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American Journal of Hematology Mar 2022Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes and myeloproliferative... (Review)
Review
DISEASE OVERVIEW
Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes and myeloproliferative neoplasms, with an inherent risk for leukemic transformation (~15% over 3-5 years).
DIAGNOSIS
Diagnosis is based on the presence of sustained (>3 months) peripheral blood monocytosis (≥1 × 10 /L; monocytes ≥10%), usually with accompanying bone marrow dysplasia. Clonal cytogenetic abnormalities occur in ~30% of patients, while >90% have somatic gene mutations. Mutations involving TET2 (~60%), SRSF2 (~50%), ASXL1 (~40%), and the oncogenic RAS pathway (~30%) are frequent, while the presence of ASXL1 and DNMT3A mutations and the absence of TET2 mutations negatively impact overall survival.
RISK-STRATIFICATION
Molecularly integrated prognostic models include the Groupe Français des Myélodysplasies, Mayo Molecular Model (MMM), and the CMML specific prognostic model. Risk factors incorporated into the MMM include presence of truncating ASXL1 mutations, absolute monocyte count >10 × 10 /L, hemoglobin <10 g/dL, platelet count <100 × 10 /L, and the presence of circulating immature myeloid cells. The MMM stratifies CMML patients into four groups: high (≥3 risk factors), intermediate-2 (2 risk factors), intermediate-1 (1 risk factor), and low (no risk factors), with median survivals of 16, 31, 59, and 97 months, respectively.
RISK-ADAPTED THERAPY
Hypomethylating agents such as 5-azacitidine and decitabine are commonly used, with overall response rates of ~40%-50% and complete remission rates of ~7%-17%; with no impact on mutational allele burdens. Allogeneic stem cell transplant is the only potentially curative option but is associated with significant morbidity and mortality.
Topics: Chromosome Aberrations; Disease-Free Survival; Humans; Leukemia, Myelomonocytic, Chronic; Neoplasm Proteins; Risk Assessment; Risk Factors; Survivors
PubMed: 34985762
DOI: 10.1002/ajh.26455 -
Hematology. American Society of... Dec 2020Myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) overlap syndromes are unique myeloid neoplasms, with overlapping features of MDS and MPN. They consist... (Review)
Review
Myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) overlap syndromes are unique myeloid neoplasms, with overlapping features of MDS and MPN. They consist of four adult onset entities including chronic myelomonocytic leukemia (CMML), MDS/MPN-ring sideroblasts-thrombocytosis (MDS/MPN-RS-T), BCR-ABL1 negative atypical chronic myeloid leukemia (aCML) and MDS/MPN-unclassifiable (MDS/MPN-U); with juvenile myelomonocytic leukemia (JMML) being the only pediatric onset entity. Among these overlap neoplasms, CMML is the most frequent and is hallmarked by the presence of sustained peripheral blood monocytosis with recurrent mutations involving TET2 (60%), SRSF2 (50%) and ASXL1 (40%); with RAS pathway mutations and JAK2V617F being relatively enriched in proliferative CMML subtypes (WBC ≥13 × 109/L). CMML usually presents in the 7th decade of life, with a male preponderance and is associated with a median overall survival of <36 months. Adverse prognosticators in CMML include increasing age, high WBC, presence of circulating immature myeloid cells, anemia, thrombocytopenia and truncating ASXL1 mutations. While allogeneic stem cell transplantation remains the only curative option, given the late onset of this neoplasm and high frequency of comorbidities, most patients remain ineligible. Hypomethylating agents such as azacitidine, decitabine and oral decitabine/cedazuridine have been US FDA approved for the management of CMML, with overall response rates of 40-50% and complete remission rates of <20%. While these agents epigenetically restore hematopoiesis in a subset of responding patients, they do not impact mutational allele burdens and eventual disease progression to AML remains inevitable. Newer treatment modalities exploiting epigenetic, signaling and splicing abnormalities commonly seen in CMML are much needed.
