters Transcription Factors in Normal and Acute Lymphoblastic Leukemia Cells.

Transcription factors control genes to maintain normal hemopoiesis, and dysregulation of some factors can lead to acute lymphoblastic leukemia (ALL). Mycoviruses are known to alter the genetics of their fungal host. The present study evaluates the effects of the products of a mycovirus-containing Aspergillus flavus (MCAF), isolated from the home of a patient with ALL, on certain transcription factors of normal and ALL cell lines. Our published studies have shown that ALL patients have antibodies to MCAF, and that exposure of the mononuclear leukocytes of patients in complete remission to its products, unlike controls, results in the re-development of genetic and cell surface phenotypes characteristic of ALL. For the present study, normal, pre-B, and B-cell leukemia cell lines were exposed to the culture of MCAF. Pre- and post-exposure levels of PAX5, Ikaros, and NF-κB were assessed. Exposure to MCAF resulted in apoptosis, cell cycle changes, and complete downregulation of all transcription factors in normal cell lines. In acute leukemia cell lines, cellular apoptosis and alterations in the cell cycle were also noted; however, while there was downregulation of all tested transcription factors, residual levels were retained. The noted alterations in the transcription factors caused by MCAF are novel findings. The possible role of MCAF in leukemogenesis needs to be further investigated. Mycovirus-containing Aspergillus flavus was initially isolated from a leukemia patient's home. Our prior published studies have illuminated intriguing associations of this organism with leukemia. Unlike controls, patients diagnosed with acute lymphoblastic leukemia (ALL) harbor antibodies to this organism. Furthermore, the exposure of mononuclear cells from patients with ALL in complete remission to the products of this organism reproduced genetic and cell phenotypes characteristic of ALL. These findings underscore the potential role of environmental factors in leukemogenesis and hint at novel avenues for therapeutic intervention and preventive strategies.

Microfluidic Affinity Selection of B-Lineage Cells from Peripheral Blood for Minimal Residual Disease Monitoring in Pediatric B-Type Acute Lymphoblastic Leukemia Patients.

Assessment of minimal residual disease (MRD) is the most powerful predictor of outcome in B-type acute lymphoblastic leukemia (B-ALL). MRD, defined as the presence of leukemic cells in the blood or bone marrow, is used for the evaluation of therapy efficacy. We report on a microfluidic-based MRD (MF-MRD) assay that allows for frequent evaluation of blood for the presence of circulating leukemia cells (CLCs). The microfluidic chip affinity selects B-lineage cells, including CLCs using anti-CD19 antibodies poised on the wall of the microfluidic chip. Affinity-selected cells are released from the capture surface and can be subjected to immunophenotyping to enumerate the CLCs, perform fluorescence in situ hybridization (FISH), and/or molecular analysis of the CLCs' mRNA/gDNA. During longitudinal testing of 20 patients throughout induction and consolidation therapy, the MF-MRD performed 116 tests, while only 41 were completed with multiparameter flow cytometry (MFC-MRD) using a bone marrow aspirate, as standard-of-care. Overall, 57% MF-MRD tests were MRD(+) as defined by CLC numbers exceeding a threshold of 5 × 10-4%, which was determined to be the limit of quantitation. Above a threshold of 0.01%, MFC-MRD was positive in 34% of patients. The MF offered the advantage of the opportunity for efficiently processing small volumes of blood (2 mL), which is important in the care of pediatric patients, especially infants. The minimally invasive means of blood collection are of high value when treating patients whose MRD is typically tested using an invasive bone marrow biopsy. MF-MRD detection can be useful for stratification of patients into risk groups and monitoring of patient well-being after completion of treatment for early recognition of potential impending disease recurrence.

Application of Gene Expression Microarray for the Classification of Ph-Like B-Cell Acute Lymphoblastic Leukemia.

