Hematopoietic stem cell transplantation for acute myeloid leukemia

Impact of "day 90" CD4+ T cells on clinical outcomes in children with relapsed/refractory acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

The severity of complications after hematopoietic stem cell transplantation (HSCT) is dictated by the degree of immune reconstitution. However, the connection between immune reconstitution and the prognosis of pediatric patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. Therefore, the aim of this study was to evaluate the impact of lymphocyte subsets in children diagnosed with refractory or relapsed acute myeloid leukemia (R/R-AML) after allo-HSCT.

METHODS

We retrospectively investigated the prognosis and lymphocyte subsets at d 90 (D90) post-allo-HSCT in 130 children diagnosed with R/R-AML between September 2019 and October 2022 at the Children's Hospital of Soochow University. Lymphocyte subgroups were assessed by flow cytometric analysis on D90 and compared among human leukocyte antigen (HLA)-matched sibling donor HSCT (MSD) (n = 14), haploidentical donor HSCT (n = 94), and HLA-matched unrelated donor HSCT (n = 22) groups. The associations between the counts and frequencies of lymphocyte subgroups and prognosis were assessed.

RESULTS

In the MSD group, CD4+ T cell frequency and count were the highest (P < 0.001). Among the examined lymphocyte subsets, a lower proportion of CD4+ T cells (<14.535 %) at D90 correlated with a higher risk of cytomegalovirus infection (P = 0.002). A higher CD4+ T cell count (>121.39/μL) at D90 after HSCT was the single predictor of a lower fatality risk across all lymphocyte subgroups (univariate: P = 0.038 cut-off: 121.39/μL; multivariate: P = 0.036). No association with relapse was observed.

CONCLUSIONS

CD4+ T cell count may be used to identify pediatric patients with R/R-AML with a greater mortality risk early after HSCT.

Finding potential targets in cell-based immunotherapy for handling the challenges of acute myeloid leukemia

Acute myeloid leukemia (AML) is a hostile hematological malignancy under great danger of relapse and poor long-term survival rates, despite recent therapeutic advancements. To deal with this unfulfilled clinical necessity, innovative cell-based immunotherapies have surfaced as promising approaches to improve anti-tumor immunity and enhance patient outcomes. In this comprehensive review, we provide a detailed examination of the latest developments in cell-based immunotherapies for AML, including chimeric antigen receptor (CAR) T-cell therapy, T-cell receptor (TCR)-engineered T-cell therapy, and natural killer (NK) cell-based therapies. We critically evaluate the unique mechanisms of action, current challenges, and evolving strategies to improve the efficacy and safety of these modalities. The review emphasizes how promising these cutting-edge immune-based strategies are in overcoming the inherent complexities and heterogeneity of AML. We discuss the identification of optimal target antigens, the importance of mitigating on-target/off-tumor toxicity, and the need to enhance the persistence and functionality of engineered immune effector cells. All things considered, this review offers a thorough overview of the rapidly evolving field of cell-based immunotherapy for AML, underscoring the significant progress made and the ongoing efforts to translate these innovative approaches into more effective and durable treatments for this devastating disease.

The prophylactic application of low-dose rabbit antithymocyte globulin in matched siblings HSCT with high-risk factors for graft-versus-host disease

Relapse and graft-versus-host disease (GVHD) are currently the predominant causes of mortality post allogeneic hematopoietic stem cell transplantation (allo-HSCT). The contentious use of antithymocyte globulin (ATG) for preventing GVHD in matched sibling HSCT scenarios has been a topic of significant debate. A retrospective analysis was conducted on matched sibling HSCT cases with high-risk factors for GVHD in our center from January 2018 to June 2023. Our assessment revealed that the group administered with ATG exhibited a 30 % incidence of acute GVHD (aGVHD), in contrast to 81.8 % in the non-ATG cohort (P = 0.037) among matched sibling HSCT cases with high GVHD risk factors. Furthermore, chronic GVHD (cGVHD) occurred in 20 % of the ATG group and 72.7 % of the non-ATG group (P = 0.03). Notably, the administration of ATG did not significantly impact disease relapse (p = 0.149), infection rates (p = 0.64), granulocyte recovery time (p = 0.15), platelet recovery time (p = 0.12), overall survival (p = 0.889), or disease-free survival time (p = 0.787). The use of rabbit antithymocyte globulin (r-ATG) at a 5 mg/kg dosage demonstrated a notable reduction in aGVHD and cGVHD incidences within sibling matched HSCT cases with high-risk factors for GVHD, without increasing rates of disease recurrence or infections. These findings highlight the potential benefit of using low-dose r-ATG in high-risk of GVHD sibling matched allogeneic HSCTs, although further validation with a larger cohort is necessary.

Pretransplant desensitization of donor-specific anti-HLA antibodies with plasmapheresis and immunoglobulin produces equivalent outcomes to patients with no donor specific antibodies in haploidentical hematopoietic cell transplant

Haploidentical hematopoietic cell transplants (haplo-HCT) with donor-specific anti-HLA antibodies (DSAs) are associated with high rates of primary graft failure and poor overall survival (OS). Limited data exists regarding the effect of desensitization. Our institution began routine desensitization for patients with DSAs in 2014. Adult patients undergoing haplo-HCT at Washington University from 2009-2021 were identified and divided into three cohorts: no DSA, untreated DSA (2009-2014) or treated DSA (2014-2021). Desensitization therapy using plasmapheresis and IVIg was performed. Retrospectively, 304 patients were identified. 14 of 30 patients with DSAs underwent desensitization. By day +2, 57% of patients cleared all DSAs. After multivariable analysis, OS was similar between treated DSA and no DSA (HR: 0.69, p = 0.37). Untreated DSA had significantly lower OS compared to no DSA group (HR 1.80, p = 0.046). Desensitization with a backbone of plasmapheresis and IVIg before haplo-HCT may produce similar outcomes to patients without DSAs.

LILRB4 in acute myeloid leukemia: From prognostic biomarker to immunotherapeutic target

ABSTRACT

Leukocyte immunoglobulin-like receptor (LILR) B4 (also known as ILT3/CD85k) is an immune checkpoint protein that is highly expressed in solid tumors and hematological malignancies and plays a significant role in the pathophysiology of cancer. LILRB4 is highly expressed in acute myeloid leukemia (AML), and this phenotype is associated with adverse patient outcomes. Its differential expression in tumors compared to normal tissues, its presence in tumor stem cells, and its multifaceted roles in tumorigenesis position it as a promising therapeutic target in AML. Currently, several immunotherapies targeting LILRB4 are undergoing clinical trials. This review summarizes advancements made in the study of LILRB4 in AML, focusing on its structure, ligands, expression, and significance in normal tissues and AML; its protumorigenic effects and mechanisms in AML; and the application of LILRB4-targeted therapies in AML. These insights highlight the potential advantages of LILRB4 as an immunotherapeutic target in the context of AML.

CAR'TCR-T cells co-expressing CD33-CAR and dNPM1-TCR as superior dual-targeting approach for AML treatment

Acute myeloid leukemia (AML), a fast-progressing hematological malignancy affecting myeloid cells, is typically treated with chemotherapy or hematopoietic stem cell transplantation. However, approximately half of the patients face relapses and 5-year survival rates are poor. With the goal to facilitate dual-specificity, boosting anti-tumor activity, and minimizing the risk for antigen escape, this study focused on combining chimeric antigen receptor (CAR) and T cell receptor (TCR) technologies. CAR'TCR-T cells, co-expressing a CD33-CAR and a transgenic dNPM1-TCR, revealed increased and prolonged anti-tumor activity in vitro, particularly in case of low target antigen expression. The distinct transcriptomic profile suggested enhanced formation of immunological synapses, activation, and signaling. Complete elimination of AML xenografts in vivo was only achieved with a cell product containing CAR'TCR-T, CAR-T, and TCR-T cells, representing the outcome of co-transduction with two lentiviral vectors encoding either CAR or TCR. A mixture of CAR-T and TCR-T cells, without CAR'TCR-T cells, did not prevent progressive tumor outgrowth and was comparable to treatment with CAR-T and TCR-T cells individually. Overall, our data underscore the efficacy of co-expressing CAR and transgenic TCR in one T cell, and might open a novel therapeutic avenue not only for AML but also other malignancies.

