scholarly journals Interleukin-1/Toll-like Receptor Inhibition Can Restore the Disrupted Bone Marrow Microenvironment in Mouse Model of Myelodysplastic Syndromes

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1510-1510
Author(s):  
Hiroki Kawano ◽  
Yuko Kawano ◽  
Mark W. LaMere ◽  
Daniel K. Byun ◽  
Caitlin L. Gordnier ◽  
...  

Abstract Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by bone marrow (BM) failure and associated with aging. We have previously shown that reversal of BM microenvironment (BMME) dysfunction in MDS mitigates MDS associated marrow failure and delays progression to acute leukemia. However, the exact mechanisms driving BMME dysfunction in MDS remain unknown. We recently reported that interleukin-1 (IL1) Receptor Type1 (IL1R1) signaling is a driver in myeloid bias via disruption of BMME in aging. In addition, we have found that IL1R1 signaling is involved in disease progression of AML. Therefore, to assess the role of IL1R1 signaling in MDS associated BMME dysfunction and marrow failure, we employed an age appropriate murine transplant model for MDS utilizing NUP98-HOXD13 (NHD13) transgenic mice. Methods: BM cells (NHD13 transgenic or wild type (WT), 7 weeks) and competitor cells were transplanted into irradiated aged recipients (WT or IL1R1 KO, 60 weeks), and subsequently monitored for development of marrow failure. When marrow failure developed, mice were euthanized and peripheral blood, BM, BM extracellular fluid (BMEF), and collagenase-1 digested bone associated cells were analyzed including flow cytometry, colony forming units (CFU) assay, and cytokine analyses. Next, BM from NHD13 (8-10 weeks) and competitor cells were transplanted into lethally irradiated aged recipients (WT, 50-60 weeks). At onset of marrow failure, mice were treated with inhibitors of IL1/Toll-like receptor signaling (IL1R antagonist, MCC950, or IL1R-associated kinase 4 protein (IRAK4) inhibitor) for fourteen days, and then euthanized and analyzed as above. Finally, we evaluated cytokine profile in the BM serum from the patients with MDS and normal donors. Results: Transplant of NHD13 BM cells into aged IL1R1 wt recipients (NHD13→IL1R1 wt) was not associated with a significant difference in survival rates or levels of NHD13 engraftment compared to NHD13 into IL1R1 ko recipients (NHD13→IL1R1 ko). IL1R1 wt developed macrocytic anemia compared to IL1R1 ko recipient (Hb 11.3±0.57 v.s 13.1±0.42 g/dL, n=12 and 9, p<0.05). In CFU-C assays, NHD13→IL1R1 wt and NHD13→IL1R1 ko demonstrated similar levels of CFU-activity whereas CFU-fibroblast (CFU-F) assays of IL1R1 wt recipients demonstrated lower numbers of large colonies (reported to contain highly proliferative mesenchymal stem cells (MSC)). Flow cytometry analysis of hematopoietic stem and progenitor cells (HSPC) population in IL1R1 wt recipients showed increased myeloid progenitors and decreased long-term HSC (LT-HSC) compared to IL1R1 ko recipients. Cytokine/chemokine profiles revealed that the inflammatory cytokines (IL-6 and TNFα) and macrophage activating cytokines (MCP-1 and M-CSF) were significantly decreased in NHD13→IL1R1 ko compared to NHD13→IL1R1 wt. Next, we treated MDS model mice with inhibitors. The pharmacological targeting of IL1R1 signaling in vivo was associated with decreased NHD13 cell burden and improvement of macrocytic anemia. CFU-C assays demonstrated some decreases in NHD13 CFU capacity post-treatment. Interestingly, non-NHD13 HSPCs assessed by CFU capacity increased in IRAK4 inhibitor treated mice. Consistent with this, flow cytometric analyses of HSPC pools demonstrated decreased NHD13 HSPCs (LT-HSC and granulocyte-monocyte progenitor cells) and increased non-NHD13 HSCs and myeloid progenitors compared to vehicle group. BMME cell populations showed that arteriolar endothelial cells and MSCs were also affected by drug treatment and both IL1R antagonist and MCC950 increased the number of large CFU-F colonies. Analysis of BMEF revealed the decreased IFNγ and IL-18 and upregulated M-CSF in MCC950 treated group. The cytokines of human BM serum revealed higher concentrations of soluble formed IL1R1, IL-18, CXCL1, and osteopontin in MDS compared to young or aged normal donors. Conclusions: Collectively, our findings demonstrate that IL1R1 signaling alters the BMME and contributes to the disease phenotype of MDS and that the effects of targeting IL1R1 pharmacologically have differing effects based on the modality of inhibition as well as the cell population. IL1R1 signaling can be a promising target to alleviate the complexity of MDS via improving inflammatory status in BMME. Disclosures No relevant conflicts of interest to declare.

