The immunobiology of myelodysplastic neoplasms: a mini-review.

This mini review summarizes the immunobiology of myelodysplastic syndromes, specifically focusing on the interactions between immune cells, cytokines, and dysplastic cells within the tumor microenvironment in the bone marrow. We elucidate in detail how immune dysregulation and evasion influence the initiation and progression of myelodysplastic syndromes, as well as resistance to therapy and progression to AML. In addition, we highlight a range of therapeutic strategies, including the most recent breakthroughs and experimental therapies for treating MDS. Finally, we address the existing knowledge gaps in the understanding of the immunobiology of MDS and propose future research directions, promising advancements toward enhancing clinical outcomes and survival for patients with MDS.

[Positive rates and distribution characteristics of pre-existing anti-human-leukocyte-antigen antibodies in patients with different hematological diseases].

Clinical data of 1 494 patients with hematological diseases who were scheduled to receive allogeneic hematopoietic stem cell transplantation and received the anti-human-leukocyte-antigen (HLA) antibody test for the first time at the First Affiliated Hospital of Soochow University from 2016 to 2018 was collected to analyze the positive rates and distribution characteristics of different types of pre-existing anti-HLA antibodies in patients with different hematological diseases. Among 1 494 patients with hematological diseases, there were 849 males and 645 females, aged [31 (17, 45)] years, and included 577 cases of acute myeloid leukemia (AML), 373 cases of acute lymphocytic leukemia (ALL), 234 cases of aplastic anemia (AA), 175 cases of myelodysplastic syndrome (MDS), and 135 cases of other diseases. The total positive rate of pre-existing anti-HLA antibodies was 25.1% (375/1 494), among which the positive rates of anti-HLA class Ⅰ, anti-HLA class Ⅱ, and anti-HLA class Ⅰ+Ⅱ antibodies were 11.2% (168/1 494), 4.9% (73/1 494), and 9.0% (134/1 494), respectively.The total positive rates of pre-existing anti-HLA antibodies in patients with MDS、AA、AML、ALL and other diseases were 40.6% (71/175), 30.8% (72/234), 26.2% (151/577), 12.3% (46/373), and 25.9% (35/135), respectively, with statistically significant difference (P<0.001). The positive rates of anti-HLA class Ⅰ, anti-HLA class Ⅱ, and anti-HLA class Ⅰ+Ⅱ antibodies in patients with different hematological diseases showed statistically significant differences (all P<0.001). Given the varying positive rates and distribution characteristics of pre-existing anti-HLA antibodies among patients with different hematological diseases, anti-HLA antibody test should be performed before receiving hematopoietic stem cell transplantation.

Identification of novel myelodysplastic syndromes prognostic subgroups by integration of inflammation, cell-type composition, and immune signatures in the bone marrow.

Mutational profiles of myelodysplastic syndromes (MDS) have established that a relatively small number of genetic aberrations, including SF3B1 and SRSF2 spliceosome mutations, lead to specific phenotypes and prognostic subgrouping. We performed a multi-omics factor analysis (MOFA) on two published MDS cohorts of bone marrow mononuclear cells (BMMNCs) and CD34 + cells with three data modalities (clinical, genotype, and transcriptomics). Seven different views, including immune profile, inflammation/aging, retrotransposon (RTE) expression, and cell-type composition, were derived from these modalities to identify the latent factors with significant impact on MDS prognosis. SF3B1 was the only mutation among 13 mutations in the BMMNC cohort, indicating a significant association with high inflammation. This trend was also observed to a lesser extent in the CD34 + cohort. Interestingly, the MOFA factor representing the inflammation shows a good prognosis for MDS patients with high inflammation. In contrast, SRSF2 mutant cases show a granulocyte-monocyte progenitor (GMP) pattern and high levels of senescence, immunosenescence, and malignant myeloid cells, consistent with their poor prognosis. Furthermore, MOFA identified RTE expression as a risk factor for MDS. This work elucidates the efficacy of our integrative approach to assess the MDS risk that goes beyond all the scoring systems described thus far for MDS.