Recent Advances in Material Technology for Leukemia Treatments

Leukemia is a widespread hematological malignancy characterized by an elevated white blood cell count in both the blood and the bone marrow. Despite notable advancements in leukemia intervention in the clinic, a large proportion of patients, especially acute leukemia patients, fail to achieve long-term remission or complete remission following treatment. Therefore, leukemia therapy necessitates optimization to meet the treatment requirements. In recent years, a multitude of materials have undergone rigorous study to serve as delivery vectors or direct intervention agents to bolster the effectiveness of leukemia therapy. These materials include liposomes, protein-based materials, polymeric materials, cell-derived materials, and inorganic materials. They possess unique characteristics and are applied in a broad array of therapeutic modalities, including chemotherapy, gene therapy, immunotherapy, radiotherapy, hematopoietic stem cell transplantation, and other evolving treatments. Here, an overview of these materials is presented, describing their physicochemical properties, their role in leukemia treatment, and the challenges they face in the context of clinical translation. This review inspires researchers to further develop various materials that can be used to augment the efficacy of multiple therapeutic modalities for novel applications in leukemia treatment.

Comparison of allo-SCT, auto-SCT and chemotherapy for the treatment of patients with low- or intermediate-risk acute myeloid leukemia: a network meta-analysis

BACKGROUND

The therapeutic status of allogeneic stem cell transplantation (allo-SCT) as a post-remission treatment for patients with high-risk acute myeloid leukemia (AML) was well-accepted. However, the optimal treatment for patients with low/favorable- or intermediate-risk AML who achieve complete remission has remained controversial. Therefore, we conducted a network meta-analysis to discuss this disputed problem.

METHODS

We compared the effects of treatment strategies including allo-SCT, autologous stem cell transplantation (auto-SCT) and consolidation chemotherapy (CT) for patients with low/favorable- or intermediate-risk AML. The pooled HRs and 95% CIs for overall survival and disease-free survival were estimated with Stata12 and R software. Thirty clinical studies with 6682 patients were included in the meta-analysis.

RESULTS

The results indicated that the treatment outcome of allo-SCT was the best, followed by auto-SCT, and CT was likely the worst in the total AML patients. In patients with low/favorable-risk AML, the treatment outcome of auto-SCT was likely ranked first, followed by allo-SCT, and CT was the worst. In patients with intermediate-risk AML, the treatment outcome of haploidentical stem cell transplantation (haplo-SCT) was the best, followed by allo-SCT (excluding haplo-SCT), and auto-SCT and CT were the worst. However, the median age of the haplo-SCT group was much younger than that of the control group, which may be one of the reasons for the better prognosis of the haplo-SCT group.

CONCLUSIONS

Patients with low/favorable- and intermediate-risk (non-high-risk) AML should prioritize allo-SCT if they are eligible for transplantation, and auto-SCT is optional. However, in the subgroup analysis, auto-SCT was the optimal treatment choice for patients with low/favorable-risk AML, and allo-SCT was the priority selection for patients with intermediate-risk AML, especially young patients. These findings could provide references for clinical practice.

The remission status of AML patients after allo-HCT is associated with a distinct single-cell bone marrow T-cell signature

ABSTRACT

Acute myeloid leukemia (AML) is a hematologic malignancy for which allogeneic hematopoietic cell transplantation (allo-HCT) often remains the only curative therapeutic approach. However, incapability of T cells to recognize and eliminate residual leukemia stem cells might lead to an insufficient graft-versus-leukemia (GVL) effect and relapse. Here, we performed single-cell RNA-sequencing (scRNA-seq) on bone marrow (BM) T lymphocytes and CD34+ cells of 6 patients with AML 100 days after allo-HCT to identify T-cell signatures associated with either imminent relapse (REL) or durable complete remission (CR). We observed a higher frequency of cytotoxic CD8+ effector and gamma delta (γδ) T cells in CR vs REL samples. Pseudotime and gene regulatory network analyses revealed that CR CD8+ T cells were more advanced in maturation and had a stronger cytotoxicity signature, whereas REL samples were characterized by inflammatory tumor necrosis factor/NF-κB signaling and an immunosuppressive milieu. We identified ADGRG1/GPR56 as a surface marker enriched in CR CD8+ T cells and confirmed in a CD33-directed chimeric antigen receptor T cell/AML coculture model that GPR56 becomes upregulated on T cells upon antigen encounter and elimination of AML cells. We show that GPR56 continuously increases at the protein level on CD8+ T cells after allo-HCT and confirm faster interferon gamma (IFN-γ) secretion upon re-exposure to matched, but not unmatched, recipient AML cells in the GPR56+ vs GPR56- CD8+ T-cell fraction. Together, our data provide a single-cell reference map of BM-derived T cells after allo-HCT and propose GPR56 expression dynamics as a surrogate for antigen encounter after allo-HCT.

Phosphoproteomic Characterization and Kinase Signature Predict Response to Venetoclax Plus 3+7 Chemotherapy in Acute Myeloid Leukemia

Resistance to chemotherapy remains a formidable obstacle in acute myeloid leukemia (AML) therapeutic management, necessitating the exploration of optimal strategies to maximize therapeutic benefits. Venetoclax with 3+7 daunorubicin and cytarabine (DAV regimen) in young adult de novo AML patients is evaluated. 90% of treated patients achieved complete remission, underscoring the potential of this regimen as a compelling therapeutic intervention. To elucidate underlying mechanisms governing response to DAV in AML, quantitative phosphoproteomics to discern distinct molecular signatures characterizing a subset of DAV-sensitive patients is used. Cluster analysis reveals an enrichment of phosphoproteins implicated in chromatin organization and RNA processing within DAV-susceptible and DA-resistant AML patients. Furthermore, kinase activity profiling identifies AURKB as a candidate indicator of DAV regimen efficacy in DA-resistant AML due to AURKB activation. Intriguingly, AML cells overexpressing AURKB exhibit attenuated MCL-1 expression, rendering them receptive to DAV treatment and maintaining them resistant to DA treatment. Moreover, the dataset delineates a shared kinase, AKT1, associated with DAV response. Notably, AKT1 inhibition augments the antileukemic efficacy of DAV treatment in AML. Overall, this phosphoproteomic study identifies the role of AURKB as a predictive biomarker for DA, but not DAV, resistance and proposes a promising strategy to counteract therapy resistance in AML.

Pretransplant Desensitization of Donor-Specific Anti-HLA Antibodies with Plasmapheresis and Immunoglobulin Produces Equivalent Outcomes to Patients with No Donor Specific Antibodies in Haploidentical Hematopoietic Cell Transplant

In patients requiring haploidentical hematopoietic cell transplant (haplo-HCT), the presence of donor specific anti-HLA antibodies (DSAs) is associated with high rates of primary graft failure and poor overall survival (OS). There is limited data regarding the effect of desensitization. Adult patients undergoing haplo-HCT at Washington University School of Medicine from 2009-2021 were identified. Patients were divided into three cohorts: no DSA, untreated DSA or treated DSA. DSA testing was performed. Desensitization therapy using plasmapheresis and IVIg (immunoglobulin) was performed. We retrospectively identified 304 patients for study inclusion. 14 of 30 patients with DSAs underwent desensitization. By day +2, 57% of patients cleared all DSAs. OS was expectedly worse in patients with untreated DSAs. There were similar results between treated DSA and patients without DSA (OS median: control: 352 days vs. treated: 1331 days vs. untreated: 137 days, p = 0.02). RFS was also significantly different between the groups however with similar RFS in treated DSA and control groups (RFS median: control: 248 vs. treated: 322 v. untreated: 119, p = 0.03). Desensitization before haplo-HCT produces similar outcomes to patients without DSAs. While the optimal desensitization protocol has not been established, all patients received a backbone of plasmapheresis and immunoglobulin.

Downregulation of RCN1 promotes pyroptosis in acute myeloid leukemia cells

Reticulocalbin-1 (RCN1) is expressed aberrantly and at a high level in various tumors, including acute myeloid leukemia (AML), yet its impact on AML remains unclear. In this study, we demonstrate that RCN1 knockdown significantly suppresses the viability of bone marrow mononuclear cells (BMMNCs) from AML patients but does not affect the viability of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSCs) from healthy donors in vitro. Downregulation of RCN1 also reduces the viability of AML cell lines. Further studies showed that the RCN1 knockdown upregulates type I interferon (IFN-1) expression and promotes AML cell pyroptosis through caspase-1 and gasdermin D (GSDMD) signaling. Deletion of the mouse Rcn1 gene inhibits the viability of mouse AML cell lines but not the hematopoiesis of mouse bone marrow. In addition, RCN1 downregulation in human AML cells significantly inhibited tumor growth in the NSG mouse xenograft model. Taken together, our results suggest that RCN1 may be a potential target for AML therapy.

