Flow Cytometric Detection of Human Telomerase Reverse Transcriptase Expression in CD34 Positive Precursor Fraction in Myelodysplastic Syndrome Bone Marrow.

Abstract Telomerase activity has been found in most common cancers indicating that telomerase detection may be a useful marker in cancer diagnosis. For detection of telomerase activity and the expression of associated genes in cells, TRAP assay and RT-PCR are customarily used. Immunohistochemical detection of hTERT is useful to detect telomerase-positive cells in a background of non- cancerous cells. We developed a method for the detection of intra-nuclear hTERT protein, in a sub-population of hematopoietic cells, using concurrent staining cell surface antigen and multi color flow cytometry. Human leukemia and myeloma cell lines showed 100% positivity, whereas neutrophils of normal subjects showed 0% positivity, it is consistent with telomerase activity assessed by TRAP assay (r=0.71, p<0.0001) and previous observations. Then we applied this method to analyze hTERT expression in myelodysplastic syndrome (MDS). Forty MDS patients samples were obtained, 36 patients were diagnosed as low risk MDS (RA), 14 patients were diagnosed as high risk MDS (RAEB or RAEB-t) according to FAB classification. All samples were acquired after informed consent was obtained from the patients. Expression of hTERT protein was higher in CD34-positive blast-gated cells than CD34-negative blast-gated cells. The percentage of the CD34+ cells expressing hTERT ranged from 9.66% to 90.91% in low risk MDS patients, whereas from 50.46% to 97.68% in high risk MDS. The expression level was higher in the high risk group compared to that in the low risk group in MDS (p=0.0054, p=0.0084). This observation implied that telomerase up-regulation and hTERT expression were important for disease progression and could be a marker of more advanced disease. In subsets of MDS and AML bone marrow specimens obtained from these patients, we examined the hTERT expression in CD34+/CD38 high cells and CD34+/CD38 low cells containing stem cell fraction. Of interest, some of the patients showed higher expression of hTERT in CD34+/CD38 low cells than in CD34+/CD38 high cells. This observation is inconsistent with previous reports describing normal bone marrow hematopoietic cell findings. We speculated that this phenomenon could be a marker of MDS abnormality and that telomerase up-regulation may be initiated in the more primitive precursor fraction containing hematopoietic stem cells during the disease progression. Telomerase studies may be useful for definition of the risks associated with disease severity. Multi-parameter nature of flow cytometry and its ability to identify cellular sub-populations will facilitate a fuller understanding of the mechanisms of activation of telomerase.

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GDF11 Increased in Patients with Myelodysplastic Syndrome

Blood ◽

10.1182/blood.v126.23.5224.5224 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5224-5224

Author(s):

Yu Han ◽

Huaquan Wang ◽

Zonghong Shao

Keyword(s):

Bone Marrow ◽

High Risk ◽

Myelodysplastic Syndrome ◽

Peripheral Blood ◽

Conflicts Of Interest ◽

Risk Group ◽

Low Risk ◽

Mean Corpuscular Hemoglobin ◽

Corpuscular Hemoglobin ◽

Normal Controls

Abstract Objective To analyze the concentration of growth differentiation factor 11(GDF11) in peripheral blood of patients with myelodysplastic syndrome (MDS), so as to evaluate the relationships between these changes and erythropoiesis functions and to explore the role of GDF11 in the pathogenesis of MDS. Methods The concentration of GDF 11 in peripheral blood was detected by enzyme-linked immuno sorbent assay in 44 MDS patients and 10 normal controls from September 2014 to June 2015 at our hospital. The percentage of nucleated erythrocyte (CD235a) in bone marrow was detected by flow cytometry. The correlation between these changes and erythropoiesis functions, including red blood cell count, hemoglobin, reticulocyte (RET%), hematokrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular-hemoglobin concentration (MCHC) and late erythroblast in bone marrow were evaluated. Results (1)The concentration of GDF11(128.67±47.62)in high-risk MDS patients was significantly higher than that of low-risk MDS patients (65.96±36.55,p<0.01)and higher than that of normal controls (29.76±10.10,p<0.01); The concentration of GDF11 in low-risk MDS patients was significantly higher than that of normal controls (p<0.05). (2) The expression of CD235a in high-risk group(38.49±5.42)was not different with that in low-risk group(42.64±7.36, p>0.05). (3)In high-risk MDS patients, the expression of GDF11 was negatively correlated with Hb, RET%, RBC, MCHC, Hct in peripheral blood and late erythroblast, CD235a+ cells in bone marrow(r=-0.437,r=-0.428,r=-0.444,r=-0.553,r=-0.661,r=-0.436,r=-0.52,all p<0.05),and the expression of GDF11 was positively correlated with MCV(r=0.52, p <0.05),but it was not correlated with MCH (p >0.05).(4) In low-risk MDS patients, the expression of GDF11 was negatively correlated with Hb, RET% (r=-0.491Ar=-0.606,both p<0.05),it was not correlated with RBC, MCHC, MCV, MCH, Hct, late erythroblast and CD235a+ cells (all p>0.05). Conclusion GDF11 increased in patients with MDS and it was negatively correlated with late erythropoiesis. Disclosures No relevant conflicts of interest to declare.

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Detection of Human Telomerase Reverse Transcriptase (hTERT) Protein Expression in Bone Marrow Cells of Hematological Disorder by Flow Cytometry.

