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An acquired CSF3R mutation in an adult chronic idiopathic neutropenia patient who developed acute myeloid leukaemia
British Journal of Haematology
... Chronic idiopathic neutropenia has been reported to have a relatively mild prognosis [2,4,17,26,32]. However, neutropenia progress to severe forms such as hematologic malignancy in congenital neutropenia [1,6,[33][34][35][36]. This study shows that severely low levels of neutrophil count during a long-term period do not necessarily lead to poor outcomes. ...
Background and objectives: Severe chronic neutropenia (SCN) is a condition in which absolute neutrophil counts remain at a low level (under 500/µL) over months or years. Because of the rare onset of SCN, its epidemiology, prognosis, and clinical manifestations have not yet been fully understood. In particular, large-cohort studies in Asian countries are still insufficient. Therefore, in this study, national health insurance data was used to investigate the epidemiologic features and prognosis of SCN in South Korea. Materials and Methods: The data from the Health Insurance Review and Assessment database recorded between 1 January 2011 and 31 December 2015 were explored. SCN was defined based on the ICD-10 code, registry of benefit extension policy, and inclusion criteria of the study. After identifying patients with SCN, annual incidence and their co-morbidities were analyzed. Results: Among the initially identified patients with severe neutropenia (N = 2145), a total of 367 patients had SCN and were enrolled. The annual incidence rate of SCN ranged from 0.12 to 0.17 per 100,000 person-year (PY) during the study period. The highest incidence was observed in pediatric patients aged between 0 to 9 years (N = 156), followed by women in their fifties (N = 43). The total incidence rate was 0.17 in females and 0.12 in males (Relative risk (RR): 1.43, 95%, CI: 1.16–1.76). The most common accompanying condition was mild respiratory infection, but about 3.2% of patients progressed to hematologic malignancy after an average of 2.4 years. Conclusions: This nationwide population-based epidemiological study showed that incidence of SCN is higher in pediatrics and middle-aged women. As progression to hematologic malignancy was significantly higher in the age of in 45–49 years old, careful follow-up is necessary in this group. However, since this study lacks the molecular information, these finding need to be interpreted with great caution.
... Five cases of CPN have been reported to develop secondary acute myeloid leukemia in the literature. [32][33][34] Only 1 had received G-CSF therapy before the onset of leukemia. In 2 of these 5 cases, a family history of hematologic and nonhematologic malignancies was suggestive of a genetic predisposition. ...
Severe chronic primary neutropenia (CPN) is a rare entity and long-term outcome and risk factors for infections in severe CPN adults have not been described to date. We report the characteristics and outcomes of 108 severe adult CPN patients enrolled in a multi institutional observational study. Severe CPN adults were mostly female (78%) and the median age at diagnosis was 28.3 years. Diagnosis was fortuitous in 62% of cases. The median absolute neutrophil count (ANC) at diagnosis was 0.4 10(9)/L and the median ANC without GCSF during follow up was 0.5 10(9)/L. Twenty-three (34.8%) of 66 evaluable patients had neutrophil autoantibodies and 6 of 47 (12.8%) a T cell clone. The presence of neutrophil autoantibodies or T cell clone was not associated with any specific clinical or biological characteristics. No death or hematological malignancies occurred and 44 severe bacterial infections were reported in 27 patients with a median follow up of 8.3 years. Fifty patients received G-CSF either sporadically (n=24) or continuously (n=26) and responded (96%). Nineteen patients received immunosuppressive therapies: overall response was 41% and median duration of response was 3 months. At diagnosis, the only predictive factor for the occurrence of severe bacterial infections was an ANC count below 0.2 10(9)/L (OR:0.76). Severe CPN in adults is characterized by a female predominance and a benign outcome with a low rate of severe bacterial infections and no secondary malignancies. G-CSF is efficient and well tolerated, but is not required in a majority of patients.
Copyright © 2015 American Society of Hematology.
