Telomere Length and Telomerase Complex Mutations in Pediatric Acute Myeloid Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1482-1482
Author(s):  
Anna M. Aalbers ◽  
Rodrigo T. Calado ◽  
Neal S. Young ◽  
Christian M. Zwaan ◽  
Colin O. Wu ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
High Risk ◽  
Telomere Length ◽  
Carrier Frequency ◽  
Myeloid Leukemia ◽  
Clinical Characteristics ◽  
Leukemic Cells ◽  
Npm1 Mutation ◽  
Pediatric Aml ◽  
Acute Myeloid

Abstract Abstract 1482 Inherited loss-of-function mutations in the telomerase complex gene TERT have recently been implicated as risk factors for acute myeloid leukemia (AML) in adults. The telomerase complex is expressed in highly proliferative cells, and is responsible for maintaining telomeres, which cap the ends of chromosomes and protect genomic DNA from eroding during cell division. Impaired telomerase function can result in extremely short telomeres, which limits the proliferative capacity of progenitor cells, and can also lead to chromosomal instability, thus predisposing to malignant transformation. In pediatric AML, the frequency of such mutations, and the association of telomere length with cytogenetic, molecular, and clinical characteristics and outcome, are unknown. In a cohort of 168 pediatric AML patients, we determined the frequency of telomerase complex gene mutations and leukemic cell telomere length, and correlated this with prognostic cytogenetic characteristics (inv(16), t(8;21), MLL rearrangements, normal karyotype, other aberrations), molecular aberrations (CEBPA double mutations, NPM1 mutations, FLT3/ITD, WT1 mutations), clinical characteristics, and outcome. No mutations were present in TERC. Three heterozygous variants in TERT, E327D, T726M, and A1062T, were identified in eight of 168 pediatric AML patients (carrier frequency 0.048). In three of six patients carrying A1062T, remission material was available, in which germ-line origin of the variant was confirmed. The variants E327D and T726M were absent, but A1062T was present in a cohort of 406 geographically matched controls (carrier frequency 0.049). Telomerase activity, as determined by TRAP assay in reconstitution experiments, of the novel E327D variant was unaffected, as was the previously published activity of T726M; the earlier reported activity of A1062T was reduced to 60%. Telomere length of leukemic cells was not associated with age, sex, prognostic cytogenetic subgroup, complex karyotype, or expression levels of telomerase and shelterin complex genes. However, patients carrying the high-risk molecular aberration FLT3/ITD had significantly shorter telomeres than did patients with favorable NPM1 mutation or CEBPA double mutations. Telomere length was not associated with overall survival, event-free survival, or cumulative incidence of relapse. We conclude that, in pediatric AML, telomerase complex mutations do not confer a risk for leukemia development, and although short telomeres correlate with the high-risk molecular aberration FLT3/ITD, telomere length of leukemic cells obtained at diagnosis does not correlate with adverse outcome in this pediatric AML cohort. Disclosures: No relevant conflicts of interest to declare.

scholarly journals EVI1 and GATA2 misexpression induced by inv(3)(q21q26) contribute to megakaryocyte-lineage skewing and leukemogenesis

2020 ◽  
Vol 4 (8) ◽  
pp. 1722-1736 ◽  
Author(s):  
Ayaka Yamaoka ◽  
Mikiko Suzuki ◽  
Saori Katayama ◽  
Daiki Orihara ◽  
James Douglas Engel ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
High Risk ◽  
Myeloid Leukemia ◽  
Chromosomal Rearrangements ◽  
Leukemic Cells ◽  
Heterozygous Deletion ◽  
Hematopoietic Stem ◽  
Cellular Origin ◽  
A Cell ◽  
Acute Myeloid

