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Open accessJournal ArticleDOI: 10.1038/S41375-021-01190-9

Clinical and prognostic significance of small paroxysmal nocturnal hemoglobinuria clones in myelodysplastic syndrome and aplastic anemia.

04 Mar 2021-Leukemia (Nature Publishing Group)-Vol. 35, Iss: 11, pp 3223-3231
Abstract: In this large single-centre study, we report high prevalence (25%) of, small (<10%) and very small (<1%), paroxysmal nocturnal hemoglobinuria (PNH) clones by high-sensitive cytometry among 3085 patients tested. Given PNH association with bone marrow failures, we analyzed 869 myelodysplastic syndromes (MDS) and 531 aplastic anemia (AA) within the cohort. PNH clones were more frequent and larger in AA vs. MDS (p = 0.04). PNH clone, irrespective of size, was a good predictor of response to immunosuppressive therapy (IST) and to stem cell transplant (HSCT) (in MDS: 84% if PNH+ vs. 44.7% if PNH−, p = 0.01 for IST, and 71% if PNH+ vs. 56.6% if PNH− for HSCT; in AA: 78 vs. 50% for IST, p < 0.0001, and 97 vs. 77%, p = 0.01 for HSCT). PNH positivity had a favorable impact on disease progression (0.6% vs. 4.9% IPSS-progression in MDS, p < 0.005; and 2.1 vs. 6.9% progression to MDS in AA, p = 0.01), leukemic evolution (6.8 vs. 12.7%, p = 0.01 in MDS), and overall survival [73% (95% CI 68–77) vs. 51% (48–54), p < 0.0001], with a relative HR for mortality of 2.37 (95% CI 1.8–3.1; p < 0.0001) in PNH negative cases, both in univariate and multivariable analysis. Our data suggest systematic PNH testing in AA/MDS, as it might allow better prediction/prognostication and consequent clinical/laboratory follow-up timing.

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11 results found

Open accessJournal ArticleDOI: 10.1182/BLOODADVANCES.2021004345
Amy E. DeZern1, Jane E. Churpek2Institutions (2)
22 Jun 2021-Blood Advances
Abstract: Establishing a diagnosis of aplastic anemia (AA) can be challenging, but it is absolutely critical to appropriate management, especially differentiating between acquired and inherited forms of the disease. The hematology field requires updated diagnostic guidelines to ensure that appropriate clinical pathways are pursued for patients and their safety. There are increasing clinical options for patients with immunosuppressive therapy and transplant once the diagnosis is made. In a case-based format, this review emphasizes the newer data on molecular (somatic and germline) findings in AA and how they are (or are not) helpful during diagnosis. There are key details on somatic mutation profiles and stated evidence where available for prognostic and treatment indications. Germline details of newer syndromes are also outlined, which make this review modern and reflect areas of uncertainty for clinicians.

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1 Citations

Open accessJournal ArticleDOI: 10.3389/FONC.2021.756589
Abstract: Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by intravascular hemolytic anemia and thrombosis and is notoriously associated with aplastic anemia and myelodysplastic syndromes. Rarer associations include myeloproliferative neoplasms (MPNs), which are also burdened by increased thrombotic tendency. The therapeutic management of this rare combination has not been defined so far. Here, we describe a 62-year-old man who developed a highly hemolytic PNH more than 10 years after the diagnosis of MPN. The patient started eculizumab, obtaining good control of intravascular hemolysis but without amelioration of transfusion-dependent anemia. Moreover, we performed a review of the literature regarding the clinical and pathogenetic significance of the association of PNH and MPN. The prevalence of PNH clones in MPN patients is about 10%, mostly in association with JAK2V617F-positive myelofibrosis. Thrombotic events were a common clinical presentation (35% of subjects), sometimes refractory to combined treatment with cytoreductive agents, anticoagulants, and complement inhibitors. The latter showed only partial effectiveness in controlling hemolytic anemia and, due to the paucity of data, should be taken in consideration after a careful risk/benefit evaluation in this peculiar setting.

