Clonal Cytogenetic Abnormalities Research Articles

Myeloid Cell Maturation Is Disrupted By Monosomy 7 or By Gain of Additional Genetic Aberrations during Clonal Evolution in Myelodysplastic Syndromes.

Background: Myelodysplastic syndromes (MDS) are associated with cytogenetic clones. To follow the maturation sequence of original clones and evolved subclones with additional cytogenetic abnormalities, progenitor cells, immature and mature myeloid cells were sorted by flow cytometry and analyzed separately by fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH).Methods: Flow cytometry sorted cell fractions from bone marrows for sixteen patients with MDS-associated cytogenetic abnormalities were evaluated by FISH. Flow cytometric cell sorting was based on CD34+/low side scatter (SS) for progenitors, CD13+/CD16-/high SS for immature myeloid cells, and CD13+/CD16+/high SS for mature myeloid cells. Customized color labeling (spectrum orange, green and aqua) of FISH probe combinations were designed to detect and to analyze clonal evolution for each patient based on their known cytogenetic abnormalities and clonal evolution patterns. Three marrow aspirates were sorted for analysis by SNP/CGH microarray.Results: The 16 bone marrow specimens evaluated by FISH were categorized into three groups: (1) eight patients with a single, good-to-intermediate cytogenetic abnormality; (2) four patients with monosomy 7; and (3) four patients with more than one chromosome abnormality with evidence of clonal evolution by conventional cytogenetic analysis, excluding monosomy 7.The Group-1 abnormalities included deletion 20q (n=4), trisomy 8 (n=2), deletion 5q (n=1), and trisomy 11 (n=1). All specimens from this group showed FISH abnormalities in equal proportions in myeloid progenitors, immature and mature myeloid cells.Group-2 had four patients with monosomy 7. All four had monosomy 7 concentrated in the progenitor cells (45-79%) compared to immature and mature myeloid compartments (less than 9-36%).For Group-3, known original clones with single cytogenetic abnormalities (deletion 20q, monosomy 3, deletion 7q or 5q) were monitored by FISH analysis. Using customized FISH panels, the presence of subclones with additional cytogenetic aberrations (trisomy 8 in three patients and gain of a marker chromosome characterized by the centromere of chromosome 4 in a fourth patient) was assessed using single-cell resolution. The progenitor and immature myeloid compartments had the original founding clones containing a single cytogenetic abnormality at 15-34% and the subclones with the additional aberrations at 23-76%. In contrast, the mature myeloid cells were comprised of the original clone at 20-40%, but the subclones with additional aberrations were absent in the mature myeloid compartment in three patients and reduced by more than half in a fourth.For three patients sorted bone-marrow fractions were analyzed by SNP/CGH microarray. In one patient with trisomy 8 as the sole abnormality, the same aberration was observed in both the immature and mature myeloid compartments. In two other patients, additional abnormalities not seen in the mature myeloid cells were detected in the progenitor and immature myeloid compartments.Conclusions: These data show two main patterns for the distribution of clonal cytogenetic abnormalities among myeloid cells in MDS: 1) A continuous distribution at all stages of maturation was found for single aberrations with good-to-intermediate prognostic associations (Group 1) and 2) A disrupted distribution pattern with accumulation of the cytogenetic aberrations in the progenitor compartment as compared to the immature and mature myeloid compartments for specimens characterized by monosomy 7 (Group 2). Similarly, subclones characterized by additional cytogenetic abnormalities (Group 3) were sequestered in the progenitor and immature myeloid compartments while the original founding clone was evenly distributed throughout maturation.These data demonstrate that specific cytogenetic abnormalities associated with poor prognosis (e.g. monosomy 7) as well as acquired cytogenetic abnormalities as a result of clonal evolution can cause disruption of myeloid cell maturation in MDS. DisclosuresZehentner:HematoLogics Inc.: Employment, Equity Ownership. Hartmann:Hematologics Inc.: Employment. Johnson:Hematologics Inc.: Employment. Bennington:HematoLogics Inc.: Employment. Fritschle:HematoLogics Inc.: Employment. Ghirardelli:HematoLogics Inc.: Employment. Broderson:HematoLogics Inc.: Employment. Chapman:Hematologics Inc.: Employment. Stephenson:Hematologics Inc.: Employment. de Baca:Hematologics Inc.: Employment. Singleton:Hematologics Inc.: Employment. Wells:HematoLogics Inc.: Employment, Equity Ownership. Loken:Hematologics: Employment, Equity Ownership.