Abstract Chromosomal rearrangements between 3q21 and 3q26 elicit high-risk acute myeloid leukemia (AML), which is often associated with elevated platelet and megakaryocyte (Mk) numbers. The 3q rearrangements reposition a GATA2 enhancer near the EVI1 (or MECOM) locus, which results in both EVI1 overexpression and GATA2 haploinsufficiency. However, the mechanisms explaining how the misexpression of these 2 genes individually contribute to leukemogenesis are unknown. To clarify the characteristics of differentiation defects caused by EVI1 and GATA2 misexpression and to identify the cellular origin of leukemic cells, we generated a system to monitor both inv(3) allele-driven EVI1 and Gata2 expression in 3q-rearranged AML model mice. A cell population in which both EVI1 and Gata2 were highly induced appeared in the bone marrows before the onset of frank leukemia. This population had acquired serial colony-forming potential. Because hematopoietic stem/progenitor cells (HSPCs) and Mks were enriched in this peculiar population, we analyzed the independent EVI1 and GATA2 contributions to HSPC and Mk. We found that inv(3)-driven EVI1 promotes accumulation of Mk-biased and myeloid-biased progenitors, Mks, and platelets, and that Gata2 heterozygous deletion enhanced Mk-lineage skewing of EVI1-expressing progenitors. Notably, inv(3)-directed EVI1 expression and Gata2 haploinsufficient expression cooperatively provoke a leukemia characterized by abundant Mks and platelets. These hematological features of the mouse model phenocopy those observed in human 3q AML. On the basis of these results, we conclude that inv(3)-driven EVI1 expression in HSPCs and Mks collaborates with Gata2 haploinsufficiency to provoke Mk-lineage skewing and leukemogenesis with excessive platelets, thus mimicking an important feature of human AML.

Clinical Characteristics and Prognostic Implications of NPM1 Mutations in Acute Myeloid Leukemia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2368-2368
Author(s):  
Tatsuya Suzuki ◽  
Hitoshi Kiyoi ◽  
Kazutaka Ozeki ◽  
Akihiro Tomita ◽  
Ritsuro Suzuki ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Clinical Characteristics ◽  
Sequential Analysis ◽  
Normal Karyotype ◽  
Npm1 Mutation ◽  
Distinct Subgroup ◽  
Paired Samples ◽  
Number Of Patients ◽  
Acute Myeloid

Abstract Nucleophosmin (NPM) is a nucleolar protein with multi-functions including centromere duplication, nuclear-cytoplasmic shuttling, ribosomal biogenesis, p53 stability. NPM1 mutations were found in a large number of patients with acute myeloid leukemia (AML) especially with normal karyotype. The mutations lead to the aberrant subcellular localization of NPM protein. However, their impacts on clinical outcome remain controversial. We screened the mutations of NPM1 in 257 AML patients and analyzed the clinical significance. NPM1 mutations were found in 64 of 257 patients (24.9%). Seven types of mutations, including four novel mutations, were identified. NPM1 mutations were associated with normal karyotype, FLT3 mutations (both FLT3-ITD and D835 mutation) but not with other gene alterations such as N-RAS, p53 mutations and partial tandem duplication of the MLL gene. In 190 patients except the M3 subgroup, who were treated according to the protocol of Japan Adult Leukemia Study Group, the multivariate analysis revealed that NPM1 mutation was a favorable factor for achieving complete remission, but significantly associated with relapse. A sequential analysis, using paired samples obtained at diagnosis and relapse in 39 patients, revealed that NPM1 mutations were lost at relapse in 2 of the seventeen patients who had NPM1 mutations at diagnosis and none of the patients, who did not have NPM1 mutations at diagnosis, gained NPM1 mutations at relapse. Our results suggest that NPM-mutated AML should be a distinct subgroup with specific clinical characteristics and outcome. Loss of NPM mutations at relapse implies that NPM mutation is not necessarily a primary genetic alteration and that these leukemic clones could be sensitive to chemotherapy.

Detection of Nucleophosmin Gene Mutations in Plasma from Patients with Acute Myeloid Leukemia: Clinical Significance and Implications.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2855-2855
Author(s):  
Wanlong Ma ◽  
Xi Zhang ◽  
Iman Jilani ◽  
Farhad Ravandi ◽  
Elihu Estey ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Gene Mutations ◽  
Leukemic Cells ◽  
Striking Difference ◽  
Plasma Dna ◽  
Npm1 Mutation ◽  
Acute Myeloid

