[Treg Cells, FoxP3 and TGF-ß Expression and Significance in Chronic Myeloid Leukemia].

OBJECTIVE: To investigate the expression and significance of regulatory T cells (Tregs), FoxP3 and transforming growth factor-ß (TGF-ß) in different phase of chronic myeloid leukemia (CML). METHODS: Peripheral blood of 73 CML patients in Department of Hematology, Heze Municipal Hospital from March 2018 to March 2021 were collected. According to patient's period in CML, they were divided into ND CML group (newly diagnosed), CP CML group (chronic period), and BP CML group (blast phase). The percentage of Tregs, expression level of FoxP3 mRNA and TGF-ß were detected by flow cytometry, RT-qPCR, and ELISA, respecitively. The roles of above indices in clinical pathogenesis of patients with CML were analyzed. RESULTS: The proportion of Treg in the ND CML group was slightly higher than the CP CML group, but the difference was not statistically significant (P =0.695), while the BP CML group was significantly higher than the other two groups (P =0.008, P <0.001). The expression levels of FoxP3 mRNA in ND CML group, CP CML group and BP CML group were 11.61±2.21, 6.46±1.35 and 8.54±2.13, respectively. Significant difference in FoxP3 mRNA levels was observed among patients in different phases of CML (F =55.199, P <0.001). The expression levels of FoxP3 mRNA both in ND CML group and BP CML group were significantly higher than that in CP CML group (P <0.001), and the ND CML group was the highest (P <0.001). However, the expression levels of TGF-ß in different phases of CML showed no statistical differences (H =0.634, P =0.728). CONCLUSION: The abnormal distribution of Treg subset in different phases of CML and the significant increase of the expression level of FoxP3 mRNA in the new onset and blast phase of CML suggest that Tregs may promote the occurrence and progression of CML through immune regulation.

Treg Cells, FoxP3 and TGF-β Expression and Significance in Chronic Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression and significance of regulatory T cells (Tregs), FoxP3 and transforming growth factor-β (TGF-β) in different phase of chronic myeloid leukemia (CML).@*METHODS@#Peripheral blood of 73 CML patients in Department of Hematology, Heze Municipal Hospital from March 2018 to March 2021 were collected. According to patient's period in CML, they were divided into ND CML group (newly diagnosed), CP CML group (chronic period), and BP CML group (blast phase). The percentage of Tregs, expression level of FoxP3 mRNA and TGF-β were detected by flow cytometry, RT-qPCR, and ELISA, respecitively. The roles of above indices in clinical pathogenesis of patients with CML were analyzed.@*RESULTS@#The proportion of Treg in the ND CML group was slightly higher than the CP CML group, but the difference was not statistically significant (P =0.695), while the BP CML group was significantly higher than the other two groups (P =0.008, P <0.001). The expression levels of FoxP3 mRNA in ND CML group, CP CML group and BP CML group were 11.61±2.21, 6.46±1.35 and 8.54±2.13, respectively. Significant difference in FoxP3 mRNA levels was observed among patients in different phases of CML (F =55.199, P <0.001). The expression levels of FoxP3 mRNA both in ND CML group and BP CML group were significantly higher than that in CP CML group (P <0.001), and the ND CML group was the highest (P <0.001). However, the expression levels of TGF-β in different phases of CML showed no statistical differences (H =0.634, P =0.728).@*CONCLUSION@#The abnormal distribution of Treg subset in different phases of CML and the significant increase of the expression level of FoxP3 mRNA in the new onset and blast phase of CML suggest that Tregs may promote the occurrence and progression of CML through immune regulation.

Improving the solubility and antileukemia activity of Wnt/ß-catenin signaling inhibitors by disrupting molecular planarity.