KMT2A is targeted by miR-361-3p and modulates leukemia cell's abilities to proliferate, migrate and invade

OBJECTIVE

The lives and safety of humans are significantly threatened by acute myeloid leukemia (AML), which is proven to be the most prevalent acute leukemia. This work is therefore intended to investigate and analyze the expressions of miR-361-3p and Histone Lysine Methyltransferase 2A (KMT2A) in tissues and cell lines of AML and identify an advanced and novel target for the therapy of AML.

METHODS

The qRT-PCR and western blot assays were conducted to find expressions of miR-361-3p/KMT2A in AML PB and cell lines. After then, tests using CCK-8 and EdU were run to see how KMT2A affected the growth of AML cells. Transwell migration and invasion assay was conducted to evaluate KMT2A's contribution to the migration and invasion of AML cells. ENCORI and miRWalk predicted the association between KMT2A and miR-361-3p, and the dual-luciferase reporter experiment verified it. Furthermore, rescue studies were used to ascertain how KMT2A affected the miR-361-3p-regulated AML cells' abilities to proliferate, migrate, and invade.

RESULTS

miR-361-3p was poorly expressed while KMT2A was abundantly expressed. Additionally, KMT2A downregulation prevented AML cells from proliferating. PCNA and Ki-67 protein levels fell when KMT2A was silent. Furthermore, AML cells' motility, invasion, and metastasis were inhibited by low KMT2A expression. KMT2A was also identified as a direct target of miR-361-3p and negatively correlated with miR-361-3p. Finally, the over-expression of KMT2A partially reversed the inhibitory effects of up-regulation of miR-361-3p.

CONCLUSION

A potential therapeutic candidate target for the treatment of AML may be miR-361-3p/KMT2A.

Corneal Descemetocele Management with Multi-Layer Amniotic Membrane Transplantation in an Ocular Graft-versus-Host Disease Case

Background: Chronic ocular graft-versus-host disease (oGVHD) is a common ocular complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT), characterized by progressive inflammation of the ocular surface and refractory dry eye. In severe cases, sterile corneal perforation can occur, which poses a significant challenge, due to the low survival rate of grafts after corneal transplantation. Case Presentation: A 47-year-old female presented to our hospital with persistent dryness, foreign body sensation, and blurred vision in her left eye. Diagnosis of graft-versus-host disease with corneal descemetocele in the left eye was made after detailed history review and thorough examination. Multi-layer amniotic membrane transplantation was performed in the affected eye, resulting in amelioration of the patient's symptoms. This amelioration of symptoms provided the patient with a level of comfort that permitted additional time while awaiting corneal transplantation. Conclusions: We report a successful case of multi-layer amniotic membrane transplantation for the management of corneal descemetocele following allo-HSCT.

Live-Cell Glycocalyx Engineering

A heavy layer of glycans forms a brush matrix bound to the outside of all the cells in our bodies; it is referred to as the "sugar forest" or glycocalyx. Beyond the increased appreciation of the glycocalyx over the past two decades, recent advances in engineering the glycocalyx on live cells have spurred the creation of cellular drugs and novel medical treatments. The development of new tools and techniques has empowered scientists to manipulate the structures and functions of cell-surface glycans on target cells and endow target cells with desired properties. Herein, we provide an overview of live-cell glycocalyx engineering strategies for controlling the cell-surface molecular repertory to suit therapeutic applications, even though the realm of this field remains young and largely unexplored.

Antibody therapies for the treatment of acute myeloid leukemia: exploring current and emerging therapeutic targets

INTRODUCTION

Acute myeloid leukemia (AML) is the most common and deadly type of leukemia affecting adults. It is typically managed with rounds of non-targeted chemotherapy followed by hematopoietic stem cell transplants, but this is only possible in patients who can tolerate these harsh treatments and many are elderly and frail. With the identification of novel tumor-specific cell surface receptors, there is great conviction that targeted antibody therapies will soon become available for these patients.

AREAS COVERED

In this review, we describe the current landscape of known target receptors for monospecific and bispecific antibody-based therapeutics for AML. Here, we characterize each of the receptors and targeted antibody-based therapeutics in development, illustrating the rational design behind each therapeutic compound. We then discuss the bispecific antibodies in development and how they improve immune surveillance of AML. For each therapeutic, we also summarize the available pre-clinical and clinical data, including data from discontinued trials.

EXPERT OPINION

One antibody-based therapeutic has already been approved for AML treatment, the CD33-targeting antibody-drug conjugate, gemtuzumab ozogamicin. Many more are currently in pre-clinical and clinical studies. These antibody-based therapeutics can perform tumor-specific, elaborate cytotoxic functions and there is growing confidence they will soon lead to personalized, safe AML treatment options that induce durable remissions.

Endocrine sequelae of hematopoietic stem cell transplantation: Effects on mineral homeostasis and bone metabolism

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic strategy for the treatment of malignant (leukemia and lymphoma) and non-malignant (thalassemia, anemia, and immunodeficiency) hematopoietic diseases. Thanks to the improvement in patient care and the development of more tolerable conditioning treatments, which has extended the applicability of therapy to the elderly, a growing number of patients have successfully benefited from HSCT therapy and, more importantly, HSCT transplant-related mortality has consistently reduced in recent years. However, concomitantly to long term patient survival, a growing incidence of late HSCT-related sequelae has been reported, being variably associated with negative effects on quality of life of patients and having a non-negligible impact on healthcare systems. The most predominantly observed HSCT-caused complications are chronic alterations of the endocrine system and metabolism, which endanger post-operative quality of life and increase morbidity and mortality of transplanted patients. Here, we specifically review the current knowledge on HSCT-derived side-effects on the perturbation of mineral metabolism; in particular, the homeostasis of calcium, focusing on current reports regarding osteoporosis and recurrent renal dysfunctions that have been observed in a percentage of HSC-transplanted patients. Possible secondary implications of conditioning treatments for HSCT on the physiology of the parathyroid glands and calcium homeostasis, alone or in association with HSCT-caused renal and bone defects, are critically discussed as well.

Twist1 Promoter Methylation Regulates the Proliferation and Apoptosis of Acute Myeloid Leukemia Cells via PI3K/AKT Pathway

Twist-related protein 1 (Twist1) is a widely recognized oncogene in acute myeloid leukemia (AML), and its promoter methylation is related with the progression of solid tumors. However, the association between Twist1 promoter methylation and AML has not been well studied. Twist1 mRNA expression was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of Twist1 and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signal were measured via western blotting. Methylation-specific PCR was performed to detect the methylation status of Twist1 promoter. CCK-8 assay and flow cytometry were used to reveal cellular biological effects. Twist1 expression and promoter methylation level were significantly upregulated in AML tissues and cell lines and were further downregulated in demethylating agent 5'-azacitidine (5-Aza)-treated cells. Ectopic expression of Twist1 increased AML cell viability, while reducing apoptosis, and attenuated the effects of 5-Aza on the proliferation and apoptosis. We also found that the PI3K/AKT signaling pathway was positively regulated by Twist1. Our findings revealed that Twist1 accelerates the tumorigenesis of AML cells by promoting its promoter methylation via the activation of PI3K/AKT signaling pathway.