Abstract Nucleotides insertion in the nucleophosphamin (NPM1) gene has been reported in about one third of patients with acute myeloid leukemia (AML). Multiple studies showed that the presence of NPM1 mutations associated with better outcome in patients with AML. Studies reported to date have analyzed leukemic cells obtained from bone marrow or peripheral blood. We tested for mutations in the NPM1 gene using peripheral blood plasma and compared results with clinical outcome from a single institution. Analyzing plasma from 98 newly diagnosed patient with AML showed NPM1 mutation in 24 (23%) of patient while only one (4%) of 28 previously untreated patients with myelodysplastic syndrome (MDS) showed NPM1 mutation. Compared with peripheral blood cells, 2 (8%) of the 24 positive patients were negative by cells; none were positive by cells and negative by plasma. Most of the mutations detected (45%) were in patients with FAB classification M2, M4 and M5. In addition to the reported 4 bp insertion, we also detected 4 bp deletion in one patient in cells and plasma. Patients with NPM1 mutation had a significantly higher white blood cell count (P = 0.0009) and a higher blast count in peripheral blood (P = 0.002) and in bone marrow (P = 0.002). Blasts in patients with NPM1 mutant expressed lower levels of HLA-DR (P = 0.005), CD13 (P = 0.02) and CD34 (P < 0.0001), but higher CD33 levels (P = 0.0004). Patients with NPM1 mutation appear to have better chance of responding to standard therapy (P = 0.06). Event free survival of patients with NPM1 mutation was longer (P = 0.056) than in patients with intermediate cytogenetic abnormalities. The most striking difference in survival was in patients who required >35 days to respond to therapy (Figure). Survival was significantly longer in patients with NPM1 mutation requiring >35 days to respond (P = 0.027). This data not only support that NPM1 plays a significant role in the biology and clinical behavior of AML, but also show that plasma DNA is enriched with leukemia-specific DNA and is a reliable source for testing. Figure Figure

Interim results of protracted low doses of temozolomide in high-risk acute myeloid leukemia

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 7052-7052
Author(s):  
B. C. Medeiros ◽  
J. R. Gotlib ◽  
S. E. Coutre ◽  
C. Jones ◽  
S. A. Khan ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
High Risk ◽  
Elderly Patients ◽  
Promoter Methylation ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Normal Karyotype ◽  
Low Doses ◽  
Npm1 Mutation ◽  
Acute Myeloid

7052 Background: High treatment-related mortality and low response rates often discourage elderly patients with acute myeloid leukemia from receiving treatment. Previous data demonstrate that only patients lacking expression of O6-alkylguanine-DNA alkyltransferase (AGAT) in leukemic blasts are sensitive to temozolomide. Protracted exposure to low doses of temozolomide can significantly inhibit AGAT enzymatic activity. Methods: Phase II clinical trial of tailored temozolomide therapy to high-risk AML patients according to AGAT methylation promoter status. Patients demonstrating evidence of AGAT promoter methylation were stratified to conventional doses of temozolomide at 200 mg/m2 orally x 7 days. Patients demonstrating lack of AGAT promoter methylation (unmethylated) received protracted doses of temozolomide (100 mg/m2 orally x 14 days) followed by conventional doses of temozolomide. Patients who achieved CR were given up to 5 consolidation treatments. Results: Fifteen patients have completed treatment to date. The median age was 78 (68–83) and nine were male. De novo AML was diagnosed in eight patients and five patients had s-AML. Nine patients had a normal karyotype and three patients had a complex karyotype. Two patients had only a NPM1 mutation and one had NPM1mut/FLT3-ITD. In 13 patients, the AGAT promoter was found to be unmethylated. AGAT protein was present in 5/11 patients. All patients had an intact mismatch repair pathway. Thirteen patients had HCT-CI scores of 0–2. Six patients (6/13) achieved a complete remission (CR) after 1 cycle of therapy (1/2 for patients with methylated and 5/11 for patients with unmethylated AGAT promoter). Nonhematologic toxicities were minimal. Drug-related hematologic toxicities were difficult to distinguish from disease-related cytopenias. Three patients remain in CR with a median duration of 22 weeks (14–36 weeks). Seven patients have died from disease progression, while two patients died of neutropenic sepsis (early deaths). With a median follow-up of 38 weeks (10–48), the median overall survival for the entire population is 12 weeks (3.5 - 38) weeks (responders 26.5 weeks). Conclusions: These preliminary results suggest that temozolomide therapy may be individually tailored to elderly patients with AML according to AGAT promoter status. [Table: see text]

