Atypical BCR-ABL1 transcript in mixed phenotype acute leukemia with bone marrow necrosis.

Mixed phenotype acute leukemia (MPAL) is a type of acute leukemia in which encompasses mixed features of myeloid, T-lymphoid, and/or B-lymphoid differentiation. Philadelphia chromosome-positive (Ph+) MPAL is a rare subgroup with a poor prognosis and accounts for ＜1% of adult acute leukemia. Until now, there is still no consensus on how to best treat Ph+ MPAL. Here, we report a 62-year-old male with Ph+ (atypical e13a2 BCR-ABL1 fusion protein) MPAL. This patient presented with recurrent and intense bone pain due to bone marrow necrosis (BMN). Besides, he did not achieve a complete remission for the first two chemotherapies, until he received flumatinib combined with hyper-CVAD (B) (a dose-intensive regimen include methotrexate and cytarabine). To our knowledge, this is the first report to describe the coexistence of BMN and atypical e13a2 BCR-ABL1 transcripts in patients with MPAL. This finding will bring new understandings in the diagnosis and treatment of Ph+ MPAL.

Label-free cell detection of acute leukemia using ghost cytometry.

Early diagnosis and prompt initiation of appropriate treatment are critical for improving the prognosis of acute leukemia. Acute leukemia is diagnosed by microscopic morphological examination of bone marrow smears and flow cytometric immunophenotyping of bone marrow cells stained with fluorophore-conjugated antibodies. However, these diagnostic processes require trained professionals and are time and resource-intensive. Here, we present a novel diagnostic approach using ghost cytometry, a recently developed high-content flow cytometric approach, which enables machine vision-based, stain-free, high-speed analysis of cells, leveraging their detailed morphological information. We demonstrate that ghost cytometry can detect leukemic cells from the bone marrow cells of patients diagnosed with acute lymphoblastic leukemia and acute myeloid leukemia without relying on biological staining. The approach presented here holds promise as a precise, simple, swift, and cost-effective diagnostic method for acute leukemia in clinical practice.

Production of donor-derived cytotoxic T lymphocytes with potent anti-leukemia activity for adoptive immunotherapy in high-risk pediatric patients given haploidentical hematopoietic stem cell transplantation.

BACKGROUND AIMS: Somatic cell therapy based on the infusion of donor-derived cytotoxic T lymphocytes (CTL) able to recognize patients' leukemia blasts (LB) is a promising approach to control leukemia relapse after allogeneic HSCT. The success of this approach strongly depends on the ex vivo generation of high-quality donor-derived anti-leukemia CTL in compliance with Good Manufacturing Practices (GMP). We previously described a procedure for generating large numbers of donor-derived anti-leukemia CTL through stimulation of CD8-enriched lymphocytes with dendritic cells (DCs) pulsed with apoptotic LB in the presence of interleukin (IL)-12, IL-7 and IL-15. Here we report that the use of IFN-DC and the addition of IFNα2b during the priming phase significantly improve the generation of an efficient anti-leukemia T cells response in vitro. METHODS: Using this approach, 20 high-risk pediatric patients given haploidentical HSCT for high-risk acute leukemia were enrolled and 51 batches of advanced therapy medical products (ATMP), anti-leukemia CTL, were produced. RESULTS: Quality controls demonstrated that all batches were sterile, free of mycoplasma and conformed to acceptable endotoxin levels. Genotype analysis confirmed the molecular identity of the ATMP based on the starting biological material used for their production. The majority of ATMP were CD3+/CD8+ cells, with a memory/terminal activated phenotype, including T-central memory populations. ATMP were viable after thawing, and most ATMP batches displayed efficient capacity to lyse patients' LB and to secrete interferon-γ and tumor necrosis factor-α. CONCLUSIONS: These results demonstrated that our protocol is highly reproducible and allows the generation of large numbers of immunologically safe and functional anti-leukemia CTL with a high level of standardization.

Two novel assays demonstrate persistent daratumumab exposure in a pediatric patient with delayed engraftment following allogeneic hematopoietic stem cell transplantation.

