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David C Dale - One of the best experts on this subject based on the ideXlab platform.
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small molecule inhibitor of neutrophil elastase and Severe Congenital Neutropenia
Blood, 2009Co-Authors: Andrew A Aprikyan, Vahagn Makaryan, Maxim Totrov, Ruben Abagyan, David C DaleAbstract:Abstract 552 Severe Congenital Neutropenia (SCN) is a rare heritable hematopoietic disorder characterized by maturation arrest at the promyelocytes, recurring Severe infections, and evolution to leukemia. Heterozygous mutations in the neutrophil elastase (NE or ELANE) gene (sporadic or autosomal-dominant SCN) or homozygous mutations in the HAX1 gene (autosomal-recessive SCN) are associated with similar clinical phenotype and a block of myeloid differentiation or “maturation arrest” in the marrow. We and others reported that human myeloid progenitor cells expressing mutant elastase exhibit impaired cell survival (Aprikyan et al, 2003, Massullo et al, 2005, Kollner et al, 2006, Grenda et al, 2007). The hetero- and homozygous deletion of NE as well as the knock-in of mutant NE identified in SCN/AML patient failed to produce Severe Neutropenia phenotype in mice. Thus, the pathomechanism of Severe Neutropenia remains largely unclear due to the lack of cellular or animal model of SCN with characteristic block of myeloid differentiation and accelerated apoptosis. We established a cellular model of SCN with inducible tet-regulated expression of del.145-152 NE mutant (identified in SCN/AML patients) in human promyelocytic tet-off HL60 cells. The ratio of normal/mutant NE products in these cells is approximately 1:1, which is similar to that expected in SCN patients with heterozygous NE mutation. Expression of mutant NE in the promyelocytic cells results in a characteristic block of myeloid differentiation with ∼70% decline in differentiated neutrophils which is similar to that observed in SCN, whereas induced expression of control wild type NE has no effect on myeloid differentiation. Reduced production of myeloid cells and accelerated apoptosis are also observed upon DMSO or retinoic acid induced granulocytic differentiation of the cells in response to mutant, but not wild type NE expression. Thus, this cellular model of SCN appears to closely recapitulate the human phenotype. Expression of mutant NE resulted in approximately 40% increase in total NE-specific proteolytic activity, suggesting that mutant elastase exhibits at least some proteolytic activity. To date there are more than 50 heterozygous mutations in the NE gene have been identified in pre-leukemic SCN patients. Molecular modeling of the NE tertiary structure revealed that these mutations predominantly affect the N-glycosylation sites or the binding pocket of neutrophil elastase. Importantly, the active site of the mutant protease appears to be intact, which suggests that NE-specific small molecule inhibitors may be useful in preventing accelerated apoptosis and the characteristic block of myeloid differentiation of myeloid progenitor cells. Screening this cellular model of SCN, we identified a proprietary cell-penetrant elastase-specific small molecule inhibitor (compound A, Merck, USA), which inhibits the proteolytic activity of NE by more than 80%. When treated with compound A, control cells with induced expression of wtNE exhibit normal myeloid differentiation and production of myeloid cells, similar to that in untreated cells. These data suggest that human NE is dispensable and that accelerated apoptosis and impaired myeloid differentiation in SCN is due to a gain-of-function effect of pro-apoptotic mutant elastase. Importantly, treatment of human promyelocytic cells expressing del.145-152 mutant NE with this small molecule inhibitor restores impaired production of myeloid cells and improves myeloid differentiation to near normal levels, thus neutralizing the pro-apoptotic effect of mutant NE. These data suggest that small molecule inhibitors of NE may represent a promising therapy in Severe Congenital Neutropenia. We have examined the effect of the inhibitor on bone marrow cells from an SCN patient positive for NE mutation. At the time of bone marrow aspiration the patient was on G-CSF and the patient's freshly isolated bone marrow CD33+ progenitor cells exhibited ∼21% apoptosis, which was gradually increased reaching 43% at 3 days of culture. However, daily treatment of SCN cells with compound A preserved the cell survival rate at the initial value resulting in approximately 2-fold reduction in apoptotic cell death at 3 days of culture. These data demonstrate that the small molecule inhibitor of NE and its analogs should be considered for clinical trials in patients with SCN that is attributable to mutant NE. Disclosures: Dale: Merck: Research support; Amgen: Consultancy, Research Funding, Speaker.
