ABSTRACT
PURPOSE: Allogeneic hematopoietic stem-cell transplantation (HSCT) is the only potentially curative treatment for patients with myelodysplastic syndromes (MDS). Several issues must be considered when evaluating the benefits and risks of HSCT for patients with MDS, with the timing of transplantation being a crucial question. Here, we aimed to develop and validate a decision support system to define the optimal timing of HSCT for patients with MDS on the basis of clinical and genomic information as provided by the Molecular International Prognostic Scoring System (IPSS-M). PATIENTS AND METHODS: We studied a retrospective population of 7,118 patients, stratified into training and validation cohorts. A decision strategy was built to estimate the average survival over an 8-year time horizon (restricted mean survival time [RMST]) for each combination of clinical and genomic covariates and to determine the optimal transplantation policy by comparing different strategies. RESULTS: Under an IPSS-M based policy, patients with either low and moderate-low risk benefited from a delayed transplantation policy, whereas in those belonging to moderately high-, high- and very high-risk categories, immediate transplantation was associated with a prolonged life expectancy (RMST). Modeling decision analysis on IPSS-M versus conventional Revised IPSS (IPSS-R) changed the transplantation policy in a significant proportion of patients (15% of patient candidate to be immediately transplanted under an IPSS-R-based policy would benefit from a delayed strategy by IPSS-M, whereas 19% of candidates to delayed transplantation by IPSS-R would benefit from immediate HSCT by IPSS-M), resulting in a significant gain-in-life expectancy under an IPSS-M-based policy (P = .001). CONCLUSION: These results provide evidence for the clinical relevance of including genomic features into the transplantation decision making process, allowing personalizing the hazards and effectiveness of HSCT in patients with MDS.
Subject(s)
Hematopoietic Stem Cell Transplantation , Myelodysplastic Syndromes , Transplantation, Homologous , Humans , Myelodysplastic Syndromes/therapy , Myelodysplastic Syndromes/genetics , Hematopoietic Stem Cell Transplantation/methods , Middle Aged , Male , Retrospective Studies , Female , Aged , Adult , Time Factors , Decision Support Systems, Clinical , Genomics , Decision Support Techniques , Risk Assessment , Young AdultABSTRACT
Macrophage activation syndrome (MAS) is a form of secondary hemophagocytic lymphohistiocytosis (HLH) when it occurs in the context of rheumatologic disorders. HLH is a rare and potentially life-threatening syndrome characterized by excessive immune system activation. It is mainly seen in children and can be genetic based or related to infections, malignancies, rheumatologic disorders, or immunodeficiency syndromes. MAS can present with nonspecific symptoms, leading to a delay in diagnosis. This report describes a case of a 64-year-old female with marginal zone lymphoma and systemic lupus erythematosus who presented with a purpuric rash and acute kidney injury. She underwent a kidney biopsy and was diagnosed with MAS. This case highlights the importance of promptly recognizing MAS's symptoms and signs, allowing timely diagnosis and early therapeutic intervention. This potentially fatal condition tends to respond well to rapid treatment initiation with corticosteroids and to address the underlying condition.