Isolated +15 in bone marrow: Disease-associated or a benign finding?

It has been controversial if trisomy 15 (+15) as an isolated clonal cytogenetic abnormality in bone marrow (BM) is disease-associated or a benign finding. To answer this question, we retrospectively reviewed our cytogenetic archives and identified 31 patients with isolated +15. Four patients presented with acute myeloid leukemia (AML), +15 was the major clone (56–95% of interphases) in BM and the clonal size of +15 was correlated with blast burden and disease status. For the remaining 27 patients, +15 was a minor clone (3–24% of interphases) in BM. Eighteen patients had a history of cytotoxic therapies and developed +15 after a median latency interval of 34 months. Six patients had BM involvement by lymphoma or myeloma, and +15 was exclusively detected in myeloid and erythroid cells, not in lymphoma or myeloma cells. With a median follow-up of 28 months, none of these 27 patients had clinical or morphological evidence of myelodysplastic syndromes. We conclude that +15 can be associated with AML, but more often isolated +15 presents as a minor clone in BM, and may not be disease associated. Clinical follow-up rather than an immediate therapeutic intervention seems most appropriate for non-leukemic patients with isolated +15.

Is the cytodiagnosis of mesothelioma any easier these days?

Is the cytodiagnosis of mesothelioma any easier these days?

PP-056 HYPEREOSINOPHILIC SYNDROME: CASE REPORT

Before the 1990s, lack of evidence for a reactive cause of hypereosinophilia or chronic eosinophilic leukemia (e.g. presence of a clonal cytogenetic abnormality or increased blood or bone marrow blasts) resulted in diagnosticians characterizing such nebulous cases as ‘idiopathic hypereosinophilic syndrome (HES)’. However, over the last decade, significant advances in our understanding of the molecular pathophysiology of eosinophilic disorders have shifted an increasing proportion of cases from this idiopathic HES ‘pool’ to genetically defined eosinophilic diseases with recurrent molecular abnormalities. The majority of these genetic lesions result in constitutively activated fusion tyrosine kinases, the phenotypic consequence of which is an eosinophilia-associated myeloid disorder. Most notable among these is the recent discovery of the cryptic FIP1L1–PDGFRA gene fusion in karyotypically normal patients with systemic mast cell disease with eosinophilia or idiopathic HES, redefining these diseases as clonal eosinophilias. Rearrangements involving PDGFRA and PDGFRB in eosinophilic chronic myeloproliferative disorders, and of fibroblast growth factor receptor 1 (FGFR1) in the 8p11 stem cell myeloproliferative syndrome constitute additional examples of specific genetic alterations linked to clonal eosinophilia. The identification of populations of aberrant T-lymphocytes secreting eosinophilopoietic cytokines such as interleukin-5 establish a pathophysiologic basis for cases of lymphocyte-mediated hypereosinophilia. This recent revival in understanding the biologic basis of eosinophilic disorders has permitted more genetic specificity in the classification of these diseases, and has translated into successful therapeutic approaches with targeted agents such as imatinib mesylate and recombinant anti-IL-5 antibody.

Molecular-defined clonal evolution in patients with chronic myeloid leukemia independent of the BCR-ABL status.

To study clonal evolution in chronic myeloid leukemia (CML), we searched for BCR-ABL-independent gene mutations in both Philadelphia chromosome (Ph)-negative and Ph-positive clones in 29 chronic-phase CML patients by targeted deep sequencing of 25 genes frequently mutated in myeloid disorders. Ph-negative clones were analyzed in 14 patients who developed clonal cytogenetic abnormalities in Ph-negative cells during treatment with tyrosine kinase inhibitors (TKI). Mutations were detected in 6/14 patients (43%) affecting the genes DNMT3A, EZH2, RUNX1, TET2, TP53, U2AF1 and ZRSR2. In two patients, the mutations were also found in corresponding Ph-positive diagnostic samples. To further investigate Ph-positive clones, 15 randomly selected CML patients at diagnosis were analyzed. Somatic mutations additional to BCR-ABL were found in 5/15 patients (33%) affecting ASXL1, DNMT3A, RUNX1 and TET2. Analysis of individual hematopoietic colonies at diagnosis revealed that most mutations were part of the Ph-positive clone. In contrast, deep sequencing of subsequent samples during TKI treatment revealed one DNMT3A mutation in Ph-negative cells that was also present in Ph-positive cells at diagnosis, implying that the mutation preceded the BCR-ABL rearrangement. In summary, BCR-ABL-independent gene mutations were frequently found in Ph-negative and Ph-positive clones of CML patients and may be considered as important cofactors in the clonal evolution of CML.

