RAEB Group Research Articles

Analysis of Cytogenetic Characteristics and Clinical Prognosis in 236 Patients with Myelodysplastic Syndrome

To investigate the relationship of cytogenetic features, clinical characteristics and prognosis in patients with myelodysplastic syndrome. The clinical characteristics and prognosis of 236 patients with MDS admitted to the Affiliated Hospital of Xuzhou Medical University from January 2013 to September 2017 were analyzed retrospectively, the follow-up observation and correlation analysis were performed. There were 33 cases of refractory cytopenia with unilateral dysplasia (RCUD), 8 cases of refractory anemia with ring-shaped iron granulocytes (RARS), 70 cases of refractory cytopenia with multiple dysplasia (RCMD), 23 cases of refractory anemia (RA), 46 cases of refractory anemia with excessive blasts (RAEB-1), 48 cases of (RAEB-2), MDS-U 2 cases, simple del(5q) 6 cases. The detection analysis showed that the chromosome abnormality rate and complex chromosome abnormality rate in RAEB group (RAEB-1 + RAEB-2) and in non-RAEB group (RARS+RCMD+RCUD+RA) were 48.94% vs 43.94%, and 18.09% vs 12.69%, respectively, which were no statistically different. The grouping according to IPSS-R and IPSS showed that the chromosome abnormality rate gradually increased along with enhancement of risk stratifi-cation (P<0.05). The cytogenetic characteristics analysis showed that a total of 108 cases had chromosomal abnormalities, the detection rate was 45.76%, Out of 108 cases, 36 cases had complicated karyotypes, accounted for 15.25% of all patients. The types of chromosomal abnormalities mainly include numbers, structural abnormalities and mixed abnormalities. The chromosome abnormality with the highest detection rate was +8, accounted for 30.56% (33/100) of patients with chromosome abnormalities; followed by -7/7q-, del(5q), del(20q), etc. -7/7q-chromosome abnormalities accounted for 29.63% of all karyotypic abnormalities (including -7/7q-chromosome abnormalities alone and other chromosome abnormalities). The median age of the patients with MDS was 61 (13-88) years old, and the male-female ratio was 1.36∶1. Analysis of blood cell characteristics showed that the three lines were reduced or increased to varying degrees. The median WBC count was 2.8 (0.3-267.1)×109/L, the median Hb level was 69 (20-156) g/L, and the median Plt count was 55 (2-1733)×109/L. The 1 year OS rate in 32 cases of chromosome 7 abnormality and 128 cases of normal chromosome was 25% and 44.53%, respectively, the difference was statistically significant (χ2=4.05, P<0.05) . Chromosome karyotype is an independent factor affecting the prognosis of patients with MDS. It is important for the diagnosis, treatment and prognosis evalnation of patients with MDS. The overall prognosis of patients with abnormal chromosome 7 is poor. .

Clinical significance of serum ferritin detection in myelodysplastic syndromes

Objective To investigate the clinical significance of serum ferritin (SF) detection in myelodysplastic syndromes (MDS). Methods A total of 42 cases of MDS without blood transfusion who were admitted to General Hospital of Huainan Eastern Hospital Group from January 2010 to July 2017 were collected. There were 27 males and 15 females, aged 46-90 years old with a median age of 72 years old. In 42 cases of MDS, 10 cases had refractory anemia (RA), 4 cases had refractory anemia with ring increased iron bead young cell (RARS), 8 cases had refractory blood cells decreased with more dysplasia (RCMD), and 20 cases had refractory anemia with primitive cells increased (RAEB). According to the International Prognostic Scoring System, 22 cases had low risk, and 20 cases had high risk. At the same time, 40 healthy checkers were chosen as healthy control group. SF levels were measured and compared between the MDS patients and healthy controls. Results The SF level in the MDS group was significantly higher than that in the healthy control group [(479±267) ng/ml vs. (153±56) ng/ml], and the difference was statistically significant (t = 7.379, P < 0.05). The difference in SF levels among the patients with different subtypes of MDS was statistically significant (F = 4.81, P = 0.006). Among them, the RA group had the lowest SF level, while the RAEB group had the highest, and the difference between the two groups was statistically significant [(346±257) ng/ml vs. (818±443) ng/ml, P = 0.005]. The SF level in the low-risk group was lower than that in the high-risk group [(456±238) ng/ml vs. (788±467) ng/ml], and the difference was statistically significant (t = 2.867, P = 0.008). Conclusion Patients with MDS show a significant increase in SF level, and high-risk patients are associated with iron overload, and SF may be an auxiliary indicator for judging the prognosis of MDS. Key words: Myelodysplastic syndromes; Serum ferritin; Prognosis

Wilms’ tumor 1 mRNA expression: a good tool for differentiating between myelodysplastic syndrome and aplastic anemia in children?