Subject(s)
Arthritis, Rheumatoid , Lymphohistiocytosis, Hemophagocytic , Lymphoma, B-Cell, Marginal Zone , Macrophage Activation Syndrome , Female , Humans , Middle Aged , Adrenal Cortex Hormones/therapeutic use , Arthritis, Rheumatoid/complications , Lymphohistiocytosis, Hemophagocytic/diagnosis , Lymphohistiocytosis, Hemophagocytic/etiology , Lymphoma, B-Cell, Marginal Zone/complications , Lymphoma, B-Cell, Marginal Zone/diagnosis , Macrophage Activation Syndrome/diagnosis , Macrophage Activation Syndrome/etiologyABSTRACT
The presence of inhibitory immune cells and difficulty in generating activated effector T cells remain obstacles to development of effective cancer vaccines. We designed a vaccine regimen combining human telomerase reverse transcriptase (hTERT) peptides with concomitant therapies targeting regulatory T cells (Tregs) and cyclooxygenase-2 (COX2)-mediated immunosuppression. This Phase 1 trial combined an hTERT-derived 7-peptide library, selected to ensure presentation by both HLA class-I and class-II in 90% of patients, with oral low-dose cyclophosphamide (to modulate Tregs) and the COX2 inhibitor celecoxib. Adjuvants were Montanide and topical TLR-7 agonist, to optimise antigen presentation. The primary objective was determination of the safety and tolerability of this combination therapy, with anti-cancer activity, immune response and detection of antigen-specific T cells as additional endpoints. Twenty-nine patients with advanced solid tumours were treated. All were multiply-pretreated, and the majority had either colorectal or prostate cancer. The most common adverse events were injection-site reactions, fatigue and nausea. Median progression-free survival was 9 weeks, with no complete or partial responses, but 24% remained progression-free for ≥6 months. Immunophenotyping showed post-vaccination expansion of CD4+ and CD8+ T cells with effector phenotypes. The in vitro re-challenge of T cells with hTERT peptides, TCR sequencing, and TCR similarity index analysis demonstrated the expansion following vaccination of oligoclonal T cells with specificity for hTERT. However, a population of exhausted PD-1+ cytotoxic T cells was also expanded in vaccinated patients. This vaccine combination regimen was safe and associated with antigen-specific immunological responses. Clinical activity could be improved in future by combination with anti-PD1 checkpoint inhibition to address the emergence of an exhausted T cell population.
Subject(s)
Cancer Vaccines , Prostatic Neoplasms , Telomerase , Male , Humans , CD8-Positive T-Lymphocytes , Telomerase/genetics , Telomerase/metabolism , Vaccination , Peptides , Cancer Vaccines/adverse effects , Receptors, Antigen, T-CellABSTRACT
Sarcoidosis, a multi-organ system disease, often presents insidiously. Thrombocytopenia in sarcoidosis is frequent because of hypersplenism, granulomas infiltrating the bone marrow, or immune thrombocytopenia (ITP). The diagnosis of ITP relies on exclusionary criteria, given the absence of a definitive laboratory diagnostic feature. In the era prior to modern ITP management, sarcoidosis-associated ITP was known to manifest severely, often showing resistance to treatment and an increased risk of mortality. In this case, we present a young male who was admitted to a district hospital's emergency room, displaying symptoms of hematuria, gingival bleeding, and a petechial rash. Blood tests revealed severe thrombocytopenia with a platelet count of 0, while all other metabolic and serological exams returned normal results. Infectious and autoimmune causes were ruled out, and a bone marrow examination excluded any hematological disorder. Initial management, including platelet transfusion and presumptive treatment for ITP with dexamethasone and Human Immunoglobulin IV (IVIG), failed to improve the patient's platelet count or alleviate the hemorrhagic diathesis. Second-line therapy with Rituximab and Methylprednisolone was initiated with no benefit. Considering the hemorrhagic signs and the delayed response of Rituximab, we shifted to third-line therapy with Romiplostim at the maximal dose and continued Methylprednisolone. The platelet count recovered completely after the second Romiplostim administration (over 350 × 109 platelets/L) and Methylprednisolone was rapidly tapered. To further study the causes of thrombocytopenia a total body CT scan was performed and it identified non-homogeneously hypodense tissue in the bilateral hilar area extending medially to the subcarinal area, suggesting possible lymphatic origin and raising suspicion of sarcoidosis. Further investigations, including Angiotensin Converting Enzyme (ACE) titration, bronchoscopy, bronchoalveolar lavage, and EndoBronchial UltraSound-guided TransBronchial Needle Aspiration (EBUS-TBNA), confirmed the diagnosis of sarcoidosis. Despite a mild restrictive insufficiency noted in spirometry, the patient remained asymptomatic with only a mild respiratory insufficiency, and hence, was enlisted for follow-up. As for the ITP, the platelet count remained normal over a year. Notably, while sarcoidosis onset often predates ITP onset by an average of 48 months, in our case the onset of the two diseases was simultaneously. Our case adds valuable information to the limited body of knowledge regarding the treatment of sarcoidosis-associated ITP.