Topics: Administration, Oral; Antineoplastic Agents; Humans; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myelomonocytic, Juvenile; Mutation; Myelodysplastic Syndromes; Neoplasm Proteins
PubMed: 33275673
DOI: 10.1182/hematology.2020000163 -
Cells Aug 2021Classically, the following three morphological states of microglia have been defined: ramified, amoeboid and phagocytic. While ramified cells were long regarded as... (Review)
Review
Classically, the following three morphological states of microglia have been defined: ramified, amoeboid and phagocytic. While ramified cells were long regarded as "resting", amoeboid and phagocytic microglia were viewed as "activated". In aged human brains, a fourth, morphologically novel state has been described, i.e., dystrophic microglia, which are thought to be senescent cells. Since microglia are not replenished by blood-borne mononuclear cells under physiological circumstances, they seem to have an "expiration date" limiting their capacity to phagocytose and support neurons. Identifying factors that drive microglial aging may thus be helpful to delay the onset of neurodegenerative diseases, such as Alzheimer's disease (AD). Recent progress in single-cell deep sequencing methods allowed for more refined differentiation and revealed regional-, age- and sex-dependent differences of the microglial population, and a growing number of studies demonstrate various expression profiles defining microglial subpopulations. Given the heterogeneity of pathologic states in the central nervous system, the need for accurately describing microglial morphology and expression patterns becomes increasingly important. Here, we review commonly used microglial markers and their fluctuations in expression in health and disease, with a focus on IBA1 low/negative microglia, which can be found in individuals with liver disease.
Topics: Animals; Antigens, CD; Antigens, Differentiation, B-Lymphocyte; Antigens, Differentiation, Myelomonocytic; Brain; Calcium-Binding Proteins; Histocompatibility Antigens Class II; Humans; Membrane Proteins; Microfilament Proteins; Microglia; Nerve Tissue Proteins; Neurodegenerative Diseases; Phagocytes; Phenotype; Receptors, Purinergic P2Y12; Signal Transduction
PubMed: 34571885
DOI: 10.3390/cells10092236 -
Cells May 2020Macrophages facilitate essential homeostatic functions e.g., endocytosis, phagocytosis, and signaling during inflammation, and express a variety of scavenger receptors... (Review)
Review
Macrophages facilitate essential homeostatic functions e.g., endocytosis, phagocytosis, and signaling during inflammation, and express a variety of scavenger receptors including CD163 and CD206, which are upregulated in response to inflammation. In healthy individuals, soluble forms of CD163 and CD206 are constitutively shed from macrophages, however, during inflammation pathogen- and damage-associated stimuli induce this shedding. Activation of resident liver macrophages viz. Kupffer cells is part of the inflammatory cascade occurring in acute and chronic liver diseases. We here review the existing literature on sCD163 and sCD206 function and shedding, and potential as biomarkers in acute and chronic liver diseases with a particular focus on Acute-on-Chronic Liver Failure (ACLF). In multiple studies sCD163 and sCD206 are elevated in relation to liver disease severity and established as reliable predictors of morbidity and mortality. However, differences in expression- and shedding-stimuli for CD163 and CD206 may explain dissimilarities in prognostic utility in patients with acute decompensation of cirrhosis and ACLF.
Topics: Acute-On-Chronic Liver Failure; Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Biomarkers; Humans; Lectins, C-Type; Macrophage Activation; Macrophages; Mannose Receptor; Mannose-Binding Lectins; Receptors, Cell Surface
PubMed: 32397365
DOI: 10.3390/cells9051175 -
Haematologica Jul 2022Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome/myeloproliferative overlap neoplasm characterized by sustained peripheral blood monocytosis and an...
Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome/myeloproliferative overlap neoplasm characterized by sustained peripheral blood monocytosis and an inherent risk for transformation to acute myeloid leukemia (15-30% over 3-5 years). While CMML is morphologically classified into CMML-0, 1 and 2 based on peripheral blood and bone marrow promonocyte/blast counts, a more clinically relevant classification into dysplastic and proliferative subtypes, based on the presenting white blood cell count, is helpful in prognostication and therapeutics. CMML is a neoplasm associated with aging, occurring on the background of clonal hematopoiesis, with TET2 and SRSF2 mutations being early initiating events. The subsequent acquisitions of ASXL1, RUNX1, SF3B1 and DNMT3A mutations usually give rise to dysplastic CMML, while ASXL1, JAK2V617F and RAS pathway mutations give rise to proliferative CMML. Patients with proliferative CMML have a more aggressive course with higher rates of transformation to acute myeloid leukemia. Allogeneic stem cell transplant remains the only potential cure for CMML; however, given the advanced median age at presentation (73 years) and comorbidities, it is an option for only a few affected patients (10%). While DNA methyltransferase inhibitors are approved for the management of CMML, the overall response rates are 40-50%, with true complete remission rates of <20%. These agents seem to be particularly ineffective in proliferative CMML subtypes with RAS mutations, while the TET2mutant/ASXL1wildtype genotype seems to be the best predictor for responses. These agents epigenetically restore hematopoiesis in responding patients without altering mutational allele burdens and progression remains inevitable. Rationally derived personalized/targeted therapies with disease-modifying capabilities are much needed.