ABSTRACTObjectives: To evaluate the value of Wilms’ tumor 1 mRNA (WT1) expression in the differential diagnosis of childhood myelodysplastic syndrome (MDS) and aplastic anemia (AA).Methods: This study compared WT1 expression levels in children of MDS and AA to evaluate its value in differential diagnosis.Results: WT1 overexpression rate and mean WT1 expression level were significantly higher in MDS compared to AA (P = 0.000 and P = 0.013, respectively). Patients with RCC and normal cytogenetics exhibited significantly greater portion of patients exposing WT1 overexpression, compared to all AA subtypes (P = 0.001, P = 0.000 and P = 0.001, respectively). ROC curve analysis revealed that WT1 expression could differentiate between RCC with normal cytogenetics and non-severe AA. Based on a cut-off value of 1.45%, WT1 expression provided a sensitivity of 23.2% and a specificity of 100%.Discussion: In the present study, WT1 overexpression rate was gradually decreased in RAEB group, RCC group and AA subtypes, and the mean WT1 expression level of the MDS patients was significantly higher than that of the AA group. It is very difficult to differentiate between RCC with normal cytogenetics and NSAA in children. Our results showed significant differences in WT1 overexpression rate between these two groups. When we set the cut-off value as 1.45%, WT1 expression levels could be used to differentiate between cases of RCC with normal cytogenetics and NSAA in children.Conclusion: WT1 expression might be useful for distinguishing between myelodysplastic syndrome and aplastic anemia in children.

IL-32 mRNA Expression of Bone Marrow Stromal Cells and Its Correlation with Cell Apoptosis in Patients with Myelodysplastic Syndrome

To investigate the IL-32 mRNA expression of bone marrow stromal cells and its correlation with apoptosis of bone marrow mononuclear cells in patients with myelodysplastic syndrome (MDS). Bone marrow samples from 26 MDS patients and 10 iron deficiency anemia (IDA, as control) patients were collected, RT-PCR was used to detect the IL-32 mRNA expression of bone marrow stromal cells, and the apoptosis of bone marrow mononuclear cells was detected by flow cytometry with Annexin V-FITC/PI dowble staining. The born marrow lymphocytes and NK cells were detected by means of direct immunofluorescence labeling whole blood hemolysis and flow cytometry. IL-32 mRNA expression of bone marrow stromal cells in the MDS patients was significantly higher than that of control group, the IL-32 mRNA expression of bone marrow stromal cells in patients with RA, RAS and RCMD was significantly higher than that in patients with RAEB. There was no obvious difference between RAEB and the control groups. The apoptosis of bone marrow mononuclear cells in MDS group was significantly higher than that in the control group, the apoptosis of bone marrow mononuclear cells in patients with RA, RAS and RCMD was significantly higher than that in RAEB. There was no significant difference between RAEB group and control group. The IL-32 mRNA expression in bone marrow stromal cells significantly correlated with the apoptosis of bone marrow mononuclear cells in MDS patients. The NK cell number in born marrow of MDS patients and the control group had no significant difference. The expression of IL-32 mRNA in bone marrow stromal cells significantly relates with the apoptosis of MDS cells, and the secretion of IL-32 by bone marrow stromal cells may be one of the reasons for the apoptosis of MDS bone marrow cells. It is speculated that the abnormal MDS bone marrow microenvironment is involved in the apoptosis of bone marrow cells.

Analysis of the karyotype abnormalities and its prognostic in 298 patients with myelodysplastic syndrome

目的探讨骨髓增生异常综合征（MDS）患者的细胞遗传学特点及其与MDS诊断分型、疾病进展和预后的关系。方法回顾性分析2008年6月至2013年10月浙江大学医学院附属第一医院收治的298例MDS患者的临床特征及预后情况，随访观察并进行相关性研究。结果难治性血细胞减少伴单系发育异常（RCUD）18例，难治性贫血伴环状铁粒幼红细胞（RARS）8例，难治性血细胞减少伴多系发育异常（RCMD）104例，难治性贫血伴原始细胞过多（RAEB）-1 76例，RAEB-2 85例，MDS不能分类5例，单纯del（5q）2例。染色体异常检出率39.6%，单纯数目异常45例，单纯结构异常31例，42例两种异常同时存在，均为不平衡易位及复杂异常。RAEB组（RAEB-1+RAEB-2）染色体异常检出率及复杂染色体异常检出率均高于非RAEB组（RARS+RCMD+RCUD）（47.2%对29.2%，P=0.002）。根据IPSS-R积分系统分组，除极低危组外，随着危险分层的递增，染色体异常检出率逐渐增加（P<0.05），且随着IPSS-R积分越高，转化为白血病的概率越高（P<0.01）。+8染色体异常占所有核型异常的19.5%，在RAEB组+8染色体异常组2年总生存率低于正常染色体组（43%对68%，P=0.005）。结论染色体核型分析是MDS患者判断预后的一个独立因素，对于MDS的诊断、治疗方案的制定及预后判断均有较大意义，+8染色体异常作为中等预后的染色体异常，在RAEB组预后差于正常染色体核型。