Impact on Outcome of Minimal Residual Disease after Hematopoietic Stem Cell Transplantation with Fludarabine, Amsacrine, and Cytosine Arabinoside-Busulfan Conditioning: A Retrospective Monocentric Study

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) after conditioning with a sequential association of fludarabine, amsacrine, and cytosine arabinoside (FLAMSA) followed by a reduced-intensity conditioning regimen has emerged for patients with high-risk acute myeloid leukemia (AML), especially in refractory or relapsing patients. Here we aimed to address retrospectively the impact of pretransplantation minimal residual disease (MRD) by flow cytometry on the outcomes of high-risk AML patients who underwent allo-HSCT after sequential FLAMSA-busulfan (FLAMSA-Bu)-based conditioning regimens. We included 165 high-risk AML patients who underwent transplantation after FLAMSA-BU in this retrospective single-center "real life" study. All patients received in vivo T cell depletion with antithymocyte globulin (5 mg/kg). MRD detection was based on a leukemia-associated immunophenotype using the European LeukemiaNet recommendations, with a threshold of .1%. Univariate and multivariate analyses were performed using R version 4.1.1 (R Foundation for Statistical Computing, Vienna, Austria). With a median follow-up of 4.0 years post-transplantation, the median overall survival (OS) was 54.9 months. Overall, 41 patients (24.8%) relapsed post-transplantation, with a resulting cumulative incidence of relapse (CIR) of 26.7% at 2 years and 34.0% at 5 years. Detectable MRD preceding allo-HSCT and refractory status were associated with worse median OS and CIR rates compared with patients without detectable MRD; however, OS was not significantly different between pre-HSCT MRD-positive and refractory patients (median, .7 year versus 2.0 years; P = .3). Conversely, pre-HSCT MRD negativity was associated with a reduced 2-year CIR. Neither European LeukemiaNet risk stratification nor age had a significant influence on OS. In the multivariate analysis, only pre-HSCT MRD positivity and lower conditioning regimen intensity were significantly associated with a poorer OS. The cumulative incidence of extensive chronic graft-versus-host disease at 2 years was 26.15%. The estimated nonrelapse mortality (NRM) of the entire cohort at 2 years was 23.1%, with age and unrelated donor identified as risk factors for higher NRM. Our data ahow that FLAMSA-Bu conditioning did not reverse the pejorative effect of detectable pre-HSCT MRD, suggesting that such patients should be offered alternative strategies before HSCT to reach deeper remission.

Emerging roles of circRNAs in leukemia and the clinical prospects: An update

BACKGROUND

Circular RNAs (circRNAs) are a new category of endogenous non-protein coding RNAs (ncRNAs), and show the characteristics of high conservation, stability, and tissue specificity. Due to rapid advances in next-generation sequencing and transcriptome profiling technologies, circRNAs have been widely discovered in many organisms and participated in the development and progress of a variety of diseases. As a type of molecular sponge, circRNAs mainly absorb micro RNAs competitively and interplay with RNA-binding proteins to modulate the splicing as well as transcription of target genes.

METHODS

This review is based on a literature search using the Medline database. Search terms used were "circular RNAs and leukemia," "circRNAs and leukemia," "circRNAs and acute lymphoblastic leukemia," "circRNAs and chronic lymphoblastic leukemia," "circRNAs and acute myeloid leukemia," "circRNAs and chronic myeloid leukemia," and "circRNAs, biomarker, and hematological system."

RESULTS

CircRNAs have been proven as potential biomarkers and therapeutic targets in a variety of tumors. Recent research has found that circRNAs aberrantly exist in hematological cancers, especially leukemia, and are significantly associated with the incidence, progress, and metastasis of diseases as well as the prognosis of patients.

CONCLUSION

The current work summarizes the latest findings on circRNAs in various types of leukemia, aiming to propose prospective therapies and new drug screening methods for the treatment of leukemia.

Ferroptosis in hematological malignant tumors

Ferroptosis is a kind of iron-dependent programmed cell death discovered in recent years. Its main feature is the accumulation of lipid reactive oxygen species in cells, eventually leading to oxidative stress and cell death. It plays a pivotal role in normal physical conditions and the occurrence and development of various diseases. Studies have shown that tumor cells of the blood system, such as leukemia cells and lymphoma cells, are sensitive to the response to ferroptosis. Regulators that modulate the Ferroptosis pathway can accelerate or inhibit tumor disease progression. This article reviews the mechanism of ferroptosis and its research status in hematological malignancies. Understanding the mechanisms of ferroptosis could provide practical guidance for treating and preventing these dreaded diseases.

Inflammatory-driven NK cell maturation and its impact on pathology

NK cells are innate lymphocytes involved in a large variety of contexts and are crucial in the immunity to intracellular pathogens as well as cancer due to their ability to kill infected or malignant cells. Thus, they harbor a strong potential for clinical and therapeutic use. NK cells do not require antigen exposure to get activated; their functional response is rather based on a balance between inhibitory/activating signals and on the diversity of germline-encoded receptors they express. In order to reach optimal functional status, NK cells go through a step-wise development in the bone marrow before their egress, and dissemination into peripheral organs via the circulation. In this review, we summarize bone marrow NK cell developmental stages and list key factors involved in their differentiation before presenting newly discovered and emerging factors that regulate NK cell central and peripheral maturation. Lastly, we focus on the impact inflammatory contexts themselves can have on NK cell development and functional maturation.

Early diagnostic value of liver stiffness measurement in hepatic sinusoidal obstruction syndrome induced by hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT)-sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease, is a clinical syndrome characterized by symptoms, such as right upper quadrant pain, jaundice, fluid retention, and hepatomegaly, and is caused by pre-treatment-related hepatotoxicity during the early stages after HSCT. Clinical diagnosis of HSCT-SOS is based on the revised Seattle or Baltimore standards. The revised standard by the European Society for Bone Marrow Transplantation in 2016 has good practicability and can be used in combination with these two standards. Eight studies have shown the value of liver stiffness measurement (LSM) in the early diagnosis of HSCT-SOS. Four studies investigated LSM specificity and sensitivity for the early diagnosis of HSCT-SOS. LSM can distinguish SOS from other post-HSCT complications, enabling a clear differential diagnosis. It has been shown that median LSM of patients with SOS is significantly higher than that of patients with other treatment-related liver complications (e.g., acute cholecystitis, cholangitis, antifungal drug-related liver injury, liver graft-versus-host disease, isolated liver biochemical changes, and fulminant Epstein Barr virus related hepatitis reactivation). Therefore, the above data confirmed the utility of LSM and strongly suggested that LSM improves the positive predictive value of the SOS diagnostic clinical score after allogeneic HSCT. Early diagnosis of SOS is beneficial in preventing severe HSCT complications.

Network pharmacology-based investigation and experimental validation of the mechanism of scutellarin in the treatment of acute myeloid leukemia

Background: It has been demonstrated that scutellarin, a natural flavone compound from Scutellaria lateriflora and Scutellaria barbata, exerts selective cytotoxicity against a range of cancer cells. However, the underlining mechanism of scutellarin on acute myeloid leukemia (AML) remains elusive.

Methods: In this study, the combination of network pharmacology and experimental verification was performed to identify the pharmacological mechanisms of scutellarin for AML therapy. The public databases, such as PharmMapper, UniProt, OMIM, GeneCards, DrugBank and PharmGkb database, were used to sceen the potential targets of scutellarin and AML. The protein-protein interaction (PPI), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted to uncover the mechanism of scutellarin in the treatment of AML. Finally, the network pharmacological results were further confirmed by in vitro and in vivo experiments.

Results: First and foremost, we totally obtained 289 target genes for scutellarin and 10998 disease targets for AML. 253 overlapping genes were preliminarily considered the potential targets of scutellarin for AML treatment. The results of PPI network analysis, GO analysis and KEGG pathway enrichment demonstrated that the anti-AML effect of scutellarin may focused on MAPK signaling pathway. Furthermore, the cytologic tests suggested that scutellarin can inhibit AML cells proliferation through the mediation of JNK/Caspase-3 pathway. Meanwhile, pretreatment with the JNK inhibitor SP600125 rescued scutellarin-induced apoptosis. Similarly, scutellarin obviously suppressed subcutaneous xenograft growth in nude mice via regulating the JNK/Caspase-3 signaling pathway.

Conclusion: In this study, we integrated network pharmacology-based prediction and experimental validation and revealed the importance of the JNK pathway in scutellarin-mediated AML treatment.