Blood ◽

10.1182/blood.v104.11.4337.4337 ◽

2004 ◽

Vol 104 (11) ◽

pp. 4337-4337

Author(s):

Hiroshi Handa ◽

Hirokazu Murakami ◽

Takafumi Matsushima

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Flow Cytometry ◽

Disease Progression ◽

Cell Line ◽

Bone Marrow Cells ◽

Telomerase Activity ◽

Expression Level ◽

Htert Expression ◽

Human Telomerase

Abstract Telomerase is a telomere-specific DNA polymerase consisting of protein and RNA components, which is activated in germline cells and the majority of cancers and serves to counter the consequences of telomere shortening. Recently, it has been reported that telomerase activity level was correlated with the progression and prognosis of hematopoietic malignancies, thus, it is important to analyze telomerase activity. The protein component, hTERT, is believed to be the catalytic subunit of human telomerase and its expression at the mRNA level correlates well with telomerase activity in vitro. Current techniques for assaying telomerase activity detect only the mean activity in a sample and unable to isolate specific cell sub-populations. We developed immuno-fluorescence flow cytometry based assay to detect hTERT expression using a monoclonal antibody. This method allows sub-population of cells to be separated according to hTERT expression more easily, combining antibody against cell surface antigen. Expression level of hTERT in T cell leukemia cell line Jurkat and myeloma cell line RPMI8226, KMS12PE, KMS28PE, were very high and well correlated in between this method and real time quantitative PCR. Human mature granulocytes supposed to have no telomerase activity did not show any hTERT expression in this flow-cytometric assay. Immuno-histochemistry demonstrated the specific nuclear expression of hTERT. Bone marrow samples were obtained from 8 MDS patients (5 RA, 1 RAEB, 2 RAEB-t) and analyzed hTERT isolating MDS blast cells. In the blast population, cells expressing hTERT were 33.1% (21.4–40.3) in RA patient sample, while those in RAEB and RAEB-t patients sample were significantly higher at 75.1% (68.2–81.9). When CD34 positive hematopoietic stem cells were analyzed, the cells expressing hTERT were higher in RAEB and RAEB-t than in RA. Mature granulocyte population in bone marrow cells did not show any positivity. Our result suggests that hTERT expression and telomerase activity in the MDS blasts or CD34 positive stem cells were up-regulated during the disease progression and the high expression level of hTERT and telomerase activity were not due to the blast expansion. This technique allows us to easily analyze hTERT expression in hematopoietic malignancy even though the malignant cells were very small in bone marrow sample, e.g. MDS, MM or MGUS of which telomerase activity were supposed to be correlated with the disease progression and prognosis.

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Mutational Characteristics and Changing Pattern from Idiopathic Cytopenia of Undetermined Significance to High-Risk Myelodysplastic Syndrome Stratified By IPSS-R

Blood ◽

10.1182/blood-2019-125236 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3009-3009

Author(s):

Eun-Ji Choi ◽

Young-Uk Cho ◽

Seongsoo Jang ◽

Chan-jeoung Park ◽

Han-Seung Park ◽

...

Keyword(s):

Bone Marrow ◽

High Risk ◽

Myelodysplastic Syndrome ◽

Rna Splicing ◽

Conflicts Of Interest ◽

Low Risk ◽

International Prognostic Scoring System ◽

Intermediate Risk ◽

Sequencing Data ◽

Undetermined Significance

Background: Unexplained cytopenia comprises a spectrum of hematological diseases from idiopathic cytopenia of undetermined significance (ICUS) to myelodysplastic syndrome (MDS). Revised International Prognostic Scoring System (IPSS-R) is the standard tool to assess risk in MDS. Here, we investigated the occurrence, characteristics, and changing pattern of mutations in patients with ICUS and MDS stratified by IPSS-R score. Methods: A total of 211 patients were enrolled: 73 with ICUS and 138 with MDS. We analyzed the sequencing data of a targeted gene panel assay covering 141 genes using the MiSeqDx platform (Illumina). The lower limit of variant allele frequency (VAF) was set to 2.0% of mutant allele reads. Bone marrow components were assessed for the revised diagnosis according to the 2016 WHO classification. Lower-risk (LR) MDS was defined as those cases with very low- or low-risk MDS according to the IPSS-R. Higher-risk (HR) MDS was defined as those cases with high- or very high-risk MDS according to the IPSS-R. Results: Patients with ICUS were classified as very low-risk (39.7%), low-risk (54.8%), and intermediate-risk (5.5%) according to the IPSS-R. Patients with MDS were classified as LR (35.5%), intermediate-risk (30.4%), and HR (34.1%). In the ICUS, 28 (38.4%) patients carried at least one mutation in the recurrently mutated genes in MDS (MDS mutation). The most commonly mutated genes were DNMT3A (11.0%), followed by TET2 (9.6%), BCOR (4.1%), and U2AF1, SRSF2, IDH1 and ETV6 (2.7% for each). IPSS-R classification was not associated with mutational VAF and the number of mutations in ICUS. In the 49 LR MDS, 28 (57.1%) patients carried at least one MDS mutation. The most commonly mutated genes were SF3B1 (20.4%), followed by TET2 (12.2%), U2AF1 (10.2%), DNMT3A (10.2%), ASXL1 (10.2%), and BCOR (6.1%). Higher VAF and number of mutations were observed in LR MDS compared to ICUS patients. In the 42 intermediate-risk MDS, 27 (64.3%) patients carried at least one MDS mutation. The most commonly mutated genes were ASXL1 (23.8%), followed by TET2 (21.4%), RUNX1 (16.7%), U2AF1 (14.3%), DNMT3A (14.3%), SF3B1 (9.5%), and SRSF2, BCOR, STAG2 and CBL (7.1% for each). In the 47 HR MDS, 36 (76.6%) patients carried at least one MDS mutation. The most commonly mutated genes were TET2 (25.5%), followed by DNMT3A (14.9%), TP53 (14.9%), RUNX1 (12.8%), U2AF1 (10.6%), ASXL1 (10.6%), and SRSF2 and KRAS (6.4% for each). As the disease progressed, VAF and number of the MDS mutations gradually increased, and mutations involving RNA splicing, histone modification, transcription factor or p53 pathway had a trend for increasing frequency. Specifically, ASXL1, TP53, and RUNX1 mutations were the most striking features in patients with advanced stage of the disease. Cohesin mutations were not detected in ICUS, whereas these mutations were detected at a relatively high frequency in HR MDS. Our data were summarized in Table 1. Conclusions: We demonstrate that on disease progression, MDS mutations are increased in number as well as are expanded in size. Furthermore, a subset of mutations tends to be enriched for intermediate- to HR MDS. The results of this study can aid both diagnostic and prognostic stratification in patients with unexpected cytopenia. In particular, characterization of MDS mutations can be useful in refining bone marrow diagnosis in challenging situations such as distinguishing LR MDS from ICUS. Disclosures No relevant conflicts of interest to declare.