Myelodysplastic syndromes: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

P. Fenaux1, D. Haase2, G. F. Sanz3, V. Santini4 & C. Buske5 on behalf of the ESMO Guidelines Working Group* Service d’Hematologie Clinique, Groupe Francophone des Myelodysplasies (GFM), Hopital St Louis (Assistance Publique, Hopitaux de Paris) and Paris 7 University, Paris, France; Clinics of Hematology and Medical Oncology, University Medicine, Goettingen, Germany; Department of Haematology, Hospital Universitario y Politecnico La Fe, Valencia, Spain; Functional Unit of Haematology, AOU Careggi, University of Florence, Firenze, Italy; Comprehensive Cancer Center Ulm, Institute of Experimental Cancer Research, University Hospital, Ulm, Germany

Isolated Clonal Cytogenetic Abnormalities after High-Dose Therapy: Do They Matter?

High-dose therapy (HDT) is effective in treating a variety of hematologic conditions. However, despite significant reductions in treatment-related mortality over the past several decades, subsequent development of therapy-related myeloid neoplasm (t-MN) remains a significant complication. A number of risk factors have been implicated in t-MN, including prior therapy, age, poor mobilization for autologous stem cell transplantation (ASCT), and conditioning regimen [1-5]. Incidence rates of t-MN have been reported as high as 24.3% after ASCT [1], and the prognosis is exceedingly poor [2,6,7]. Although most cases of t-MN harbor clonal marrow cytogenetic abnormalities (CMCA) [6,7], the clinical significance of CMCA without morphologic or clinical features of t-MN is less well established. In this issue, Showel et al. report on 1 of the largest series to date of CMCA after HDT, detailing the Johns Hopkins experience with patients receiving ASCT or high-dose cyclophosphamide [8]. Of 31 patients with CMCA in this series, 20 developed t-MN. The remaining 11 patients did not meet criteria for t-MN over the duration of follow-up. Four of these patients had only transient CMCA. At least another 4 patients had follow-up that was insufficient to confirm persistence of the CMCA and/or to provide adequate time for development of t-MN (given a delay of up to 3.2 years from initial discovery of CMCA until overt t-MN in this cohort). One patient did not develop t-MN, despite persistence of a CMCA for 3 years and an additional 2.5 years of follow-up. Notably, 2 patients, each with at least 5 years of follow-up from first discovery of CMCA, did not develop t-MN, in spite of complex karyotypes in both cases and transient, clinically significant cytopenias in 1. The authors conclude that CMCA alone are not sufficient to establish a diagnosis of t-MN and that correlation with morphology is also required. At the very least, CMCA appears to be a risk factor for subsequent t-MN, as 64.5% of patients with known CMCA ultimately developed t-MN in this series. This equates to a>18fold higher risk of t-MN in these patients than for the cohort as awhole (whichhada 3.5% incidence of t-MN). Conversely, 95%

Clinically silent clonal cytogenetic abnormalities arising in patients treated for lymphoid neoplasms

Newly emerged clonal cytogenetic abnormalities (CCA) in patients with prior cytotoxic therapy are highly concerning for therapy-related myeloid neoplasms (t-MN). In some patients, however, CCA appeared to be clinically “silent”. In this study, we describe 25 patients who developed CCA after they received cytotoxic therapies for lymphoid neoplasms but never developed t-MN. These clinically “silent” CCA were always present as single abnormalities, often detected in a small subset of cells, and tended to disappear over time. We conclude that the occurrence of CCA is not always associated with t-MN. Clinical correlation is essential to guide a proper management of these patients.

Chronic myelomonocytic leukemia: Next-generation sequencing in 30 treatment-naive cases.

7051 Background: Chronic myelomonocytic leukemia (CMML) belongs to a subtype of myeloid neoplasms called myelodysplastic / myelproliferative neoplasms. While clonal cytogenetic abnormalities have b...