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Topics: Eculizumab (63%), Paroxysmal nocturnal hemoglobinuria (62%), Myeloproliferative neoplasm (56%) ... show more

Open accessJournal ArticleDOI: 10.1186/S13023-021-02036-4
Abstract: Congenital hemolytic anemias (CHAs) comprise defects of the erythrocyte membrane proteins and of red blood cell enzymes metabolism, along with alterations of erythropoiesis. These rare and heterogeneous conditions may generate several difficulties from the diagnostic point of view. Membrane defects include hereditary spherocytosis and elliptocytosis, and the group of hereditary stomatocytosis; glucose-6-phosphate dehydrogenase and pyruvate kinase, are the most common enzyme deficiencies. Among ultra-rare forms, it is worth reminding other enzyme defects (glucosephosphate isomerase, phosphofructokinase, adenylate kinase, triosephosphate isomerase, phosphoglycerate kinase, hexokinase, and pyrimidine 5′-nucleotidase), and congenital dyserythropoietic anemias. Family history, clinical findings (anemia, hemolysis, splenomegaly, gallstones, and iron overload), red cells morphology, and biochemical tests are well recognized diagnostic tools. Molecular findings are increasingly used, particularly in recessive and de novo cases, and may be fundamental in unraveling the diagnosis. Notably, several confounders may further challenge the diagnostic workup, including concomitant blood loss, nutrients deficiency, alterations of hemolytic markers due to other causes (alloimmunization, infectious agents, rare metabolic disorders), coexistence of other hemolytic disorders (autoimmune hemolytic anemia, paroxysmal nocturnal hemoglobinuria, etc.). Additional factors to be considered are the possible association with bone marrow, renal or hepatic diseases, other causes of iron overload (hereditary hemochromatosis, hemoglobinopathies, metabolic diseases), and the presence of extra-hematological signs/symptoms. In this review we provide some instructive clinical vignettes that highlight the difficulties and confounders encountered in the diagnosis and clinical management of CHAs.

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Open accessJournal ArticleDOI: 10.3389/FIMMU.2021.751630
Abstract: Immune phenomena are increasingly reported in myeloid neoplasms, and include autoimmune cytopenias/diseases and immunodeficiency, either preceding or complicating acute myeloid leukemia, myelodysplastic syndromes (MDS), chronic myeloproliferative neoplasms, and bone marrow failure (BMF) syndromes. Autoimmunity and immunodeficiency are the two faces of a dysregulated immune tolerance and surveillance and may result, along with contributing environmental and genetic factors, in an increased incidence of both tumors and infections. The latter may fuel both autoimmunity and immune activation, triggering a vicious circle among infections, tumors and autoimmune phenomena. Additionally, alterations of the microbiota and of mesenchymal stem cells (MSCs) pinpoint to the importance of a permissive or hostile microenvironment for tumor growth. Finally, several therapies of myeloid neoplasms are aimed at increasing host immunity against the tumor, but at the price of increased autoimmune phenomena. In this review we will examine the epidemiological association of myeloid neoplasms with autoimmune diseases and immunodeficiencies, and the pivotal role of autoimmunity in the pathogenesis of MDS and BMF syndromes, including the paroxysmal nocturnal hemoglobinuria conundrum. Furthermore, we will briefly examine autoimmune complications following therapy of myeloid neoplasms, as well as the role of MSCs and microbiota in these settings.

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Topics: Myeloid leukemia (59%), Myeloid (56%), Immunodeficiency (54%) ... show more

Open accessJournal ArticleDOI: 10.3389/FONC.2021.748610
Abstract: Large granular lymphocytes (LGL) are lymphoid cells characterized by either a T-cell or a natural killer phenotype whose expansion may be reactive to toxic, infectious, and neoplastic conditions, or result from clonal selection. Recently, the higher attention to LGL clones led to their detection in many clinical conditions including myeloid neoplasms and bone marrow failures. In these contexts, it is still unclear whether LGL cells actively contribute to anti-stem cell autoimmunity or are only a reaction to dysplastic/leukemic myelopoiesis. Moreover, some evidence exists about a common clonal origin of LGL and myeloid clones, including the detection of STAT3 mutations, typical of LGL, in myeloid precursors from myelodysplastic patients. In this article we reviewed available literature regarding the association of LGL clones with myeloid neoplasms (myelodysplastic syndromes, myeloproliferative neoplasms, and acute myeloid leukemias) and bone marrow failures (aplastic anemia and pure red cell aplasia, PRCA) focusing on evidence of pathogenic, clinical, and prognostic relevance. It emerged that LGL clones may be found in up to one third of patients, particularly those with PRCA, and are associated with a more cytopenic phenotype and good response to immunosuppression. Pathogenically, LGL clones seem to expand after myeloid therapies, whilst immunosuppression leading to LGL depletion may favor leukemic escape and thus requires caution.