ABSTRACT
The antitumor activity of adoptive T cell therapies (ACT) is highly dependent on the expansion, persistence, and continued activity of adoptively transferred cells. Clinical studies using ACTs have revealed that products that possess and maintain less differentiated phenotypes, including memory and precursor T cells, show increased antitumor efficacy and superior patient outcomes owing to their increased expansion, persistence, and ability to differentiate into effector progeny that elicit antitumor responses. Strategies that drive the differentiation into memory or precursor-type T cell subsets with high potential for persistence and self-renewal will enhance adoptively transferred T cell maintenance and promote durable antitumor efficacy. Because of the high costs associated with ACT manufacturing, ACTs are often only offered to patients after multiple rounds of systemic therapy. An essential factor to consider in producing autologous ACT medicinal products is the impact of the patient's initial T cell fitness and subtype composition, which will likely differ with age, disease history, and treatment with prior anti-cancer therapies. This study evaluated the impact of systemic anti-cancer therapy for non-small cell lung cancer treatment on the T cell phenotype of the patient at baseline and the quality and characteristics of the genetically modified autologous T cell therapy product after manufacturing.
ABSTRACT
BACKGROUND: Vaccination has played a pivotal role in reducing the burden of COVID-19. Despite numerous studies highlighting its benefits in reducing the risk of severe disease and death, we still lack a quantitative understanding of how varying vaccination roll-out rates influence COVID-19 mortality. METHODS: We developed a framework for estimating the number of avertable COVID-19 deaths (ACDs) by vaccination in Iran. To achieve this, we compared Iran's vaccination roll-out rates with those of eight model countries that predominantly used inactivated virus vaccines. We calculated net differences in the number of fully vaccinated individuals under counterfactual scenarios where Iran's per-capita roll-out rate was replaced with that of the model countries. This, in turn, enabled us to determine age specific ACDs for the Iranian population under counterfactual scenarios where number of COVID-19 deaths are estimated using all-cause mortality data. These estimates covered the period from the start of 2020 to 20 April 2022. RESULTS: We found that while Iran would have had an approximately similar number of fully vaccinated individuals under counterfactual roll-out rates based on Bangladesh, Nepal, Sri Lanka, and Turkey (~ 65-70%), adopting Turkey's roll-out rates could have averted 50,000 (95% confidence interval: 38,100-53,500) additional deaths, while following Bangladesh's rates may have resulted in 52,800 (17,400-189,500) more fatalities in Iran. Surprisingly, mimicking Argentina's slower roll-out led to only 12,600 (10,400-13,300) fewer deaths, despite a higher counterfactual percentage of fully vaccinated individuals (~ 79%). Emulating Montenegro or Bolivia, with faster per capita roll-out rates and approximately 50% counterfactual full vaccination, could have prevented more deaths in older age groups, especially during the early waves. Finally, replicating Bahrain's model as an upper-bound benchmark, Iran could have averted 75,300 (56,000-83,000) deaths, primarily in the > 50 age groups. CONCLUSIONS: Our analysis revealed that faster roll-outs were consistently associated with higher numbers of averted deaths, even in scenarios with lower overall coverage. This study offers valuable insights into future decision-making regarding infectious disease epidemic management through vaccination strategies. It accomplishes this by comparing various countries' relative performance in terms of timing, pace, and vaccination coverage, ultimately contributing to the prevention of COVID-19-related deaths.