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prevalence of mutations in elane gfi1 hax1 sbds was and g6pc3 in patients with Severe Congenital Neutropenia
British Journal of Haematology, 2009Co-Authors: Audrey Anna Bolyard, Elin Rodger, Steve Stein, David C Dale, Andrew A G Aprikyan, Daniel C LinkAbstract:Severe Congenital Neutropenia (SCN) is a genetically heterogeneous syndrome associated with mutations of ELANE (ELA2), HAX1, GFI1, WAS, CSF3R or G6PC3. We investigated the prevalence of mutations of ELANE in a cohort of 162 SCN patients for whom blood or bone marrow samples were submitted to the North American Severe Chronic Neutropenia Tissue Repository. Mutations of ELANE were found in 90 of 162 patients (55.6%). Subsequently, we conducted an analysis of a subset of 73 of these cases utilizing a high throughput sequencing approach to determine the prevalence of other mutations associated with SCN. Among the 73 patients, mutations of ELANE were detected in 28. In the remaining 45 patients with wild type ELANE alleles, 5 patients had mutations: GFI1 (1), SBDS (1), WAS (1) and G6PC3 (2); no mutations of HAX1 were detected. In approximately 40% of our cases, the genetic basis of SCN remains unknown. These data suggest that for genetic diagnosis of SCN, ELANE genotyping should first be performed. In patients without ELANE mutations, other known SCN-associated gene mutations will be found rarely and genotyping can be guided by the clinical features of each patient.
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prevalence of mutations in elane gfi1 hax1 sbds was and g6pc3 in patients with Severe Congenital Neutropenia
British Journal of Haematology, 2009Co-Authors: Jun Xia, Elin Rodger, Steve Stein, David C Dale, Audrey Anna Bolyard, Andrew A Aprikyan, Daniel C LinkAbstract:Severe Congenital Neutropenia (SCN) is a genetically heterogeneous syndrome associated with mutations of ELANE (ELA2), HAX1, GFI1, WAS, CSF3R or G6PC3. We investigated the prevalence of mutations of ELANE in a cohort of 162 SCN patients for whom blood or bone marrow samples were submitted to the North American Severe Chronic Neutropenia Tissue Repository. Mutations of ELANE were found in 90 of 162 patients (55.6%). Subsequently, we conducted an analysis of a subset of 73 of these cases utilising a high throughput sequencing approach to determine the prevalence of other mutations associated with SCN. Among the 73 patients, mutations of ELANE were detected in 28. In the remaining 45 patients with wild type ELANE alleles, five patients had mutations: GFI1 (1), SBDS (1), WAS (1) and G6PC3 (2); no mutations of HAX1 were detected. In approximately 40% of our cases, the genetic basis of SCN remains unknown. These data suggest that for genetic diagnosis of SCN, ELANE genotyping should first be performed. In patients without ELANE mutations, other known SCN-associated gene mutations will be found rarely and genotyping can be guided by the clinical features of each patient.
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the many causes of Severe Congenital Neutropenia
The New England Journal of Medicine, 2009Co-Authors: David C Dale, Daniel C LinkAbstract:Drs. David Dale and Daniel Link discuss the genetic variants of Severe Congenital Neutropenia. The recent advances in our understanding of the genetic basis of this disorder have important clinical implications.
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functional interaction between mutations in the granulocyte colony stimulating factor receptor in Severe Congenital Neutropenia
British Journal of Haematology, 2008Co-Authors: Alister C Ward, Ivo P Touw, Judith Gits, Fidel Majeed, Andrew A Aprikyan, Rowena S Lewis, Lynda A Osullivan, Melvin H Freedman, Sarah Shigdar, David C DaleAbstract:Most Severe Congenital Neutropenia (SCN) cases possess constitutive neutrophil elastase mutations; a smaller cohort has acquired mutations truncating the granulocyte colony-stimulating factor receptor (G-CSF-R). We have described a case with constitutive extracellular G-CSF-R mutation hyporesponsive to ligand. Here we report two independent acquired G-CSF-R truncation mutations and a novel constitutive neutrophil elastase mutation in this patient. Co-expression of a truncated receptor chain restored STAT5 signalling responses of the extracellular G-CSF-R mutant, while constitutively-active STAT5 enhanced its proliferative capacity. These data add to our knowledge of SCN and further highlight the importance of STAT5 in mediating proliferative responses to G-CSF.
Göran Carlsson - One of the best experts on this subject based on the ideXlab platform.