INTRODUCTION: Ph-like ALL has gene expression profile similar to Ph-positive ALL but without the BCR::ABL1 fusion. The disease presents higher rates of severe clinical features and is associated with unfavorable outcomes. There is still no standard pipeline for molecular characterization of the disease, and no valid predictor gene panel is available worldwide. METHODS: We performed expression microarray on 25 B-cell ALL and 6 Ph-positive B-cell ALL to cluster and identify the transcriptional signature of Ph-like ALL. qRT-PCR was used to confirm the expression of candidate genes. RESULTS: Four out of 25 samples (16%) shared gene expression signatures related to and clustered with control Ph-positive samples. Analysis of genes differentially expressed in Ph-like B-cell ALL and evidentially functional in normal blood cell development and leukemogenesis, we selected genes as potential biomarkers for Ph-like B-cell ALL in our dataset: ADGRE2, CD9, EPHA7, FAM129C, TCL1A, and VPREB1. Those genes were filtered by Ph-like gene signatures obtained from distinct reliable data, resulting in five genes, CA6, CHN2, JAK1, JCHAIN, and PON2, selected for validation by qRT-PCR. The Ct values of genes, including CA6 (p = 0.0017), PON2 (p = 0.0210), TCL1A (p = 0.0064), and VPREB1 (p = 0.0338), were significant in Ph-like ALL. GSEA analysis identified VPREB1 as enrichment in the KRAS signaling pathway, and several genes that interact with VPREB1 were reported as critical molecules involved in the leukemogenesis of B-cell ALL. CONCLUSION: In summary, we demonstrate using a gene expression microarray for classifying Ph-like B-cell ALL and highlight VPREB1 as a potential biomarker for this disease.

Enhancer looping protein LDB1 modulates MYB expression in T-ALL cell lines in vitro by cooperating with master transcription factors.

BACKGROUND: Despite significant progress in the prognosis of pediatric T-cell acute lymphoblastic leukemia (T-ALL) in recent decades, a notable portion of children still confronts challenges such as treatment resistance and recurrence, leading to limited options and a poor prognosis. LIM domain-binding protein 1 (LDB1) has been confirmed to exert a crucial role in various physiological and pathological processes. In our research, we aim to elucidate the underlying function and mechanisms of LDB1 within the background of T-ALL. METHODS: Employing short hairpin RNA (shRNA) techniques, we delineated the functional impact of LDB1 in T-ALL cell lines. Through the application of RNA-Seq, CUT&Tag, and immunoprecipitation assays, we scrutinized master transcription factors cooperating with LDB1 and identified downstream targets under LDB1 regulation. RESULTS: LDB1 emerges as a critical transcription factor co-activator in cell lines derived from T-ALL. It primarily collaborates with master transcription factors (ERG, ETV6, IRF1) to cooperatively regulate the transcription of downstream target genes. Both in vitro and in vivo experiments affirm the essential fuction of LDB1 in the proliferation and survival of cell lines derived from T-ALL, with MYB identified as a significant downstream target of LDB1. CONCLUSIONS: To sum up, our research establishes the pivotal fuction of LDB1 in the tumorigenesis and progression of T-ALL cell lines. Mechanistic insights reveal that LDB1 cooperates with ERG, ETV6, and IRF1 to modulate the expression of downstream effector genes. Furthermore, LDB1 controls MYB through remote enhancer modulation, providing valuable mechanistic insights into its involvement in the progression of T-ALL.

The significance of MRD-based strategy by dynamic assessment to guide treatment decisions in B-ALL - the enlightenment provided by demonstrating survival differences in the retrospective study.

PURPOSE: The study aimed to access the impact of related factors on the long-term survival of patients with B-cell acute lymphoblastic leukemia (B-ALL) by analyzing clinical characteristics of B-ALL patients, and observed the significance of dynamic measurable residual disease (MRD) assessment for the prognosis and treatment selection of B-ALL patients, aiming to deepen the understanding of the disease and improve the survival prognosis of B-ALL patients. METHODS: The clinical characteristics of 65 patients with B-ALL were collected to calculate the median overall survival (OS) and median disease-free survival (PFS), and to evaluate the significance of survival analysis guided by dynamic MRD assessment. RESULTS: The survival analysis based on dynamic MRD assessment suggested that B-ALL patients who maintained MRD negative status during dynamic assessment after induction chemotherapy had better survival outcomes in the comparison of progression-free survival between subgroups, with statistically significant differences (P = 0.0002 (HR: 0.26, 95% CI: 0.13-0.51)). High-risk B-ALL patients who maintained negative MRD status during dynamic assessment after induction chemotherapy had longer median progression - free survival, and the survival difference between subgroups was statistically significant (P = 0.0016 (HR: 0.28, 95% CI: 0.09-0.48)). CONCLUSION: Dynamic MRD assessment had significant clinical value: maintaining negative MRD status during dynamic assessment can improve the prognosis and survival of B-ALL patients; dynamic MRD assessment after induction chemotherapy can help guide subsequent treatment, which could provide reference for the advancement of future treatment strategies.