FLT3, NPM1 and MLL Mutations Help Risk Stratification in Pediatric Acute Myeloid Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1574-1574
Author(s):  
Shuhong Shen ◽  
Yin Liu ◽  
JingYan Tang ◽  
Long-Jun Gu
Keyword(s):  
Acute Myeloid Leukemia ◽  
Risk Stratification ◽  
Myeloid Leukemia ◽  
Tandem Duplication ◽  
De Novo ◽  
Genetic Alterations ◽  
Npm1 Mutation ◽  
De Novo Aml ◽  
Pediatric Aml ◽  
Acute Myeloid

Abstract Abstract 1574 Poster Board I-600 Introduction Acute myeloid leukemia (AML) is a heterogeneous disease which harbors various genetic alterations. Among theses genetic events, Mutations of FLT3, NPM1, MLL and other genes often predict prognosis, particularly in cases cytogenetic normal (CN-AML). Could these be criteria for risk stratification in Pediatric AML ? Patients and Methods 155 cases of de novo AML were diagnosed routinely according to morphology, immunology, cytogenetics, and molecular biology examination on bone marrow (BM) aspirates between Jan. 2002 and Dec. 2008. All patients received chemotherapy according to the AML-XH-99 protocol, which consist of Daunorubicin, Cytosine arabinoside, Etoposide, Homoharringtonine. For acute promyelocytic leukemia, all-trans retinoic acid and Arsenic trioxide were also included. Meanwhile, total RNA of leukemic cells form all diagnostic BM samples were extracted, and then reverse transcribed. MLL partial tandem duplication (MLL/PTD) fusion transcripts were screened by real-time quantitative polymerase chain reaction. FLT3 internal tandem duplication (FLT3/ITD), FLT3 tyrosine kinase domain mutation (FLT3/TKD) and NPM1 mutation were examined by High resolution melting analysis. Results Of the 155 children with de novo AML, 121(78.1%) had received chemotherapy for more than one week with data available for analysis. Among them, 55(45.5%) was cytogenetically normal (CN-AML). In this total cohort of patients 49(27.09%) had FLT3/ITD (32.70% in CN-AML), 14 (9.03%) had FLT3/TKD (7.30% in CN-AML), 62 (40%) had NPM1 mutation (49% in CN-AML), and additional 8 (5.16%) had MLL/PTD (5.50% in CN-AML). In this cohort of patients 98 (63.22%) had at least one mutation. The clinical outcomes were listed in table 1. Generally, patients with FLT3 mutation (ITD or TKD mutation) usually have worse results after chemotherapy, as reported previously by other researchers. Meanwhile, NPM1 mutations usually predict better prognosis in our cohort of AML patients. MLL/PTD always predicts the worst outcome in AML as other MLL rearrangements in leukemia. Among CN-AML patients, 5-year EFS and OS were similar to whole cohort of patients according to those mutations. Cox regression analysis in a univariate model revealed that the presence of FLT3/ITD and NPM1 was significant prognostic factor of EFS, (P<0.05). We therefore proposed a molecular-risk classification of pediatric AML patients based on the data we got in this study. For the newly classified groups of low, medium and high risk groups, EFS rate was 62.03%±8.42%, 45.42%±4.52%, and 14.85%±2.99%, respectively, P=0.00. CRD for the 3 groups was 27.69±21.34 months, 22.62±19.64 months, 13.26±11.95 months, respectively, p=.022. Our results indicate that combinations of these couple of molecular events may be the useful tool for further classify AML in children. Disclosures No relevant conflicts of interest to declare.

IDH1 and IDH2 Mutations In Pediatric Acute Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1699-1699
Author(s):  
Anna Andersson ◽  
David Miller ◽  
John Lynch ◽  
Andrew Lemoff ◽  
Zhongling Cai ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Leukemic Cells ◽  
Myeloid Malignancies ◽  
Idh1 Mutations ◽  
Idh1 And Idh2 Mutations ◽  
Pediatric Aml ◽  
Normal Cytogenetics ◽  
Acute Myeloid