Isolated Clonal Cytogenetic Abnormalities after High-Dose Therapy

Therapy-related myeloid neoplasms (t-MN) are well-recognized complications of high-dose cytotoxic therapy (HDT), such as autologous stem cell transplantation (ASCT). Clonal marrow cytogenetic abnormalities (CMCA) in the setting of normal bone marrow pathology have also been reported after HDT, but their significance remains unclear. We retrospectively evaluated occurrences of CMCA and t-MN in 785 patients treated with HDT at Johns Hopkins University between 1997 and 2007. Most patients received ASCT, but 106 patients who received high-dose cyclophosphamide without ASCT were also included in this study, as this is our institutional standard for malignant and nonmalignant lymphoproliferative disorders in need of HDT. Twenty-two patients developed t-MN, with an estimated cumulative incidence of 3.5% at 4 years. Eleven patients developed isolated CMCA, either transient or persistent without pathologic evidence of t-MN. Altogether, only 20 of the patients with reported CMCA subsequently developed t-MN during the follow-up period. Therefore, in the absence of pathologic evidence of t-MN, CMCA should not be considered diagnostic of t-MN.

Chronic myelomonocytic leukaemia: a concise clinical and pathophysiological review

Chronic myelomonocytic leukaemia (CMML) is a clonal haematopoietic stem cell disorder with myelodysplastic and myeloproliferative overlap features, and an inherent tendency to transform to acute myeloid leukaemia. Approximately 30% of patients present with clonal cytogenetic abnormalities, while almost 90% have molecular aberrations involving epigenetic regulation, the spliceosome component machinery, tumour suppressor genes and transcription factors/regulators. Numerous prognostic models exist for CMML, with more recent models incorporating prognostic mutations, such as those involving ASXL1. Other variables that seem to consistently affect outcomes include the degree of leucocytosis/monocytosis, anaemia and thrombocytopenia. Allogeneic stem cell transplant remains the only curative option for CMML, while hypomethylating agents can be used for transplant-ineligible patients or those without suitable stem cell sources. Targeting biological pathways activated in CMML offers potential hope for more effective and less toxic therapies.

Clinicopathological analysis of 64 case of angioimmunoblastic T-cell lymphoma

To explore the clinical and pathological characteristics of angioimmunoblastic T-cell lymphoma (AITL). Sixty-four cases of AITL were retrospectively analyzed by histopathological and immunohistochemical methods. There were 35 men and 29 women, the median age was 59 years (range, 25-84 ys). AITL typically presented with advanced stage, generalized lymphadenopathy, hepatosplenomegaly and systemic symptoms. Morphologically, the lymph nodes showed partial or total obliteration of the normal architecture by a polymorphic infiltration of lymphocytes, and by proliferation of follicular dendritic cells and that of high endothelial venules. Most cases contained a monoclonal T-cell population as well as clonal cytogenetic abnormalities. Immunophenotype analysis showed that neoplastic cells expressed the following markers: CXCL13 (positive rate 95.3%), PD-1 (positive rate 75.0%), CD10 (positive rate 25.0%), Bcl- 6 (positive rate 40.0%), CD2 (positive rate 96.0%), CD3 (positive rate 95.0%), CD4 (positive rate 84.0%), CD5 (positive rate 73.0%), EBER (positive rate 39.5%) and Ki-67 (average positive rate 55.0%), and frequently showed aberrant loss or reduced expression of CD7 and CD8. The neoplastic cells of AITL showed features of CD4+ TFH, with peculiar clinical features. Peripheral T-cell lymphomas with a follicular growth pattern may show overlapping features with focal AITL.

Lymph node hyperplasia: clonal chromosomal and genomic rearrangements. Report of two new cases and literature review

Cytogenetic analysis is not routinely performed on lymph node hyperplasia (LH). We describe clonal chromosomal rearrangements in two unrelated cases of LH. Lymph nodes of both patients showed typical morphologic features of benign follicular hyperplasia. Cytogenetic analysis revealed clonal chromosomal rearrangements in both cases. Patient 1 showed interstitial 14q and 6q mosaic deletions, whereas patient 2 showed a terminal 14q mosaic deletion. Fluorescence in situ hybridization with IGH break-apart probes identified a partial deletion of IGH in both cases, but the loss of the LSI IGH in patient 2 and loss of the LSI IGHV in patient 1 were observed on the morphologically normal chromosome 14. In the latter case, the finding of two morphologically normal chromosomes 14 with the IGHV deletion in one of the chromosomes suggested that the first mutational event was the IGH deletion and the second event was the interstitial deletion of chromosome 14 with the IGH intact. Array comparative genomic hybridization performed on both biopsies confirmed the IGH deletion at mosaic, but not the chromosomal deletion. Patient 1 was re-biopsied after 9 months and a marginal zone lymphoma was diagnosed. The finding of clonal cytogenetic abnormalities in LH highlighted the difficulties in interpretation of results and clinical follow-up.