Case report: sub-clinical extramedullary B-ALL in the setting of relapse following targeted therapy.

Standard testing for disease evaluation in B-cell acute lymphoblastic leukemia (B-ALL) includes examination of the bone marrow and cerebrospinal fluid. Radiographic or functional imaging are indicated when clinical signs of non-CNS extramedullary disease are present but are not standard in the relapsed/refractory setting. We describe two cases of patients with relapsed/refractory B-ALL with prior exposure to blinatumomab and/or inotuzumab ozogamicin presenting for CAR-T cell treatment. Both patients were thought to only have minimal residual disease (MRD) at the pre-CAR disease assessment, with MRD of 6,648 (0.66%) and 100 (0.01%) cells per million cells, respectively, as measured by next-generation sequencing (NGS) in their bone marrows. Both patients for distinct reasons unrelated to non-CNS extra-medullary (EM) symptoms had PET-MRIs prior to lymphodepletion and CAR T cell infusion. In both cases patients were found to have significant bulky subclinical EM disease that required changes in clinical management. In the newly-emergent era of antigen-targeted immunotherapy, it is foundational that incidence and relapse patterns following targeted therapy are well-understood. Herein we contribute to a growing body of literature addressing this fundamental clinical gap and highlight a future role for formal prospective imaging studies to better establish response, toxicity and relapse patterns following CAR-T cell therapy in EM B-ALL.

Selected stem cell populations in pediatric acute lymphoblastic leukemia.

Introduction: Acute lymphoblastic leukemia is characterized by a disturbed maturation of hematopoietic stem cells (HSCs) resulting in development of a malignant clone. Despite relatively positive outcome, there are still instances of disease relapse occurring due to ineffective disease eradication or primary leukemic clone alterations. Unclear significance of stem cells in the course of ALL led us to investigate and establish crucial changes in two stem cell populations - very small embryonic-like stem cells (VSELs) and HSCs during the induction phase of treatment. Methods: In a retrospective study selected stem cells in peripheral blood and bone marrow of 60 pediatric ALL subjects and 48 healthy controls were subjected to flow cytometric analysis at 4 different time points. Results: Both VSELs and HSCs were elevated at the moment of ALL diagnosis compared to healthy controls, but profoundly decline until day 15. Further observations revealed an increase in HSCs with a concomitant depletion of VSELs until week 12. ALL patients with high HSCs showed positive correlation with bone marrow blasts at diagnosis. Patients with lower VSELs or HSCs at diagnosis had slightly improved response to applied therapy. We observed higher initial bone marrow lymphoblast values in patients with lower VSELs or higher HSCs in the high-risk group. The significance of VSELs in predicting treatment outcome can be illustrated by lower day 15 MRD level of patients with lower VSELs at diagnosis. Discussion: We found HSCs and VSELs to be valid participants in pediatric ALL with possible contribution in the neoplastic process and prediction of initial treatment outcome.

Adult Philadelphia-Positive Acute Lymphoblastic Leukemia: A Single-Institution Experience in Limited-Resource Setting.

L. K. RajeevBackground Adult Philadelphia-positive (Ph + ) acute lymphoblastic leukemia (ALL) is a distinct entity with poor prognosis. Treatment with tyrosine kinase inhibitors improved responses but still with poor outcomes. We evaluated treatment outcomes in these patients treated in limited-resource settings in the absence of availability of allogeneic stem cell transplantation (ASCT). Materials and Methods We studied case record files of the adult patients diagnosed with Ph+ ALL. Results A total of 18 patients were evaluated retrospectively. The median age of presentation was 28 years. Male-to-female ratio was 1:1. Patients presented with fever and fatigue. Six patients (33.33%) presented with cervical lymphadenopathy. Clinical splenomegaly was present in 16 (88.88%) patients on palpation, whereas on ultrasonographic evaluation, all 18 patients had splenomegaly. The median size of the spleen was 15 cm. Hepatomegaly was seen in 5 (27%) patients. All 18 patients had anemia at the time of presentation. Leukocytosis was seen in 17 (94.44%) patients, whereas 1 (5.56%) patient presented with low total leukocyte count. The median platelet count at the time of presentation was 30,000/mm. 3 On peripheral smear, median number of blast cells was 55%, and on bone marrow aspiration samples, median blast percentage seen was 70%. Conventional cytogenetics was done in all the patients on bone marrow aspiration samples. Ten patients (55.55%) had t(9;22) - Ph chromosome. One patient (5.56%) on cytogenetics showed double Ph chromosome. The median value of breakpoint cluster region-ABL1 transcript in IS% was 13%. Seventeen (94.44%) received ALL protocol (BFM95) along with tyrosine kinase inhibitor (imatinib). One (5.56%) patient refused aggressive cytotoxic chemotherapy. No patient underwent ASCT. The median duration of follow-up was 7.5 months, ranging from 3 to 16 months. Median overall survival (OS) was 7.5 months and 2-year OS was 33.33%. Conclusion Poor prognosis of this disease, especially in the absence of ASCT, remains a major challenge in the treatment.