BACKGROUND AIMS: Daratumumab, a human IgG monoclonal antibody targeting CD38, is a promising treatment for pediatric patients with relapsed or refractory T-cell acute lymphoblastic leukemia (T-ALL). We describe a case of delayed engraftment following a mismatched, unrelated donor hematopoietic stem cell transplant (HSCT) in a 14-year-old female with relapsed T-ALL, treated with daratumumab and chemotherapy. By Day 28 post-HSCT, the patient had no neutrophil engraftment but full donor myeloid chimerism. METHODS: We developed two novel, semi-quantitative, antibody-based assays to measure the patient's bound and plasma daratumumab levels to determine if prolonged drug exposure may have contributed to her slow engraftment. RESULTS: Daratumumab levels were significantly elevated more than 30 days after the patient's final infusion, and levels inversely correlated with her white blood cell counts. To clear daratumumab, the patient underwent several rounds of plasmapheresis and subsequently engrafted. CONCLUSIONS: This is the first report of both delayed daratumumab clearance and delayed stem cell engraftment following daratumumab treatment in a pediatric patient. Further investigation is needed to elucidate the optimal dosing of daratumumab for treatment of acute leukemias in pediatric populations as well as daratumumab's potential effects on hematopoietic stem cells and stem cell engraftment following allogenic HSCT.

Clinical characteristics of SARS-CoV-2 Omicron variant infection in children with acute leukemia.

Hematologic diseases and various therapeutic stages can impact the presentation of SARS-CoV-2 Omicron variant infection. This study retrospectively analyzed data on Omicron infection in children with acute leukemia treated at our hospital between January 16, 2023, and February 25, 2023, using questionnaires. The prevalence of Omicron infection in children undergoing consolidation chemotherapy, maintenance chemotherapy, drug withdrawal, and healthy children was 81.8%, 75.2%, 55.2%, and 61.9%, respectively. The observed differences were statistically significant (P < 0.05). During the course of infection, children with leukemia undergoing chemotherapy, including both the consolidation and maintenance chemotherapy groups, exhibited a prolonged time to achieve SARS-CoV-2 negativity compared to the drug withdrawal and healthy groups. However, there was no significant increase in the incidence of symptoms across all body systems, and no children experienced serious sequelae or death. Furthermore, our observations indicated that all manifestations of Omicron infection in children with leukemia after drug withdrawal were not significantly different from those in healthy children. This suggested, to a certain extent, that the immune function of children with leukemia recovers effectively after the cessation of drug treatment. These findings are crucial for guiding clinical management and alleviating concerns about infection for both children with leukemia and their parents.

Donor's age influences outcome in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide - a single center experience.

Haploidentical stem cell transplantation (haplo-SCT) using post-transplantation cyclophosphamide (post-Cy) is considered a reasonable therapeutic option for patients who lack matched donor or who urgently need transplant procedure due to high risk disease. We analyzed the results of haplo-SCT performed in years 2018-2023. Eighty one patients (46 males) at median age of 52 years underwent haplo-SCT using peripheral blood as a stem cell source in most cases. Indications included hematological malignancies (acute leukemias in 88% of cases). In 25 cases (31%) transplantation was performed in relapsed/refractory disease. Majority of patients (61%) presented with very high and high disease risk index (DRI). Conditioning regimens were as follows: nonmyeloablative - 46 cases (57%), myeloablative - in 18 (22%) and reduced intensity - 17(20%). 90% of patients engrafted. All patients received unified immunosuppressive treatment (post-Cy/TAC/MMF). Median follow-up time was 12 months The cumulative incidence of acute and chronic GVHD was 37.5% and 37.6%, respectively. Estimated 2-year overall survival (OS) was 43.1% and donor's age was the only factor influencing survival. The 2-year progression-free survival (PFS) was 42.5%, whereas relapse incidence (RI) - 35%. The cumulative incidence of non-relapse mortality (NRM) was 44% and was mostly due to infections. Haplo-SCT is a feasible treatment option for hematological patients. Younger donor improves post-transplant survival. Strategies to reduce infection-related mortality and relapse rate remain a challenge.

Outcomes of patients undergoing third hematopoietic cell transplantation for hematologic malignancies.

With advancements in novel therapeutics, it is unclear whether third hematopoietic cell transplantation (HCT3) has a place in the treatment of recurrent hematopoietic malignancies. We evaluated patients with hematologic malignancies who underwent HCT3 between 2000-2020. Nine patients, with a median age of 18 (9-68) years at HCT3 with acute myelogenous leukemia (n = 5), acute lymphoblastic leukemia (n = 2), myelodysplastic syndrome (n = 1), or undifferentiated acute leukemia (n = 1), were identified. The median time between first HCT and HCT3 was 3.9 (0.7-13.6) years. Indication for HCT3 was relapse (n = 8) or graft failure (n = 1) after second HCT. At HCT3, seven of nine patients were in complete remission by flow cytometry. All experienced robust donor engraftment by one month after HCT3 (≥ 90% CD3) while one died at day + 24 of multi-organ failure and was not evaluable for chimerism. In total, eight patients died from relapse (n = 4), non-relapse, (n = 3) or unknown (n = 1) causes at a median of 0.6 (range, 0.1 - 9.9) years after HCT3. After HCT3, estimated overall survival at 6 months, 1 year, and 5 years was 88%, 63%, and 22%, respectively. In this highly selected group, HCT3 provided a treatment option although long-term survival was still dismal.