Leukemia cells depend on the Wnt/ß-catenin signaling pathway for their growth. Pyrvinium, a known Wnt signaling inhibitor, has demonstrated promising efficacy in the treatment of the aggressive blast phase chronic myeloid leukemia (BP-CML). We previously developed potent inhibitors 1-2 for the Wnt/ß-catenin signaling pathway. However, the further application of these compounds as anti-leukemia agents is limited by their modest anti-leukemia activity in cells and poor aqueous solubility, due to the high molecular planarity of the chemical scaffold. Here, we reported our efforts in the synthesis and in vitro evaluation of 18 new compounds (4a-r) that have been designed to disrupt the molecular planarity of the chemical scaffold. Several compounds of the series showed significantly improved anti-leukemia activity and aqueous solubility. As a highlight, compounds 4c not only maintained excellent inhibitory potency (IC50 = 1.3 nM) for Wnt signaling but also demonstrated good anti-leukemia potency (IC50 = 0.9 µM) in the CML K562 cells. Moreover, compound 4c had an aqueous solubility of 5.9 µg/mL, which is over 50-fold enhanced compared to its parents 1-2.

The bioengineered HALOA complex induces anoikis in chronic myeloid leukemia cells by targeting the BCR-ABL/Notch/Ikaros/Redox/Inflammation axis.

Blast crisis (BC) is an outcome that arises during the treatment process of chronic myeloid leukemia (CML), which is possibly attained by the dysregulation of the Notch and Ikaros signaling pathways, BCR-ABL translocation, redox, and inflammatory factors. This study demonstrated that biotherapeutic agents target aberrant molecular axis in CML-BC cells. The HALOA complex was synthesized by simple mixing of apo α-lactalbumin with oleic acid, which manages to inhibit BCR-ABL (b3a2 in K562 cells) translocation. It elevates the production of reactive oxygen species (ROS), reactive nitrogen species (RNS), and protein carbonyl, which induces DNA fragmentation in K562 cells but not in NIH cells. The complex manages to reduce the toxicity surrounding apoptotic cells by enhancing the production of superoxide dismutase (SOD) and the total antioxidant level. The HALOA complex increases leptin to maintain normoxic conditions, ultimately preventing angiogenesis. This complex downregulates the expression of IL-8 and MMP-9 and elevates the expression levels of Notch 4, Ikaros, and integrin alpha-D/CD-11d (tumor-suppressive), which conjointly prevents inflammation, metastasis, and epithelial-mesenchymal transition (EMT) in CML cells. Meanwhile, the complex downregulates Notch 1 and 2 (oncogenic), consequently inducing anoikis in CML cells. Overall, the HALOA complex shows credibility by targeting the combined molecular factors responsible for the pathogenesis of the disease and will also help to overcome MDR conditions in leukemia.

Blastic plasmacytoid dendritic-cell neoplasia: a challenging case report.

Blastic plasmacytoid dendritic-cell neoplasm (BPDCN) is an extremely rare disease that originates from dendritic cells and is associated with a poor overall survival (OS). Diagnostic and therapeutic standards are less well-established in comparison to other leukemic conditions and standards of care are lacking. Morphologic and molecular similarities to acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) are hard to distinguish. We here report a BPDCN patient with a long, challenging diagnostic period. While bone marrow biopsies initially failed to prove the correct diagnosis, a cutaneous biopsy finally identified a CD45+/CD56+/CD4+/CD123+/CD33+/MPO- population suggestive of BPDCN which was confirmed by flow cytometry. Molecular analysis revealed an ASXL-1, TET2 and SRSF2-mutation, cytogenetic analysis showed a normal karyotype. Treatment with the recently approved CD123-cytotoxin Tagraxofusp showed initially a very good response. This case reflects diagnostic and therapeutic difficulties in BPDCN as very rare, easily misdiagnosed neoplasia and the need for precise diagnostic care.