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Topics: Myeloid (58%), Myeloproliferative neoplasm (55%), Pure red cell aplasia (53%) ... show more


20 results found

Open accessJournal ArticleDOI: 10.1002/CYTO.B.20525
Abstract: Background: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematopoietic stem cell disorder characterized by a somatic mutation in the PIGA gene, leading to a deficiency of proteins linked to the cell membrane via glycophosphatidylinositol (GPI) anchors. While flow cytometry is the method of choice for identifying cells deficient in GPI-linked proteins and is, therefore, necessary for the diagnosis of PNH, to date there has not been an attempt to standardize the methodology used to identify these cells. Methods: In this document, we present a consensus effort that describes flow cytometric procedures for detecting PNH cells. Results: We discuss clinical indications and offer recommendations on data interpretation and reporting but mostly focus on analytical procedures important for analysis. We distinguish between routine analysis (defined as identifying an abnormal population of 1% or more) and high-sensitivity analysis (in which as few as 0.01% PNH cells are detected). Antibody panels and gating strategies necessary for both procedures are presented in detail. We discuss methods for assessing PNH populations in both white blood cells and red blood cells and the relative advantages of measuring each. We present steps needed to validate the more elaborate high-sensitivity techniques, including the need for careful titration of reagents and determination of background rates in normal populations, and discuss technical pitfalls that might affect interpretation. Conclusions: This document should both enable laboratories interested in beginning PNH testing to establish a valid procedure and allow experienced laboratories to improve their techniques. © 2010 Clinical Cytometry Society

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282 Citations

Open accessJournal ArticleDOI: 10.1182/BLOOD-2005-06-2485
15 Feb 2006-Blood
Abstract: We investigated the clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria (PNH)-type blood cells in patients with acquired aplastic anemia (AA). We quantified CD55-CD59- granulocytes and red blood cells (RBCs) in peripheral blood from 122 patients with recently diagnosed AA and correlated numbers of PNH-type cells and responses to immunosuppressive therapy (IST). Flow cytometry detected 0.005% to 23.1% of GPI-AP- cells in 68% of patients with AA. Sixty-eight of 83 (91%) patients with an increased proportion of PNH-type cells (PNH+) responded to antithymocyte globulin (ATG) + cyclosporin (CsA) therapy, whereas 18 of 39 (48%) without such an increase (PNH-) responded. Failure-free survival rates were significantly higher (64%) among patients with PNH+ than patients with PNH- (12%) at 5 years, although overall survival rates were comparable between the groups. Numbers of PNH-type and normal-type cells increased in parallel among most patients with PNH+ who responded to IST, suggesting that these cells are equally sensitive to immune attack. These results indicate that a minor population of PNH-type cells represents a reliable marker of a positive IST response and a favorable prognosis among patients with AA. Furthermore, immune attack against hematopoietic stem cells that allows PNH clonal expansion might occur only at the onset of AA.

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Topics: Aplastic anemia (60%), Bone marrow failure (58%), Paroxysmal nocturnal hemoglobinuria (57%) ... show more