Abstract Abstract 1699 Pediatric de novo acute myeloid leukemia (AML) is a heterogeneous disease that can be divided into clinically distinct subtypes based on the presence of specific chromosomal abnormalities, gene mutations, or morphologic and immunophenotypic features. The best characterized subtypes include leukemias with alterations of the gene encoding the core-binding transcription factor complex, (t(8;21)[AML1- ETO] and inv(16)/t(16;16)[CBFβ-MYH11], rearrangements of the MLL gene on chromosome 11q23, normal cytogenetics, or distinct morphology including acute promyeloctic leukemia with t(15;17)[PML-RARA] and acute megakaryoblastic leukemia (FAB-M7). In AMLs with normal cytogenetics, mutations have also been identified in a number of genes, with alterations in NPM1, FLT3 and CEBPA occurring at an appreciable frequency and influencing therapeutic responses. Recent genome-wide sequencing efforts have led to the identification of a number of new candidate genes involved in the pathogenesis of this disease. Foremost among this list are isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2). IDH1 mutations were initially identified in a whole exome sequencing of glioblastoma multiforme (GBM), but were subsequently shown to be mutated in a variety of myeloid malignancies including up to 16% of adult AMLs with normal cytogenetics. The mutations in both GBM and myeloid malignancies have been heterozygous and restricted to arginine 132 in exon 4 of IDH1, or to either the homologous residue in IDH2, R172, or to a second arginine, R140, also located in its substrate binding pocket. Although the distribution of specific IDH1/IDH2 mutations varies between GBM and AML, each of the analyzed mutations result in a loss of the enzymes ability to catalyze the oxidative carboxylation of isocitrate to a-ketoglutarate (a-KG), coupled with a gain-of-function to catalyze the NADPH-dependent reduction of a–KG to 2-hydroxyglutarate (2-HG). This shift in enzymatic activity results in a dramatic increase in the levels of 2-HG within the leukemic cells; however, how the increase in this metabolite contributes to transformation remains to be determined. To investigate the frequency of IDH1 and IDH2 mutations in pediatric AML, we sequenced these genes in diagnostic samples from 227 pediatric AML patients. Our analysis identified somatic IDH1/2 mutations in 4% of cases (IDH1 N=3 and IDH2 N=5), with the frequency slightly higher in AMLs with a normal karyotype (7%). IDH1 mutations occurred in codon 132 resulting in replacement of arginine with either cysteine (N=2) or histidine (N=1). By contrast, the mutations in IDH2 did not affect the homologous residue but instead altered codon 140, resulting in replacement of an arginine with either glutamine (N=4) or tryptophan (N=1). Structural modeling studies of IDH2 suggested that the codon 140 mutations should disrupt the enzyme's ability to bind its substrate isocitrate. Consistent with this prediction, enzymology studies showed that recombinant IDH2 R140Q and R140W were unable to carry out the decarboxylation of isocitrate to α-ketoglutarate (α-KG), but instead gained the neomorphic activity to reduce α-KG to R(-)-2-hydroxyglutarate (2-HG). Analysis of primary leukemic blasts using mass spectrometry confirmed high levels of 2-HG in samples with IDH1/2 mutations. Interestingly, 3/5 leukemias also had FLT3 activating mutations, raising the possibility that these two mutations directly cooperate in leukemogenesis. Defining the biological role of the IDH1/2 mutations in leukemogenesis will benefit by a direct assessment of the biological effect of the mutations on normal murine hematopoietic cell differentiation using both in vitro and in vivo systems. Disclosures: No relevant conflicts of interest to declare.

Presence of FLT3-ITD and high BAALC expression are independent prognostic markers in childhood acute myeloid leukemia

Blood ◽  
2011 ◽  
Vol 118 (22) ◽  
pp. 5905-5913 ◽  
Author(s):  
Anna Staffas ◽  
Meena Kanduri ◽  
Randi Hovland ◽  
Richard Rosenquist ◽  
Hans Beier Ommen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Prognostic Markers ◽  
Npm1 Mutation ◽  
Mutation Status ◽  
Expression Levels ◽  
Pediatric Aml ◽  
Gene Expression Levels ◽  
Acute Myeloid

Abstract Mutation status of FLT3, NPM1, CEBPA, and WT1 genes and gene expression levels of ERG, MN1, BAALC, FLT3, and WT1 have been identified as possible prognostic markers in acute myeloid leukemia (AML). We have performed a thorough prognostic evaluation of these genetic markers in patients with pediatric AML enrolled in the Nordic Society of Pediatric Hematology and Oncology (NOPHO) 1993 or NOPHO 2004 protocols. Mutation status and expression levels were analyzed in 185 and 149 patients, respectively. Presence of FLT3-internal tandem duplication (ITD) was associated with significantly inferior event-free survival (EFS), whereas presence of an NPM1 mutation in the absence of FLT3-ITD correlated with significantly improved EFS. Furthermore, high levels of ERG and BAALC transcripts were associated with inferior EFS. No significant correlation with survival was seen for mutations in CEBPA and WT1 or with gene expression levels of MN1, FLT3, and WT1. In multivariate analysis, the presence of FLT3-ITD and high BAALC expression were identified as independent prognostic markers of inferior EFS. We conclude that analysis of the mutational status of FLT3 and NPM1 at diagnosis is important for prognostic stratification of patients with pediatric AML and that determination of the BAALC gene expression level can add valuable information.