MTH1 Inhibitor TH1579 Induces Oxidative DNA Damage and Mitotic Arrest in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy, exhibiting high levels of reactive oxygen species (ROS). ROS levels have been suggested to drive leukemogenesis and is thus a potential novel target for treating AML. MTH1 prevents incorporation of oxidized nucleotides into the DNA to maintain genome integrity and is upregulated in many cancers. Here we demonstrate that hematologic cancers are highly sensitive to MTH1 inhibitor TH1579 (karonudib). A functional precision medicine ex vivo screen in primary AML bone marrow samples demonstrated a broad response profile of TH1579, independent of the genomic alteration of AML, resembling the response profile of the standard-of-care treatments cytarabine and doxorubicin. Furthermore, TH1579 killed primary human AML blast cells (CD45+) as well as chemotherapy resistance leukemic stem cells (CD45+Lin-CD34+CD38-), which are often responsible for AML progression. TH1579 killed AML cells by causing mitotic arrest, elevating intracellular ROS levels, and enhancing oxidative DNA damage. TH1579 showed a significant therapeutic window, was well tolerated in animals, and could be combined with standard-of-care treatments to further improve efficacy. TH1579 significantly improved survival in two different AML disease models in vivo. In conclusion, the preclinical data presented here support that TH1579 is a promising novel anticancer agent for AML, providing a rationale to investigate the clinical usefulness of TH1579 in AML in an ongoing clinical phase I trial. SIGNIFICANCE: The MTH1 inhibitor TH1579 is a potential novel AML treatment, targeting both blasts and the pivotal leukemic stem cells while sparing normal bone marrow cells.

Blast cells surviving acute myeloid leukemia induction therapy are in cycle with a signature of FOXM1 activity.

BACKGROUND: Disease relapse remains common following treatment of acute myeloid leukemia (AML) and is due to chemoresistance of leukemia cells with disease repopulating potential. To date, attempts to define the characteristics of in vivo resistant blasts have focused on comparisons between leukemic cells at presentation and relapse. However, further treatment responses are often seen following relapse, suggesting that most blasts remain chemosensitive. We sought to characterise in vivo chemoresistant blasts by studying the transcriptional and genetic features of blasts from before and shortly after induction chemotherapy using paired samples from six patients with primary refractory AML. METHODS: Leukemic blasts were isolated by fluorescence-activated cell sorting. Fluorescence in situ hybridization (FISH), targeted genetic sequencing and detailed immunophenotypic analysis were used to confirm that sorted cells were leukemic. Sorted blasts were subjected to RNA sequencing. Lentiviral vectors expressing short hairpin RNAs were used to assess the effect of FOXM1 knockdown on colony forming capacity, proliferative capacity and apoptosis in cell lines, primary AML cells and CD34+ cells from healthy donors. RESULTS: Molecular genetic analysis revealed early clonal selection occurring after induction chemotherapy. Immunophenotypic characterisation found leukemia-associated immunophenotypes in all cases that persisted following treatment. Despite the genetic heterogeneity of the leukemias studied, transcriptional analysis found concerted changes in gene expression in resistant blasts. Remarkably, the gene expression signature suggested that post-chemotherapy blasts were more proliferative than those at presentation. Resistant blasts also appeared less differentiated and expressed leukemia stem cell (LSC) maintenance genes. However, the proportion of immunophenotypically defined LSCs appeared to decrease following treatment, with implications for the targeting of these cells on the basis of cell surface antigen expression. The refractory gene signature was highly enriched with targets of the transcription factor FOXM1. shRNA knockdown experiments demonstrated that the viability of primary AML cells, but not normal CD34+ cells, depended on FOXM1 expression. CONCLUSIONS: We found that chemorefractory blasts from leukemias with varied genetic backgrounds expressed a common transcriptional program. In contrast to the notion that LSC quiescence confers resistance to chemotherapy we find that refractory blasts are both actively proliferating and enriched with LSC maintenance genes. Using primary patient material from a relevant clinical context we also provide further support for the role of FOXM1 in chemotherapy resistance, proliferation and stem cell function in AML.

Intracellular ROS profile in hematopoietic progenitors of MDS patients: association with blast count and iron overload.