2010 ◽  
Vol 88 (2) ◽  
pp. 293-298 ◽  
Author(s):  
Nobuo Kuninaka ◽  
Morito Kurata ◽  
Kouhei Yamamoto ◽  
Shiho Suzuki ◽  
Shigeaki Umeda ◽  
...  

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Cristina Bono ◽  
Alba Martínez ◽  
Javier Megías ◽  
Daniel Gozalbo ◽  
Alberto Yáñez ◽  
...  

ABSTRACT Toll-like receptor (TLR) agonists drive hematopoietic stem and progenitor cells (HSPCs) to differentiate along the myeloid lineage. In this study, we used an HSPC transplantation model to investigate the possible direct interaction of β-glucan and its receptor (dectin-1) on HSPCs in vivo. Purified HSPCs from bone marrow of B6Ly5.1 mice (CD45.1 alloantigen) were transplanted into dectin-1−/− mice (CD45.2 alloantigen), which were then injected with β-glucan (depleted zymosan). As recipient mouse cells do not recognize the dectin-1 agonist injected, interference by soluble mediators secreted by recipient cells is negligible. Transplanted HSPCs differentiated into macrophages in response to depleted zymosan in the spleens and bone marrow of recipient mice. Functionally, macrophages derived from HSPCs exposed to depleted zymosan in vivo produced higher levels of inflammatory cytokines (tumor necrosis factor alpha [TNF-α] and interleukin 6 [IL-6]). These results demonstrate that trained immune responses, already described for monocytes and macrophages, also take place in HSPCs. Using a similar in vivo model of HSPC transplantation, we demonstrated that inactivated yeasts of Candida albicans induce differentiation of HSPCs through a dectin-1- and MyD88-dependent pathway. Soluble factors produced following exposure of HSPCs to dectin-1 agonists acted in a paracrine manner to induce myeloid differentiation and to influence the function of macrophages derived from dectin-1-unresponsive or β-glucan-unexposed HSPCs. Finally, we demonstrated that an in vitro transient exposure of HSPCs to live C. albicans cells, prior to differentiation, is sufficient to induce a trained phenotype of the macrophages they produce in a dectin-1- and Toll-like receptor 2 (TLR2)-dependent manner. IMPORTANCE Invasive candidiasis is an increasingly frequent cause of serious and often fatal infections. Understanding host defense is essential to design novel therapeutic strategies to boost immune protection against Candida albicans. In this article, we delve into two new concepts that have arisen over the last years: (i) the delivery of myelopoiesis-inducing signals by microbial components directly sensed by hematopoietic stem and progenitor cells (HSPCs) and (ii) the concept of “trained innate immunity” that may also apply to HSPCs. We demonstrate that dectin-1 ligation in vivo activates HSPCs and induces their differentiation to trained macrophages by a cell-autonomous indirect mechanism. This points to new mechanisms by which pathogen detection by HSPCs may modulate hematopoiesis in real time to generate myeloid cells better prepared to deal with the infection. Manipulation of this process may help to boost the innate immune response during candidiasis.