Prophylactic Cranial Irradiation prior to HCT for Acute Lymphoblastic Leukemia: To Boost or Not To Boost.

Background: Total body irradiation (TBI) with or without cranial radiation boost (CRB) is an integral component of conditioning prior to allogeneic hematopoietic cell transplantation (allo-HCT) in acute lymphoblastic leukemia (ALL). The benefit of CRB is not yet established. Methods: This is a retrospective single center cohort study. Between January of 2003 and April of 2019, electronic medical records of 166 patients with ALL were retrospectively reviewed. One hundred forty-three patients with ALL and no prior central nervous system (CNS) involvement were included. Patients were divided into two cohorts according to cranial radiation boost (cohort-1: CNS-/CRB+ (110/143, 77%) and cohort-2: CNS-/CRB- (n=33/143; 23%). No patients received post-transplant prophylactic intrathecal chemotherapy. Results: Following alloHCT, 15 patients (10.5%) experienced relapse; 11 relapses (10%) in cohort-1, and 4 (12%) in cohort-2. Four patients (26.6%) experienced systemic medullary relapse with initial central nervous system (CNS) involvement. One patient (6.6%) experienced isolated first central nervous system relapse after allotransplant with no difference between the two cohorts (6.6% vs 0; P-0.59). Age at transplant and phenotypic subtype were predictive of first central nervous system relapse after allotransplant with respective P-values of 0.001 and 0.015.At a median follow-up of 30 months (range: 2.5-128 months), the estimated 3-year overall survival was 61% (95% CI: 53-69), relapse free survival was 60% (95% CI: 52-69) and 3-year central nervous system-relapse-free survival was 99% and 100% in in cohort-1 and cohort-2 respectively, when systemic relapses were censored. There was no statistical significant difference in either survival or relapse free survival between the two cohorts (P > 0.69). Conclusions: Our results suggest that augmenting total body irradiation with cranial radiation boost in patients with ALL with no prior CNS involvement did not improve relapse risk in central nervous system or survival outcomes.

Peripheral Blood Neutrophil Nadir and Time to Platelet Recovery during Induction Chemotherapy: Predictors of Clinical Outcomes and Markers for Optimizing Induction Treatment Intensity in Acute Lymphoblastic Leukemia.

OBJECTIVE: To study the kinetics of blood count nadir and time to recovery and find its association with clinical outcomes in a cohort of Acute Lymphoblastic Leukemia (ALL). METHODS: Data from 243 cases treated between January 2018 to December 2020 was retrospectively analysed. Along with baseline data, serial measures of peripheral blood counts, nadir, and time to partial and complete recovery of counts during course of induction chemotherapy were recorded. Post-induction Complete Remission (CR) status, Event-Free Survival (EFS) , and Overall Survival (OS) were recorded as clinical outcomes for analysis. RESULTS: Median age was 15 (range,1-62) years. Immunophenotype was B-ALL in 71% (n=172), and T-ALL in 27% (n=66). Good steroid response (D8) was seen in 89%(n=216), CR in 79% (n=192), and induction mortality in 12% (n=29). Median neutrophil nadir was 0.06(0-0.49) *109/L and median day to nadir was D17. Median time to partial and complete platelet recovery was D18 and D25. Late neutrophil nadir (>D15) was independent predictor of refractory disease post-induction [OR=5.43 (95%CI 1.06-27.75)]. Late partial platelet recovery (>D22) was independent predictor of poorer EFS and OS [HR = 1.63 (95%CI 1.07-2.47)] and [HR = 1.5 (95% CI 1-2.4)] respectively. CONCLUSION: We found that a longer time to neutrophil nadir independently predicts refractory disease post-induction and late partial platelet recovery is an independent factor for poorer EFS and OS. Thus, Blood count kinetics as independent predictors of induction outcomes can provide a simple, easy-to-use tool for balancing toxicity-efficacy during induction therapy for ALL.