High Cytogenetic or Molecular Genetic Risk Acute Myeloid Leukemia

Hematology ◽  
2010 ◽  
Vol 2010 (1) ◽  
pp. 474-480 ◽  
Author(s):  
Elihu Estey
Keyword(s):  
Acute Myeloid Leukemia ◽  
High Risk ◽  
Myeloid Leukemia ◽  
Hematopoietic Cell ◽  
Remission Induction ◽  
Cell Transplant ◽  
Hematopoietic Cell Transplant ◽  
Npm1 Mutation ◽  
Monosomal Karyotype ◽  
Acute Myeloid

Abstract Resistance, manifested as failure to enter remission despite living long enough to do so or as relapse from remission, is the principal cause of therapeutic failure in acute myeloid leukemia, even in patients age ≥ 75. Recently, a “monosomal karyotype” in acute myeloid leukemia blasts has been found to be a principal predictor of resistance. It is also clear that patients with a normal karyotype, and other intermediate prognosis karyotypes, can be placed into a high-risk group based on the absence of a mutation in the NPM1 gene or the presence of an internal tandem duplication (ITD) of the Fms-like tyrosine kinase 3 gene (FLT3) gene, particularly if there is loss of the wild-type FLT3 allele. The effects of other genetic abnormalities have been inconsistent, perhaps reflecting differences in expression of the abnormality and its translation into protein. Several reports have shown the prognostic potential of profiling global gene expression, micro-RNA expression, DNA methylation, and proteomics. Although routine application of these approaches is still premature, pretreatment assessment of the nucleophosmin 1 (NPM1) mutation and FLT3 ITD status, as well as cytogenetics, should be routine. These results can be used to guide the choice of remission induction therapy, for example, by placing patients with monosomal karyotype or FLT3 ITDs on clinical trials. Allogeneic hematopoietic cell transplant in first complete remission is generally indicated for high-risk patients. However, new approaches are needed to reduce the high rates of relapse, even after hematopoietic cell transplant.

scholarly journals Acute Myeloid Leukemia Relapse Presenting as Complete Monocular Vision Loss due to Optic Nerve Involvement

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Shyam A. Patel
Keyword(s):  
Acute Myeloid Leukemia ◽  
Optic Nerve ◽  
High Risk ◽  
Myeloid Leukemia ◽  
Vision Loss ◽  
Intrathecal Chemotherapy ◽  
Monocular Vision ◽  
Leukemic Cells ◽  
Leptomeningeal Disease ◽  
Acute Myeloid

Acute myeloid leukemia (AML) involvement of the central nervous system is relatively rare, and detection of leptomeningeal disease typically occurs only after a patient presents with neurological symptoms. The case herein describes a 48-year-old man with relapsed/refractory AML of the mixed lineage leukemia rearrangement subtype, who presents with monocular vision loss due to leukemic eye infiltration. MRI revealed right optic nerve sheath enhancement and restricted diffusion concerning for nerve ischemia and infarct from hypercellularity. Cerebrospinal fluid (CSF) analysis showed a total WBC count of 81/mcl with 96% AML blasts. The onset and progression of visual loss were in concordance with rise in peripheral blood blast count. A low threshold for diagnosis of CSF involvement should be maintained in patients with hyperleukocytosis and high-risk cytogenetics so that prompt treatment with whole brain radiation and intrathecal chemotherapy can be delivered. This case suggests that the eye, as an immunoprivileged site, may serve as a sanctuary from which leukemic cells can resurge and contribute to relapsed disease in patients with high-risk cytogenetics.