Subject(s)
COVID-19 , Perinatal Death , Vaccines , Female , Humans , Aged , COVID-19/epidemiology , COVID-19/prevention & control , Iran/epidemiology , Vaccination , Vaccination CoverageABSTRACT
Tumor-associated macrophages (TAMs) are a heterogeneous population of cells that facilitate cancer progression. However, our knowledge of the niches of individual TAM subsets and their development and function remain incomplete. Here, we describe a population of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1)-expressing TAMs, which form coordinated multi-cellular "nest" structures that are heterogeneously distributed proximal to vasculature in tumors of a spontaneous murine model of breast cancer. We demonstrate that LYVE-1+ TAMs develop in response to IL-6, which induces their expression of the immune-suppressive enzyme heme oxygenase-1 and promotes a CCR5-dependent signaling axis, which guides their nest formation. Blocking the development of LYVE-1+ TAMs or their nest structures, using gene-targeted mice, results in an increase in CD8+ T cell recruitment to the tumor and enhanced response to chemotherapy. This study highlights an unappreciated collaboration of a TAM subset to form a coordinated niche linked to immune exclusion and resistance to anti-cancer therapy.
Subject(s)
Neoplasms , Mice , Animals , Neoplasms/pathology , Macrophages/metabolismABSTRACT
PURPOSE: Synthetic data are artificial data generated without including any real patient information by an algorithm trained to learn the characteristics of a real source data set and became widely used to accelerate research in life sciences. We aimed to (1) apply generative artificial intelligence to build synthetic data in different hematologic neoplasms; (2) develop a synthetic validation framework to assess data fidelity and privacy preservability; and (3) test the capability of synthetic data to accelerate clinical/translational research in hematology. METHODS: A conditional generative adversarial network architecture was implemented to generate synthetic data. Use cases were myelodysplastic syndromes (MDS) and AML: 7,133 patients were included. A fully explainable validation framework was created to assess fidelity and privacy preservability of synthetic data. RESULTS: We generated MDS/AML synthetic cohorts (including information on clinical features, genomics, treatment, and outcomes) with high fidelity and privacy performances. This technology allowed resolution of lack/incomplete information and data augmentation. We then assessed the potential value of synthetic data on accelerating research in hematology. Starting from 944 patients with MDS available since 2014, we generated a 300% augmented synthetic cohort and anticipated the development of molecular classification and molecular scoring system obtained many years later from 2,043 to 2,957 real patients, respectively. Moreover, starting from 187 MDS treated with luspatercept into a clinical trial, we generated a synthetic cohort that recapitulated all the clinical end points of the study. Finally, we developed a website to enable clinicians generating high-quality synthetic data from an existing biobank of real patients. CONCLUSION: Synthetic data mimic real clinical-genomic features and outcomes, and anonymize patient information. The implementation of this technology allows to increase the scientific use and value of real data, thus accelerating precision medicine in hematology and the conduction of clinical trials.
Subject(s)
Hematology , Leukemia, Myeloid, Acute , Humans , Precision Medicine , Artificial Intelligence , AlgorithmsABSTRACT
Myelodysplastic syndrome (MDS) describes a group of bone marrow malignancies with variable morphologies and heterogeneous clinical features. The aim of this study was to systematically appraise the published clinical, laboratory, and pathologic characteristics and identify distinct clinical features of MDS in the Middle East and North Africa (MENA) region. We conducted a comprehensive search of the PubMed, Web of Science, EMBASE, and Cochrane Library databases from 2000 to 2021 to identify population-based studies of MDS epidemiology in MENA countries. Of 1935 studies, 13 independent studies published between 2000 and 2021 representing 1306 patients with MDS in the MENA region were included. There was a median of 85 (range 20 to 243) patients per study. Seven studies were performed in Asian MENA countries (732 patients, 56%) and six in North African MENA countries (574 patients, 44%). The pooled mean age was 58.4 years (SD 13.14; 12 studies), and the male-to-female ratio was 1.4. The distribution of WHO MDS subtypes was significantly different between MENA, Western, and Far East populations (n = 978 patients, p < 0.001). More patients from MENA countries were at high/very high IPSS risk than in Western and Far East populations (730 patients, p < 0.001). There were 562 patients (62.2%) with normal karyotypes and 341 (37.8%) with abnormal karyotypes. Our findings establish that MDS is prevalent within the MENA region and is more severe than in Western populations. MDS appears to be more severe with an unfavorable prognosis in the Asian MENA population than the North African MENA population.