Blood ◽  
1996 ◽  
Vol 88 (8) ◽  
pp. 2859-2870 ◽  
Author(s):  
OJ Borge ◽  
V Ramsfjell ◽  
OP Veiby ◽  
MJ Jr Murphy ◽  
S Lok ◽  
...  

The recently cloned c-mpl ligand, thrombopoietin (Tpo), has been extensively characterized with regard to its ability to stimulate the growth, development, and ploidy of megakaryocyte progenitor cells and platelet production in vitro and in vivo. Primitive hematopoietic progenitors have been shown to express c-mpl, the receptor for Tpo. In the present study, we show that Tpo efficiently promotes the viability of a subpopulation of Lin-Sca-1+ bone marrow progenitor cells. The ability of Tpo to maintain viable Lin-Sca-1+ progenitors was comparable to that of granulocyte colony-stimulating factor and interleukin-1, whereas stem cell factor (SCF) promoted the viability of a higher number of Lin-Sca-1+ progenitor cells when incubated for 40 hours. However, after prolonged (> 40 hours) preincubation, the viability-promoting effect of Tpo was similar to that of SCF. An increased number of progenitors surviving in response to Tpo had megakaryocyte potential (37%), although almost all of the progenitors produced other myeloid cell lineages as well, suggesting that Tpo acts to promote the viability of multipotent progenitors. The ability of Tpo to promote viability of Lin-Sca-1+ progenitor cells was observed when cells were plated at a concentration of 1 cell per well in fetal calf serum-supplemented and serum-depleted medium. Finally, the DNA strand breakage elongation assay showed that Tpo inhibits apoptosis of Lin-Sca-1+ bone marrow cells. Thus, Tpo has a potent ability to promote the viability and suppress apoptosis of primitive multipotent progenitor cells.


2019 ◽  
Vol 3 (24) ◽  
pp. 4271-4279 ◽  
Author(s):  
Frederic Picou ◽  
Christine Vignon ◽  
Christelle Debeissat ◽  
Sébastien Lachot ◽  
Olivier Kosmider ◽  
...  

Abstract Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal stem cell disorders with an inherent tendency for transformation in secondary acute myeloid leukemia. This study focused on the redox metabolism of bone marrow (BM) cells from 97 patients compared with 25 healthy controls. The level of reactive oxygen species (ROS) was quantified by flow cytometry in BM cell subsets as well as the expression level of 28 transcripts encoding for major enzymes involved in the antioxidant cellular response. Our results highlight increased ROS levels in BM nonlymphoid cells and especially in primitive CD34posCD38low progenitor cells. Moreover, we identified a specific antioxidant signature, dubbed “antioxidogram,” for the different MDS subgroups or secondary acute myeloblastic leukemia (sAML). Our results suggest that progression from MDS toward sAML could be characterized by 3 successive molecular steps: (1) overexpression of enzymes reducing proteic disulfide bonds (MDS with <5% BM blasts [GLRX family]); (2) increased expression of enzymes detoxifying H2O2 (MDS with 5% to 19% BM blasts [PRDX and GPX families]); and finally (3) decreased expression of these enzymes in sAML. The antioxidant score (AO-Score) defined by logistic regression from the expression levels of transcripts made it possible to stage disease progression and, interestingly, this AO-Score was independent of the revised International Scoring System. Altogether, this study demonstrates that MDS and sAML present an important disturbance of redox metabolism, especially in BM stem and progenitor cells and that the specific molecular antioxidant response parameters (antioxidogram, AO-Score) could be considered as useful biomarkers for disease diagnosis and follow-up.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 31-31
Author(s):  
Wen-Shu Wu ◽  
Dong Xu ◽  
Stefan Heinrichs ◽  
A. Thomas Look