Immune-dysregulation harnessing in myeloid neoplasms.

Myeloid malignancies arise in bone marrow microenvironments and shape these microenvironments in favor of malignant development. Immune suppression is one of the most important stages in myeloid leukemia progression. Leukemic clone expansion and immune dysregulation occur simultaneously in bone marrow microenvironments. Complex interactions emerge between normal immune system elements and leukemic clones in the bone marrow. In recent years, researchers have identified several of these pathological interactions. For instance, recent works shows that the secretion of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), from bone marrow stromal cells contributes to immune dysregulation and the selective proliferation of JAK2V617F+ clones in myeloproliferative neoplasms. Moreover, inflammasome activation and sterile inflammation result in inflamed microenvironments and the development of myelodysplastic syndromes. Additional immune dysregulations, such as exhaustion of T and NK cells, an increase in regulatory T cells, and impairments in antigen presentation are common findings in myeloid malignancies. In this review, we discuss the role of altered bone marrow microenvironments in the induction of immune dysregulations that accompany myeloid malignancies. We also consider both current and novel therapeutic strategies to restore normal immune system function in the context of myeloid malignancies.

Anti-synthetase and myelodysplastic syndromes with deep morphea: an example of shared immunopathogenesis? A case-based review.

Anti-synthetase syndrome (AS) is a subset of idiopathic inflammatory myopathy (IIM) characterized by the presence of anti-aminoacyl-transfer RNA synthetase accompanied by myositis, interstitial lung disease and other clinical features. According to a recent multicentric study, 31% of AS patients present skin lesions compatible with dermatomyositis, but sclerodermiform features are rare. Therefore, we aimed to report the case of a patient with simultaneous diagnosis of AS, deep morphea, vasculitic neuropathy, and myelodysplastic syndrome and review the current literature regarding these uncommon associations. A 57 year old man with axial and symmetrical proximal muscle weakness, skin thickening and B symptoms, later diagnosed with PL7 + AS, deep morphea, myelodysplastic syndrome (MDS) and vasculitic neuropathy documented by histopathologic studies and immunologic assessments. Since both AS and deep morphea share the vasculopathic changes and type II interferon-induced inflammation, we hypothesize that they may share pathogenic mechanisms. The muscle biopsy of the patient was consistent with AS and showed focal neutrophil infiltration. The patient received intensive immunosuppressive therapy for AS and vasculitic neuropathy, with high dose steroids, intravenous immunoglobulin (IVIg) and rituximab. Nonetheless, he suffered an unfavorable evolution with a fatal outcome due to septic shock. Albeit sclerodermiform features are rare in patients with AS, we propose a pathogenic link among AS, deep morphea and the autoimmune/autoinflammatory signs of MDS. The vasculopathic changes along with the activation of the innate and adaptive immune system leading to the production of proinflammatory cytokines may have been one of the contributing factors for the coexisting diagnosis of the patient.

Current Insights into CAR T-Cell-Based Therapies for Myelodysplastic Syndrome.

Myelodysplastic syndromes (MDS) are due to defective hematopoiesis in bone marrow characterized by cytopenia and dysplasia of blood cells, with a varying degree of risk of acute myeloid leukemia (AML). Currently, the only potentially curative strategy is hematopoietic stem cell transplantation (HSCT). Many patients are ineligible for HSCT, due to late diagnosis, presence of co-morbidities, old age and complications likely due to graft-versus-host disease (GvHD). As a consequence, patients with MDS are often treated conservatively with blood transfusions, chemotherapy, immunotherapy etc. based on the grade and manifestations of MDS. The development of chimeric antigen receptor (CAR)-T cell therapy has revolutionized immunotherapy for hematological malignancies, as evidenced by a large body of literature. However, resistance and toxicity associated with it are also a challenge. Hence, there is an urgent need to develop new strategies for immunological and hematopoetic management of MDS. Herein, we discuss current limitations of CAR T-cell therapy and summarize novel approaches to mitigate this. Further, we discuss the in vivo activation of tumor-specific T cells, immune check inhibitors (ICI) and other approaches to normalize the bone marrow milieu for the management of MDS.