Molecular Profiling of High-Risk Pediatric Acute Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5250-5250
Author(s):  
Lianna J Marks ◽  
Jennifer A Oberg ◽  
Julia L Glade-Bender ◽  
Susan J Hsiao ◽  
Danielle Pendrick ◽  
...  
Keyword(s):  
High Risk ◽  
Myeloid Leukemia ◽  
Clinical Characteristics ◽  
Molecular Profiling ◽  
Genetic Alterations ◽  
Genomic Profiling ◽  
Gene Fusions ◽  
Ras Pathway ◽  
Pediatric Aml ◽  
Acute Myeloid

Abstract Background: Several landmark genomic profiling studies have dramatically advanced our understanding of the origin, progression and clonal evolution of adult acute myeloid leukemia (AML) and directly impacted clinical care. However, very little is known about the mutational landscape of pediatric AML, a distinct entity that shares few genetic and clinical characteristics with adult AML. To investigate potential drivers of high-risk pediatric AML, comprehensive genomic profiling was performed on high-risk AML samples as part of a prospective clinical next-generation sequencing program. Methods:Samples obtained from patients with known high-risk features at diagnosis or with refractory or relapsed AML were selected for molecular profiling. Comprehensive testing included whole-exome sequencing (WES) of matched tumor (bone marrow or chloroma tissue) and normal tissue (peripheral blood or buccal swab) samples and transcriptome analysis (RNAseq). Targeted sequencing of 467 cancer-associated genes was used when tumor tissue was limited. Sequencing was performed on Illumina's HiSeq 2500 with 150X and 500X average coverage for WES and targeted sequencing, respectively. Variants were filtered to select alterations in cancer-related genes or genes relevant for patient care. Results:Fifteen patients with AML (mean age 7.7 yrs; range 0.75-19 yrs) met high-risk criteria (high-risk features at diagnosis = 4, relapsed disease = 8, refractory disease = 3) and were selected for profiling. WES and RNAseq were performed on 11 samples, WES only on 3 samples and targeted DNA sequencing on 1 sample. The median number of variants was 60 (range 14- 5950) per case. After filtering, 54 mutations were identified in 35 genes with a mean of 3.6 mutated genes per patient sample (range 0-14); two samples only carried a fusion gene with no other genetic alterations. At least one driver genetic alteration was detected in each patient sample. Thirteen samples carried mutations in at least one gene known to be altered in AML (e.g. IDH1, WT1, TP53, NRAS) (mean, 2; range, 1-6) and 5 samples carried novel mutations in 15 genes not previously implicated in AML (e.g. CARD9, CHD9, Axin1). Mutations in 11 AML related genes were detected in more than one sample including NRAS in 4, TP53 in 3 and KRAS, PTPN11 PHF6, JAK3 in 2 samples each; genes not previously implicated in AML were only mutated in single patients. Of note, mutations in genes encoding members of the RAS pathway occurred in 60% of cases (9/15 samples). RNAseq identified gene fusions in 7/11 samples (63%). Four fusions involving KMT2A and core binding factor genes were also detected by FISH while three fusions were detected by RNAseq only: NUP98-NSD1 in two patients and CBFA2T3-GLIS2 in one patient. Samples carrying driver gene fusions had the lowest number of mutated genes (0-1) compared to samples lacking a gene fusion (1-5 mutated genes), with one exception of a patient with history of infant ALL who later developed KMT2A-AFF1AML with the highest number of mutated genes (n=14). There was no correlation between the number of mutated genes and age, clinical characteristics, initial risk classification at diagnosis or intensity of therapy prior to sequencing. Conclusion:Our study provides an initial overview of the genetic alterations that characterize high-risk, chemo-resistant pediatric AML. Analysis of the data highlights the overall low genetic complexity of high-risk AML despite the aggressive clinical behavior and exposure to intense chemotherapy, including stem cell transplant. Of interest, similar to adult AML, we found that mutations leading to aberrant activation of the RAS pathway were also very frequent in our cohort of pediatric high-risk AML, while genes typically mutated early in the process of leukemogenesis in adult AML, such as NPM1, DNMT3A, FLT3, IDH1, IDH2 were not affected. Such findings suggest that distinct, age-specific mechanisms of leukemogenesis might exist. Furthermore, our data also highlights the important role of RNA sequencing in complementing current standard diagnostic tools, allowing the identification of driver fusion genes in samples for which no other driver event is detected. Larger studies, preferably including diagnostic samples and utilizing broader approaches, are needed to better understand the mechanisms responsible for the initiation and progression of childhood AML. Disclosures No relevant conflicts of interest to declare.

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