Abstract An antiapoptotic role for Slug/Snail in mammals was suggested by studies in C. elegans, where CES-1/Scratch, a member of the Slug/Snail superfamily, was found to control the apoptotic death of NSM sister neurons by acting as a transcriptional repressor of EGL-1, a BH3-only proapoptotic protein. Identification of Slug as the target gene of the E2A-HLF oncoprotein in human pro-B leukemia cells led us to demonstrate its antiapoptotic function in IL-3-dependent murine pro-B cells. In contrast to its aberrant expression in pro-B leukemia cells, endogenous Slug is normally expressed in both LT-HSC and ST-HSC, as well as committed progenitors of the myeloid series, but not in pro-B and pro-T cells, implying its function in myelopoiesis. Using Slug−/− mice produced in our laboratory, we showed that these knockouts are much more radiosensitive than Slug+/− and wild-type mice, and that apoptotic cells increase significantly in the hematopoietic progenitor cells of Slug−/− mice as compared to wild-type mice following γ-irradiation, indicating a radioprotective function in vivo. We showed here that although the development of myeloid progenitors is not impaired under steady-state conditions, their repopulation is incomplete γ-irradiated in in Slug−/− mice. We demonstrate further the radiation-induced death of Slug−/− mice is exclusively a result of bone marrow failure with no apparent contribution from systemic injures to other tissues. By two-way bone marrow transplantation, we provide firm evidence that Slug protects mice from γ-irradiation-induced death in a cell-autonomous manner. Interestingly, regenerative capacity of hematopoietic stem cells (HSC) was retained in irradiated Slug−/− mice, which could be rescued by wild-type bone marrow cells after irradiation, indicating that Slug exerts its radioprotective function in myeloid progenitors rather than HSCs. Furthermore, we establish that Slug radioprotects mice by antagonizing downstream of the p53-mediated apoptotic signaling through inhibition of the p53-resposive proapoptotic gene Puma, leading in turn to inhibition of the mitochondria-dependent apoptotic pathway activated by γ-irradiation in myeloid progenitors. More interestingly, we observed that Slug is inducible by γ-irradiation in a p53-dependent manner. Together, our findings implicate a novel Slug-mediated feedback mechanism by which p53 control programmed cell death in myeloid progenitor cells in vivo in response to γ-irradiation.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2615-2615
Author(s):  
Wolfgang Kern ◽  
Claudia Schoch ◽  
Susanne Schnittger ◽  
Torsten Haferlach

The diagnosis and classification of myelodysplastic syndromes (MDS) are based on cytomorphology (CM) and cytogenetics. A high degree of experience in CM is required to allow the accurate identification of dysmyelopoiesis and quantification of bone marrow blasts. The identification of dysplastic features in all lineages by multiparameter flow cytometry (MFC) has been shown feasible. To further analyze the potential role of MFC in the diagnostic work-up of MDS we analyzed 224 bone marrow samples from patients with suspected of proven MDS by MFC, CM, and cytogenetics in parallel. Blast counts as determined by CM and MFC, respectively, ranged from 0% to 21% (median, 5%) and from 0% to 33% (median, 4%; correlation: r=0.192, p=0.018). The median number of aberrant features detected by MFC were 0 for blasts (range, 0 to 4), 2 for granulocytes (0 to 7), 1 for monocytes (0 to 5), and 0 for erythrocytes (0 to 2). The most frequent dysplastic features observed in the blast populations included aberrant coexpression of CD11b (20.5%), CD15 (14.3%) and CD64 (14.3%). The most frequent dysplastic features observed in the granulocytic cell populations included reduced side-scatter signal corresponding to hypogranulation (71.4%), aberrant coexpression of CD56 (29.0%), aberrant pattern of CD13/CD16 expression (26.3%), aberrant pattern of CD11b/CD16 expression (25.9%), reduced expression of CD64 (17.0%), and aberrant expression of HLA-DR (14.7%). The most frequent dysplastic features observed in the monocytic cell populations included aberrant coexpression of CD56 (31.3%), aberrant coexpression of CD16 (26.3%), an aberrant pattern of CD11b/HLA-DR expression (6.7%), and aberrant coexpression of CD2 (5.8%). The most frequent dysplastic features observed in the erythroid cell populations included an aberrantly strong expression of CD71 and CD235a (23.7%), a lack of CD71 expression (10.7%), and an aberratly homogeneous expression of CD71 (7.1%). The presence of dysplastic features by CM as well as the presence of cytogenetic aberrations tended to be associated with a higher number of dysplastic features by MFC. These data suggest that the identification of dysplastic features by MFC is feasible although there is a large heterogeneity in aberrantly expressed antigens. Thus, a comprehensive panel of antibodies must be applied to allow the detection of dysplasia. Future studies will define the role of MFC in optimizing the diagnosis of MDS in cooperation with CM and cytogenetics.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3492-3492
Author(s):  
Laura A. Paganessi ◽  
Andrew L. Walker ◽  
Stephanie A. Gregory ◽  
Henry C. Fung ◽  
Kent W. Christopherson