ABSTRACT
PURPOSE: Myelodysplastic syndromes (MDS) are heterogeneous myeloid neoplasms in which a risk-adapted treatment strategy is needed. Recently, a new clinical-molecular prognostic model, the Molecular International Prognostic Scoring System (IPSS-M) was proposed to improve the prediction of clinical outcome of the currently available tool (Revised International Prognostic Scoring System [IPSS-R]). We aimed to provide an extensive validation of IPSS-M. METHODS: A total of 2,876 patients with primary MDS from the GenoMed4All consortium were retrospectively analyzed. RESULTS: IPSS-M improved prognostic discrimination across all clinical end points with respect to IPSS-R (concordance was 0.81 v 0.74 for overall survival and 0.89 v 0.76 for leukemia-free survival, respectively). This was true even in those patients without detectable gene mutations. Compared with the IPSS-R based stratification, the IPSS-M risk group changed in 46% of patients (23.6% and 22.4% of subjects were upstaged and downstaged, respectively).In patients treated with hematopoietic stem cell transplantation (HSCT), IPSS-M significantly improved the prediction of the risk of disease relapse and the probability of post-transplantation survival versus IPSS-R (concordance was 0.76 v 0.60 for overall survival and 0.89 v 0.70 for probability of relapse, respectively). In high-risk patients treated with hypomethylating agents (HMA), IPSS-M failed to stratify individual probability of response; response duration and probability of survival were inversely related to IPSS-M risk.Finally, we tested the accuracy in predicting IPSS-M when molecular information was missed and we defined a minimum set of 15 relevant genes associated with high performance of the score. CONCLUSION: IPSS-M improves MDS prognostication and might result in a more effective selection of candidates to HSCT. Additional factors other than gene mutations can be involved in determining HMA sensitivity. The definition of a minimum set of relevant genes may facilitate the clinical implementation of the score.
Subject(s)
Myelodysplastic Syndromes , Neoplasm Recurrence, Local , Humans , Prognosis , Retrospective Studies , Myelodysplastic Syndromes/diagnosis , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/therapy , Risk FactorsABSTRACT
Patients with myelodysplastic syndrome and ring sideroblasts (MDS-RS) present with symptomatic anemia due to ineffective erythropoiesis that impedes their quality of life and increases morbidity. More than 80% of patients with MDS-RS harbor splicing factor 3B subunit 1 (SF3B1) mutations, the founder aberration driving MDS-RS disease. Here, we report how mis-splicing of coenzyme A synthase (COASY), induced by mutations in SF3B1, affects heme biosynthesis and erythropoiesis. Our data revealed that COASY was up-regulated during normal erythroid differentiation, and its silencing prevented the formation of erythroid colonies, impeded erythroid differentiation, and precluded heme accumulation. In patients with MDS-RS, loss of protein due to COASY mis-splicing led to depletion of both CoA and succinyl-CoA. Supplementation with COASY substrate (vitamin B5) rescued CoA and succinyl-CoA concentrations in SF3B1mut cells and mended erythropoiesis differentiation defects in MDS-RS primary patient cells. Our findings reveal a key role of the COASY pathway in erythroid maturation and identify upstream and downstream metabolites of COASY as a potential treatment for anemia in patients with MDS-RS.