Topics: Humans; Leukemia, Myelomonocytic, Chronic; Leukemia, Myelomonocytic, Juvenile; Mutation; Myelodysplastic-Myeloproliferative Diseases; Prognosis
PubMed: 35236051
DOI: 10.3324/haematol.2021.279500 -
Journal of Clinical Medicine Jul 2021Juvenile myelomonocytic leukemia (JMML) is a rare pediatric leukemia characterized by mutations in five canonical RAS pathway genes. The diagnosis is made by typical... (Review)
Review
Juvenile myelomonocytic leukemia (JMML) is a rare pediatric leukemia characterized by mutations in five canonical RAS pathway genes. The diagnosis is made by typical clinical and hematological findings associated with a compatible mutation. Although this is sufficient for clinical decision-making in most JMML cases, more in-depth analysis can include DNA methylation class and panel sequencing analysis for secondary mutations. -initiated JMML is heterogeneous and adequate management ranges from watchful waiting to allogeneic hematopoietic stem cell transplantation (HSCT). Upfront azacitidine in patients can achieve long-term remissions without HSCT; if HSCT is required, a less toxic preparative regimen is recommended. Germline patients often experience spontaneous resolution of the leukemia or exhibit stable mixed chimerism after HSCT. JMML driven by or is often rapidly progressive, requires swift HSCT and may benefit from pretransplant therapy with azacitidine. Because graft-versus-leukemia alloimmunity is central to cure high risk patients, the immunosuppressive regimen should be discontinued early after HSCT.
PubMed: 34300250
DOI: 10.3390/jcm10143084 -
American Journal of Blood Research 2021Juvenile myelomonocytic leukemia (JMML) is a rare pediatric myelodysplastic/myeloproliferative neoplasm overlap disease. JMML is associated with mutations in the RAS... (Review)
Review
Juvenile myelomonocytic leukemia (JMML) is a rare pediatric myelodysplastic/myeloproliferative neoplasm overlap disease. JMML is associated with mutations in the RAS pathway genes resulting in the myeloid progenitors being sensitive to granulocyte monocyte colony-stimulating factor (GM-CSF). Karyotype abnormalities and additional epigenetic alterations can also be found in JMML. Neurofibromatosis and Noonan's syndrome have a predisposition for JMML. In a few patients, the genes (, and ) are mutated at the germline and this usually results in a transient myeloproliferative disorder with a good prognosis. JMML with somatic mutation behaves aggressively. JMML presents with cytopenias and leukemic infiltration into organs. The laboratory findings include hyperleukocytosis, monocytosis, increased hemoglobin-F levels, and circulating myeloid precursors. The blast cells in the peripheral blood/bone-marrow aspirate are less than 20% and the absence of the BCR-ABL translocation helps to differentiate from chronic myeloid leukemia. JMML should be differentiated from immunodeficiencies, viral infections, intrauterine infections, hemophagolymphohistiocytosis, other myeloproliferative disorders, and leukemias. Chemotherapy is employed as a bridge to HSCT, except in few with less aggressive disease, in which chemotherapy alone can result in long term remission. Azacitidine has shown promise as a single agent to stabilize the disease. The prognosis of JMML is poor with about 50% of patients surviving after an allogeneic hematopoietic stem cell transplant (HSCT). Allogeneic HSCT is the only known cure for JMML to date. Myeloablative conditioning is most commonly used with graft versus host disease (GVHD) prophylaxis tailored to the aggressiveness of the disease. Relapses are common even after HSCT and a second HSCT can salvage a third of these patients. Novel options in the treatment of JMML e.g., hypomethylating agents, MEK inhibitors, JAK inhibitors, tyrosine kinase inhibitors, etc. are being explored.