The incidence and prognosis of clonal hematopoiesis in patients with isolated neutropenia among patients with idiopathic cytopenia of undetermined significance (ICUS), known as ICUS-N or chronic idiopathic neutropenia (CIN) patients, is poorly defined. In the present study we sought to investigate the frequency and clinical significance of mutations of genes implicated in myeloid malignancies using next generation sequencing, in CIN patients (n=185) with a long follow-up. We found that 21/185 patients (11.35%) carried totally 25 somatic mutations in 6 genes with median variant allele frequency (VAF) 12.75%. The most frequently mutated genes were DNMT3A and TET2 involving more than 80% of patients followed by IDH1/2, SRSF2 and ZRSR2. The frequency of transformation to a myeloid malignancy was low in the total group of patients (5/185 patients; 2.70%). However, from the transformed patients four belonged to the clonal (4/21; 19.05%) and one to the non-clonal (1/164; 0.61%) group, indicating that the presence of mutation(s) confers a relative risk for transformation 31.24 (P = 0.0017). The VAF of the mutant clones in the transformed patients was higher than 10% in all cases and the genes most frequently associated with malignant transformation were the SRSF2 and IDH1. No significant differences were identified between clonal and non-clonal groups in the severity of neutropenia. Patients with clonal disease were older compared to non-clonal patients. These data contribute to the better understanding of the heterogeneous entities underlying ICUS and highlight the importance of the mutation analysis for the diagnosis and prognosis of patients with unexplained neutropenias.
Koala retrovirus is thought to be an underlying cause of high levels of neoplasia and immunosuppression in koalas. While epidemiology studies suggest a strong link between KoRV and disease it has been difficult to prove causality because of the complex nature of the virus, which exists in both endogenous and exogenous forms. It has been difficult to identify koalas completely free of KoRV, and infection studies in koalas or koala cells are fraught with ethical and technical difficulties, respectively. This study uses KoRV infection of the susceptible human cell line HEK293T and RNAseq to demonstrate gene networks differentially regulated upon KoRV infection. Many of the pathways identified are those associated with viral infection, such as cytokine receptor interactions and interferon signalling pathways, as well as viral oncogenesis pathways. This study provides strong evidence that KoRV does indeed behave similarly to infectious retroviruses in stimulating antiviral and oncogenic cellular responses. In addition, it provides novel insights into KoRV oncogenesis with the identification of a group of histone family genes that are part of several oncogenic pathways as upregulated in KoRV infection.
Background
Avian leukosis virus subgroup J (ALV-J) causes tumours and immunosuppression in chickens. The host-ALV interactions at the transcriptional level are unknown. In this study, gene expression profiling was performed to analyse the bursa response induced by ALV-J strain JS09GY3 in chickens.
Results
A total of 594 gene transcripts displaying differential expression during ALV-J infection were identified. These differentially expressed genes are involved in binding, biological regulation, metabolic processes (MYF6 and FABP3), response to stimulus (F13A1 and CNGA3) and immune system processes (LY86, CATHL2, CCL4, and OASL), and several differentially expressed genes (e.g., ETV7, MMP9, and NOV) are involved in tumourigenesis. Eight differentially expressed genes were confirmed by quantitative reverse transcription-PCR (qRT-PCR). Based on pathway analysis, the notable signalling pathways mainly included cytokine-cytokine receptor interaction, the JAK-STAT signalling pathway and the RIG-1-like receptor signalling pathway.
Conclusions
The gene expression profile obtained in this study may aid a better understanding of the molecular pathogenesis of ALV-J infection in chickens.
The acquisition of nonsense mutations in the gene encoding the transmembrane granulocyte-colony-stimulating factor receptor, also known as the colony-stimulating factor 3 receptor (CSF3R), is a characteristic feature of patients with severe congenital neutropenia (SCN).¹ Somatic CSF3R gene mutations occur on a background of inherited mutations affecting genes such as ELANE, HAX1 and G6PC3.² The incidence of CSF3R mutations dramatically increases when SCN patients progress from chronic neutropenia (30–40%) to acute myeloid leukemia (AML, 80%).1, 3, 4, 5 Most of the somatic CSF3R mutations that occur in this context truncate the carboxyl terminus from the CSF3R protein (Figure 1), which hampers its ability to transduce signals required for neutrophil differentiation.
It is likely that leukemia results, at least in part, from mutations that lead to a block in the normal process of differentiation. A defined region of the cytoplasmic domain of the granulocyte colony-stimulating factor receptor (G-CSF-R) transmits signals for maturation or differentiation of myeloid progenitor cells. Mutations in this region have been found in some patients with severe congenital neutropenia (SCN) who subsequently evolved to acute myeloid leukemia (AML). To determine if mutations of the G-CSF-R are more widespread in hematological malignancies, we have investigated a total of 47 patients, including 29 patients with blast crisis of chronic myeloid leukemia (CML-BC) and 18 patients with de novo acute leukemia as well as 19 normal controls, by RT-PCR and SSCP analysis. Two point mutations were found in a single individual with secondary AML (FAB type M1). The first was heterozygous and is predicted to replace the normal glutamine at position 718 with a stop codon, leading to a truncated protein. An identical mutation has been described previously and shown to act in a dominant negative manner. The second mutation was homozygous and would substitute a lysine for the normal glutamic acid at position 785. No mutations were found in any other patient or control samples. We conclude that mutations in the cytoplasmic domain of the G-CSF-R are infrequent in CML-BC or acute leukemia but may contribute to malignant transformation in some cases.