Subject(s)
Anemia , Myelodysplastic Syndromes , Humans , Erythropoiesis , Pantothenic Acid , Quality of Life , Transcription Factors , Heme , RNA Splicing Factors , PhosphoproteinsABSTRACT
BACKGROUND: Prenatal exposure to elevated interleukin (IL)-6 levels is associated with increased risk for psychiatric disorders with a putative neurodevelopmental origin, such as schizophrenia (SZ), autism spectrum condition (ASC) and bipolar disorder (BD). Although rodent models provide causal evidence for this association, we lack a detailed understanding of the cellular and molecular mechanisms in human model systems. To close this gap, we characterized the response of human induced pluripotent stem cell (hiPSC-)derived microglia-like cells (MGL) and neural progenitor cells (NPCs) to IL-6 in monoculture. RESULTS: We observed that human forebrain NPCs did not respond to acute IL-6 exposure in monoculture at both protein and transcript levels due to the absence of IL6R expression and soluble (s)IL6Ra secretion. By contrast, acute IL-6 exposure resulted in STAT3 phosphorylation and increased IL6, JMJD3 and IL10 expression in MGL, confirming activation of canonical IL6Ra signaling. Bulk RNAseq identified 156 up-regulated genes (FDR < 0.05) in MGL following acute IL-6 exposure, including IRF8, REL, HSPA1A/B and OXTR, which significantly overlapped with an up-regulated gene set from human post-mortem brain tissue from individuals with schizophrenia. Acute IL-6 stimulation significantly increased MGL motility, consistent with gene ontology pathways highlighted from the RNAseq data and replicating rodent model indications that IRF8 regulates microglial motility. Finally, IL-6 induces MGLs to secrete CCL1, CXCL1, MIP-1α/ß, IL-8, IL-13, IL-16, IL-18, MIF and Serpin-E1 after 3 h and 24 h. CONCLUSION: Our data provide evidence for cell specific effects of acute IL-6 exposure in a human model system, ultimately suggesting that microglia-NPC co-culture models are required to study how IL-6 influences human cortical neural progenitor cell development in vitro.
Subject(s)
Interleukin-6 , Microglia , Neural Stem Cells , Receptors, Interleukin-6 , Humans , Induced Pluripotent Stem Cells/drug effects , Induced Pluripotent Stem Cells/metabolism , Interferon Regulatory Factors/metabolism , Interleukin-6/adverse effects , Interleukin-6/metabolism , Interleukin-6/pharmacology , Microglia/drug effects , Microglia/metabolism , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , Receptors, Interleukin-6/metabolismABSTRACT
Despite widespread use of Pegylated forms of Inteferon in the management of Myeloproliferative Neoplasms (MPN), most clinicians have experience predominantly with peginterferon alfa-2a (Pegasys). Third generation pegylated IFNα, ropeginterferon alfa-2b (ropegIFN; Besremi), was recommended by the European Medicine Authority (EMA) for treatment of Polycythaemia Vera (PV) following a Phase III trial (PROUD-PV / CONTINUATION-PV). FDA approval for PV, regardless of treatment history, was subsequently granted in November 2021. We hereby demonstrate the safety and tolerability of ropegIFN in a series of MPN patients at variable doses. It corroborates reports of efficacy of ropegIFN in patients with PV and use in pregnancy.
ABSTRACT
Dasatinib is a multi-kinase inhibitor with activity against the SRC kinase LCK, which plays a critical role in T-cell receptor signaling. Dasatinib, initially developed as an immunosuppressive agent, is by contrast, also noted to result in enhanced tumor immunity in a subset of patients. We studied the impact of dasatinib in chronic myeloid leukemia patients and compared it with patients taking other tyrosine kinase inhibitors (TKI) and healthy controls. We found that patients on dasatinib showed inhibition of both T-cell receptor (TCR) and STAT5 signaling pathways, and reduced expression of Teffector pro-inflammatory cytokines. In addition, dasatinib induced selective depletion of regulatory T cells (Tregs) and effector Tregs, particularly in patients with clonal expansion of effector CD8+ T cells, who demonstrated greater and preferential inhibition of Treg TCR intracellular signaling. In addition, we show that dasatinib selectively reduces Treg STAT5 phosphorylation via reduction of IL-2, in relation with the marked reduction of plasma IL-2 levels in patients taking dasatinib. Finally, patients on other TKI had significantly increased TCR signaling in TIM3+ cells compared to patients taking dasatinib, suggesting that chronic SRC kinase inhibition by dasatinib may play a role in preventing TIM-3-mediated T-cell exhaustion and preserve anti-tumor immunity. These data provide further insight into the selective immunomodulatory effects of dasatinib and its potential use for pharmacologic control of immunotherapies.