Abstract The exopeptidase CD26 (also known as DPPIV/dipeptidylpeptidase IV) cleaves dipeptides from the N-terminus of proteins that contain the required X-Pro or X-Ala motif. We have previously reported that inhibition or loss of CD26 activity results in a deficiency in normal granulocyte-colony stimulating factor (G-CSF) induced mobilization, suggesting that CD26 is a necessary component of mobilization (Christopherson, et al Blood 2003 and Christopherson, et al Exp Hematol 2003). The chemokine CXCL12 (SDF-1, stromal cell derived factor-1) contains the appropriate recognition sequence for CD26 induced cleavage. This combined with the importance of CXCL12 in the trafficking of hematopoietic stem and progenitor cells (HSC/HPC) suggests CXCL12 as a likely functional target of CD26 during G-CSF induced mobilization. For this reason we therefore decided to investigate whether genetically engineered mice lacking CD26 (CD26−/−) could be mobilized utilizing the CXCR4 antagonist, AMD3100. To evaluate this, ten week old C57BL/6 and CD26−/− mice (also on a C57BL/6 background) received a single subcutaneous injection of AMD3100 (1mg/1kg). One hour following injection the mice were euthanized by CO2 inhalation. Peripheral blood was then obtained by heart stick with a 1.2 ml syringe containing EDTA as an anticoagulant. A complete blood count was taken for each peripheral blood sample. Following red blood cell lysis, cells were plated for myeloid colony formation in a standard 1% methylcellulose colony assay containing the appropriate cytokines. Following 7 days of incubation at 5% O2, 5% CO2 and 37°C plates were scored for colony-forming units-granulocyte macrophage (CFU-GM), burst-forming units-erythroid (BFU-E), and colony-forming units-granulocyte, erythroid, macrophage, and megakaryocytic (CFU-GEMM). Data is presented as the number of colonies per femur for the bone marrow and as the number of colonies per ml of whole blood for the peripheral blood. AMD3100 treatment resulted in an increase in white blood cell (WBC) counts from 5.05±0.48 × 106/ml in untreated mice to 10.21±0.88×106/ml in treated mice (p≤0.01). An increase in WBC counts was also observed during AMD3100 treatment in CD26−/− mice from 7.77±1.28×106/ml in untreated mice to 16.7 ±2.11 × 106/ml in treated mice (p<0.01). AMD3100 treatment resulted in an increase in circulating myeloid progenitors in the peripheral blood of C57BL/6 and CD26−/− mice as compared to untreated C57BL/6 and CD26−/− mice respectively (p≤0.01). Specifically, a 2.38, 3.75, 12.33 fold increase in CFU-GM, BFU-E, and CFU-GEMM were observed in the peripheral blood of C57BL/6 mice after treatment. A 2.63, 5.48, 14.29 fold increase in CFU-GM, BFU-E, and CFU-GEMM were observed in the peripheral blood of CD26−/− mice after treatment. Existing pre-clinical and clinical data suggest that the CXCR4 antagonist, AMD3100, rapidly mobilizes hematopoietic progenitor cells from the bone marrow into the periphery. The results presented here provide pre-clinical evidence that disruption of the interaction between the CXCR4 chemokine receptor and CXCL12, via sub-cutaneous injection of AMD3100, mobilizes significant numbers of myeloid progenitors in mice, even in the absence of CD26. These results support the notion that CD26 is downstream of G-SCF treatment. Additionally, these results support the potential use of AMD3100 to treat patients that may have an altered ability to respond to G-CSF treatment as a result of a reduction or loss in CD26 activity. Future studies are warranted to evaluate potential variations in CD26 levels or activity in the general population, in differing patient populations, and during different treatment regimens.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4130-4130
Author(s):  
Daniel L. Kraft ◽  
Vartan Ghazarossian ◽  
Mike Crocker ◽  
Sergio Najar ◽  
Antonio A. Carrasco-Yalðn