Management of acute appendicitis in pediatric patients with acute leukemia: Insights from a single-center study.

Acute appendicitis (AA) in pediatric patients with acute leukemia mandates prompt treatment. Diagnosis presents challenges, relying on clinical and radiological assessments, often leading to treatment delays that may disrupt leukemia management. Our study on 14 such cases underscores the pivotal role of swift intervention. While conservative AA treatment may pose no risk to healthy children, our findings mandate the performance of laparoscopic appendectomy within 24 hours of diagnosis. This strategy yielded successful surgical outcomes while ensuring uninterrupted leukemia care. Our experience contributes important insights to the limited understanding of navigating this complex clinical scenario.

Detection of Hybrid Fusion Transcripts, Aberrant Transcript Expression, and Specific Single Nucleotide Variants in Acute Leukemia and Myeloid Disorders with Recurrent Gene Rearrangements.

INTRODUCTION: A variety of gene rearrangements and molecular alterations are key drivers in the pathobiology of acute leukemia and myeloid disorders; current classification systems increasingly incorporate these findings in diagnostic algorithms. Therefore, clinical laboratories require versatile tools, which can detect an increasing number and variety of molecular and cytogenetic alterations of clinical significance. METHODS: We validated an RNA-based next-generation sequencing (NGS) assay that enables the detection of: (i) numerous hybrid fusion transcripts (including rare/novel gene partners), (ii) aberrantly expressed EVI1 (MECOM) and IKZF1 (Del exons 4-7) transcripts, and (iii) hotspot variants in KIT, ABL1, NPM1 (relevant in the context of gene rearrangement status). RESULTS: For hybrid fusion transcripts, the assay showed 98-100% concordance for known positive and negative samples, with an analytical sensitivity (i.e., limit of detection) of approximately 0.8% cells. Samples with underlying EVI1 (MECOM) translocations demonstrated increased EVI1 (MECOM) expression. Aberrant IKZF1 (Del exons 4-7) transcripts detectable with the assay were also present on orthogonal reverse transcription PCR. Specific hotspot mutations in KIT, ABL1, and NPM1 detected with the assay showed 100% concordance with orthogonal testing. Lastly, several illustrative samples are included to highlight the assay's clinically relevant contributions to patient workup. CONCLUSION: Through its ability to simultaneously detect various gene rearrangements, aberrantly expressed transcripts, and hotspot mutations, this RNA-based NGS assay is a valuable tool for clinical laboratories to supplement other molecular and cytogenetic methods used in the diagnostic workup and in clinical research for patients with acute leukemia and myeloid disorders.

Assessing the impact of COVID-19 on acute leukemia patients: a comparative analysis of hematological and biochemical parameters.

BACKGROUND: The impact of COVID-19 infection on the blood system remains to be investigated, especially with those encountering hematological malignancies. It was found that a high proportion of cancer patients are at an elevated risk of encountering COVID-19 infection. Leukemic patients are often suppressed and immunocompromised, which would impact the pathology following COVID-19 infection. Therefore, this research aims to bring valuable insight into the mechanism by which COVID-19 infection influences the hematological and biochemical parameters of patients with acute leukemia. METHODS: This retrospective investigation uses repeated measures to examine changes in hematological and biochemical parameters among patients with acute leukemia before and after COVID-19 infection at a major Saudi tertiary center. The investigation was conducted at the Ministry of National Guard-Health Affairs in Riyadh, Saudi Arabia, on 24 acute leukemia patients with COVID-19 between April 2020 and July 2023. The impact of COVID-19 on clinical parameters, comorbidities, and laboratory values was evaluated using data obtained from the electronic health records at four designated time intervals. The relative importance of comorbidities, testing preferences, and significant predictors of survival was ascertained. RESULTS: The majority of leukemic COVID-19-infected patients, primarily detected through PCR tests, were diagnosed with acute lymphoblastic leukemia (70.8%). The hematological and biochemical parameters exhibited stability, except for a brief increase in ALT and a sustained rise in AST. These changes were not statistically significant, and parameters remained normal at all time points. Additionally, an increase in monocyte count was shown at time point-3, as well as platelet counts at time point 2. CONCLUSION: While this study did not detect statistically significant effects of COVID-19 on biochemical and hematological parameters in acute leukemia patients, further investigation is needed to fully understand the potential adverse reactions and modifications following COVID-19 infection.