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FLIP (Long) and FLIP (Short) Expression in Bone Marrow Cells in Patients with Myelodysplastic Syndrome: Correlation with FAB and WHO Classification.

Blood ◽

10.1182/blood.v106.11.4926.4926 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4926-4926

Author(s):

Paula Campos ◽

Fabiola Traina ◽

Adriana Duarte ◽

Bruno Benites ◽

Marcelo Brandao ◽

...

Keyword(s):

Bone Marrow ◽

High Risk ◽

Myelodysplastic Syndrome ◽

Mrna Expression ◽

Who Classification ◽

Fas Ligand ◽

Low Risk ◽

World Health ◽

Caspase 8 ◽

Marrow Cells

Abstract The paradox of peripheral cytopenias despite of normo/hypercellular marrow in myelodysplastic syndrome (MDS) has been ascribed to excessive intramedullary hematopoietic cell apoptosis. Several apoptosis-inducing systems, including Fas/Fas ligand and TNF-related apoptosis-inducing ligand (TRAIL) and its receptors, are upregulated in MDS. FLIP (FLICE (FAS-associated death-domain-like IL-1β-converting enzyme)-inhibitory protein) was identified as a FAS and TRAIL signal inhibitor. The largest variant FLIPLong (FLIPL) was originally characterized as a molecule with inhibitory activity on caspase-8. The short splice form termed FLIPShort (FLIPS) has also been characterized as a potent (TRAIL-induced) apoptosis inhibitor. However, whereas FLIPL and FLIPS have been described as death receptor pathway inhibitors, recent data suggest that physiologically, FLIPL may have caspase-8-activating properties. This study aims to characterize the expression of FLIPL and FLIPS based on mRNA, by Real-time quantitative PCR, in marrow cells from MDS patients and to correlate the expression with French-American-British (FAB) and World Health Organization (WHO) classification. For each sample, results were first calculated as a ratio of the total transcript number of FLIPL or FLIPS and the total transcript number of the endogenous reference gene (β-actin) to obtain a normalized target value. Transcript ratios of each sample were normalized against the respective ratio of a pool of 6 normal bone marrow donors (NBM), and the ratio between the two was used as measure for the relative FLIPL or FLIPS level. We hypothesized that FLIPL and FLIPS expression differed between low and high risk of MDS. Marrow aspirates were obtained from 6 NBM and 16 patients with MDS out of treatment (7 males, 9 females; 23–78 (median 64) yo). The National Ethical Committee Board approved this study, informed-written consent was obtained from all patients and donors. According to FAB classification, patients were distributed as: 10 RA, 2 RARS and 4 RAEB. According to WHO classification: 10 RCMD, 2 RCMD-RS, 3 RAEB-1 and 1 RAEB-2. FLIPS mRNA expression were significantly higher in high risk DS according to FAB and WHO classification; RA/RARS compared with AREB (0.08 [0.0–2.3] vs 0.67 [0.36–1.54]; P = 0.03); RCMD and RCMD-RS compared with RAEB-1 and RAEB-2 (0.08 [0.0–2.3] vs 0.67 [0.36–1.54]; P = 0.03). However, FLIPL mRNA expression also tended to be higher in high risk MDS according to FAB and WHO classification, though not significantly different: RA/RARS compared with AREB (1.18 [0.06–3.43] vs 1.65 [0.51–3.63]; P = 0.46); RCMD and RCMD-RS compared with RAEB-1 and RAEB-2 (1.18 [0.06–3.43] vs 1.65 [0.51–3.63]; P = 0.46). Lower FLIPS level in low risk MDS marrows, in addition to the well described upregulation of extracellular proapoptotic signals, would explain the increased susceptibility of hematopoietic cells in low risk MDS marrow to death-inducing stimuli. The fact that FLIPL expression did not differ according to FAB and WHO classification could be related to the hypothesis that FLIPL may have caspase-8-activating properties rather than anti-apoptotic activity. Differential regulation of FLIPL and FLIPS according to risk groups in MDS patients might result in different rates of apoptosis. Further studies are needed to elucidate the mechanisms controlling and regulating FLIP expression in normal and malignant hemopoietic cells.