Objectives: Reactive oxygen species (ROS) are under scrutiny as a participant in the pathophysiology of myelodysplastic syndrome (MDS) and the progression of MDS to acute myeloid leukemia (AML). Measurement of intracellular ROS (iROS) is particularly important since iROS is a direct indicator of cellular health and integrity.Methods: We developed a technique to measure standardize iROS (siROS) level in lymphocytes and bone marrow (BM) CD34+ hematopoietic progenitors using the fluorescent probe dichlorofluorescein (DCF). We then quantified the siROS in 38 consecutive BM specimens from 27 MDS patients over the course of 10 months. Disease outcome of these patients were also assessed.Results: High serum ferritin, high blast count and poor IPSS were associated with inferior survival and AML progression in this cohort. High blast MDS patients had lower siROS in their BM CD34+ cells than those of low blast patients, consistent with increased reliance on glycolysis and enhanced ROS defense in high blast MDS. We also observed narrower siROS distribution in the BM CD34+ cells of high blast patients, suggesting that loss of heterogeneity in ROS content accompanies the clonal evolution of MDS. Furthermore, we observed a strong correlation between CD34+ cells siROS and serum ferritin level in high blast patients. In one case, iron chelation therapy (ICT) resulted in parallel decreases in serum ferritin and CD34+ cells siROS.Conclusion: Our findings established the siROS profile in early hematopoietic cells of MDS patients and its relationship with blast count and iron overload.

RAG enhances BCR-ABL1-positive leukemic cell growth through its endonuclease activity in vitro and in vivo.

BCR-ABL1 gene fusion associated with additional DNA lesions involves the pathogenesis of chronic myelogenous leukemia (CML) from a chronic phase (CP) to a blast crisis of B lymphoid (CML-LBC) lineage and BCR-ABL1+ acute lymphoblastic leukemia (BCR-ABL1+ ALL). The recombination-activating gene RAG1 and RAG2 (collectively, RAG) proteins that assemble a diverse set of antigen receptor genes during lymphocyte development are abnormally expressed in CML-LBC and BCR-ABL1+ ALL. However, the direct involvement of dysregulated RAG in disease progression remains unclear. Here, we generate human wild-type (WT) RAG and catalytically inactive RAG-expressing BCR-ABL1+ and BCR-ABL1- cell lines, respectively, and demonstrate that BCR-ABL1 specifically collaborates with RAG recombinase to promote cell survival in vitro and in xenograft mice models. WT RAG-expressing BCR-ABL1+ cell lines and primary CD34+ bone marrow cells from CML-LBC samples maintain more double-strand breaks (DSB) compared to catalytically inactive RAG-expressing BCR-ABL1+ cell lines and RAG-deficient CML-CP samples, which are measured by γ-H2AX. WT RAG-expressing BCR-ABL1+ cells are biased to repair RAG-mediated DSB by the alternative non-homologous end joining pathway (a-NHEJ), which could contribute genomic instability through increasing the expression of a-NHEJ-related MRE11 and RAD50 proteins. As a result, RAG-expressing BCR-ABL1+ cells decrease sensitivity to tyrosine kinase inhibitors (TKI) by activating BCR-ABL1 signaling but independent of the levels of BCR-ABL1 expression and mutations in the BCR-ABL1 tyrosine kinase domain. These findings identify a surprising and novel role of RAG in the functional specialization of disease progression in BCR-ABL1+ leukemia through its endonuclease activity.

Accelerated Phase of Myeloproliferative Neoplasms.