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Severe Congenital Neutropenia associated jagn1 mutations unleash a calpain dependent cell death programme in myeloid cells
British Journal of Haematology, 2021Co-Authors: Avinash Khandagale, Magnus Nordenskjold, Göran Carlsson, Jan-inge Henter, Teresa Holmlund, Miriam Entesarian, Daniel Nilsson, Krzysztof Kalwak, Maja Klaudeldreszler, Bengt FadeelAbstract:Severe Congenital Neutropenia (SCN) of autosomal recessive inheritance, also known as Kostmann disease, is characterised by a lack of neutrophils and a propensity for life-threatening infections. Using whole-exome sequencing, we identified homozygous JAGN1 mutations (p.Gly14Ser and p.Glu21Asp) in three patients with Kostmann-like SCN, thus confirming the recent attribution of JAGN1 mutations to SCN. Using the human promyelocytic cell line HL-60 as a model, we found that overexpression of patient-derived JAGN1 mutants, but not silencing of JAGN1, augmented cell death in response to the pro-apoptotic stimuli, etoposide, staurosporine, and thapsigargin. Furthermore, cells expressing mutant JAGN1 were remarkably susceptible to agonists that normally trigger degranulation and succumbed to a calcium-dependent cell death programme. This mode of cell death was completely prevented by pharmacological inhibition of calpain but unaffected by caspase inhibition. In conclusion, our results confirmed the association between JAGN1 mutations and SCN and showed that SCN-associated JAGN1 mutations unleash a calcium- and calpain-dependent cell death in myeloid cells.
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jagn1 is required for fungal killing in neutrophil extracellular traps implications for Severe Congenital Neutropenia
Journal of Leukocyte Biology, 2018Co-Authors: Avinash Khandagale, Göran Carlsson, Beatrice Lazzaretto, Mikael Sundin, Sulman Shafeeq, Ute Romling, Bengt FadeelAbstract:Mutations in the gene JAGN1 were recently discovered in patients with Severe Congenital Neutropenia (SCN). Neutrophils release neutrophil extracellular traps (NETs) consisting of decondensed chromatin decorated with various granular proteins such as neutrophil elastase and myeloperoxidase (MPO) to combat microbial infections. However, whether JAGN1 is required for the formation or function of NETs is not known. Here, we analyzed primary neutrophils from a patient with homozygous JAGN1 mutations with respect to phorbol myristate acetate (PMA)-induced NET formation. NET release was observed, but there appeared to be a reduced level of expression of MPO in the NETs. To study this further, we differentiated HL-60 cells into neutrophil-like cells and silenced JAGN1 expression by transfection with siRNA. These cells remained capable of producing NETs, but MPO expression was Severely affected, and NETs released by JAGN1-silenced cells were ineffective in killing Candida albicans. The candidacidal function was restored upon treatment with GM-CSF or addition of MPO. GM-CSF also up-regulated the expression of calprotectin in NETs. Notably, JAGN1 did not impact on N-glycosylation of MPO in neutrophil-like HL-60 cells. These studies shed light on the susceptibility of SCN patients to fungal infections and the role of JAGN1 for the antimicrobial function of neutrophils exerted by NETs.
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ovarian failure in hax1 deficient patients is there a gender specific difference in pubertal development in Severe Congenital Neutropenia or kostmann disease
Acta Paediatrica, 2013Co-Authors: Göran Carlsson, Bengt Fadeel, Magnus Nordenskjold, Berit Kriström, Jan-inge HenterAbstract:Aim Severe Congenital Neutropenia (SCN) is a rare disorder of myelopoiesis characterized by Neutropenia, recurrent bacterial infections and a maturation arrest of the myelopoiesis in the bone marro ...