Myeloid-derived suppressor cells: Implication in myeloid malignancies and immunotherapy.

Myeloid malignancies stem from a modified hematopoietic stem cell and predominantly include acute myeloid leukemia, myelodysplastic neoplasms, myeloproliferative malignancies, and chronic myelomonocytic leukemia. Myeloid-derived suppressor cells (MDSCs) exhibit immunoregulatory properties by governing the innate and adaptive immune systems, creating a permissive and supportive environment for neoplasm growth. This review examines the key characteristics of MDSCs in myeloid malignancies, highlighting that an increased MDSC count corresponds to heightened immunosuppressive capabilities, fostering an immune-tolerant neoplasm microenvironment. Also, this review analyzes and describes the potential of combined cancer therapies, focusing on targeting MDSC generation, expansion, and their inherent immunosuppressive activities to enhance the efficacy of current cancer immunotherapies. A comprehensive understanding of the implications of myeloid malignancies may enhance the exploration of immunotherapeutic strategies for their potential application.

Analyzing Differences in Hematological and Immunological Characteristics Related to Common Gene Mutations in Myelodysplastic Syndromes.

BACKGROUND: Genetic mutations play a crucial role in the development and progression of myelodysplastic syndromes (MDS), impacting the immune microenvironment and influencing the choice of treatment regimen, as well as the efficacy and prognosis of patients. The objective of this study was to examine variations in hematological and immunological characteristics associated with common gene mutations in MDS patients and establish a foundation for the precise treatment of MDS. METHODS: The hematological, immunological, and other clinical features of 71 recently diagnosed MDS patients from January 1, 2019, to July 31, 2023, were retrospectively analyzed. These patients were categorized based on their gene mutations, and the variances in hematological and immunological characteristics among distinct groups were compared. RESULTS: Hematological variances were observed among different gene mutation groups. Specifically, platelet counts in the splicing factor 3B subunit 1 (SF3B1) mutation group were notably higher compared to the wild-type group (p = 0.009). Conversely, in the additional sex combs like 1 (ASXL1) mutation groups, monocyte ratios were significantly elevated in comparison to the wild-type group (p = 0.046), and in the ten-eleven translocation 2 (TET2) mutation group, lymphocyte ratios were significantly lower (p = 0.022). Additionally, the leukocyte (p = 0.005), neutrophil ratio (p = 0.002), and lymphocyte ratio (p = 0.001) were significantly higher in the Runt-related transcription factor 1 (RUNX1) mutation group. Regarding immunological distinctions, the Natural Killer (NK) cell ratio demonstrated a significant increase in the SF3B1 mutation group (p = 0.005). Moreover, the TET2 mutation group exhibited a significantly higher Interleukin-8 (IL-8) level (p = 0.017). In contrast, the U2 small nuclear RNA auxiliary factor 1 (U2AF1) group displayed significantly lower levels of IL-1ß (p = 0.033), IL-10 (p = 0.033), and Tumour Necrosis Factor-α (TNF-α) (p = 0.009). CONCLUSION: Distinct variations exist in the immune microenvironment of MDS associated with different genetic mutations. Further studies are imperative to delve into the underlying mechanisms that drive these differences.

Comparative analysis of immunological changes following realgar and arsenic trioxide treatments in a murine model of myelodysplastic syndrome.

BACKGROUND: Myelodysplastic syndrome (MDS) is a prevalent hematological neoplastic disorder in clinics and its immunopathogenesis has garnered growing interest. Oral and intravenous arsenic agents have long been used to treat hematological malignancies. The main component of oral arsenic is realgar (arsenic disulfide), while arsenic trioxide is the main component of intravenous arsenic. METHODS: This study aimed to assess the effects of ATO and Realgar on the enhancement of peripheral blood, drug safety, and T cell immune status in the NUP98-HOXD13 (NHD13) mice model of MDS, specifically in the peripheral blood, spleen, and liver. RESULTS: The study findings indicate that realgar and arsenic trioxide (ATO) can improve peripheral hemogram in mice, whereas realgar promotes higher peripheral blood cell production than ATO. Furthermore, the clinical administration method and dose did not cause significant toxicity or side effects and thus can be considered safe. Coexistence and interconversion of hyperimmune function and immunosuppression in mice were also observed in this study. In addition, there were interactions between immune cells in the peripheral blood, spleen, and liver to regulate the immune balance of the body and activate immunity via T-cell activation. CONCLUSION: In summary, oral and intravenous arsenic agents are beneficial in improving peripheral hemogram and immunity in mice.