BACKGROUND: Myeloproliferative neoplasms (MPNs) can transform into blast phase MPN (leukemic transformation; MPN-BP), typically via accelerated phase MPN (MPN-AP), in ∼20-25% of the cases. MPN-AP and MPN-BP are characterized by 10-19% and ≥20% blasts, respectively. MPN-AP/BP portend a dismal prognosis with no established conventional treatment. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the sole modality associated with long-term survival. SUMMARY: MPN-AP/BP has a markedly different mutational profile from de novo acute myeloid leukemia (AML). In MPN-AP/BP, TP53 and IDH1/2 are more frequent, whereas FLT3 and DNMT3A are rare. Higher incidence of leukemic transformation has been associated with the most aggressive MPN subtype, myelofibrosis (MF); other risk factors for leukemic transformation include rising blast counts above 3-5%, advanced age, severe anemia, thrombocytopenia, leukocytosis, increasing bone marrow fibrosis, type 1 CALR-unmutated status, lack of driver mutations (negative for JAK2, CALR, or MPL genes), adverse cytogenetics, and acquisition of ≥2 high-molecular risk mutations (ASXL1, EZH2, IDH1/2, SRSF2, and U2AF1Q157). The aforementioned factors have been incorporated in several novel prognostic scoring systems for MF. Currently, elderly/unfit patients with MPN-AP/BP are treated with hypomethylating agents with/without ruxolitinib; these regimens appear to confer comparable benefit to intensive chemotherapy but with lower toxicity. Retrospective studies in patients who acquired actionable mutations during MPN-AP/BP showed positive outcomes with targeted AML treatments, such as IDH1/2 inhibitors, and require further evaluation in clinical trials. Key Messages: Therapy for MPN-AP patients represents an unmet medical need. MF patients, in particular, should be appropriately stratified regarding their prognosis and the risk for transformation. Higher-risk patients should be monitored regularly and treated prior to progression to MPN-BP. MPN-AP patients may be treated with hypomethylating agents alone or in combination with ruxolitinib; also, patients can be provided with the option to enroll in rationally designed clinical trials exploring combination regimens, including novel targeted drugs, with an ultimate goal to transition to transplant.

New routes to eradicating chronic myelogenous leukemia stem cells by targeting metabolism.

Chronic myelogenous leukemia (CML) stem cells are the cellular source of the vast majority of mature CML cells and responsible for relapse of CML disease post-tyrosine kinase inhibitor (TKI) therapy. Although mature CML cells, whose active division is driven by BCR-ABL1 oncogene-dependent signaling, are reduced by TKI therapy, CML stem cells are resistant because they become quiescent via a heretofore elusive mechanism that is independent of oncogene signaling. Recent advances in highly sensitive metabolomics analyses, however, have unveiled new metabolic pathways that are essential for the survival of CML stem cells. With respect to glucose metabolism, CML stem cells elevate anaplerosis to sustain the TCA cycle. Blast crisis (BC)-CML stem cells increase their branched-chained amino acid (BCAA) metabolism. Recently, we showed that CML stem cell quiescence in vivo is regulated by lysophospholipid metabolism that is specific to these cells, namely cooperation between the stemness factors FOXO and ß-catenin. These findings reveal biologically significant links between CML stemness and novel metabolic mechanisms. In this review, I describe these links in the contexts of glucose, amino acid, and lipid metabolism, and speculate on how innovative therapeutics might be designed to eradicate CML stem cells in vivo and overcome disease relapse post-TKI therapy.

CD44: a potential therapeutic target in chronic myeloid leukemia.

Development of tyrosine kinase inhibitors (TKIs) achieved great success in the treatment of chronic phase chronic myeloid leukemia (CML). However, patients with CML still relapse without taking TKIs and cases in the accelerated phase or aggressive blast crisis rarely achieved deep response to TKIs. Drug resistance and persistence of leukemia stem cell (LSC) remain great challenges. BCR-ABL kinase dependent or independent mechanism of action are still far from being understood. To achieve a stable deep molecular response and treatment-free remission, finding new targets, eliminating LSC, reducing recurrence and improving prognosis are problems urgently to be solved. It is revealed that tumor microenvironment is crucial for survival, invasion and metastasis of tumor cells. As an adhesion molecule, CD44, a single-chain transmembrane glycoprotein, is not only being identified as a marker for cancer stem cells, but also plays a crucial role in microenvironmental communication and transmitting intracellular signaling for cell proliferation, differentiation, migration, and contributes to tumorigenesis. In this review, we focus on current data relevant to CD44, and outline CD44 structure, the regulation of CD44, functional properties of CD44 in survival, resistance, CML stem cells as well as the potential CD44-targeting therapy for CML management.