Abstract INTRODUCTION: Bone marrow (BM) contains a rich supply of adult stem and progenitor cells, including hematopoieitic and mesenchymal stem cells which are used in Bone Marrow Transplantation (BMT) and an increasing array of regenerative therapies. Traditional marrow harvest methods utilize percutaneous large bore needle aspiration, result in marrow highly diluted by peripheral blood, and are crude, tedious, labor intensive and expensive, usually requiring general anesthesia, and &gt;100 serial small volume aspirates to obtain adequate cell numbers for BMT. BM is showing increasing long-term advantages over mobilized PBSC for many alloegeneic BMTs, in terms of less cGVHD and in some cases improved survival. Improved BM harvest methods are needed. A novel device, the “MarrowMiner” (MM), was developed for the minimally invasive harvest of BM to enable the rapid, convenient, outpatient harvest of large quantities of BM under local anesthesia for use in allogeneic and autologous BMT and cell therapies utilizing autologous marrow derived cells. The MarrowMiner utilizes a single marrow entry site into the anterior or posterior iliac, through which the flexible, powered, guidable FlexShaft catheter can access the majority of the marrow space and aspirate rich marrow. Extensive testing in human cadavers and porcine models demonstrated a 10X increase in stem cells activity/ml (by CFU) compared to that of traditional needle harvests. The MM recently received both FDA and CE Mark regulatory approved, and ‘First In Human’ trials were successfully completed under local anesthesia, demonstrating safety, efficacy and higher stem cell yields compared to traditional methods. METHODS: In an ongoing prospective study, 10 patients undergoing autologous marrow derived therapy for use in regenerative medicine, had marrow harvested from their anterior or posterior ileac by the MM under local anesthesia on one hip, with direct comparison to standard needle serial marrow aspirates on the patients opposite hip (up to 350 ml per side). Cell viability, counts, CD34+, T cell, and MSC populations were assessed by flow cytometry. RESULTS: The MM successfully harvested marrow from a single entry sites and 2–3 paths under local anesthesia, without complications. Compared to standard harvest in the same patients, MM harvests had significantly number of Total Nucleated Cells ml compared to marrow harvested from the same patient by standard needle ( mean 1.98 fold greater TNC (range 0.87–3.36, p&lt;.05). Viability was equivalent at (&gt;99). In addition to higher TNC/ml, significantly higher levels (mean 3.56 fold) of Aldeflour/ALDH+ cells/ml, CD34+, and phenotypic MSC (CD45−,34−,90+,105+) and endothelial progenitor cells were obtained, as measured by flow cytometry. Mean CD3+ T-cell counts per ml were lower with MM harvests. CONCLUSIONS: The novel FDA approved MarrowMiner system demonstrated safety and efficacy in clinical use, harvesting more stem cells per unit volume in a single entry compared to standard harvest methods. These results suggests the MM may enable improved clinical stem cell harvests in a more rapid and minimally invasive manner in the outpatient setting, while harvesting a richer marrow product with less peripheral blood contamination. Such a system, facilitating convenient, on demand stem cell collection may have significant application for BMT and other marrow based cellular therapies.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2519-2519
Author(s):  
Marilyn L Slovak ◽  
Ya-Hsuan Hsu ◽  
Hseuh-Hua Chen ◽  
Yongbao Wang ◽  
Philip N Mowrey ◽  
...  