Supportive Care for Patients With Myelodysplastic Syndromes.

ABSTRACT: Myelodysplastic syndromes are a heterogeneous group of bone marrow disorders characterized by ineffective hematopoiesis, progressive cytopenias, and an innate capability of progressing to acute myeloid leukemia. The most common causes of morbidity and mortality are complications related to myelodysplastic syndromes rather than progression to acute myeloid leukemia. Although supportive care measures are applicable to all patients with myelodysplastic syndromes, they are especially essential in patients with lower-risk disease who have a better prognosis compared with their higher-risk counterparts and require longer-term monitoring of disease and treatment-related complications. In this review, we will address the most frequent complications and supportive care interventions used in patients with myelodysplastic syndromes, including transfusion support, management of iron overload, antimicrobial prophylaxis, important considerations in the era of COVID-19 (coronavirus infectious disease 2019), role of routine immunizations, and palliative care in the myelodysplastic syndrome population.

[The Distribution and Significance of Activated T Cells and Lymphocyte Subsets in Myelodysplastic Syndrome].

OBJECTIVE: To investigate the distribution of bone marrow lymphocyte subsets in patients with myelodysplastic syndrome(MDS),the proportion of activated T cells with immunophenotype CD3+HLA-DR+ in the lymphocytes and its clinical significance, and to understand the effects of different types of MDS, different immunophenotypes, and different expression levels of WT1 on the proportion of lymphocyte subsets and activated T cells. METHODS: The immunophenotypes of 96 MDS patients, the subsets of bone marrow lymphocytes and activated T cells were detected by flow cytometry. The relative expression of WT1 was detected by real-time fluorescent quantitative PCR, and the first induced remission rate (CR1) was calculated, the differences of lymphocyte subsets and activated T cells in MDS patients with different immunophenotype, different WT1 expression, and different course of disease were analyzed. RESULTS: The percentage of CD4+T lymphocyte in MDS-EB-2, IPSS high-risk, CD34+ cells >10%, and patients with CD34+CD7+ cell population and WT1 gene overexpression at intial diagnosis decreased significantly (P<0.05), and the percentage of NK cells and activated T cells increased significantly (P<0.05), but there was no significant difference in the ratio of B lymphocytes. Compared with the normal control group, the percentage of NK cells and activated T cells in IPSS-intermediate-2 group was significantly higher(P<0.05), but there was no significant difference in the percentage of CD3+T, CD4+T lymphocytes. The percentage of CD4+T cells in patients with complete remission after the first chemotherapy was significantly higher than in patients with incomplete remission(P<0.05), and the percentage of NK cells and activated T cells was significantly lower than that in patients with incomplete remission (P<0.05). CONCLUSION: In MDS patients, the proportion of CD3+T and CD4+T lymphocytes decreased, and the proportion of activated T cells increased, indicating that the differentiation type of MDS is more primitive and the prognosis is worse.

Epigenetic therapy in combination with a multi-epitope cancer vaccine targeting shared tumor antigens for high-risk myelodysplastic syndrome - a phase I clinical trial.