5-aminoimidazole-4-carboxamide ribonucleoside induces differentiation in a subset of primary acute myeloid leukemia blasts.

BACKGROUND: All-trans retinoic acid (ATRA)-based treatment of acute promyelocytic leukemia (APL) is the most successful pharmacological treatment of acute myeloid leukemia (AML). Recent development of inhibitors of mutated isocitrate dehydrogenase and dihydroorotate dehydrogenase (DHODH) has revived interest in differentiation therapy of non-APL AML. Our previous studies demonstrated that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr) induced differentiation of monocytic cell lines by activating the ATR/Chk1 via pyrimidine depletion. In the present study, the effects of AICAr on the viability and differentiation of primary AML blasts isolated from bone marrow of patients with non-APL AML were tested and compared with the effects of DHODH inhibitor brequinar and ATRA. METHODS: Bone marrow samples were obtained from 35 patients and leukemia blasts were cultured ex vivo. The cell viability was assessed by MTT assay and AML cell differentiation was determined by flow cytometry and morphological analyses. RNA sequencing and partial data analysis were conducted using ClusterProfiler package. Statistical analysis was performed using GraphPad Prism 6.0. RESULTS: AICAr is capable of triggering differentiation in samples of bone marrow blasts cultured ex vivo that were resistant to ATRA. AICAr-induced differentiation correlates with proliferation and sensitivity to DHODH inhibition. RNA-seq data obtained in primary AML blasts confirmed that AICAr treatment induced downregulation of pyrimidine metabolism pathways together with an upregulation of gene set involved in hematopoietic cell lineage. CONCLUSION: AICAr induces differentiation in a subset of primary non-APL AML blasts, and these effects correlate with sensitivity to a well-known, potent DHODH inhibitor.

Embryonic Program Activated during Blast Crisis of Chronic Myelogenous Leukemia (CML) Implicates a TCF7L2 and MYC Cooperative Chromatin Binding.

Chronic myeloid leukemia (CML) is characterized by an inherent genetic instability, which contributes to the progression of the disease towards an accelerated phase (AP) and blast crisis (BC). Several cytogenetic and genomic alterations have been reported in the progression towards BC, but the precise molecular mechanisms of this event are undetermined. Transcription Factor 7 like 2 (TFC7L2) is a member of the TCF family of proteins that are known to activate WNT target genes such as Cyclin D1. TCF7L2 has been shown to be overexpressed in acute myeloid leukemia (AML) and represents a druggable target. We report here that TCF7L2 transcription factor expression was found to be correlated to blast cell numbers during the progression of the disease. In these cells, TCF7L2 CHIP-sequencing highlighted distal cis active enhancer, such as elements in SMAD3, ATF5, and PRMT1 genomic regions and a proximal active transcriptional program of 144 genes. The analysis of CHIP-sequencing of MYC revealed a significant overlapping of TCF7L2 epigenetic program with MYC. The ß-catenin activator lithium chloride and the MYC-MAX dimerization inhibitor 10058-F4 significantly modified the expression of three epigenetic targets in the BC cell line K562. These results suggest for the first time the cooperative role of TCF7L2 and MYC during CML-BC and they strengthen previous data showing a possible involvement of embryonic genes in this process.

Interleukin 6 and disease transformation in chronic myeloid leukemia: A Northeast Indian population study.