To date, constitutively activating point mutations reported in hematopoietic growth factor receptors in patients with acute myeloid leukemia (AML) have been restricted to receptors with intrinsic tyrosine kinase activity such as c-kit and FLT3. We describe here a Thr617Asn mutation in the transmembrane domain of the non-tyrosine kinase receptor for granulocyte colony-stimulating factor (G-CSF) in the blast cells of two out of 555 AML patients examined. The mutant receptor conferred growth factor independence on factor-dependent Ba/F3 cells. In the absence of ligand, immunoblotting showed weak phosphorylation of JAK2, STAT3, ERKs 1 and 2 and the receptor itself, and there was approximately 70% of maximal growth in a proliferation assay. All signals were significantly enhanced in the presence of G-CSF. Retroviral transduction of mutant receptor into primary hematopoietic CD34+ cells induced G-CSF independent myeloid differentiation as assessed by the development of neutrophils and surface expression of CD11b and CD14. These results confirm the importance of the transmembrane domain for receptor function and suggest that introduction of an asparagine residue can cause sufficient stabilization of helix-helix interactions in the absence of ligand to activate downstream signaling pathways involved in directing proliferation and differentiation.
Severe congenital neutropenia (SCN) is an inborn disorder of granulopoiesis. Like most other bone marrow failure syndromes, it is associated with a marked propensity to transform into a myelodysplastic syndrome (MDS) or acute leukemia, with a cumulative rate of transformation to MDS/leukemia that exceeds 20%. The genetic (and/or epigenetic) changes that contribute to malignant transformation in SCN are largely unknown. In this study, we performed mutational profiling of 14 genes previously implicated in leukemogenesis using 14 MDS/leukemia samples from patients with SCN. We used high-throughput exon-based resequencing of whole-genome-amplified genomic DNA with a semiautomated method to detect mutations. The sensitivity and specificity of the sequencing pipeline was validated by determining the frequency of mutations in these 14 genes using 188 de novo AML samples. As expected, mutations of tyrosine kinase genes (FLT3, KIT, and JAK2) were common in de novo AML, with a cumulative frequency of 30%. In contrast, no mutations in these genes were detected in the SCN samples; instead, mutations of CSF3R, encoding the G-CSF receptor, were common. These data support the hypothesis that mutations of CSF3R may provide the "activated tyrosine kinase signal" that is thought to be important for leukemogenesis.
Patients with severe congenital neutropenia (SCN) are at increased risk for the development of acute myelogenous leukemia (AML). In the subset of patients with SCN that progresses to AML, acquired mutations in the receptor for granulocyte colony-stimulating factor (G-CSF) have been detected that result in the expression of truncated forms of the G-CSF receptor (G-CSFR) protein. G-CSFR truncation mutants from these patients transduce hyperproliferative growth responses. In this paper, we show that the most frequently isolated mutant G-CSFR form from patients with SCN/AML (delta716) confers resistance to apoptosis and prolongs cell survival through a mechanism involving Akt, a downstream target of PI3-kinase. G-CSF stimulation of cells expressing the G-CSFR truncation mutant induces sustained activation of Akt and prolonged phosphorylation of the pro-apoptotic protein Bad, resulting in enhanced cell survival. Extension of cell survival allowing for sufficient time for the acquisition of additional oncogenic events may represent an important mechanism by which G-CSFR mutations contribute to leukemogenesis. These data provide further insight into the pathophysiologic contribution of G-CSFR mutations to AML. (Blood. 2000;95:2132-2137)
There is strong evidence that non-immune chronic idiopathic neutropenia of adult is a cytokine-mediated syndrome characterized by (a) neutropenia of varying degree associated with a low number of lineage-specific CD34+ cells and increased production of inhibitors of hematopoiesis, including transforming growth factor-beta1 and tumor necrosis factor-alpha; (b) lymphopenia due to selective loss of primed/memory T-cells and NK cells; (c) increased splenic volume on ultrasonography in 48.1% of patients; (d) osteopenia and/or osteoporosis in 60.0% of patients; (e) anemia, mostly of the type of anemia of chronic disease, in 15.6% of patients; (f) features of chronic antigenic stimulation, including increased proportion of bone marrow plasma cells, increased serum levels of IgG1 and/or IgA, increased frequency of monoclonal gammopathy of undetermined significance, increased frequency of antinuclear antibodies with specific reactivity, and increased serum levels of circulating immune complexes; and (g) increased concentrations of a variety of macrophage-derived pro-inflammatory cytokines and chemokines capable of affecting bone metabolism, bone marrow function, and leukocyte trafficking. All these findings are suggestive of the existence of an unrecognized low-grade chronic inflammatory process which may be involved in the pathogenesis of the disorder. Neutropenia in these patients is probably the result of a combination of at least three factors, reduced neutrophil production in bone marrow, enhanced neutrophil extravasation, and increased sequestration and/or extravasation of neutrophils into the spleen.