BACKGROUND: Standard care for patients with high-risk myelodysplastic syndrome (MDS) is hypomethylating agents such as azacitidine (AZA), which can induce expression of methylated tumor-associated antigens and therefore potentiate immunotherapeutic targeting. METHOD: In this phase 1 trial, we combined AZA with a therapeutic peptide vaccine targeting antigens encoded from NY-ESO-1, MAGE-A3, PRAME, and WT-1, which have previously been demonstrated to be upregulated by AZA treatment. RESULT: Five patients who had responded to AZA monotherapy were included in the study and treated with the vaccine. The combination therapy showed only few adverse events during the study period, whereof none classified as serious. However, no specific immune responses could be detected using intracellular cytokine staining or ELISpot assays. Minor changes in the phenotypic composition of immune cells and their expression of stimulatory and inhibitory markers were detected. All patients progressed to AML with a mean time to progression from inclusion (TTP) of 5.2 months (range 2.8 to 7.6). Mean survival was 18.1 months (range 10.9 to 30.6) from MDS diagnosis and 11.3 months (range 4.3 to 22.2) from inclusion. Sequencing of bone marrow showed clonal expansion of malignant cells, as well as appearance of novel mutations. CONCLUSION: The patients progressed to AML with an average time of only five months after initiating the combination therapy. This may be unrelated to the experimental treatment, but the trial was terminated early as there was no sign of clinical benefit or immunological response. Why the manuscript is especially interesting This study is the first to exploit the potential synergistic effects of combining a multi-peptide cancer vaccine with epigenetic therapy in MDS. Although our results are negative, they emphasize challenges to induce immune reactivity in patients with high-risk MDS.

Increased Circulating CD4+CXCR5+ Cells and IgG4 Levels in Patients with Myelodysplastic Syndrome with Autoimmune Diseases.

OBJECTIVES: Immune abnormalities play an important role in the pathogenesis and progression of myelodysplastic syndrome (MDS). Some patients with MDS have autoimmune diseases (AI). Follicular helper T (Tfh) cells help B cells produce antibodies. The role of Tfh in MDS with AI has not been studied. METHODS: We enrolled 21 patients with MDS with AI and 21 patients with MDS without AI. The proportion of peripheral blood CD4+CXCR5+ cells and the PD1 expression on CD4+CXCR5+ cells were detected by flow cytometry. Serum levels of immunoglobulin G (IgG) and IgG4 were measured. The survival and progression of MDS to acute myeloid leukemia (AML) in MDS patients with or without AI were compared. RESULTS: MDS with AI accounted for 19.6% of all MDS cases in our study. The overall response rate was 81% (17/21) in MDS patients with AI for the first-line treatment. The proportion of circulating CD4+CXCR5+ cells was increased, but the expression of PD1 was decreased in MDS patients with AI. Serum IgG4 levels were also increased in MDS patients with AI. The proportion of peripheral blood CD4+CXCR5+ cells and the level of serum IgG4 decreased after therapy, but the expression of PD1 increased. There were no differences in overall survival and progress to acute myeloid leukemia between MDS with AI and without AI groups. CONCLUSION: CD4+CXCR5+ cells and IgG4 levels increased in patients with MDS and AI.

Molecular Targeted Therapy and Immunotherapy for Myelodysplastic Syndrome.

Myelodysplastic syndrome (MDS) is a heterogeneous, clonal hematological disorder characterized by ineffective hematopoiesis, cytopenia, morphologic dysplasia, and predisposition to acute myeloid leukemia (AML). Stem cell genomic instability, microenvironmental aberrations, and somatic mutations contribute to leukemic transformation. The hypomethylating agents (HMAs), azacitidine and decitabine are the standard of care for patients with higher-risk MDS. Although these agents induce responses in up to 40-60% of patients, primary or secondary drug resistance is relatively common. To improve the treatment outcome, combinational therapies comprising HMA with targeted therapy or immunotherapy are being evaluated and are under continuous development. This review provides a comprehensive update of the molecular pathogenesis and immune-dysregulations involved in MDS, mechanisms of resistance to HMA, and strategies to overcome HMA resistance.

Mutant U2AF1-induced alternative splicing of H2afy (macroH2A1) regulates B-lymphopoiesis in mice.