Fluoroquinolone Prophylaxis during Conventional Chemotherapy or Hematopoietic Stem Cell Transplantation for Acute Leukemia - Pros and Cons.

BACKGROUND: Prophylaxis with fluoroquinolones (FQ) is commonly used in patients with acute leukemia (AL) during neutropenia. This practice is supported by an older meta-analysis reporting reduced mortality using FQ prophylaxis. Later meta-analyses have failed to reproduce this finding, presumably due to higher background FQ resistance rates limiting their effectiveness. SUMMARY: This article reviews the pros and cons of FQ prophylaxis mainly in patients with AL. Most current guidelines do not support universal prophylaxis but rather recommend a selective approach, weighing the benefits against the risks. This recommendation is based on the lack of mortality benefit reported in more recent meta-analyses. FQ prophylaxis was demonstrated to reduce bacteremia and febrile neutropenia episodes, although mostly in trials performed in low-resistance settings (<20%), whereas current FQ resistance rates may reach 30-60%. Other disadvantages of FQ include potential adverse events, antibiotic resistance development, cost, increase in Gram-positive infections and resistant Gram-negative infections following prophylaxis, Clostridioides difficile infection, and an effect on gut microbiota. KEY MESSAGES: Taking the above into consideration, alternative approaches other than universal FQ prophylaxis should be considered. Centers with high FQ resistance rates may consider either withholding prophylaxis or providing selective prophylaxis for high-risk patients screened negative for FQ-resistant bacteria.

Biologic and Clinical Characteristics of Isochromosome der(17)(q10)t(15;17) in Acute Promyelocytic Leukemia.

INTRODUCTION: Acute promyelocytic leukemia (APL) is genetically characterized by the fusion of promyelocytic leukemia (PML) gene with retinoic acid receptor alpha (RARα) resulting from a t(15;17)(q24;q21) chromosomal translocation. An infrequent but recurrent finding in APL is the formation of an isochromosome of the derivative chromosome 17; ider(17)(q10)t(15;17) or ider(17q). This rearrangement in APL results in an additional copy of the PML-RARα fusion gene as well as loss of 17p/TP53. Due to the infrequent occurrence of the ider(17q), the prognostic impact of this genetic finding is not well known. Case Presentation(s): Here, we describe the clinical characteristics and outcomes of our case series of 5 patients with ider(17q) APL treated at the University of Maryland and Johns Hopkins University. CONCLUSION: In our series, patients with APL with ider(17q) did not have a worse prognosis.

Changes in skeletal muscle function during chemotherapy and related factors in patients with acute leukemia.

INTRODUCTION: Skeletal muscle function is an important prognostically relevant indicator in patients with acute leukemia (AL), but skeletal dysfunction during chemotherapy is not well understood. This study aimed to investigate the factors that influence changes in skeletal muscle function from before the start of chemotherapy to before allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: This was a retrospective cohort study that included 90 patients with AL who underwent chemotherapy before transplantation to perform allo-HSCT (men, 67.3%; median age, 53 years). The outcome measure was defined as changes in skeletal muscle function from before chemotherapy to before allo-HSCT, and was assessed by measuring the psoas muscle index (PMI) as skeletal muscle quantity and computed tomography values (CTV) as skeletal muscle quality using a computed tomography scanner. We examined the differences in PMI and CTV before chemotherapy and allo-HSCT, and the factors associated with changes in PMI. RESULT: The mean PMI for before chemotherapy and allo-HSCT were 4.6 ± 1.4 cm2/m2 and 4.0 ± 1.3 cm2/m2 and significant differences were observed (p < 0.001). However, the mean CTV before chemotherapy and allo-HSCT were 47.3 ± 4.5 HU and 47.4 ± 5.0 HU, respectively, and no significant differences were found (p = 0.798). In stepwise multiple regression analysis, age and sex were identified as factors related to changes in PMI (age, p = 0.019; sex, p = 0.001). CONCLUSION: We found that skeletal muscle quantity decreased during chemotherapy in patients with AL and was influenced by male sex and older age. TRIAL REGISTRATION NUMBER:   TRIAL REGISTRATION NUMBER: 34-096(11,243). Date of registration: September 11, 2023.