What Is Different in Acute Hematologic Malignancy-Associated ARDS? An Overview of the Literature

Background and Objectives: Acute hematologic malignancies are a group of heterogeneous blood diseases with a high mortality rate, mostly due to acute respiratory failure (ARF). Acute respiratory distress syndrome (ARDS) is one form of ARF which represents a challenging clinical condition. The paper aims to review current knowledge regarding the variable pathogenic mechanisms, as well as therapeutic options for ARDS in acute hematologic malignancy patients. Data collection: We provide an overview of ARDS in patients with acute hematologic malignancy, from an etiologic perspective. We searched databases such as PubMed or Google Scholar, including articles published until June 2022, using the following keywords: ARDS in hematologic malignancy, pneumonia in hematologic malignancy, drug-induced ARDS, leukostasis, pulmonary leukemic infiltration, pulmonary lysis syndrome, engraftment syndrome, diffuse alveolar hemorrhage, TRALI in hematologic malignancy, hematopoietic stem cell transplant ARDS, radiation pneumonitis. We included relevant research articles, case reports, and reviews published in the last 18 years. Results: The main causes of ARDS in acute hematologic malignancy are: pneumonia-associated ARDS, leukostasis, leukemic infiltration of the lung, pulmonary lysis syndrome, drug-induced ARDS, radiotherapy-induced ARDS, diffuse alveolar hemorrhage, peri-engraftment respiratory distress syndrome, hematopoietic stem cell transplantation-related ARDS, transfusion-related acute lung injury. Conclusions: The short-term prognosis of ARDS in acute hematologic malignancy relies on prompt diagnosis and treatment. Due to its etiological heterogeneity, precision-based strategies should be used to improve overall survival. Future studies should focus on identifying the relevance of such etiologic-based diagnostic strategies in ARDS secondary to acute hematologic malignancy.

Post-remission measurable residual disease directs treatment choice and improves outcomes for patients with intermediate-risk acute myeloid leukemia in CR1

Objectives

This study retrospectively investigated in which cycle measurable residual disease (MRD) is associated with prognosis in patients in first complete remission (CR1) of intermediate-risk acute myeloid leukemia (AML).

Methods

The study enrolled 235 younger patients with intermediate-risk AML. MRD was evaluated by multiparameter flow cytometry after the 1st, 2nd, and 3rd chemotherapy cycles (MRD1–3, respectively).

Results

No significant association was detected after the 1st and 2nd cycles. However, the 5-year incidence of relapse was higher in the MRD3-positive group (n = 99) than in the negative group (n = 136) (48.7% vs. 13.7%, P = 0.005), while 5-year disease-free survival (DFS) and overall survival (OS) were lower in the MRD3-positive group than in the negative group (43.2% vs. 81.0% and 45.4% vs. 84.1%; P = 0.003 and 0.005, respectively). Allogeneic hematopoietic stem cell transplantation led to a lower 5-year relapse, and higher DFS and OS rates than chemotherapy in the MRD3-positive group (22.3% vs. 71.5%, 65.9% vs. 23.0%, and 67.1% vs. 23.9%; P < 0.001, 0.002, and 0.022, respectively), but did not affect the MRD-negative group.

Conclusions

MRD3 could serve as an indicator for post-remission treatment choice and help improve outcomes for intermediate-risk AML in CR1.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12185-022-03441-6.

Dental Pulp-Derived Stem Cells Reduce Inflammation, Accelerate Wound Healing and Mediate M2 Polarization of Myeloid Cells

This work aimed to validate the potential use of dental pulp-derived stem cells (DPSCs) for the treatment of inflammation by defining their mechanisms of action. We planned to investigate whether priming of DPSC with proinflammatory molecules had any impact on their behavior and function. In the first step of our validation in vitro, we showed that priming of DPSCs with the bioactive agents LPS, TNF-α, or IFN-γ altered DPSCs’ immunologic properties by increasing their expression levels of IL-10, HGF, IDO, and IL-4 and by decreasing their mitochondrial functions. Moreover, DPSCs induced accelerated wound healing irrespective of priming, as determined by using a gut epithelial cell line in a scratch wound assay. Wound healing of gut epithelial cells was mediated by regulating the expressions of AKT, NF-κB, and ERK1/2 proteins compared to the control epithelial cells. In addition, primed DPSCs altered monocyte polarization toward an immuno-suppressive phenotype (M2), where monocytes expressed higher levels of IL-4R, IL-6, Arg1, and YM-1 compared to monocytes cultured with control DPSCs. In silico analysis revealed that this was accomplished in part by the interaction between kynurenine and PPARγ, which regulated the expression of M2 differentiation-related genes. Collectively, these data provided evidence that the DPSCs reduced inflammation, induced M2 polarization of myeloid cells, and healed damaged gut epithelial cells through inactivation of inflammation and modulating constitutively active signaling pathways.

Prognostic value and potential mechanism of long non-coding RNA Lnc-SMIM20-1 in acute myeloid leukemia

OBJECTIVES

Acute myeloid leukemia (AML) is a common hematologic malignancy with high heterogeneity and poor prognosis. Although long non-coding RNAs (lncRNAs) have been used as biomarkers for tumors, the clinical relevance of numerous lncRNAs in AML remains to be investigated.

RESEARCH DESIGN AND METHODS

Differentially expressed lncRNAs between AML and normal peripheral blood samples were identified using DESeq2. Pan-cancer analysis was performed by GEPIA tool. Kaplan-Meier survival curve was applied for prognosis analysis. KEGG pathway analysis and GSEA were used for functional enrichment. The ceRNA network was constructed by GDCRNAtools.

RESULTS

Lnc-SMIM20-1 was most highly expressed in AML and up-regulated in the TCGA-AML cohort compared to normal tissues. Patients with high expression of Lnc-SMIM20-1 had poor overall prognosis both in the TCGA adult AML cohort and the TARGET pediatric AML cohort, no matter whether they were treated with chemotherapy or allo-HSCT. Lnc-SMIM20-1 might participate in cancer-associated signaling pathways and immune-related signaling pathways by interacting with four microRNAs and 20 mRNAs.

CONCLUSION

Lnc-SMIM20-1 was up-regulated in AML acting as a stable poor prognostic factor. The prognostic impact of Lnc-SMIM20-1 cannot be overcome by allo-HSCT. Our findings provide insight into the clinical relevance of Lnc-SMIM20-1 in AML; aiming to progress the development of novel therapeutics.

The association of socioeconomic deprivation with access and survival after hematopoietic stem cell transplantation in New Zealand

BACKGROUND

Socioeconomic deprivation (SED) is a risk factor for reduced survival of hematopoietic stem cell transplant (HSCT) recipients. This study aimed to evaluate access and long-term survival of HSCT recipients.

METHODS

This was a hospital HSCT Registry-based retrospective cohort study. Patients who underwent HSCT from January 2010 to June 2020 were identified. HSCT recipients younger than 16 years of age, patients who reported their residential address as a post office box or the Department of Corrections, and those who left the country after HSCT were excluded from the study. HSCT recipients with the 2018 New Zealand deprivation index (NZDep2018) deciles 8, 9, and 10 were assigned to the higher SED group and those with NZDep2018 deciles from 1 to 7 were allocated to the lower SED group. The total number of New Zealanders in the higher and lower SED strata was obtained from the 2018 Census.

RESULTS

Eight hundred fifty-one HSCT recipients met the eligibility criteria. HSCT recipients from the higher and lower SED strata of the New Zealand population had similar access to HSCT (odds ratio = .9; 95% confidence interval (CI): .77-1.04; p = .155). Mortality in the higher and lower SED groups of HSCT recipients was 9.6/100 person-years (95% CI: 7.7-12/100 person-years) and 8.1/100 person-years (95% CI: 6.9-9.4/100 person-years), respectively. The mortality ratio was 1.2 (95% CI: .9-1.6), p = .098. Both groups had similar survival.

CONCLUSION

New Zealand residents from the higher and lower SED strata have similar access to HSCT. SED is not associated with reduced survival in adult HSCT recipients.

Effects of Chemotherapy on Fertility Preservation in Patients with Tumors of the Hematopoietic and Lymphoid Tissues

Fertility preservation is an important concern for young cancer patients. Oocyte or embryo cryopreservation prior to chemotherapy administration is desirable but often difficult for patients with hematopoietic and lymphoid tissue tumors. In this study, we examined the results of fertility preservation therapy in patients with hematopoietic and lymphoid tissue tumors. We retrospectively examined hematopoietic and lymphoid tissue tumors of five patients who underwent oocyte cryopreservation as a fertility preservation therapy after chemotherapy, at Showa University Hospital from February 2017 to September 2020. Eleven treatment cycles were administered (one of which was cancelled). The mean age of the patients was 28.6 years. The mean controlled ovarian stimulation duration for 10 cycles was 15.9 days, the mean total gonadotropin dose was 3705 IU, and the mean peak E2 was 502.8 (pg/mL). The mean number of eggs retrieved was 3.2, the mean number of mature oocytes was 2.1, and the mean maturation rate (mature oocytes/returned oocytes) was 70.7%. Fertility preservation procedures in the early period after chemotherapy may be viable because they allow for the acquisition of mature oocytes, even though the procedures may take longer and yield fewer oocytes.