High-risk acute myelogenous leukemia: treatment today … and tomorrow

High-risk acute myelogenous leukemia (AML) constitutes a distinct subset of disease based on clinical and biological characteristics and comprises a significant percentage of all cases of adult AML. Biologic features such as distinct clonal cytogenetic and molecular abnormalities identify a subgroup of AML patients characterized by poor response to induction chemotherapy and poor long-term survival after treatment with consolidation chemotherapy. Clinical variables that predict for poor response include AML relapsed after less than 1 year of remission and AML characterized by resistance to conventional agents. We review here our understanding of the defining biologic subtypes of AML and discuss how adequate initial evaluation can be used to inform the choice of treatment. By defining high-risk biologic and clinical variables, a strong case can be made for treating patients with investigational agents, with treatment directed at distinct cytogenetic or molecular abnormalities. Allogeneic transplantation is the only form of therapy available outside of the setting of a clinical trial that may offer a chance for long-term survival for patients with high-risk AML.

Single Nucleotide Polymorphism Array Analysis Of Bone Marrow Failure Patients Reveals Characteristic Patterns Of Genetic Changes

Bone marrow failure syndromes (BMFS) are a diverse group of rare life-threatening blood disorders characterized by inadequate hematopoiesis, clonal evolution, and increased risk of hematologic malignancies. Despite recent advances in the understanding of the molecular pathogenesis of BMFS, the ability to diagnose, risk-stratify, and treat patients with these rare disorders remains limited. In both the acquired and the inherited BMFS, the major contributors to mortality are complications of progressive cytopenias, and, albeit to a lesser extent—transformation to myelodysplastic syndrome (MDS) and acute myeloid leukemia. The main predictor of malignant transformation is acquisition of clonal cytogenetic abnormalities. Recently, single nucleotide polymorphism arrays (SNP-A) were proposed as a promising tool for high resolution cytogenetic analysis and surveillance of early clonal changes in BMFS, however, their clinical utility still remains to be established. In 2009, the Comprehensive Bone Marrow Failure Center at the Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania incorporated high-density SNP-A as an adjunct to conventional cytogenetics in evaluation of BMFS patients. Here we present a comprehensive analysis of genetic changes in BMFS using 124 SNP-A from 91 patients, who were referred for evaluation of bone marrow failure. SNP-A genotyping was correlated with medical histories, hematopathology, cytogenetic, and molecular data. To assess the potential role of SNP-A in screening for early clonal evolution, longitudinal analysis of SNP-A was performed in 25 patients. We found that acquired copy number-neutral loss of heterozygosity (CN-LOH) was significantly more frequent in acquired aplastic anemia (aAA) than in other BMFS (OR 12.240, 95% CI 1.333-573.696, p<0.01). In contrast, acquired copy number alterations (CNAs) were more typical of MDS and unclassified BMFS. Extended tracts of homozygosity were common, frequently unmasking recessive loci in cases of inherited BMFS. Copy number variants (CNVs) were frequently polymorphic, and we identified several CNVs that are enriched in patients with aAA and neutropenia and may serve as disease modifiers. Clinical utilization analysis revealed that SNP-A can be helpful as an adjunct to conventional cytogenetics at the time of initial diagnosis (e.g. to identify regions of acquired CN-LOH and inherited homozygosity, acquired CNAs with a small clone size, and CNVs). Our longitudinal analysis showed that the likelihood of detecting a new acquired abnormality in a follow-up SNP-A was significantly higher in the setting of relapse than in the setting of stable disease (OR 27, 95% CI 1.23 to 808.54, p=0.035). Our results suggest that acquired CN-LOH is a general phenomenon in aAA, likely mechanistically and prognostically distinct from typical CN-LOH of myeloid malignancies. Our analysis of clinical utility of SNP-A shows the highest yield of detecting new clonal hematopoiesis at diagnosis and at relapse. Disclosures:No relevant conflicts of interest to declare.