Analysis of retinal and choroidal microvascular changes using optical coherence tomography and optical coherence tomography angiography in patients with acute leukemia.

PURPOSE: Although leukemic retinopathy accounts for 80% of ocular complications in acute leukemia, its pathogenesis remains unclear. To evaluate changes in retinal and choroicapillaris and structural parameters in patients with acute leukemia, we analyzed the correlation between vascular perfusion metrics and laboratory parameters and assessed the changes after hematopoietic stem cell transplantation (HSCT). METHODS: Herein, 104 eyes of 52 patients aged 18 and above with acute leukemia were enrolled. 80 eyes of 40 healthy patients were recruited as control participants. All participants underwent optical coherence tomography (OCT) and OCT angiography (OCTA) at baseline. RESULTS: Patients with acute leukemia had a significantly thicker ganglion cell-inner plexiform layer (GCIPL) and lower circularity index than the control participants. Post-HSCT perfusion metrics did not differ significantly, but parafoveal thickness decreased significantly. During the active phase of acute leukemia, lower platelet levels were associated with significant GCIPL thickening and increased foveal avascular zone and perimeter. D-dimer levels positively correlated with GCIPL thickness. CONCLUSION: Patients with acute leukemia had subclinical retinal microvascular deficits on OCTA and GCIPL thickening on OCT, possibly associated with bone marrow function. GCIPL thickness may indicate acute ischemia in such patients. Further studies must elucidate their clinical and prognostic significance.

Disseminated Basidiobolomycosis Caused by Basidiobolus omanensis in a Child with Acute Lymphoblastic Leukemia (ALL). Case Report and Literature Review.

Basidiobolomycosis is an uncommon fungal infection caused by the genus Basidiobolus. In immunocompetent children, it usually causes cutaneous infection and rarely affects the gastrointestinal tract, and it is extremely rare for the disease to spread. The present study reports the first case of disseminated basidiobolomycosis caused by Basidiobolus omanensis in a child with acute lymphoblastic leukemia who died as a result of uncontrolled infection and multi-organ failure despite surgical and antifungal therapy with L-AMB and voriconazole. A review of the literature yielded 76 cases, including the current case with the majority of which were reported as invasive gastrointestinal infection. The median age was 4 years (61 male and 15 female) and the majority of these children were from the Middle East (80%), specifically Saudi Arabia (45%). Most patients were treated with systemic antifungal agents (mostly itraconazole and amphotericin B). Surgical intervention was done in 25% of these patients and the death rate was 12%.

Biomarkers of Response to Venetoclax Therapy in Acute Myeloid Leukemia.

Recent progress in the use of massive sequencing technologies has greatly enhanced our understanding of acute myeloid leukemia (AML) pathology. This knowledge has in turn driven the development of targeted therapies, such as venetoclax, a BCL-2 inhibitor approved for use in combination with azacitidine, decitabine, or low-dose cytarabine for the treatment of newly diagnosed adult patients with AML who are not eligible for intensive chemotherapy. However, a significant number of AML patients still face the challenge of disease relapse. In this review, we will explore biomarkers that may predict disease progression in patients receiving venetoclax-based therapy, considering both clinical factors and genetic changes. Despite the many advances, we conclude that the identification of molecular profiles for AML patients who will respond optimally to venetoclax therapy remains an unmet clinical need.

Batimastat Induces Cytotoxic and Cytostatic Effects in In Vitro Models of Hematological Tumors.

The role of metalloproteinases (MMPs) in hematological malignancies, like acute myeloid leukemia (AML), myelodysplastic neoplasms (MDS), and multiple myeloma (MM), is well-documented, and these pathologies remain with poor outcomes despite treatment advancements. In this study, we investigated the effects of batimastat (BB-94), an MMP inhibitor (MMPi), in single-administration and daily administration schemes in AML, MDS, and MM cell lines. We used four hematologic neoplasia cell lines: the HL-60 and NB-4 cells as AML models, the F36-P cells as an MDS model, and the H929 cells as a model of MM. We also tested batimastat toxicity in a normal human lymphocyte cell line (IMC cells). BB-94 decreases cell viability and density in a dose-, time-, administration-scheme-, and cell-line-dependent manner, with the AML cells displaying higher responses. The efficacy in inducing apoptosis and cell cycle arrests is dependent on the cell line (higher effects in AML cells), especially with lower daily doses, which may mitigate treatment toxicity. Furthermore, BB-94 activated apoptosis via caspases and ERK1/2 pathways. These findings highlight batimastat's therapeutic potential in hematological malignancies, with daily dosing emerging as a strategy to minimize adverse effects.