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MDM2 SNP309 and TP53 SNPArg72Pro Polymorphisms in Myelodysplastic Syndrome.

Blood ◽

10.1182/blood.v114.22.1745.1745 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1745-1745

Author(s):

João Agostinho Machado Neto ◽

Fabiola Traina ◽

Paula Melo Campos ◽

Marilisia Andreoli ◽

Irene Lorand Metze ◽

...

Keyword(s):

Overall Survival ◽

High Risk ◽

Myelodysplastic Syndrome ◽

Disease Progression ◽

Low Risk ◽

Healthy Controls ◽

Mdm2 Snp309 ◽

P53 Pathway ◽

Hematopoietic Stem ◽

High Risk Disease

Abstract Abstract 1745 Poster Board I-771 Introduction Myelodysplastic syndrome (MDS) encompasses a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, refractory cytopenia and a tendency to progress towards acute myeloid leukemia (AML). The progression of the disease may be associated with genetic or epigenetic alterations and a possible change in protein function. MDM2/P53 pathway plays an important role in the control of apoptotic and proliferation mechanisms. Single nucleotide polymorphisms (SNPs) were identified in the TP53 and MDM2 genes. MDM2 SNP309 results in higher levels of MDM2 and attenuates p53 pathway. The SNP in codon 72 of the TP53 gene results in either a C or G nucleotide and leads to either Proline (Pro) or Arginine (Arg), respectively. The Arg variant has been shown to be more potent in apoptosis induction and the Pro variant has been shown to be better in inducing cell-cycle arrest and to have a greater ability to repair damaged-DNA. The aim of the present study was to investigate the incidence of MDM2 and TP53 polymorphisms in MDS patients and to correlate the frequency of these SNPs with age, neutrophis and platelets at diagnosis, low risk versus high risk disease according to FAB (RA and RARS versus AREB and AREBt) and IPSS (Low and Int-1 versus Int-2 and high), cytogenetic risk (low versus intermediate and high risk), disease progression and overall survival. Patients and Methods We studied 103 healthy controls and 63 patients with MDS. According to FAB, patients were distributed as follows: 43 RA, 10 RARS, 7 RAEB, 1 RAEBt and 2 CMML. The median follow-up time was 40 months (range 2 – 159 months). Samples were obtained from peripheral blood or bone marrow and were screened for the presence of polymorphisms MDM2 SNP309 and TP53 SNPArg72Pro, by PCR analysis with specific primers and appropriate restriction enzyme. Appropriate statistical analyses were used for each test. Results The frequencies of genotypes for MDM2 SNP309 and TP53Pro7Arg were similar between MDS and healthy controls; MDM2 SNP309: 51% vs 53%, for TT, 38% vs 32% for TG, and 11% vs 15% for GG, TP53Pro7Arg: 47.5% vs 44%, for Arg/Arg, 47,5% vs 42% for Pro/Arg, and 5% vs 14% for Pro/Pro. No differences were observed between MDS patients with presence or absence of the polymorphisms in relation to age, neutrophis and platelets at diagnosis, low risk versus high risk disease according to FAB, IPSS and cytogenetic risk, disease progression and overall survival. Conclusions MDM2 and TP53 polymorphisms have been described to affect the risk for cancer, onset age and overall survival in solid tumors and leukemias. This was the first study to report these SNPs in MDS and leads to believe that these polymorphisms are not associated with risk for the disease and with clinical data. Keywords: MDM2, p53, myelodysplasia, polymorphisms Disclosures No relevant conflicts of interest to declare.

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Hesk Ratio: A Complementary Tool for the Diagnosis of Myelodysplastic Syndromes and a Novel Method for Flow Cytometry Analysis

Blood ◽

10.1182/blood.v120.21.4946.4946 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4946-4946

Author(s):

Evgenia Verigou ◽

Georgia Kolliopoulou ◽

Nikoleta Smirni ◽

Elisavet Hala ◽

Polixeni Lampropoulou ◽

...

Keyword(s):