Abstract Abstract 2519 The myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal hematopoietic diseases characterized by ineffective hematopoiesis, cytopenias, and dysplasia in the erythroid, myeloid or megakaryocytic lineages. However, MDS can be difficult to recognize when blasts are not increased. Subtle phenotypic shifts in early MDS can be detected using higher-dimensional flow cytometry, by DNA mutation profiling, or by detection of a range of large and small genomic abnormalities by genome-wide SNP microarray. We compared the diagnostic potential of these 3 modalities in a group of 33 patients >50 years old referred for workup of cytopenia (17 blood, 16 bone marrow aspirate samples). Platforms compared were an oligo/SNP 2.6 million-probe microarray (Cytoscan HD, Affymetrix), a 161-amplicon targeted exome sequencing assay that includes TET2, ASXL1, EZH2, IDH1, IDH2, JAK2, KRAS, and NRAS (Ion Torrent protocol with PCR/product harvesting using Fluidigm Access Array), and flow cytometry using a 6-color, 22-marker panel and an 8-color, 26-marker panel (BD FACS Canto II). Nine patients had increased myeloblasts consistent with MDS (up to 20% in blood or 5%–20% in bone marrow)(Group 1), 23 had cytopenia(s) without increase in blasts (Group 2); an additional patient had a B-cell lymphoma. Group 1 patients all had aberrations detected by at least 1 of the 3 modalities (Table). In Group 2, 1 patient had unequivocal alterations by all 3 methods, 8 by 2 assays, and 6 by 1 assay; the other 9 patients had no unequivocal aberrations (Table). Copy-neutral loss of homozygosity (CN-LOH) of >10 Mb was the sole genomic aberration observed in 3 cases of cytopenia without an increase in blasts (affecting 5q, 7q and 20q), whereas others had losses/gains at chromosomal sites characteristic of MDS [i.e., partial 1q trisomy, del(5q), del(7q), +8, del(13q) and del(20q)]. Genes with mutations detected by sequencing Submicroscopic gene deletions or CN-LOH detected by array Flow cytometry abnormality Group 1: Cytopenia(s) with increased blasts (n=9) ASXL1 (2)
 TET2 (1)
 KRAS (1)
 EZH2 (1)
 JAK2 (1) BRAF (3)
 EZH2 (3)
 FLT3 (2)
 TP53 (2)
 RPS14 (2)
 EPO (2)
 ASXL1 (1)
 ETV6 (1) Myeloid maturation (9/9)
 CD56 expression (5/9) Group 2: Cytopenia(s) without increased blasts (n=24) TET2 (4)
 ASXL1 (2)
 KRAS (2)
 IDH2 (1) BRAF (2)
 EZH2 (2)
 TET2 (2)
 ASXL1 (1)
 ETV6 (1)
 RPS14 (1)
 EPO (1)
 TP53 (1) Myeloid maturation (9/24)
 CD56 expression (1/24) Among older MDS patients with cytopenias(s) but no increase in blasts, phenotypic and genomic profiling can frequently identify aberrations similar to those seen in higher-grade MDS. Locations of some submicroscopic deletions included loci commonly implicated in MDS pathogenesis. Detection of these aberrations in peripheral blood should facilitate the diagnosis of early MDS. Disclosures: No relevant conflicts of interest to declare.


Sign in / Sign up

Export Citation Format

Share Document