Effectiveness of a family empowerment program on caregiving capacity and adverse mood in caregivers of children with acute leukemia: a quasi-experimental study.

BACKGROUND: Family-centered empowerment programs have been widely used in the pediatric field. Therefore, the current study investigated the effectiveness of family empowerment programs on caregiving ability and adverse mood among caregivers of children with acute leukemia. OBJECTIVE: To evaluate the effect of a family empowerment program on the caregiving ability and adverse mood of caregivers of children with acute leukemia. METHODS: Sixty-eight children with acute leukemia and their family caregivers admitted to our hospital were selected for the study. The control group received routine care during hospitalization, and the family empowerment program was implemented in the intervention group to compare the changes in caregiving capacity (FCTI), illness uncertainty (PPUS) and anxiety(SAS)of the caregivers of the two groups. RESULTS: After 8 weeks of intervention, the FCTI score of the intervention group was significantly lower than that of the control group (P < 0.001), and the difference between the scores before and after the intervention was statistically significant (P < 0.001); the PPUS score of the intervention group was significantly lower than that of the control group (P < 0.05), and the difference between the scores before and after the intervention was statistically significant (P < 0.001); the SAS score of the intervention group was lower than that of the control group after intervention(P < 0.05), and the score difference before and after intervention was statistically significant (P < 0.001). CONCLUSION: Family empowerment program is beneficial in improving caregiving capacity and reducing disease uncertainty and anxiety among caregivers of children with acute leukemia. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300073476 2023-07-12 Retrospectively registered.

Mixed-phenotype (B-lymphocytic/myeloid) acute leukemia with ETV6-ABL1 expression.

Objectives: Mixed-phenotype acute leukemia (MPAL) is rare in the clinic, accounting for approximately 2%-5% of acute leukemia cases. Methods: In this study the cohort included 126 patients, of which 125 cases were from re-examined published data and current patients from Shenzhen Longhua District Central Hospital, carrying an ETV6-ABL1 rearrangement from April 15, 2020 to December 19, 2020. The ETS variant transcription factor 6-Abelson proto-oncogene 1 (ETV6-ABL1) fusion gene is mainly seen in malignant hematological diseases such as acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), myeloproliferative neoplasms (MPNs). Positivity of both MPAL and ETV6-ABL1 suggest a poor prognosis. This is the first report of B lymphocytic/myeloid mixed-phenotype acute leukemia with ETV6-ABL1 fusion gene positivity. Complete remission was achieved with chemotherapy for lymphoid and myeloid leukemia and targeted therapy with tyrosine kinase inhibitors (TKIs). Results: The level of ETV6-ABL1/ABL decreased from 23.056% to 11.165%. After consolidation chemotherapy, the patient underwent allogeneic hematopoietic stem cell transplantation but died due to intestinal rejection. There are 126 cases of ETV6-ABL1 fusion gene transcript expression in numerous hematologic malignancies reported to date, including 48 cases of ALL, 12 of AML, and 65 of MPN. Eosinophilia is a common characteristic, especially in MPN patients. Conclusion: Survival analysis suggests that the survival time of ALL and MPN patients receiving TKI treatment is better than that of patients not receiving this treatment. Dasatinib or nilotinib, especially the former, is more effective than imatinib for MPN.

Combined proteomics and CRISPR‒Cas9 screens in PDX identify ADAM10 as essential for leukemia in vivo.

BACKGROUND: Acute leukemias represent deadly malignancies that require better treatment. As a challenge, treatment is counteracted by a microenvironment protecting dormant leukemia stem cells. METHODS: To identify responsible surface proteins, we performed deep proteome profiling on minute numbers of dormant patient-derived xenograft (PDX) leukemia stem cells isolated from mice. Candidates were functionally screened by establishing a comprehensive CRISPR‒Cas9 pipeline in PDX models in vivo. RESULTS: A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) was identified as an essential vulnerability required for the survival and growth of different types of acute leukemias in vivo, and reconstitution assays in PDX models confirmed the relevance of its sheddase activity. Of translational importance, molecular or pharmacological targeting of ADAM10 reduced PDX leukemia burden, cell homing to the murine bone marrow and stem cell frequency, and increased leukemia response to conventional chemotherapy in vivo. CONCLUSIONS: These findings identify ADAM10 as an attractive therapeutic target for the future treatment of acute leukemias.