Study of myelodysplastic syndrome overt leukemia

Aims: Myelodysplastic syndrome (MDS) overt leukemia is very poor prognosis. Many cases are elderly patients and mostly indicated cytogenetic abnormality. Also MDS overt leukemia shows treatment resistance in many cases. We investigate myelodysplastic syndrome overt leukemia. Material and methods: From 2003 to 2012, we intended for 229 patients who suffered from leukemia and myelodysplastic syndrome overt leukemia. MDS overt leukemia cases are 45 cases in that and all patients were followed up until death or until December 2012. And we studied about age, gender, cytogenetic abnormality, therapy, clinical outcome, and prognosis. Results: All cases are 45 cases, gender are male 28 cases and female 17 cases, median age is 74 years (ranged 54–90 years). Cytogenetic examination performed 40 cases. 29 cases revealed abnormality (72.5%), 11 cases indicated normal. About therapy, 9 cases received conventional chemotherapy as first remission induction therapy (daunorbicine 3 days + Cytarabine arabinocide 7 days; DC3-7 therapy, Idarubicine 2 days + Cytarabine arabinocide 7 days;IC2-7 therapy, Cytarabine arabinocide 14 days + Acracinon 4 days + Granulocyte stimulate factor 14 days; CAG therapy, Cytarabine arabinocide 7 days; Ara-C monotherapy). 19 cases received transfusion only, 15 cases received palliative chemotherapy (hydroxycarbamide 500–2000 mg/day) predonisoron (20–50 mg/day), low dose cytarabine arabinocide(continuos div25–50 mg/body 3–7 days), 2 cases did not receive any therapy except pain control or improving dehydration. About clinical outcome in conventional chemotherapy, patients who achieved at complete remission were 5 cases (55.6%), progression free survival was 6 months (ranged 3–18 months), median survival time was 14 months (ranged 7–21 months), in transfusion, median survival time was 6 month (ranged 1–14 months), in palliative chemotherapy, median survival time was 7 months (ranged 1–16 months). Discussion and conclusion: The MDS are a group of clonal hematopoietic stem cell disease characterized by cytopenia or cytopenias, dysplasia in one or more of cell lines. MDS occur principally in older adults with a median age of 70 years. As another characteristic, clonal cytogenetic abnormalities are observed frequently, about 50% or more of MDS cases. Cytogenetic and molecular studies have a major role in the evaluation of patients with MDS in regard to prognosis, determination of clonality, and the recognition of cytogenetic, morphologic, and clinical correlates. About strategy of therapy for myelodysplastic syndrome, it is difficult to cure using conventional chemotherapy, by the present, only bone marrow transplantation has possibility to cure. But because of there are many elderly people, there are few cases that could receive bone marrow transplantation. Many cases selected palliative therapy, in our study, 40 cases received palliative therapy, but there is no difference on the overall median survival time. This study suggested that therapy choice was case by case and does not hesitate selecting palliative therapy.

Acute myeloid leukemia following exposure to benzene more closely resembles de novo than therapy related‐disease

Benzene (Bz) is widely regarded as a prototype environmental leukemogen and individuals chronically exposed are at risk for myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). It is widely assumed that initiation and pathogenesis of AML following Bz exposure (Bz-AML) is similar or identical to therapy-related AML (t-AML), in which clonal cytogenetic abnormalities, including aneuploidy, are initiating events. However, this assumption is not supported by studies reporting actual disease outcomes together with cytogenetic analyses. Here, using clinically relevant cytogenetic, hematologic, and epidemiological methods, we directly show for 722 consecutive AML cases that the pattern of clonal cytogenetic abnormalities encountered in Bz-exposed cases (n = 78) more closely resembles de novo-AML than t-AML. The prevalence of aneuploidy in Bz-exposed- and de novo-AML cases was identical (23%), and no significant increases in -5/5q- (RR = 0.79) (95% CI: 0.29-2.12) or -7/7q- (RR = 1.27) (95% CI: 0.55-2.92) abnormalities were observed between Bz- vs de novo-AML, respectively. Previous studies have suggested a role for autoimmunity in Bz related MDS including immune mediated inflammatory features and positive responses to immunosuppressive therapy which are indistinguishable from those reported in MDS with low risk of progression to AML. These observations are more consistent with an epigenetic model for initiation of Bz-AML in which altered homeostatic regulation in the bone marrow niche, not direct cytogenetic injury, predominates in the initial development of the leukemic stem cell phenotype, a mechanism biologically distinct from previous models of clonal cytogenetic injury. These findings are important for further understanding the biological basis of AML, particularly in environmental and occupational settings.