Autologous hematopoietic stem cell transplantation followed by interleukin-2 for adult acute myeloid leukemia patients with favorable or intermediate risk after complete remission

High-dose chemotherapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) is generally the optimal option for patients with acute myeloid leukemia (AML). However, for favorable- and intermediate-risk patients, the regimen remains less understood due to graft versus host disease (GVHD) and increased non-relapsed mortality (NRM) caused by allo-HSCT. Additionally, the benefit of maintenance therapy has not yet been conclusively proven. Here, we conducted a retrospective study on the long-term outcome of AML patients with favorable or intermediate risk who underwent autologous hematopoietic stem cell transplantation (auto-HSCT) followed by interleukin-2 (IL-2) subcutaneous injection as maintenance therapy. A total of 49 patients from 2007 to 2019 were included in our study. They all received a daunorubicin + cytarabine regimen as induction chemotherapy followed by four to six cycles of consolidation therapy with medium- or high-dose cytarabine. Once patients achieved complete remission (CR1), they started receiving auto-HSCT followed by IL-2 injections. The results showed that no patients stopped receiving IL-2 injections on account of adverse side effects, and the 5-year overall survival (OS) and leukemia-free survival (LFS) rates were 85.6 ± 5.0% and 78.5 ± 6.1%, respectively. The multivariate analysis also suggested that age, gender, initial white blood cell (WBC) count, AML subtype, cytogenetic risk, and conditioning regimen did not affect the prognosis. In conclusion, auto-HSCT followed by IL-2 injection is an effective treatment that can improve the prognosis of AML for patients with favorable or intermediate risk.

Downregulation of HLA class II is associated with relapse after allogeneic stem cell transplantation and alters recognition by antigen-specific T cells

Genomic deletion of donor-patient-mismatched HLA alleles in leukemic cells is a major cause of relapse after allogeneic hematopoietic stem cell transplantation (HSCT). Mismatched HLA is frequently lost as an individual allele or a whole region in HLA-class I, however, it is downregulated in HLA-class II. We hypothesized that there might be a difference in T cell recognition capacity against epitopes associated with HLA-class I and HLA-class II and consequently such allogeneic immune pressure induced HLA alterations in leukemic cells. To investigate this, we conducted in vitro experiments with T cell receptor-transduced T (TCR-T) cells. The cytotoxic activity of NY-ESO-1-specific TCR-T cells exhibited similarly against K562 cells with low HLA-A*02:01 expression. However, we demonstrated that the cytokine production against low HLA-DPB1*05:01 expression line decreased gradually from the HLA expression level approximately 2-log lower than normal expressors. Using sort-purified leukemia cells before and after HSCT, we applied the next-generation sequencing, and revealed that there were several marked downregulations of HLA-class II alleles which demonstrated consistently low expression from pre-transplantation. The marked downregulation of HLA-class II may lead to decreased antigen recognition ability of antigen-specific T cells and may be one of immune evasion mechanism associated with HLA-class II downregulation.

miR-143-3p represses leukemia cell proliferation by inhibiting KAT6A expression

The present study is designed to investigate the expressions of microRNA-143-3p (miR-143-3p) and Lysine acetyltransferase 6A (KAT6A) in acute myeloid leukemia (AML) samples and AML cell lines and to explore the possible effects and underlying mechanisms of miR-143-3p on the proliferation of AML cells. The expressions of miR-143-3p and KAT6A in AML samples and cell lines were detected by RT-qPCR assay. CCK-8 and flow cytometry were performed to evaluate the role of KAT6A in viability of AML cells. EdU assay was performed to determine the effects of KAT6A on proliferation of AML cells. Western blot analysis was utilized to assess the impacts of KAT6A on proliferation-related protein expressions of AML cells. ELISA assay was adopted to illustrate the influence of KAT6A on inflammatory responses of AML cells. In addition, the relationship between KAT6A and miR-143-3p was predicted by ENCORI and miRWalk, and confirmed by dual-luciferase reporter assay. Moreover, the effects of KAT6A on the proliferation of AML cells mediated with miR-143-3p were carried out by rescue experiment. The expression of KAT6A was significantly upregulated, while miR-134-4p was downregulated both in the AML tissues and in AML cell lines. In addition, the silence of KAT6A significantly inhibited the viability of AML cells. Besides, KAT6A silencing notably suppressed the proliferation of AML cells and reduced the protein expressions of Ki-67 and PCNA. Knockdown of KAT6A notably decreased the expression levels of IL-1β, TNF-α and IL-6, and increased the expression levels of TGF-β and IL-10. Moreover, overexpression of miR-143-3p repressed viability and proliferation of AML cells and overexpression of KAT6A partially reversed the inhibitory effects of miR-143-3p mimic on viability and proliferation of AML cells. miR-143-3p/KAT6A played an essential role in the viability and proliferation of AML cells.

First report from a single center retrospective study in Kazakhstan on acute myeloid leukemia treatment outcomes

Acute myeloid leukemia (AML) is the most common hematological malignancy in adults. In the last decade, internationally approved AML treatment guidelines, including hematopoietic stem cell transplantation are widely used in Kazakhstan. The categorization of acute myeloid leukemia was done according to the French-American British classification. The prognosis of patients at the time of diagnosis was determined by cytogenetic tests following the guidelines of the European LeukemiaNet. The overall survival and event-free survival were analyzed using the Kaplan-Meier method, and hazard ratios were defined with Cox regression. In total, 398 patients with AML were treated in the National Research Oncology Center between 2010 and 2020. The mean age was 38.3 years. We found a correlation between ethnicity, cytogenetic group, white blood cell count, and treatment approaches with overall and event-free survival. There was a significantly longer OS in a cytogenetic group with a good prognosis compared with intermediate and poor prognosis. The median survival time in the group with a good prognosis was 43 months, 23 months in the intermediate group (p = 0.7), and 12 months in the poor prognosis group (p = 0.016). There was a significantly longer OS for the group of patients who received hematopoietic stem cell transplantation (HSCT), 52 months versus 10 months in the group who received chemotherapy only, p-value < 0.0001. Prognostic factors, such as cytogenetic group, initial WBC count, and treatment approaches are significantly associated with patient survival. Our study data were consistent with the most recent studies, available in the literature adjusted for the population in question.

The Role of T Cell Immunotherapy in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease associated with various alterations in T cell phenotype and function leading to an abnormal cell population, ultimately leading to immune exhaustion. However, restoration of T cell function allows for the execution of cytotoxic mechanisms against leukemic cells in AML patients. Therefore, long-term disease control, which requires multiple therapeutic approaches, includes those aimed at the re-establishment of cytotoxic T cell activity. AML treatments that harness the power of T lymphocytes against tumor cells have rapidly evolved over the last 3 to 5 years through various stages of preclinical and clinical development. These include tissue-infiltrated lymphocytes (TILs), bispecific antibodies, immune checkpoint inhibitors (ICIs), chimeric antigen receptor T (CAR-T) cell therapy, and tumor-specific T cell receptor gene-transduced T (TCR-T) cells. In this review, these T cell-based immunotherapies and the potential of TILs as a novel antileukemic therapy will be discussed.

Topical neurokinin-1 receptor antagonist Fosaprepitant ameliorates ocular graft-versus-host disease in a preclinical mouse model

PURPOSE

to assess the effect of topical administration of the Neurokin-1 receptor (NK1R) antagonist Fosaprepitant in a pre-clinical model of ocular Graft-versus-Host disease (GVHD).

METHODS

BALB/c mice were pre-conditioned by myeloablative total body irradiation and subjected to allogeneic bone marrow transplantation and mature T cell infusion (BM + T). BM-transplanted mice (BM) were used as controls. Ocular GVHD was specifically assessed by quantifying corneal epithelial damage, tear secretion, blepharitis and phimosis, 3 times/week for 28 days post-transplantation. A group of BM + T mice received Fosaprepitant 10 mg/mL, 6 times/day, topically, from day 7-29 after transplantation. After sacrifice, the expression of NK1R, CD45, CD3, and CXCL10 was quantified in the cornea, conjunctiva, and lacrimal gland by immunohistochemistry.