Mathematical Model ◽

Bone Marrow ◽

Flow Cytometry ◽

High Risk ◽

Myelodysplastic Syndromes ◽

Myeloid Cells ◽

Antigen Expression ◽

Low Risk ◽

Empirical Parameter ◽

Analytical Approaches

Abstract Abstract 4946 Establishing the diagnosis of Myelodysplastic Syndromes (MDS) is a challenging task for hematologists due to the heterogeneity of this clinical entity. Several attempts have been made to include findings from advanced technologies to the diagnostic criteria of MDS, but still in the majority of cases, morphology of peripheral blood and bone marrow remains the cornerstone for the diagnosis. Flow cytometry(FC) can identify abnormal antigen expression on myeloid cells. FC has been proposed as a complementary method in the diagnosis of low and intermediate risk MDS, particularly for patients not exhibiting characteristic karyotype abnormalities. On the other hand, recent literature suggests that these findings are not MDS-related, questioning the specificity of immunophenotyping for the diagnosis of MDS. The aim of the present study is to maximize the utility of FC data and simplify their interpretation for the diagnosis of MDS, by developing new analytical approaches of digital data, other than the conventional sequential biparametric analysis. The applied methodology was based on a mathematical model of scale analysis. Bone marrow(BM) samples from 50 subjects were analysed for the expression of CD45PC7, CD11bPC5, CD16FITC and CD13PE (antigens by Beckman Coulter, FC500 flow cytometer Beckman Coulter). 36 patients were diagnosed with MDS (23 low risk, 13 high risk) and 14 patients had other than an MDS diagnosis (ITP, chronic idiopathic neutropenia, systemic lupus erythematosus, LGL leukemia, age-related cytopenias, aplastic anemia, myelofibrosis etc). Additionally, 3 BM samples of patients with post-MDS acute myeloid leukemia(AML) were analysed. The data used for the development of the mathematical model were the following: two populations (neutro1, neutron2) were gated according to their CD45 and CD13/CD16 antigen expression (Figure 1i-1v).Seven subpopulations of Neutrophils were defined on CD11b/CD16 density plot N=g+h+i and O=k+j (Figure 1vi). In an attempt to identify correlations between data that cannot be routinely revealed by sequential biparametric analysis, we have developed the HeSK* ratio, which is given by: where x is the median of CD11b in gate O, y is the median of CD16 in gate O, z is the median of CD45 in gate neutro, pO is the percentage of gate O in the total CD11b/CD16 diagram gated in neutro, pN is the percentage of gate N in the total CD11b/CD16 gated in neutro and 1000 is an empirical parameter. The HeSK ratio combines fluorescence levels of CD16, CD11b and CD45 with the percentage of two distinct neutrophil populations (N and O), which differ in their maturation and differentiation stage. The ratio can quantify the abnormal differentiation profile of mature myeloid cells and thus distinguish MDS from non-MDS samples with statistical significance P<0. 0001 (Kruskal Wallis test) as indicated in graph 1. Descriptive statistics are shown in table 1. · HeSK ratio is based upon a novel FC analysis method that could change the conventional biparametric routine FC analysis and quantify patterns that are not evaluated properly. Mathematical modeling of antigen expression patterns optimizes the interpretation of single immunophenotype findings. · The present study proposes HeSK as a complementary diagnostic tool for MDS and a strong indicator for the classification of the patients according to their prognosis as well. *the name HeSK comes from the initials of the 4 main authors (H=Hala, e=Evgenia, S=Smirni, K=Kolliopoulou). Table 1 non MDS low risk MDS high risk MDS Number of values 14 23 13 Minimum 50,76 4,789 0,2850 25% Percentile 304,8 26,11 17,05 Median 2133 92,52 47,64 75% Percentile 10650 228,9 144,3 Maximum 55040 3043 671,7 Mean 10320 316,1 122,7 Std. Deviation 17860 647,9 185,1 Std. Error 4773 135,1 51,33 Figure 1 Figure 1. Disclosures: No relevant conflicts of interest to declare.

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Towards CD177 As a Predictive Biomarker for Hypomethylating Agent Response in Myelodysplastic Syndrome

Blood ◽

10.1182/blood-2021-153761 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4665-4665

Author(s):

James Ignatz-Hoover ◽

Pingfu Fu ◽

Shufen Cao ◽

Benjamin Tomlinson ◽

Howard Meyerson

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

High Risk ◽

Risk Stratification ◽

Myelodysplastic Syndrome ◽

Treatment Response ◽

Myelodysplastic Syndromes ◽

Bone Marrow Biopsies ◽

Wide Range ◽

Very High

Abstract Background Myelodysplastic syndrome (MDS) represents a heterogenous spectrum of pre-leukemic conditions with a wide range of outcomes. Higher risk MDS as classified by the revised international prognostic scoring system (IPSS-R) score is associated with poor overall survival and up to 30% of patients progressing to acute myeloid leukemia. Hypomethylating agents (HMA) such as azacitadine can improve cytopenias and delay progression to leukemia in about 30% of patients, but these agents may take months to promote response and initially exacerbate cytopenias. Thus treatment related biomarkers that help predict eventual hematologic response are of interest. CD177 is expressed in neutrophils and plays a role in cellular adhesion. In healthy cells, it exhibits bimodal expression by flow cytometry that is stable over time within an individual. The percentage of CD177 positive neutrophils is often decreased in hematopoietic malignancies and myelodysplastic syndromes. Our group has demonstrated that CD177 has diagnostic utility in the identification of myelodysplastic syndromes. As transcription of CD177 is regulated by CpG methylation of its promotor, we hypothesized that treatment with HMAs may improve CD177 expression in clinical responders and potentially guide continuation of HMA therapy. Methods To interrogate the above, we performed a retrospective review of patients with a diagnosed with MDS or MDS/MPN overlap syndromes who received disease modifying therapy with HMA at our institution from 2015 to 2018. Inclusion criteria required documentation of serial bone marrow biopsies with aspirate flow cytometry analysis. CD177 positivity was determined by increase in mean florescence intensity compared to isotype controls. Data was analyzed with using cox multivariate and univariate analysis correlating to treatment response. Results Of the 237 patients, 27 patients met the above criteria. Their average age was 62 (21 to 77) at time of diagnosis with 20 men and 7 women. They exhibited a range of R-IPSS risk stratification with four very high risk, eight high risk, six intermediate risk, and four low risk. Five cases were MDS/MPN overlap. Patients received on average 10 months of HMA treatment with a wide range from 1 month to 42 months of treatment. Median baseline CD177 positivity was 16, 31, 28.5, and 72 percent respectively amongst R-IPSS groups. Of the 27 patients analyzed with repeat bone marrow biopsies, eight patients exhibited 20% or greater increase in CD177(+) neutrophils, ten exhibited a decrease in CD177(+) neutrophils of 20% or greater, and nine exhibited less than a 20% change in CD177(+) neutrophils. with similar distribution of R-IPSS risk stratification amongst groups. (CD177-decreased: 1 very high, 3 high, 1 intermediate, 2 low risk, CD177-stable 1 very high, 2 high, 2 intermediate, and 1 low, Improved-CD177 1 very high, 4 high, 2 intermediate and 1 low). Cox proportional hazard analysis suggests that patients exhibiting a decrease or stable CD177 were less likely to exhibit a treatment response with results trending to significance (OR= 0.13 p=0.099). Conclusion Our initial data suggests that change in CD177 may help predict HMA treatment response. More uniform prospective analysis is indicated to compared CD177 changes over initial treatment. Furthermore, CD177 in peripheral blood and bone marrow samples correlate excellently (R 2=0.95). Prospective studies are underway to correlate CD177 change and initial treatment response utilizing flow analysis of pre-treatment CBCs. Disclosures No relevant conflicts of interest to declare.