Clonal chromosomal abnormalities in Philadelphia-negative cells in chronic myeloid leukemia patients treated with nilotinib used in first-line therapy

Nilotinib is an effective option for the first-line treatment of chronic myeloid leukemia (CML) patients in chronic phase (CP). In CML patients, clonal cytogenetic abnormalities (CAs) in Philadelphia-negative (Ph-) metaphases have been widely observed after treatment with imatinib, or dasatinib/nilotinib following failure with imatinib. However, such abnormalities in CML patients treated with nilotinib as the first-line therapy have not been reported. Thirteen CML CP patients with Philadelphia-positive (Ph+) cells were initially diagnosed in our hospital from December 2010 to July 2011. Patients were followed up by clinical assessment, cytogenetic analysis, and BCR-ABL transcriptional level every 3 to 6 months. Retrospective fluorescence in situ hybridization was performed on stored bone marrow specimens of patients when the cytogenetic analysis showed CAs. During nilotinib therapy, 12 (92.3 %), 5 (38.5 %), and 2 (15.4 %) patients achieved complete cytogenetic response, major molecular response, and complete molecular response at 18 months, respectively. Two patients developed CAs in Ph- cells, including trisomy 8 and monosomies 20 and 21. Monosomies 20 and 21 appeared in the same patient simultaneously. Our data confirmed that clonal CAs in Ph- cells is a general phenomenon in Ph+ CML patient treated with tyrosine kinase inhibitors (TKIs), including nilotinib. The clinical significance of these CAs that arise in Ph+ CML patient treated with TKIs and whether these CAs exist before or after treatment of TKIs are not clear.

Targeted Pathologic Evaluation of Bone Marrow Donors Identifies Previously Undiagnosed Marrow Abnormalities

Potential bone marrow donors are screened to ensure the safety of both the donor and recipient. At our institution, potential donors with abnormal peripheral blood cell counts, a personal history of malignancy, or age >60 years are evaluated to ensure that they are viable candidates for donation. Evaluation of the marrow includes morphologic, flow cytometric, and cytogenetic studies. A total of 122 potential donors were screened between the years of 2001and 2011, encompassing approximately 10% of all donors. Of the screened potential donors, the mean age was 59 years and there were 59 men and 63 women. The donors were screened because of age >60 years (n = 33), anemia (n = 22), cytopenias other than anemia (n = 27), elevated peripheral blood counts without a concurrent cytopenia (n = 20), elevated peripheral blood counts with a concurrent cytopenia (n = 10), history of malignancy (n = 4), abnormal peripheral blood differential (n = 3), prior graft failure (n = 1), history of treatment with chemotherapy (n = 1), and body habitus (n = 1). Marrow abnormalities were detected in 9% (11 of 122) of donors. These donors were screened because of anemia (5 of 22, 23%), age >60 years (2 of 33, 6%), history of malignancy (2 of 4, 50%), elevated peripheral blood counts (1 of 20, 5%), and body habitus (1 of 1, 100%). Abnormalities included plasma cell dyscrasia (n = 3), abnormal marrow cellularity (n = 3), clonal cytogenetic abnormalities (n = 2), low-grade myelodysplastic syndrome (1), a mutated JAK2 V617F allele (n = 1), and monoclonal B cell lymphocytosis (n = 1). Our experience indicates that extended screening of potential donors identifies a significant number of donors with previously undiagnosed marrow abnormalities.

A case report of AML with myelodysplasia-related changes with aggressive course in association with t(3;8)(q26;q24)

Myelodysplastic syndrome (MDS) is frequently associated with clonal cytogenetic abnormalities which are major predictors of the disease outcome. t(3;8)(q26;q24) was reported as a rare recurrent cytogenetic abnormality in MDS/acute myeloid leukemia (AML) with poor prognosis. Here, we present a case of MDS which rapidly advanced to AML with t(3;8)(q26;q24) in an elderly patient. Anemia and prominent megakaryocytic dysplasia in the absence of marked thrombocytopenia were distinct morphologic features. Patient progressed to leukemia and succumbed to the disease within 7 months from the initial diagnosis. Morphologic and clinical features in this patient resembled “3q21q26 syndrome” which is also associated with poor prognosis. Reports of unfavorable outcome in the patients with t(3;8)(q26;q24) highlight the probable significance of this cytogenetic abnormality for risk stratification in MDS/AML.