RESULTS

BM + T mice developed corneal epithelial damage (day 0-29, p < 0.001), blepharitis (day 0-29, p < 0.001), and phimosis (day 0-29, p < 0.01), and experienced decreased tear secretion (day 21, p < 0.01) compared to controls. NK1R was found upregulated in corneal epithelium (p < 0.01) and lacrimal gland (p < 0.01) of BM + T mice. Fosaprepitant administration significantly reduced corneal epithelial damage (p < 0.05), CD45⁺ (p < 0.05) and CD3⁺ (p < 0.01) immune cell infiltration in the cornea and conjunctiva (p < 0.001 and p < 0.001, respectively). In addition, Fosaprepitant reduced the expression of CXCL10 in the cornea (p < 0.05) and in the lacrimal gland (p < 0.05).

CONCLUSIONS

Our results suggest that NK1R represents a novel druggable pathway for the therapy of ocular GVHD.

CAR-T after Stem Cell Transplantation in B-Cell Lymphoproliferative Disorders: Are They Really Autologous or Allogenic Cell Therapies?

Allogenic hematopoietic stem cell transplantation (allo-HSCT) is one of the standard treatments for B-cell lymphoproliferative disorders; however, deep relapses are common after an allo-HSCT, and it is associated with poor prognosis. A successful approach to overcome these relapses is to exploit the body's own immune system with chimeric antigen receptor (CAR) T-cells. These two approaches are potentially combinatorial for treating R/R B-cell lymphoproliferative disorders. Several clinical trials have described different scenarios in which allo-HSCT and CAR-T are successively combined. Further, for all transplanted patients, assessment of chimerism is important to evaluate the engraftment success. Nonetheless, for those patients who previously received an allo-HSCT there is no monitorization of chimerism before manufacturing CAR T-cells. In this review, we focus on allo-HSCT and CAR-T treatments and the different sources of T-cells for manufacturing CAR T-cells.

Epigenetic Therapy Promotes the Ratio of Th1/Th17 Lineage to Reverse Immune Evasion and Treat Leukemia Relapse Post-allogeneic Stem Cell Transplantation in Non-APL AML Patients

To reverse the early-stage relapse post-hematopoietic stem cell transplantation, we investigated the safety and efficacy of a new epigenetic regimen (chidamide and decitabine plus thymalfasin simultaneously) on acute myeloid leukemia patients (excluding acute promyelocytic leukemia). Twenty-four patients were enrolled in this observational study during April 2015 to May 2018. The most common adverse event was reversible CTCAE grade 2 thrombocytopenia (20/24). Strikingly, all 24 patients had response to this epigenetic regimen accompanied with decreased measurable residual disease. The overall survival rate is 79.2% (19/24), with a relapse-free survival rate of 79.2% (19/24). During this regimen treatment, Th1 cells and CD3+CD4-CD8+T cells increased, and Th17 cells decreased gradually. The status of high Th1 and low Th17 cells was still observed on the 3rd month after discontinuation of this regimen. Interestingly, the significantly elevated ratio of Th1/Th17 seemed to reflect the treatment-related immune effect, which may be a valuable marker to be monitored in the early-relapse stage for evaluating the efficacy and prognosis.

Safety of FLT3 inhibitors in patients with acute myeloid leukemia

Introduction: Acute myeloblastic leukemia (AML) is the most frequent type of acute leukemia in adults with an incidence of 4.2 cases per 100,000 inhabitants and poor 5-year survival. Patients with mutations in the FMS-like tyrosine kinase 3 (FLT3) gene have poor survival and higher relapse rates compared with wild-type cases.Areas covered: Several FLT3 inhibitors have been proved in FLT3^mut AML patients, with differences in their pharmacokinetics, kinase inhibitory and adverse events profiles. First-generation multi-kinase inhibitors (midostaurin, sorafenib, lestaurtinib) target multiple proteins, whereassecond-generation inhibitors (crenolanib, quizartinib, gilteritinib) are more specific and potent inhibitors of FLT3, so they are associated with less off-target toxic effects. All of these drugs have primary and acquired mechanisms of resistance, and therefore their combinations with other drugs (checkpoint inhibitors, hypomethylating agents, standard chemotherapy) and its application in different clinical settings are under study.Expert opinion: The recent clinical development of various FLT3 inhibitors for the treatment of FLT3^mut AML is an effective therapeutic strategy. However, there are unique toxicities and drug-drug interactions that need to be resolved. It is necessary to understand the mechanisms of toxicity in order to recognize and manage them adequately.

A New Predictive Technology for Perinatal Stem Cell Isolation Suited for Cell Therapy Approaches

The use of stem cells for regenerative applications and immunomodulatory effect is increasing. Amniotic epithelial cells (AECs) possess embryonic-like proliferation ability and multipotent differentiation potential. Despite the simple isolation procedure, inter-individual variability and different isolation steps can cause differences in isolation yield and cell proliferation ability, compromising reproducibility observations among centers and further applications. We investigated the use of a new technology as a diagnostic tool for quality control on stem cell isolation. The instrument label-free separates cells based on their physical characteristics and, thanks to a micro-camera, generates a live fractogram, the fingerprint of the sample. Eight amniotic membranes were processed by trypsin enzymatic treatment and immediately analysed. Two types of profile were generated: a monomodal and a bimodal curve. The first one represented the unsuccessful isolation with all recovered cell not attaching to the plate; while for the second type, the isolation process was successful, but we discovered that only cells in the second peak were alive and resulted adherent. We optimized a Quality Control (QC) method to define the success of AEC isolation using the fractogram generated. This predictive outcome is an interesting tool for laboratories and cell banks that isolate and cryopreserve fetal annex stem cells for research and future clinical applications.

Prognostic Significance of CD56 Antigen Expression in Patients with De Novo Non-M3 Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous group of disorders with distinct characteristics and prognoses. Although cytogenetic changes and gene mutations are associated with AML prognosis, there is a need to identify further factors. CD56 is considered a prognostic factor for AML, which is abnormally expressed in leukemia cells. However, a clear consensus for this surface molecule is lacking, which has prompted us to investigate its prognostic significance. Bone marrow samples of de novo non-M3 AML were collected to detect CD56 expression using multiparameter flow cytometry (FCM). As a result, the CD56 expression in de novo non-M3 AML was found to be significantly higher than that in acute lymphoma leukemia (ALL, P = 0.017) and healthy controls (P = 0.02). The X-Tile program produced a CD56 cutoff point at a relative expression level of 24.62%. Based on this cutoff point, high CD56 expression was observed in 29.21% of de novo non-M3 AML patients. CD56-high patients had a poor overall survival (OS, P = 0.015) compared to CD56-low patients. Bone marrow transplantation (BMT) improved OS (P = 0.004), but a poor genetic risk was associated with an inferior OS (P = 0.002). Compared with CD56-low patients, CD56-high patients had lower peripheral blood platelet (PLT) counts (P = 0.010). Our research confirmed that high CD56 expression is associated with adverse clinical outcomes in de novo non-M3 AML patients, indicating that CD56 could be used as a prognostic marker for a more precise stratification of de novo non-M3 AML patients.

A Review of Infections After Hematopoietic Cell Transplantation Requiring PICU Care: Transplant Timeline Is Key

Despite major advances in antimicrobial prophylaxis and therapy, opportunistic infections remain a major cause of morbidity and mortality after pediatric hematopoietic cell transplant (HCT). Risk factors associated with the development of opportunistic infections include the patient's underlying disease, previous infection history, co-morbidities, source of the donor graft, preparative therapy prior to the graft infusion, immunosuppressive agents, early and late toxicities after transplant, and graft-vs.-host disease (GVHD). Additionally, the risk for and type of infection changes throughout the HCT course and is greatly influenced by the degree and duration of immunosuppression of the HCT recipient. Hematopoietic cell transplant recipients are at high risk for rapid clinical decompensation from infections. The pediatric intensivist must remain abreast of the status of the timeline from HCT to understand the risk for different infections. This review will serve to highlight the infection risks over the year-long course of the HCT process and to provide key clinical considerations for the pediatric intensivist by presenting a series of hypothetical HCT cases.