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incidence of Severe Congenital Neutropenia in sweden and risk of evolution to myelodysplastic syndrome leukaemia
British Journal of Haematology, 2012Co-Authors: Göran Carlsson, Bengt Fadeel, Magnus Nordenskjold, Jan-inge Henter, Jan Palmblad, Anders Fasth, Elisabet Berglof, Kristina LagerstedtrobinsonAbstract:Summary Severe Congenital Neutropenia (SCN) is characterized by low blood neutrophil counts, early bacterial infections, and risk of leukaemia development. As yet, no population-based incidence estimates of SCN have been reported. Children less than 16 years of age with SCN were sought in Sweden during the 20-year period 1987–2006 by a questionnaire to all Swedish Departments of Paediatrics and by reviewing the Swedish Health and Welfare Statistical Databases. Thirty-two patients were diagnosed with Congenital Neutropenia during this period. All received treatment with recombinant granulocyte-colony stimulating factor (G-CSF). Twenty-one patients were diagnosed as SCN or probable SCN, corresponding to 1·0 per 100 000 live births. Nine (43%) had ELANE mutations, four (19%) HAX1 mutations and eight (38%) were children with disease of unknown genetic aetiology. Four out of 21 patients (19%) developed myelodysplastic syndrome/leukaemia and three (14%) died, all with leukaemia. The cumulative incidence of myelodysplastic syndrome/leukaemia was 31%. The observed incidence of SCN in this population-based study was higher than previously estimated, possibly because genetic testing now can identify SCN cases previously thought to be idiopathic or benign Neutropenia. The risk of developing myelodysplastic syndrome/leukaemia is considerable. ELANE mutations are the most commonly identified genetic defects.
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mutations in the elane gene are associated with development of periodontitis in patients with Severe Congenital Neutropenia
Journal of Clinical Immunology, 2011Co-Authors: Göran Carlsson, Mats Andersson, Biniyam Wondimu, Annika Fahlen, Jenny Karlssonsjoberg, Lars Engstrand, Tulay Yucellindberg, Thomas Modeer, Katrin PutsepAbstract:Background Patients with Severe Congenital Neutropenia (SCN) often develop periodontitis despite standard medical and dental care. In light of previous findings that mutations in the neutrophil elastase gene, ELANE, are associated with more Severe neutropenic phenotypes, we hypothesized an association between the genotype of SCN and development of periodontitis.
Nima Rezaei - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the effects of mesenchymal stem cells on neutrophils isolated from Severe Congenital Neutropenia patients
International Immunopharmacology, 2020Co-Authors: Mahsa Taghavifarahabadi, Mohammad Mahmoudi, Seyed Mahmoud Hashemi, Nima RezaeiAbstract:Neutrophils are the most abundant, yet with the shortest lifespan among the circulating leukocytes. These cells are produced in the bone marrow during granulopoiesis process. Severe Congenital Neutropenia (SCN) is a hematological disorder with disturbance in granulopoiesis process, in which the neutrophils apoptosis rate is escalated. Previous reports indicated that mesenchymal stem cells (MSCs), as an immunomodulator cell, could increase neutrophil lifespan in addition to the supportive effects on cardiomyocytes or the neuroprotective effects. In this study, MSCs were co-cultured with neutrophils isolated from SCN patients and healthy individuals. Then, we evaluated the MSC co-culture effects on neutrophils survival (annexin V/PI assay), reactive oxygen species (ROS) production (colorimetric NBT assay), and phagocytic activity (Giemsa staining after exposure to yeasts). It was demonstrated that MSC co-culture could increase neutrophil lifespan and phagocytic activity of the neutrophils isolated from SCN patients. Regarding healthy donors' neutrophils, only phagocytic activity improvement was seen. It could be concluded that MSCs could be considered as novel candidates for treatment of SCN patients.
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hax1 mutation in an infant with Severe Congenital Neutropenia
Turkish Journal of Pediatrics, 2010Co-Authors: Aziz Eghbali, Peyman Eshghi, Fatemeh Malek, Hengameh Abdollahpour, Nima RezaeiAbstract:SUMMARY: Eghbali A, Eshghi P, Malek F, Abdollahpour H, Rezaei N. HAX1 mutation in an infant with Severe Congenital Neutropenia. Turk J Pediatr 2010; 52: 81-84.Severe Congenital Neutropenia (SCN) is a rare primary myelopoiesis disorder, characterized by persistent Severe Neutropenia and early-onset bacterial infections.Herein, we describe an 11-month-old male who was referred with recurrent cutaneous infections and chronic diarrhea. Serial complete blood counts indicated persistent Neutropenia. Bone marrow aspiration of the patient demonstrated maturation arrest of myeloid series at promyelocyte-myelocyte stages. W44X mutation in the HAX1 gene confirmed the diagnosis of SCN. The patient was successfully treated with granulocyte colony-stimulating factor.Severe Congenital Neutropenia should be considered in children with early-onset recurrent infections and Neutropenia, since early diagnosis and appropriate treatment can prevent further complications. Key words: Severe Congenital Neutropenia, HAX1 mutation, granulocyte colony-stimulating factor.