BACKGROUND: Interleukin 6 (IL6) has been suggested to be a valuable prognostic marker in chronic myeloid leukemia (CML). IL6 is a pleiotropic cytokine and plays an important role in immune response, hematopoiesis, and acute phase response. IL6 is regarded as a prominent target for clinical interventions. OBJECTIVE: The aim of the present study was to investigate the serum levels of IL6 in CML to provide greater insight to their role in disease transformation in Indian patients. MATERIALS AND METHODS: A total of 50 CML cases and 10 acute lymphocytic leukemia (ALL) cases along with 20 healthy controls were included in the study between 2015 and 2016. About 4 mL blood samples were collected from all cases in plain vial and serum was separated. Levels of IL6 were determined in all cases by enzyme-linked immunosorbent assay. RESULTS: The study suggests that both ALL and CML are associated with significantly elevated serum IL6 level than the healthy control group. Mean levels of serum IL6 are 223.4 ± 53.403 pg/mL in CML, 71.020 ± 29.549 pg/mL in ALL, and 5.360 ± 0.467 pg/mL in healthy control group. Serum IL6 correlated with different phases of CML. Mean IL6 levels are 50.93 ± 29.37 pg/mL in chronic phase (CP), 69.02 ± 22.60 pg/mL in accelerated phase (AP), and 652.77 ± 124.62 pg/mL in blast crisis (BC) phase of CML. In compared to CP and AP, in BC, IL-6 is significantly elevated ( P = 0.00 and 0.00, respectively); however, we did not find a significant difference in IL-6 serum levels between CP and AP ( P = 0.703). CONCLUSION: Study suggests that the detection of IL6 level in newly diagnosed patient can predict the severity of the disease. There might be association of level of IL6 with the disease transformation.

Concordance among hematopathologists in classifying blasts plus promonocytes: A bone marrow pathology group study.

Enumeration of blasts and promonocytes is essential for World Health Organization (WHO) classification of myelomonocytic neoplasms. The accuracy of distinguishing blasts, promonocytes and monocytes, including normal vs abnormal monocytes, remains controversial. The objective of this analysis is to assess concordances between experienced hematopathologists in classifying cells as blasts, promonocytes, and monocytes according to WHO criteria. Each of 11 hematopathologists assessed glass slides from 20 patients [12 with chronic myelomonocytic leukemia (CMML) and 8 with acute myeloid leukemia (AML)] including blood and BM aspirate smears, and limited nonspecific esterase (NSE) stains. All cases were blindly reviewed. Fleiss' extension of Cohen's kappa for multiple raters was used on these variables, separately for peripheral blood (PB) and bone marrow (BM). Spearman's rank correlation was used to assess correlations between each pair of hematopathologists for each measurement. For the classification based on the sum of blasts and promonocytes in the BM, Fleiss' kappa was estimated as 0.744. For PB, categorizing patients according to the sum of blasts and promonocytes, Fleiss' kappa was estimated as 0.949. Distinction of abnormal monocytes from normal monocytes in PB did not achieve a good concordance and showed strong evidence of differences between hematopathologists (P < .0001). The hematopathologists achieved a good concordance rate of 74% in CMML vs AML classification and a high k rate, confirming that criteria for defining the blasts equivalents (blasts plus promonocytes) could be applied consistently. Identification of monocyte subtypes (abnormal vs normal) was not concordant. Our results support the practice of combining blasts/promonocytes into a single category.

Impact of marrow blasts percentage on high-grade myelodysplastic syndrome assessed using revised international prognostic scoring system.

Clinical trials and treatment guidelines for myelodysplastic syndrome depend on several prognostic scoring systems to stratify patients by risk. These include different variables: the degree of cytopenia, percentage of bone marrow blasts, and cytogenetics. Little is known about the impact of bone marrow blasts in patients with adverse cytogenetics. In this retrospective study, we analyzed 536 patients with high-grade myelodysplastic syndrome to examine the differences in survival for patients with different percentages of bone marrow blasts. The median overall survival in patients with ≥ 5% marrow blasts was not statistically different from that for patients with < 5% marrow blasts; however, the former group had a higher risk of progression to acute myeloid leukemia (p < 0.001). Therefore, cytogenetics is the most important factor in our prognostic tools to determine survival outcomes for patients with myelodysplastic syndrome, and patients with high-risk disease have poor prognosis irrespective of their marrow blasts percentage.