T cell Tolerance in Early Life

T cell-mediated immune tolerance is a state of unresponsiveness of T cells towards specific self or non-self antigens. This is particularly essential during prenatal/neonatal period when T cells are exposed to dramatically changing environment and required to avoid rejection of maternal antigens, limit autoimmune responses, tolerate inert environmental and food antigens and antigens from non-harmful commensal microorganisms, promote maturation of mucosal barrier function, yet mount an appropriate response to pathogenic microorganisms. The cell-intrinsic and cell extrinsic mechanisms promote the generation of prenatal/neonatal T cells with distinct features to meet the complex and dynamic need of tolerance during this period. Reduced exposure or impaired tolerance in early life may have significant impact on allergic or autoimmune diseases in adult life. The uniqueness of conventional and regulatory T cells in human umbilical cord blood (UCB) may also provide certain advantages in UCB transplantation for hematological disorders.

PEDF promotes the repair of bone marrow endothelial cell injury and accelerates hematopoietic reconstruction after bone marrow transplantation

Background

Preconditioning before bone marrow transplantation such as irradiation causes vascular endothelial cells damage and promoting the repair of damaged endothelial cells is beneficial for hematopoietic reconstitution. Pigment epithelium-derived factor (PEDF) regulates vascular permeability. However, PEDF’s role in the repair of damaged endothelial cells during preconditioning remains unclear. The purpose of our study is to investigate PEDF’s effect on preconditioning-induced damage of endothelial cells and hematopoietic reconstitution.

Methods

Damaged endothelial cells induced by irradiation was co-cultured with hematopoietic stem cells (HSC) in the absence or presence of PEDF followed by analysis of HSC number, cell cycle, colony formation and differentiation. In addition, PEDF was injected into mice model of bone marrow transplantation followed by analysis of bone marrow injury, HSC number and peripheral hematopoietic reconstitution as well as the secretion of cytokines (SCF, TGF-β, IL-6 and TNF-α). Comparisons between two groups were performed by student t-test and multiple groups by one-way or two-way ANOVA.

Results

Damaged endothelial cells reduced HSC expansion and colony formation, induced HSC cell cycle arrest and apoptosis and promoted HSC differentiation as well as decreased PEDF expression. Addition of PEDF increased CD144 expression in damaged endothelial cells and inhibited the increase of endothelial permeability, which were abolished after addition of PEDF receptor inhibitor Atglistatin. Additionally, PEDF ameliorated the inhibitory effect of damaged endothelial cells on HSC expansion in vitro. Finally, PEDF accelerated hematopoietic reconstitution after bone marrow transplantation in mice and promoted the secretion of SCF, TGF-β and IL-6.

Conclusions

PEDF inhibits the increased endothelial permeability induced by irradiation and reverse the inhibitory effect of injured endothelial cells on hematopoietic stem cells and promote hematopoietic reconstruction.

Automation, Monitoring, and Standardization of Cell Product Manufacturing

Although regenerative medicine products are at the forefront of scientific research, technological innovation, and clinical translation, their reproducibility and large-scale production are compromised by automation, monitoring, and standardization issues. To overcome these limitations, new technologies at software (e.g., algorithms and artificial intelligence models, combined with imaging software and machine learning techniques) and hardware (e.g., automated liquid handling, automated cell expansion bioreactor systems, automated colony-forming unit counting and characterization units, and scalable cell culture plates) level are under intense investigation. Automation, monitoring and standardization should be considered at the early stages of the developmental cycle of cell products to deliver more robust and effective therapies and treatment plans to the bedside, reducing healthcare expenditure and improving services and patient care.

A comprehensive review of genetic alterations and molecular targeted therapies for the implementation of personalized medicine in acute myeloid leukemia

Acute myeloid leukemia (AML) is an extremely heterogeneous disease defined by the clonal growth of myeloblasts/promyelocytes not only in the bone marrow but also in peripheral blood and/or tissues. Gene mutations and chromosomal abnormalities are usually associated with aberrant proliferation and/or block in the normal differentiation of hematopoietic cells. So far, the combination of cytogenetic profiling and molecular and gene mutation analyses remains an essential tool for the classification, diagnosis, prognosis, and treatment for AML. This review gives an overview on how the development of novel innovative technologies has allowed us not only to detect the genetic alterations as early as possible but also to understand the molecular pathogenesis of AML to develop novel targeted therapies. We also discuss the remarkable advances made during the last decade to understand the AML genome both at primary and relapse diseases and how genetic alterations might influence the distinct biological groups as well as the clonal evolution of disease during the diagnosis and relapse. Also, the review focuses on how the persistence of epigenetic gene mutations during morphological remission is associated with relapse. It is suggested that along with the prognostic and therapeutic mutations, the novel molecular targeted therapies either approved by FDA or those under clinical trials including CART-cell therapy would be of immense importance in the effective management of AML.

Expression level of ACOT7 influences the prognosis in acute myeloid leukemia patients

BACKGROUND

ACOT plays an important role in lipid metabolism and recent studies found that ACOT participates in some kinds of tumorigenesis. However, both the role of ACOT and its significance have not been revealed in AML. Therefore, we conduct this study in order to investigate the association between AML and ACOT, and hopefully contributed to the management of AML.

METHODS

One hundred and fifty-six AML patients were enrolled in our study whose data were derived from the Cancer Genome Atlas database. There were 85 patients who received only chemotherapy and other 71 patients underwent allo-HSCT.

RESULTS

Patients in high ACOT7 group had a significant lower EFS and OS, while patients in high versus low expression levels of other types of ACOT showed no significant difference on the outcome. High level of ACOT7 related with poor outcome in both chemotherapy-only group and HSCT group.

CONCLUSIONS

High expression level of ACOT7 indicates unfavorable outcome in AML patients. Allo-HSCT could not overcome the unfavorable effect of ACOT7 in these patients.

Soluble Interleukin-2 Receptor Index Predicts Outcomes After Cord Blood Transplantation

BACKGROUND

Our previous study demonstrated that the soluble interleukin-2 receptor (sIL-2R) index, defined as the ratio of serum sIL-2R levels at neutrophil engraftment to that before conditioning, is a biomarker that can predict acute graft-vs-host disease (GVHD) after unrelated bone marrow transplantation. In the present study, we evaluated the significance of the sIL-2R index among patients who underwent cord blood transplantation (CBT).

METHODS

We retrospectively analyzed 31 patients who underwent single-unit CBT as their first transplantation for hematologic malignancies.

RESULTS

The median sIL-2R index was 4.2. The cumulative incidence of grade II to IV acute GVHD was not associated with the sIL-2R index. However, the cumulative incidence of relapse at 3 years after transplantation was significantly lower, with an sIL-2R index ≥ 3.7 than with an index < 3.7 (12.8% vs 50.0%; P = .04). As a result, the probability of overall survival at 3 years after transplantation was significantly higher in the former group than in the latter (79.8% vs 20.0%; P < .01). Only the dose of corticosteroid administered in the pre-engraftment period influenced the sIL-2 index.

CONCLUSION

The sIL-2R index can predict the incidence of relapse and probability of survival after CBT, possibly reflecting a graft-vs-leukemia effect.

Prognostic implications of TdT expression in acute myeloid leukemia with an intermediate-risk karyotype

Terminal deoxynucleotidyl transferase (TdT) is expressed on precursor lymphoblastic neoplasms and some acute myeloid leukemia (AML) cells. The clinical impact of TdT expression on AML outcomes remains unclear. Here, we conducted a retrospective analysis to identify prognostic implications of TdT expression in AML with an intermediate-risk karyotype. Forty-eight cases of intermediate-risk AML were enrolled. TdT positivity was defined as expression on ≥ 10% of the gated cells. Of 48 cases, 12 (25%) were positive for TdT [median expression rate of TdT 0.9% (range 0-86.9%)]. No significant differences in patient characteristics or complete remission rate were observed between TdT-positive and TdT-negative cases. The probability of overall survival (OS) and event-free survival (EFS) at 1 year was not significantly different between TdT-positive and TdT-negative cases (OS: 58.3% vs. 65.2%, p = 0.32; EFS: 33.3% vs. 57.1%, p = 0.06). Relapse-free survival (RFS) probability at 1 year was significantly lower for TdT-positive than TdT-negative cases (10% vs. 71.3%, p = 0.002). Multivariate analyses revealed that TdT positivity was an independent significant adverse factor for RFS [hazard ratio: 3.309, 95% confidence interval: 1.334-8.209, p = 0.009]. Our results suggest that TdT expression is associated with increased risk of relapse in patients with intermediate-risk AML.