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Severe Congenital Neutropenia in 2 siblings of consanguineous parents the role of hax1 deficiency
Journal of Investigational Allergology and Clinical Immunology, 2009Co-Authors: Setareh Mamishi, Jana Diestelhorst, Nima Parvaneh, Shadi Abdar Esfahani, Nima RezaeiAbstract:■ Abstract Severe Congenital Neutropenia (SCN) is a rare primary immunodefi ciency disease that is characterized by persistent Severe Neutropenia and Severe early-onset bacterial infections. We report the case of 2 siblings with SCN who were the children of consanguineous parents. The HAX1 mutation was identifi ed in both siblings. Both patients suffered from oral ulcers, candidiasis, respiratory tract infections, and diarrhea. A bone marrow biopsy, performed to determine the cause of their persistent Severe Neutropenia, revealed myeloid maturation arrest; thus confi rming the diagnosis of SCN. Granulocyte colony-stimulating factor and prophylactic antibiotics were started. A molecular study revealed a homozygous W44X mutation of the HAX1 gene in both cases. HAX1 defi ciency should be considered in any child with Severe infections and Neutropenia, especially in children of consanguineous parents. Early diagnosis and appropriate treatment could prevent complications in this group of patients.
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Severe Congenital Neutropenia or hyper igm syndrome a novel mutation of cd40 ligand in a patient with Severe Neutropenia
International Archives of Allergy and Immunology, 2008Co-Authors: Nima Rezaei, Asghar Aghamohammadi, Asghar Ramyar, Qiang Panhammarstrom, Lennart HammarstromAbstract:Severe Congenital Neutropenia (SCN) and CD40 ligand deficiency (CD40LD) are two primary immunodeficiency diseases caused by different underlying genetic defects. In this report, we present a case who clinically presented as a SCN patient, but subsequent mutation analysis of this patient was compatible with CD40LD. The patient is a 3-year-old boy, who was referred to our center because of pneumonia, oral and anal ulcers, and periodontitis. As Severe consistent Neutropenia and maturation arrest in the myeloid series were observed in the bone marrow, a diagnosis of SCN was made. However, no mutations were found in the ELA2 and HAX1 genes. As functional T cell defects were observed, we suspected CD40LD. DNA sequencing showed a 17-base pair deletion in the CD40L gene. Although the patient did not have a decreased serum level of IgA, and his serum IgM level was within the normal range, the diagnosis of CD40LD was confirmed, suggesting that CD40LD should be suspected in any male patient with recurrent infections and Neutropenia.
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necrosis of nasal cartilage due to mucormycosis in a patient with Severe Congenital Neutropenia due to hax1 deficiency
Journal of Investigational Allergology and Clinical Immunology, 2008Co-Authors: A Fahimzad, Christoph Klein, Hengameh Abdollahpour, Zahra Chavoshzadeh, Nima RezaeiAbstract:■ Abstract Severe Congenital Neutropenia (SCN) is a primary immunodefi ciency disease characterized by early onset of Severe bacterial infection and persistent Severe Neutropenia. We describe an SCN patient with a history of recurrent infections. The clinical course was complicated by necrosis of the nasal cartilage due to mucormycosis. Molecular studies revealed a homozygous germline HAX1 mutation. Fungal infections may lead to serious complications in immunodefi cient patients. Recurrent and Severe infections should alert physicians to possible immunodefi ciency disease. Early diagnosis and appropriate treatment are the most important keys to preventing irreversible organ damage.
Bengt Fadeel - One of the best experts on this subject based on the ideXlab platform.
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Severe Congenital Neutropenia associated jagn1 mutations unleash a calpain dependent cell death programme in myeloid cells
British Journal of Haematology, 2021Co-Authors: Avinash Khandagale, Magnus Nordenskjold, Göran Carlsson, Jan-inge Henter, Teresa Holmlund, Miriam Entesarian, Daniel Nilsson, Krzysztof Kalwak, Maja Klaudeldreszler, Bengt FadeelAbstract:Severe Congenital Neutropenia (SCN) of autosomal recessive inheritance, also known as Kostmann disease, is characterised by a lack of neutrophils and a propensity for life-threatening infections. Using whole-exome sequencing, we identified homozygous JAGN1 mutations (p.Gly14Ser and p.Glu21Asp) in three patients with Kostmann-like SCN, thus confirming the recent attribution of JAGN1 mutations to SCN. Using the human promyelocytic cell line HL-60 as a model, we found that overexpression of patient-derived JAGN1 mutants, but not silencing of JAGN1, augmented cell death in response to the pro-apoptotic stimuli, etoposide, staurosporine, and thapsigargin. Furthermore, cells expressing mutant JAGN1 were remarkably susceptible to agonists that normally trigger degranulation and succumbed to a calcium-dependent cell death programme. This mode of cell death was completely prevented by pharmacological inhibition of calpain but unaffected by caspase inhibition. In conclusion, our results confirmed the association between JAGN1 mutations and SCN and showed that SCN-associated JAGN1 mutations unleash a calcium- and calpain-dependent cell death in myeloid cells.