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Genetic Mutation in Cytopenic Patients: Distinctive Genomic Profile between Preclinical Vs. Clinical Myelodysplastic Syndrome

Blood ◽

10.1182/blood-2019-128037 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 5429-5429

Author(s):

Kritanan Songserm ◽

Amornchai Suksusut ◽

Sunisa Kongkiatkamon ◽

Kitsada Wudhikarn ◽

Chinnachote Teerapakpinyo ◽

...

Keyword(s):

Bone Marrow ◽

High Risk ◽

Myelodysplastic Syndrome ◽

Somatic Mutations ◽

Conflicts Of Interest ◽

Gene Mutations ◽

Genetic Alterations ◽

Genetic Mutation ◽

Low Risk ◽

Genomic Profile

Genetic mutation in cytopenic patients: Distinctive genomic profile between preclinical vs. clinical myelodysplastic syndrome. Introduction Myelodysplastic syndromes (MDS) are heterogeneous groups of clonal hematopoietic disorders. The current diagnosis of MDS is based on morphologic assessments of dysplasia which are subjected to inter-observer variability and cytogenetic abnormalities which are frequently absent. Somatic mutations in myeloid-related genes have been identified in MDS. However, they are also found in idiopathic cytopenia of unknown significance (ICUS) that shows no significant dysplasia. Therefore, we aimed to explore the clinical implications of genetic mutations in ICUS and compared with MDS. The secondary objective was to find association between degree of dysplasia and somatic mutations. Materials and Methods The patients with peripheral cytopenia ≥1 lineage (ANC < 1,800/mm3, hemoglobin < 10 gm/dL, platelet < 100x109/mL) without explainable causes were enrolled. Bone marrow aspirates were evaluated independently by 2 hematologists. Of note, dysplasia are defined by WHO 2008 classification (eg. Erythroid lineage: ring sideroblasts, megaloblastoid change; granulocytic lineage: hypogranularity, pseudopelger-huet anomaly; megakaryocytic lineage: hypolobate, micro-megakaryocyte). The significant dysplasia cut off was 10% in single lineage or more. If there was a discrepancy, the third hematologist would help to reach the final consensus. We extracted DNA from bone marrow and performed next generation sequencing (NGS) that targeted 143 myeloid-related genes. Results Forty-eight patients were enrolled in this study. The median age at diagnosis was 70 years (71-96). Results of bone marrow examinations were categorized by morphology into 3 groups; non-significant dysplasia (dysplasia < 10%) 27%, low risk MDS (IPSS-R ≤3.5) 42% and high-risk MDS/sAML (IPSS-R >3.5/Blast≥20% in BM or peripheral blood) 31%. Most of cases (77%) carried normal cytogenetics while other genetic alterations were complex chromosome (6%), -Y (6%), del(5q) (4%), trisomy 8 (2%), del(20q) (2%), i(17q) (2%). Thirty from 48 cases (62%) harbored more than 1 somatic mutation. Twenty-eight gene mutations were identified. Mutations were detected 1.6 mutation per 1 patient in average. Most frequent somatic mutations were ASXL1:10/80 (12%), TET2:9/80 (11%), MFDS11: 6/80 (7%), TP53:6/80 (7%), and RUNX1:5/80 (6.25%). The proportions of cases with somatic mutations were not different across the groups (no dysplasia 50%, non-significant dysplasia 80% and significant dysplasia 62%). According to mutation types in each group, mutations in epigenetic pathways were the most frequent mutations across all patient subgroups (ICUS 64.7%, low-risk MDS 51.8 %, and high-risk MDS 52.5%). Mutations in transcription factor were predominated in MDS (18.5% and 25.0% in low-risk and high-risk MDS, respectively) compared to ICUS (11.7%). Individual average frequency of gene mutations was significantly different between disease subtype (high risk MDS 2.7 gene/person, low risk MDS 1.1 gene/person, ICUS 1.3 gene/person (P=.038). Higher variant allele frequency (VAF) of mutated genes was significantly observed in high risk MDS (38.3%) compared to low risk MDS (30.8%) and preclinical MDS (29.0%) (P=.03). Conclusion In conclusion, molecular profiling was significantly different between preclinical MDS and MDS groups in terms of types of somatic mutations and VAF. This unique contrast could be used to distinguish between preclinical MDS and clinically significant MDS. In contrast, degree of marrow dysplasia was not associated with number of gene mutations in this study. Prediction for clinical consequent of somatic mutations in CCUS requires long term follow up. Disclosures No relevant conflicts of interest to declare.