PubMed: 33796386
DOI: No ID Found -
International Journal of Molecular... Jul 2020The macrophage is a key cell in the pro- and anti-inflammatory response including that of the inflammatory microenvironment of malignant tumors. Much current drug... (Review)
Review
The macrophage is a key cell in the pro- and anti-inflammatory response including that of the inflammatory microenvironment of malignant tumors. Much current drug development in chronic inflammatory diseases and cancer therefore focuses on the macrophage as a target for immunotherapy. However, this strategy is complicated by the pleiotropic phenotype of the macrophage that is highly responsive to its microenvironment. The plasticity leads to numerous types of macrophages with rather different and, to some extent, opposing functionalities, as evident by the existence of macrophages with either stimulating or down-regulating effect on inflammation and tumor growth. The phenotypes are characterized by different surface markers and the present review describes recent progress in drug-targeting of the surface marker CD163 expressed in a subpopulation of macrophages. CD163 is an abundant endocytic receptor for multiple ligands, quantitatively important being the haptoglobin-hemoglobin complex. The microenvironment of inflammation and tumorigenesis is particular rich in CD163 macrophages. The use of antibodies for directing anti-inflammatory (e.g., glucocorticoids) or tumoricidal (e.g., doxorubicin) drugs to CD163 macrophages in animal models of inflammation and cancer has demonstrated a high efficacy of the conjugate drugs. This macrophage-targeting approach has a low toxicity profile that may highly improve the therapeutic window of many current drugs and drug candidates.
Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Humans; Inflammation; Macrophages; Molecular Targeted Therapy; Neoplasms; Receptors, Cell Surface; Tumor Microenvironment
PubMed: 32752088
DOI: 10.3390/ijms21155497 -
Haematologica Oct 2019Chronic myelomonocytic leukemia (CMML) is a myeloid neoplasm characterized by dysplasia, abnormal production and accumulation of monocytic cells and an elevated risk of... (Review)
Review
Chronic myelomonocytic leukemia (CMML) is a myeloid neoplasm characterized by dysplasia, abnormal production and accumulation of monocytic cells and an elevated risk of transforming into acute leukemia. Over the past two decades, our knowledge about the pathogenesis and molecular mechanisms in CMML has increased substantially. In parallel, better diagnostic criteria and therapeutic strategies have been developed. However, many questions remain regarding prognostication and optimal therapy. In addition, there is a need to define potential pre-phases of CMML and special CMML variants, and to separate these entities from each other and from conditions mimicking CMML. To address these unmet needs, an international consensus group met in a Working Conference in August 2018 and discussed open questions and issues around CMML, its variants, and pre-CMML conditions. The outcomes of this meeting are summarized herein and include diag nostic criteria and a proposed classification of pre-CMML conditions as well as refined minimal diagnostic criteria for classical CMML and special CMML variants, including oligomonocytic CMML and CMML associated with systemic mastocytosis. Moreover, we propose diagnostic standards and tools to distinguish between 'normal', pre-CMML and CMML entities. These criteria and standards should facilitate diagnostic and prognostic evaluations in daily practice and clinical studies in applied hematology.
Topics: Aged; Congresses as Topic; Female; Humans; Leukemia, Myelomonocytic, Chronic; Male; Middle Aged; Practice Guidelines as Topic; Precancerous Conditions
PubMed: 31048353
DOI: 10.3324/haematol.2019.222059 -
The Journal of Experimental Medicine Apr 2020Experimental and clinical evidence suggests that tumor-associated macrophages (TAMs) play important roles in cancer progression. Here, we have characterized the ontogeny...
Experimental and clinical evidence suggests that tumor-associated macrophages (TAMs) play important roles in cancer progression. Here, we have characterized the ontogeny and function of TAM subsets in a mouse model of metastatic ovarian cancer that is representative for visceral peritoneal metastasis. We show that the omentum is a critical premetastatic niche for development of invasive disease in this model and define a unique subset of CD163+ Tim4+ resident omental macrophages responsible for metastatic spread of ovarian cancer cells. Transcriptomic analysis showed that resident CD163+ Tim4+ omental macrophages were phenotypically distinct and maintained their resident identity during tumor growth. Selective depletion of CD163+ Tim4+ macrophages in omentum using genetic and pharmacological tools prevented tumor progression and metastatic spread of disease. These studies describe a specific role for tissue-resident macrophages in the invasive progression of metastatic ovarian cancer. The molecular pathways of cross-talk between tissue-resident macrophages and disseminated cancer cells may represent new targets to prevent metastasis and disease recurrence.
Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Disease Models, Animal; Disease Progression; Female; Gene Expression Profiling; Macrophages; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Omentum; Ovarian Neoplasms; Peritoneal Neoplasms; Phenotype; Receptors, Cell Surface; Transcriptome
PubMed: 31951251
DOI: 10.1084/jem.20191869