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jagn1 is required for fungal killing in neutrophil extracellular traps implications for Severe Congenital Neutropenia
Journal of Leukocyte Biology, 2018Co-Authors: Avinash Khandagale, Göran Carlsson, Beatrice Lazzaretto, Mikael Sundin, Sulman Shafeeq, Ute Romling, Bengt FadeelAbstract:Mutations in the gene JAGN1 were recently discovered in patients with Severe Congenital Neutropenia (SCN). Neutrophils release neutrophil extracellular traps (NETs) consisting of decondensed chromatin decorated with various granular proteins such as neutrophil elastase and myeloperoxidase (MPO) to combat microbial infections. However, whether JAGN1 is required for the formation or function of NETs is not known. Here, we analyzed primary neutrophils from a patient with homozygous JAGN1 mutations with respect to phorbol myristate acetate (PMA)-induced NET formation. NET release was observed, but there appeared to be a reduced level of expression of MPO in the NETs. To study this further, we differentiated HL-60 cells into neutrophil-like cells and silenced JAGN1 expression by transfection with siRNA. These cells remained capable of producing NETs, but MPO expression was Severely affected, and NETs released by JAGN1-silenced cells were ineffective in killing Candida albicans. The candidacidal function was restored upon treatment with GM-CSF or addition of MPO. GM-CSF also up-regulated the expression of calprotectin in NETs. Notably, JAGN1 did not impact on N-glycosylation of MPO in neutrophil-like HL-60 cells. These studies shed light on the susceptibility of SCN patients to fungal infections and the role of JAGN1 for the antimicrobial function of neutrophils exerted by NETs.
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ovarian failure in hax1 deficient patients is there a gender specific difference in pubertal development in Severe Congenital Neutropenia or kostmann disease
Acta Paediatrica, 2013Co-Authors: Göran Carlsson, Bengt Fadeel, Magnus Nordenskjold, Berit Kriström, Jan-inge HenterAbstract:Aim Severe Congenital Neutropenia (SCN) is a rare disorder of myelopoiesis characterized by Neutropenia, recurrent bacterial infections and a maturation arrest of the myelopoiesis in the bone marro ...
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incidence of Severe Congenital Neutropenia in sweden and risk of evolution to myelodysplastic syndrome leukaemia
British Journal of Haematology, 2012Co-Authors: Göran Carlsson, Bengt Fadeel, Magnus Nordenskjold, Jan-inge Henter, Jan Palmblad, Anders Fasth, Elisabet Berglof, Kristina LagerstedtrobinsonAbstract:Summary Severe Congenital Neutropenia (SCN) is characterized by low blood neutrophil counts, early bacterial infections, and risk of leukaemia development. As yet, no population-based incidence estimates of SCN have been reported. Children less than 16 years of age with SCN were sought in Sweden during the 20-year period 1987–2006 by a questionnaire to all Swedish Departments of Paediatrics and by reviewing the Swedish Health and Welfare Statistical Databases. Thirty-two patients were diagnosed with Congenital Neutropenia during this period. All received treatment with recombinant granulocyte-colony stimulating factor (G-CSF). Twenty-one patients were diagnosed as SCN or probable SCN, corresponding to 1·0 per 100 000 live births. Nine (43%) had ELANE mutations, four (19%) HAX1 mutations and eight (38%) were children with disease of unknown genetic aetiology. Four out of 21 patients (19%) developed myelodysplastic syndrome/leukaemia and three (14%) died, all with leukaemia. The cumulative incidence of myelodysplastic syndrome/leukaemia was 31%. The observed incidence of SCN in this population-based study was higher than previously estimated, possibly because genetic testing now can identify SCN cases previously thought to be idiopathic or benign Neutropenia. The risk of developing myelodysplastic syndrome/leukaemia is considerable. ELANE mutations are the most commonly identified genetic defects.