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Methylation of HAI-2/SPINT2 in Bone Marrow Mesenchymal Stromal Cells of MDS and AML Patients Affects Hematopoietic Stem Cell Survival and Adhesion

Blood ◽

10.1182/blood.v126.23.2847.2847 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2847-2847

Author(s):

Fernanda Marconi Roversi ◽

Nathalia Moreno Cury ◽

Matheus Rodrigues Lopes ◽

Fernando Vieira Pericole ◽

Marisa Claudia Alvarez Prax ◽

...

Keyword(s):

Bone Marrow ◽

Cell Adhesion ◽

High Risk ◽

Tumor Microenvironment ◽

Disease Progression ◽

Stromal Cell ◽

Low Risk ◽

Hematopoietic Stem ◽

Protein Levels

Abstract In recent years, the role of tumor microenvironment in neoplasm initiation and malignant evolution has been increasingly recognized. However, the bone marrow mesenchymal stem/stromal cell (BMMSC) contribution to disease progression remains poorly explored. We had previously performed a microarray analysis of myelodysplastic syndrome (MDS) patient-derived BMMSC (MDS-BMMSC) and found an underexpression of HAI-2/SPINT2, an endogenous inhibitor of the hepatocyte growth factor (HGF) activator. This gene has been described as methylated in various cancer types and has been associated with disease progression. Despite of being related to the pathogenesis of several neoplasms, the role of HAI-2/SPINT2 has not yet been fully elucidated in hematological diseases, such as MDS and acute myeloid leukemia (AML). Thus, the aim of this study was to evaluate HAI-2/SPINT2 expression in derived BMMSC and total bone marrow (BM) of healthy donors (HD), MDS and AML patients as well as in BMMSC treated with 5-Azacitidine (Aza), a DNA methyltransferase (DNMT) inhibitor. To achieve this, we collected BM hematopoietic cells and plastic-adherent BMMSC from aspirates of HD, MDS and AML patients. BMMSC were expanded to passage 4 and defined as CD73+/CD90+/CD105+/CD45-/CD34-/CD31-/HLA-DR-. A total of 29 HD and 121 patients at diagnosis (MDS=72 [low-risk=46, high-risk=26], AML with myelodysplastic related changes (AML-MRC)=17 and de novo AML=32) were included. HAI-2/SPINT2 mRNA was significantly decreased in MDS- (0.34[0.01-2.06];P <.01) compared to HD-BMMSC (0.89[0.46-1.59]). When patients were stratified according to WHO classification, HAI-2/SPINT2 expression was lower in both low-risk (0.31[0.01-1.33]) and high-risk (0.43[0.01-2.06]) MDS-BMMSC. Similar results were found in total BM: HAI-2/SPINT2 transcripts were significantly decreased in MDS (0.41[0.01-2.53];P <.01), AML-MRC (0.38[0.014-0.84];P <.01) and AML patients (0.33[0.01-2.07];P <.001) compared to HD (0.91[0.19-4.79]). To investigate whether this loss of expression was due to HAI-2/SPINT2 methylation, BMMSC were treated with Aza (1µM or IC50 value) for 48h. In MDS- and AML-BMMSC, Aza treatment resulted in a pronounced upregulation of HAI-2/SPINT2 mRNA and protein levels. Moreover, Aza treatment of HD-BMMSC did not improve the HAI-2/SPINT2 mRNA and protein levels as much as the observed in MDS- and AML-BMMSC. To better understand the role of HAI-2/SPINT2 downregulation in BMMSC physiology, its expression was inhibited in a BM stromal cell line (HS5). As previously reported, HAI-2/SPINT2 silencing resulted in an increased secretion of HGF, known to be overexpressed in plasma of MDS patients and considered a prognostic factor in MDS and AML patients (Matsuda et al., Leukemia, 2004). Moreover, after co-culture, HAI-2/SPINT2 knockdown improved survival of blasts isolated from AML-MRC and AML patients. We also observed an increased adhesion of CD34+ hematopoietic stem cells (HSC) to HAI-2/SPINT2 silenced HS5 cells. This prompted us to analyze the expression of cell adhesion molecules in MDS- and AML-BMMSC. We observed a significant augment in the expression of CD49b and CD49d integrins in MDS- and AML-compared to HD-BMMSC. Taken together, SPINT2 inhibition improves HGF secretion, consequently with alteration in molecule receptor adhesion, resulting in an increased expression of integrins (CD49b and CD49d) responsible for cell-to-cell adhesion. Thus, reactivation of HAI-2/SPINT2 levels after Aza treatment indicates that this gene is probably epigenetically silenced by methylation in MDS and AML, and is possibly a tumor suppressor gene. Interestingly, nowadays, epigenetic therapy by Aza is the first-line treatment for MDS patients, and induces prolonged survival and delayed AML evolution. Likewise, our results suggest that HAI-2/SPINT2 may play a role in deregulation of HGF cytokine secretion with consequently alteration in HSC adhesion and growth/survival. Tumor microenvironment niche is currently known to play a critical role in cancer initiation and progression, thus HAI-2/SPINT2 may contributes to functional and morphological abnormalities of microenvironment niche and with the stem/progenitor cancer cell progression. Hence, downregulation in HAI-2/SPINT2 gene expression, due to methylation in MDS- and AML-BMMSC, provides novel insights into the pathogenic role of the leukemic bone marrow microenvironment. Disclosures No relevant conflicts of interest to declare.