252 Citations

Journal ArticleDOI: 10.1182/BLOOD-2002-03-0799
Hongbo Wang1, Tatsuya Chuhjo2, Tatsuya Chuhjo1, Shizuka Yasue1  +5 moreInstitutions (2)
01 Dec 2002-Blood
Abstract: A minor population of blood cells deficient of glycosylphosphatidylinositol (GPI)–anchored membrane proteins is often detected in patients with aplastic anemia (AA), though the clinical significance of such paroxysmal nocturnal hemoglobinuria (PNH)–type cells remains unclear. To clarify this issue, we studied 164 patients with myelodysplastic syndrome (MDS) for the presence of CD55−CD59− granulocytes and red blood cells using sensitive flow cytometry. Among the different subgroups of MDS, a significant increase (ie, at least 0.003%) of PNH-type cells was detected in 21 of 119 patients with refractory anemia (RA); this frequency (17.6%) of RA patients with increased PNH-type cells (PNH+ patients) was much lower than what we previously reported (52.0%) for AA patients. PNH+ RA patients had distinct clinical features compared with RA patients without increased PNH-type cells (PNH− patients), such as less pronounced morphologic abnormality of blood cells, more severe thrombocytopenia, lower rates of karyotypic abnormality (4.8% vs 32.8%) and of progression to acute leukemia (0% vs 6.2%), higher probability of response to cyclosporine therapy (77.8% vs 0%), and higher incidence of HLA-DR15 (90.5% vs 18.5%). These data indicate that the presence of a minor population of PNH-type cells suggests a benign type of bone marrow failure, probably caused by an immunologic mechanism. To choose an appropriate therapy, peripheral blood should be tested using sensitive flow cytometry for the presence of PNH-type cells in all patients with bone marrow failure before treatment.

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Topics: Bone marrow failure (63%), Paroxysmal nocturnal hemoglobinuria (62%), Aplastic anemia (61%) ... show more

196 Citations

Open accessJournal ArticleDOI: 10.1111/J.1365-2141.2008.07450.X
Abstract: Horse anti-thymocyte globulin (h-ATG) and ciclosporin are the initial therapy for most patients with severe aplastic anaemia (SAA), but there is no practical and reliable method to predict response to this treatment. To determine whether pretreatment blood counts discriminate patients with SAA who have a higher likelihood of haematological response at 6 months to immunosuppressive therapy (IST), we conducted a single institution retrospective analysis on 316 SAA patients treated with h-ATG-based IST from 1989 to 2005. In multivariate analysis, younger age, higher baseline absolute reticulocyte count (ARC), and absolute lymphocyte count (ALC) were highly predictive of response at 6 months. Patients with baseline ARC > or = 25 x 10(9)/l and ALC > or = 1 x 10(9)/l had a much greater probability of response at 6 months following IST compared to those with lower ARC and ALC (83% vs. 41%, respectively; P < 0.001). This higher likelihood of response translated to greater rate of 5-year survival in patients in the high ARC/ALC group (92%) compared to those with a low ARC/ALC (53%). In the era of IST, the baseline ARC and ALC together serve as a simple predictor of response following IST, which should guide in risk stratification among patients with SAA.

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162 Citations

Open accessJournal ArticleDOI: 10.1111/J.1365-2141.2009.07822.X
Chiharu Sugimori1, Kanako Mochizuki1, Zhirong Qi1, Naomi Sugimori1  +6 moreInstitutions (1)
Abstract: Peripheral blood from 489 recently diagnosed patients with aplastic anaemia (AA) and 316 with refractory anaemia (RA) of myelodysplastic syndrome was evaluated to characterize CD55(-)CD59(-) [paroxysmal nocturnal haemoglobinuria (PNH)]-type blood cells associated with bone marrow (BM) failure. PNH-type cells were detected in 57% and 20% of patients with AA and RA, respectively. The percentages of PNH-type granulocytes ranged from 0.003% to 94.2% and the distribution was log-normal with a median of 0.178%. Serial analyses of 75 patients with PNH-type cells over 5 years revealed that the percentage of PNH-type cells constantly increased in 13 (17%), persisted in 44 (59%), disappeared in the remaining 18 (24%) although even in the 'Disappearance' group, PNH-type granulocytes persisted for at least 6 months. A scattergram profile of PNH-type cells unique to each patient persisted regardless of the response to immunosuppressive therapy and only single PIGA mutations were detected in PNH-type granulocytes sorted from four patients. These findings suggest that the PNH-type cells in patients with BM failure are derived from single PIGA mutant haematopoietic stem cells even when their percentages are <1% and their fate depends on the proliferation and self-maintenance properties of the individual PIGA mutants.

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Topics: Bone marrow failure (59%), Aplastic anemia (57%), Bone marrow (57%) ... show more

76 Citations

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