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hematopoietic stem cell transplantation in Severe Congenital Neutropenia
Pediatric Blood & Cancer, 2011Co-Authors: Göran Carlsson, Magnus Nordenskjold, Jan-inge Henter, Jan Palmblad, Ivo P Touw, Jacek Winiarski, Per Ljungman, Olle Ringden, Jonas Mattsson, Bengt FadeelAbstract:Background Severe Congenital Neutropenia (SCN) is an immunodeficiency characterized by disturbed myelopoiesis and an absolute neutrophil count (ANC) <0.5 × 109/L. SCN is also a premalignant condition; a significant proportion of patients develop myelodysplastic syndrome or leukemia (MDS/L). Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for SCN. Procedure Since 2004, eight HSCT have been performed in seven patients at our center. The indications were transformation to MDS/L (n = 2), granulocyte colony-stimulating factor receptor (CSF3R) mutation(s) (n = 2), granulocyte colony-stimulating factor (G-CSF) resistance (n = 2), and at the patient's own request (n = 1). Results The mean age at transplantation was 13 years (2.8–28 years) (mean follow-up 32 months, range 21–60). Three patients harbored ELANE mutations, three HAX1 mutations, and in one patient no causative mutation was identified. Two of the ELANE mutations were novel mutations. Three patients initially received myeloablative conditioning and four had reduced intensity conditioning (RIC). Three grafts were from HLA-identical siblings, three from matched unrelated donors and two were cord blood units. Engraftment occurred in all patients. Two of seven (29%) patients died; both had MDS/L and both were among the three that underwent myeloablative conditioning. One patient has chronic GVHD 2 years post-transplant. Conclusions The role of HSCT should be explored further in patients with SCN. In particular, the influence of the conditioning regime needs to be evaluated in a larger cohort of patients. Pediatr Blood Cancer 2011;56:444–451. © 2010 Wiley-Liss, Inc.
Karl Welte - One of the best experts on this subject based on the ideXlab platform.
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Ultra-Sensitive CSF3R Deep Sequencing in Patients With Severe Congenital Neutropenia
Frontiers in Immunology, 2019Co-Authors: Maksim Klimiankou, Murat Uenalan, Siarhei Kandabarau, Rainer Nustede, Ingeborg Steiert, Sabine Mellor-heineke, Cornelia Zeidler, Julia Skokowa, Karl WelteAbstract:: High frequency of acquired CSF3R (colony stimulating factor 3 receptor, granulocyte) mutations has been described in patients with Severe Congenital Neutropenia (CN) at pre-leukemia stage and overt acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Here, we report the establishment of an ultra-sensitive deep sequencing of a CSF3R segment encoding the intracellular "critical region" of the G-CSFR known to be mutated in CN-MDS/AML patients. Using this method, we achieved a mutant allele frequency (MAF) detection rate of 0.01%. We detected CSF3R mutations in CN patients with different genetic backgrounds, but not in patients with other types of bone marrow failure syndromes chronically treated with G-CSF (e.g., Shwachman-Diamond Syndrome). Comparison of CSF3R deep sequencing results of DNA and cDNA from the bone marrow and peripheral blood cells revealed the highest sensitivity of cDNA from the peripheral blood polymorphonuclear neutrophils. This approach enables the identification of low-frequency CSF3R mutant clones, increases sensitivity, and earlier detection of CSF3R mutations acquired during the course of leukemogenic evolution of pre-leukemia HSCs of CN patients. We suggest application of sequencing of the entire CSF3R gene at diagnosis to identify patients with inherited lost-of-function CSF3R mutations and annual ultra-deep sequencing of the critical region of CSF3R to monitor acquisition of CSF3R mutations.
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Digenic mutations in Severe Congenital Neutropenia
Haematologica, 2010Co-Authors: Manuela Germeshausen, Manfred Stuhrmann, Matthias Ballmaier, Marina Lanciotti, Cornelia Zeidler, Karl WelteAbstract:Severe Congenital Neutropenia a clinically and genetically heterogeneous disorder. Mutations in different genes have been described as causative for Severe Neutropenia, e.g. ELANE, HAX1 and G6PC3. Although Congenital Neutropenia is considered to be a group of monogenic disorders, the phenotypic heterogeneity even within the yet defined genetic subtypes points to additional genetic and/or epigenetic influences on the disease phenotype. We describe Congenital Neutropenia patients with mutations in two candidate genes each, including 6 novel mutations. Two of them had a heterozygous ELANE mutation combined with a homozygous mutation in G6PC3 or HAX1, respectively. The other 2 patients combined homozygous or compound heterozygous mutations in G6PC3 or HAX1 with a heterozygous mutation in the respective other gene. Our results suggest that digenicity may underlie this disorder of myelopoiesis at least in some Congenital Neutropenia patients.