Subject(s)
Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Leukemia, Myeloid, Chronic-Phase , Humans , Dasatinib/pharmacology , Dasatinib/therapeutic use , STAT5 Transcription Factor/metabolism , Interleukin-2/therapeutic use , Pyrimidines/pharmacology , Pyrimidines/therapeutic use , Thiazoles/pharmacology , Thiazoles/therapeutic use , Signal Transduction , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , src-Family Kinases , Receptors, Antigen, T-Cell , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Leukemia, Myeloid, Chronic-Phase/drug therapySubject(s)
COVID-19 Vaccines , COVID-19 , Humans , SARS-CoV-2 , COVID-19/prevention & control , mRNA VaccinesABSTRACT
Challenges in haematopoietic stem cell transplantation such as low bone marrow (BM) engraftment, graft versus host disease (GvHD) and the need for long-term immunosuppression could be addressed using T regulatory cells (Tregs) resident in the tissue of interest, in this case, BM Tregs. Controlling the adverse immune response in haematopoietic stem cell transplantation (HSCT) and minimising the associated risks such as infection and secondary cancers due to long-term immunosuppression is a crucial aspect of clinical practice in this field. While systemic immunosuppressive therapy could achieve reasonable GvHD control in most patients, related side effects remain the main limiting factor. Developing more targeted immunosuppressive strategies is an unmet clinical need and is the focus of several ongoing research projects. Tregs are a non-redundant sub-population of CD4+ T cells essential for controlling the immune homeostasis. Tregs are known to be reduced in number and function in autoimmune conditions. There is considerable interest in these cells as cell therapy products since they can be expanded in vitro and infused into patients. These trials have found Treg therapy to be safe, well-tolerated, and with some early signs of efficacy. However, Tregs are a heterogeneous subpopulation of T cells, and several novel subpopulations have been identified in recent years beyond the conventional thymic (tTregs) and peripheral (pTregs). There is increasing evidence for the presence of resident and tissue-specific Tregs. Bone marrow (BM) Tregs are one example of tissue-resident Tregs. BM Tregs are enriched within the marrow, serving a dual function of immunosuppression and maintenance of haematopoietic stem cells (HSCs). HSCs maintenance is achieved through direct suppression of HSCs differentiation, maintaining a proliferating pool of HSCs, and promoting the development of functional stromal cells that support HSCs. In this review, we will touch upon the biology of Tregs, focusing on their development and heterogeneity. We will focus on the BM Tregs from their biology to their therapeutic potential, focusing on their use in HSCT.
Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Humans , Bone Marrow , T-Lymphocytes, Regulatory , Hematopoietic Stem Cell Transplantation/adverse effects , Bone Marrow Transplantation/methods , Graft vs Host Disease/etiology , Graft vs Host Disease/prevention & controlABSTRACT
Multiparameter flow cytometry (MFC) is one of the essential ancillary methods in bone marrow (BM) investigation of patients with cytopenia and suspected myelodysplastic syndrome (MDS). MFC can also be applied in the follow-up of MDS patients undergoing treatment. This document summarizes recommendations from the International/European Leukemia Net Working Group for Flow Cytometry in Myelodysplastic Syndromes (ELN iMDS Flow) on the analytical issues in MFC for the diagnostic work-up of MDS. Recommendations for the analysis of several BM cell subsets such as myeloid precursors, maturing granulocytic and monocytic components and erythropoiesis are given. A core set of 17 markers identified as independently related to a cytomorphologic diagnosis of myelodysplasia is suggested as mandatory for MFC evaluation of BM in a patient with cytopenia. A myeloid precursor cell (CD34+ CD19- ) count >3% should be considered immunophenotypically indicative of myelodysplasia. However, MFC results should always be evaluated as part of an integrated hematopathology work-up. Looking forward, several machine-learning-based analytical tools of interest should be applied in parallel to conventional analytical methods to investigate their usefulness in integrated diagnostics, risk stratification, and potentially even in the evaluation of response to therapy, based on MFC data. In addition, compiling large uniform datasets is desirable, as most of the machine-learning-based methods tend to perform better with larger numbers of investigated samples, especially in such a heterogeneous disease as MDS.