Somatic mutations in spliceosome genes are found in ∼50% of patients with myelodysplastic syndromes (MDS), a myeloid malignancy associated with low blood counts. Expression of the mutant splicing factor U2AF1(S34F) alters hematopoiesis and mRNA splicing in mice. Our understanding of the functionally relevant alternatively spliced target genes that cause hematopoietic phenotypes in vivo remains incomplete. Here, we demonstrate that reduced expression of H2afy1.1, an alternatively spliced isoform of the histone H2A variant gene H2afy, is responsible for reduced B cells in U2AF1(S34F) mice. Deletion of H2afy or expression of U2AF1(S34F) reduces expression of Ebf1 (early B cell factor 1), a key transcription factor for B cell development, and mechanistically, H2AFY is enriched at the EBF1 promoter. Induced expression of H2AFY1.1 in U2AF1(S34F) cells rescues reduced EBF1 expression and B cells numbers in vivo. Collectively, our data implicate alternative splicing of H2AFY as a contributor to lymphopenia induced by U2AF1(S34F) in mice and MDS.

Therapeutic targeting of the inflammasome in myeloid malignancies.

Even though genetic perturbations and mutations are important for the development of myeloid malignancies, the effects of an inflammatory microenvironment are a critical modulator of carcinogenesis. Activation of the innate immune system through various ligands and signaling pathways is an important driver of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). The DAMPs, or alarmins, which activate the inflammasome pathway via the TLR4/NLR signaling cascade causes the lytic cell death of hematopoietic stem and progenitor cells (HSPCs), ineffective hematopoiesis, and ß-catenin-induced proliferation of cancer cells, leading to the development of MDS/AML phenotype. It is also associated with other myeloid malignancies and involved in the pathogenesis of associated cytopenias. Ongoing research suggests the interplay of inflammasome mediators with immune modulators and transcription factors to have a significant role in the development of myeloid diseases, and possibly therapy resistance. This review discusses the role and importance of inflammasomes and immune pathways in myeloid malignancies, particularly MDS/AML, to better understand the disease pathophysiology and decipher the scope of therapeutic interventions.

Risk of infection according to the gamma globulin level in the 100 days following allogeneic stem cell transplantations.

BACKGROUND: Immunoglobulin replacement therapy is recommended in case of severe hypogammaglobulinemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the supposed increased risk of infection in case of hypogammaglobulinemia has not been confirmed in allo-HSCT. In this study, we assessed the relationship between the gamma globulin level and the risk of infection during the 100 days following the allo-HSCT. METHODS: We gathered the weekly laboratory tests from day 7 to day 100 of 76 allograft patients, giving a total of 1 044 tests. 130 infections were documented clinically, by imaging, or microbiologically. RESULTS: Average gamma globulin levels between D-7 and D100 did not differ between patients with or without infection (642 ± 232 and 671 ± 246 mg/dL, respectively, P = .65). Gamma globulin level <400 mg/dl was not associated with the occurrence of infection between the test studied and the next one (aOR 1.33 [0.84-2.15], P = .24). The gamma globulin level was not predictive of bacterial or fungal infections (AUC 0.54 [95%CI: 0.47-0.61]) nor of viral reactivations (AUC 0.51 [95%CI: 0.43-0.60]). CONCLUSIONS: This confirmed that the humoral deficiency is a minor part of the immune deficiency in the 100 days post-transplant. This questions the relevance of the indications of immunoglobulin substitution during this period.

Innate immune pathways and inflammation in hematopoietic aging, clonal hematopoiesis, and MDS.

With a growing aged population, there is an imminent need to develop new therapeutic strategies to ameliorate disorders of hematopoietic aging, including clonal hematopoiesis and myelodysplastic syndrome (MDS). Cell-intrinsic dysregulation of innate immune- and inflammatory-related pathways as well as systemic inflammation have been implicated in hematopoietic defects associated with aging, clonal hematopoiesis, and MDS. Here, we review and discuss the role of dysregulated innate immune and inflammatory signaling that contribute to the competitive advantage and clonal dominance of preleukemic and MDS-derived hematopoietic cells. We also propose how emerging concepts will further reveal critical biology and novel therapeutic opportunities.