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A Phase II Study of Low Dose Intravenous Clofarabine for Elderly Myelodysplastic Syndrome Patients Who Have Failed 5-Azacytidine

Blood ◽

10.1182/blood.v116.21.4955.4955 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4955-4955

Author(s):

Seah H Lim ◽

John McMahan ◽

Jian Zhang ◽

Yana Zhang

Keyword(s):

Bone Marrow ◽

Myelodysplastic Syndrome ◽

Disease Progression ◽

Phase Ii ◽

Low Dose ◽

Response Rate ◽

Phase Ii Study ◽

Low Risk ◽

The Other ◽

Low Doses

Abstract Abstract 4955 Based on the observations of changes in DNA methylation status of various tumor suppressor genes, epigenetic targeting of myelodysplastic syndrome (MDS) with DNA hypomethylating agents are currently used for these patients. However, only up to 40% of the patients respond to these treatments. Therapeutic options for non-responders or responders whose disease progresses while on therapy are very limited. Based on our recent findings that low concentration clofarabine induced DNA hypomethylation, we carried out a Phase II study of elderly MDS patients who had failed 5-azacytidine (5-aza) therapy to determine the efficacy and toxicities of low dose intravenous clofarabine (ClinicalTrials.gov Identifier NCT00700011). Patients in Cohort 1 received intravenous clofarabine at 10 mg/m2/day and patients in Cohort 2 5 mg/m2/day for 5 days, each infusion given over 2 hours and each cycle repeated every 4 to 8 weeks, depending on the rate of bone marrow recovery. Eight patients were planned for each of the treatment dose. The patients were treated until disease progression or intolerable toxicities. The International Working Group response criteria were used. The study was closed after 10 patients were treated. Of the 10 patients (6 males and 4 females) treated, ei8 received 10 mg/m2/day (Cohort 1) of clofarabine and 2 patients 5 mg/m2/day (Cohort 2). The median age was 73 years (range 65–78). Five patients had only received 5-aza prior to being treated with clofarabine while the other 5 patients had also received other therapy (lenolidomide and decitabine). Three patients received 1 cycle, 4 patients received 2 cycles, 1 patient received 3 cycles and 2 patients received 4 cycles of clofarabine. The following responses were observed in the 9 evaluable patients: 1 CR (11%), 1 PR (11%), 2 HI (22%), 3 SD and 2 PD. The overall response rate was 44% in this group of elderly patients. All responses were observed in patients who received clofarabine 10 mg/m2/day. Response rate of 67% (4/6) was observed in patients with low risk MDS (IPSS < 1). In contrast, all 3 evaluable patients with high risk/Int.-2 MDS showed disease progression. The median time to response was 6 weeks (range 4–6 weeks) and 1 cycle of clofarabine. The patient who achieved a CR remained in CR for 14 months. The 2 patients who achieved HI both restored the erythroid-responsiveness to recombinant erythropoietin and became transfusion-independent, both for 10 months (1 patient received only 1 cycle and the other patient 2 cycles of clofarabine). As of July 31, 2010, diseases in all four responders have relapsed/progressed. The median duration of response was 10 months (range 5–14). Despite using low doses of clofarabine, severe and prolonged pancytopenia was observed in all 10 patients. All 10 patients needed considerable blood and platelet transfusions. Eight of these ten patients also needed hospitalization for neutropenic fever. Of the 22 cycles of clofarabine administered, there were a total of 13 hospital admissions with 100 hospital days. A total of 169 units of irradiated packed red blood cells (median 10 units/cycle; range 1.5–14 units/cycle) and 211 units of irradiated single donor platelets (median 10 units/cycle; range 2–30.5 units/cycle) were used. One patient died, within 2 weeks of completing cycle 1 of clofarabine, from intracranial bleed despite intensive support of severe thrombocytopenia with aggressive platelet transfusion. This patient was already thrombocytopenic prior to starting clofarabine and had a history of severe thrombocytopenic gastrointestinal bleed prior to starting on clofarabine. Nonhematologic toxicities occurred very infrequently and were mainly Grade 2 or lower. In all cases, clofarabine was discontinued due to either disease progression (2 patients) or toxicities (8 patients). With a median follow-up of 7.5 months (range 0.5–22), the overall survival for the whole group was 50%. In conclusion, elderly MDS patients, especially those with low risk disease, who have failed 5-aza may respond to low dose clofarabine. However, even at the low doses used in this study, bone marrow toxicity was significant. It remains to be determined whether the dose of clofarabine can be reduced further to minimize toxicities without compromising efficacy in this group of patients. Future studies should investigate the role of low dose clofarabine in low risk MDS patients. Study supported by Genzyme Corporation, Cambridge, MA, USA Disclosures: No relevant conflicts of interest to declare.

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