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in vivo expansion of cells expressing acquired csf3r mutations in patients with Severe Congenital Neutropenia
Blood, 2009Co-Authors: Manuela Germeshausen, Karl Welte, Matthias BallmaierAbstract:Severe Congenital Neutropenia (CN) is a rare bone marrow failure syndrome with a high incidence of acute leukemia. In previous studies, we could show that point mutations in the gene for the granulocyte colony-stimulating factor (G-CSF) receptor CSF3R are a highly predictive marker for leukemic development in CN patients. To find out at which stage of hematopoietic development these mutations emerge and how they are propagated during hematopoietic differentiation, we analyzed single cells of different hematopoietic subpopulations from CN patients with CSF3R mutations. We found that CSF3R mutations are not restricted to the myeloid compartment but are also detectable in lymphoid cells, although at a much lower percentage. From our observations, we conclude that CSF3R mutations are acquired in multipotent hematopoietic progenitor cells in CN patients and that they are clonally expanded in myeloid cells expressing the G-CSF receptor due to the growth advantage mediated by the CSF3R mutation.
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incidence of csf3r mutations in Severe Congenital Neutropenia and relevance for leukemogenesis results of a long term survey
Blood, 2007Co-Authors: Manuela Germeshausen, Matthias Ballmaier, Karl WelteAbstract:Point mutations in the gene for the granulocyte colony-stimulating factor (G-CSF) receptor CSF3R have been implicated in the progression of Severe Congenital Neutropenia (CN) to leukemia. In this study we present data on a total of 218 patients with chronic Neutropenia, including 148 patients with CN (23/148 with secondary malignancies). We detected CSF3R nonsense mutations at 17 different nucleotide positions (thereof 10 new mutations) which lead to a loss of 1 to all 4 tyrosine residues in the intracellular domain of the receptor. Of 23 patients with CN with signs of malignant transformation, 18 (78%) were shown to harbor a CSF3R mutation, indicating that these mutations, although not a necessary condition, are highly predictive for malignant transformation even if detected in a low percentage of transcripts. In serial analyses of 50 patients with CSF3R mutations we were able to follow the clonal dynamics of mutated cells. We could demonstrate that even a highly clonal hematopoiesis did not inevitably show a rapid progression to leukemia. Our results strongly suggest that acquisition of a CSF3R mutation is an early event in leukemogenesis that has to be accompanied by cooperating molecular events, which remain to be defined.
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Severe Congenital Neutropenia inheritance and pathophysiology
Current Opinion in Hematology, 2007Co-Authors: Julia Skokowa, Manuela Germeshausen, Cornelia Zeidler, Karl WelteAbstract:Purpose of review Severe Congenital Neutropenia is a heterogeneous disorder of hematopoiesis characterized by a maturation arrest of granulopoiesis at the level of promyelocytes with peripheral blood absolute neutrophil counts below 0.5 × 109/l. In this review we summarize our current knowledge on inheritance and pathophysiolgy of Congenital Neutropenia. Recent findings There are two major subtypes of Congenital Neutropenia as judged by inheritance: autosomal dominant trait defined by neutrophil elastase mutations consisting of 60% of patients and autosomal recessive trait comprising approximately 30% of patients. This genetic heterogeneity suggests that several pathologic mechanisms may lead to the same phenotype due to downregulation of common myeloid transcription factors. Lymphoid enhancer-binding factor 1 is the most promising candidate, as its abrogation together with downregulation of lymphoid enhancer-binding factor 1 target genes is compatible with this phenotype. Congenital Neutropenia is considered as a preleukemic syndrome, since after 10 years of observation the cumulative incidence for leukemia is 21%. Acquired granulocyte colony-stimulating factor receptor mutations are detected in approximately 80% of Congenital Neutropenia patients who developed acute myeloid leukemia. Summary Congenital Neutropenia is a Congenital disorder of hematopoiesis inherited by autosomal dominant or recessive traits. Downregulation of lymphoid enhancer-binding factor 1 is involved in the pathophysiology of all Congenital Neutropenia patients. Congenital Neutropenia patients with acquired granulocyte colony-stimulating factor receptor mutations define a group with high risk for development of leukemia.