It has been suggested that some cases of nonimmune chronic idiopathic neutropenia of adults (NI-CINA) may be considered preleukemic disorders. This paper describes two patients with NI-CINA who developed acute myeloid leukemia (AML) 34 and 64 months, respectively, following NI-CINA diagnosis. Patient 1 presented erythema nodosum and patient 2 polyarthritis of the large joints 9 and 2 months, respectively, before AML. Patient 1 had AML M4 disease associated with aberrant expression of CD7 and CD19 cell surface markers and one abnormal clone in bone marrow karyotype. Patient 2 had myeloid/natural killer (NK) cell leukemia with expression of CD7 and CD56 molecules and four derivative abnormal clones in the karyotype. Both patients had del(5)(q22q35) in common. No mutations in the transmembrane or the intracytoplasmic domain of the granulocyte colony-stimulating factor (G-CSF) receptor were found. The first patient had disease resistant to chemotherapy from the beginning of the treatment and the second following a brief complete hematological remission. On the basis of these observations, we concluded that a causal link of AML with the underlying NI-CINA cannot be presently justified, but the unusual findings noted in our patients prompt the description of additional cases for a further investigation of the relationships, if any, between these two granulocytic disorders.
Severe chronic neutropenia (SCN) is defined as an absolute neutrophil (ANC) of less than 0.5 x 10(9)/L, lasting for months or years. Congenital, cyclic, and idiopathic neutropenia are principal categories of SCN. Since 1994, the Severe Chronic Neutropenia International Registry (SCNIR) has collected data to monitor the clinical course, treatments, and disease outcomes for SCN patients. This report summarizes data for 853 patients, almost all treated with daily or alternate-day recombinant human granulocyte colony-stimulating factor (G-CSF or Filgrastim). G-CSF treatment increased the ANC overall from 0.34 x 10(9)/L +/- 0.018 pre-treatment to 3.70 x 10(9)/L +/- 0.18 during the first year of treatment. For most patients, the responses were durable with patients remaining on the same dose of G-CSF for many years. Long-term hematological observations showed stable mean leukocyte and neutrophil counts and gradually increasing hemoglobin levels. Thrombocytopenia developed in 4% of patients. As of January 1, 2000, myelodysplasia (MDS) or acute myelogenous leukemia (AML) has occurred in 35 of 387 patients with congenital neutropenia with a cumulative risk of 13% after 8 years of G-CSF treatment. This event occurred without a predictable relationship to the duration or dose of G-CSF treatment. No patients with cyclic or idiopathic neutropenia developed MDS or AML. Other important adverse events included hepatomegaly, osteoporosis, vasculitis, glomerulonephritis, and deaths in 4 of 14 cases requiring splenectomy. Growth and development and the outcome of pregnancy appeared to be unaffected by G-CSF treatment. These data indicate that congenital, cyclic, and idiopathic neutropenia can be effectively treated with long-term G-CSF. The risk of leukemia, osteoporosis, other potentially adverse events, and pregnancy outcome need to be further evaluated with continuing long-term observations.
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.
Chronic idiopathic neutropenia (CIN) has been well recognized as a granulocytic disorder not associated with increased risk to malignant transformation. Four cases, however, of acute myeloid leukemia have been recently reported in patients with CIN. In the current paper, we report on a CIN patient who developed acute myeloid/natural killer (NK) precursor cell leukemia 11 years after diagnosis and 4 months after initiation of treatment with recombinant human granulocyte colony-stimulating factor (rhG-CSF). Leukemic cells had trisomy 4 as the sole cytogenetic abnormality and, also, a novel point mutation in the extracellular domain of the G-CSF receptor (G-CSFR) leading to truncated protein with a loss of 36 amino acids. There was no evidence that this receptor transmitted signals even in the presence of high doses of rhG-CSF in the cultures. We consider that CIN may be a preleukemic condition, at least in a subset of patients, and that rhG-CSF administration is unlikely to be involved in the leukemic transformation in this patient, although such a possibility could not be completely ruled out.