MRNA expression of notch ligand-delta-like-1 and jagged-1 in mesenchymal stem cells of MDS patients

This study was aimed to investigated the mRNA expression levels of Notch ligands- Delta-like-1 and Jagged-1 in bone marrow mesenchymal stem cells of patients with myelodysplastic syndrome (MDS), and to explore their relation with onset of MDS. Bone marrow mesenchymal stem cells of 38 patients with MDS and 16 normal subjects as control were collected to detect mRNA expression of Delta-like-1 and Jagged-1 by using real-time quantitative polymerase chain reaction. The results showed that the expression levels of Delta-like-1 and Jagged-1 in mesenchymal stem cells of MDS patients were significantly higher than that in normal controls (P < 0.05). According to WHO criteria, the mRNA expression of Delta-like-1 in RA/RAS, RCMD and RAEB groups were significantly higher than that in normal controls (P < 0.05), the mRNA expression of Jagged-1 in RAEB group was also significantly higher than that in normal controls (P < 0.05). The mRNA expression of Delta-like-1 was significantly correlated with the proportion of blasts in the bone marrow of MDS patients (r = 0.502, P < 0.05). The expression levels of Delta-like-1 and Jagged-1 in MDS patients with abnormal karyotypes were significantly higher than those in MDS patients with normal karyotypes (P < 0.05). The mRNA expression of Delta-like-1 in higher risk group according to International Prognostic Scoring System was significantly higher than that in lower risk group (P < 0.05), there was no significant difference in Jagged-1 expression levels between higher risk group and lower risk group (P > 0.05). It is concluded that the changes of Delta-like-1 and Jagged-1 expression level in MSC may play a role in the pathogenesis of myelodysplastic syndrome.

Development of a Multiplex Assay for Rapid Assessment of Gene Expression Profiling of Rho GTPases Family Genes In MDS Patients

AbstractAbstract 2907We have previously identified a panel of genes by gene expression profiling which differentially expressed between primary bone marrow CD34+ cell of MDS patients and the normal control cells. The expression pattern of these genes were also confirmed individually by qRT-PCR in expanded cohort of MDS patients. To further explore the feasibility of using proper number of these genes as biomarkers and evaluate the clinical significance in the diagnosis and prognostic prediction of MDS patients, a convenient, robust, sensitive, specific and less expensive method need to be developed. Therefore, endeavors have been made to establish a bead-based flow-cytometric multiplex assay.To establish this method, a technique called Multiplex ligation-dependent probe amplification (MLPA) was employed to amplify several targeted cDNAs by using single pair of identical primers. Each MLPA probe consists of two short synthetic oligonucleotide, and the tag which was coupled chemically to the fluorescent beads was complementary to one probe. Just as a pilot study to simultaneously detect the expression of four genes of the Rho GTPase family, five beads with different fluorescence intensity coupled to RAC2, RhoBTB3, SPA-1, Rap1GAP and GAPDH were designed. Biotinylated PCR amplicons were then hybridized to the complementary tag on each bead set. Bound amplicons were then detected by flow cytometry using a streptavidin-linked reporter dye, PE. 111 BM specimens were analyzed in total, consisting of RA(22), RAEB(22), RAEBt(9), AML(33), and control group (22, including hyperplastic anemia, iron deficiency anemia, aplastic anemia etc). The difference in the transcriptional level of RAC2, RhoBTB3, SPA-1 and Rap1GAP relative to GAPDH were analyzed using wilcoxon non-parametric test and SNK method among different groups. The results were confirmed by qRT-PCR.The bead-based flow-cytometric array had a excellent sensitivity and a wide linear range, could get a positive signal for PCR product from 0.0025 to 0.1umol, the fine specificity was proved by no cross-hybridization signals presented among different bead set, and the reproducibility were also good enough(P<0.001). the expression profiling of RAC2, RhoBTB3, SPA-1,Rap1GAP and GAPDH detected by this liquid bead-based flow-cytometric array were thus obtained. A significant difference among five groups for the expression level of RAC2, RhoBTB3, SPA-1 and Rap1GAP relative to GAPDH was found (P<0.0001, P=0.0491, P=0.0206 and P=0.0046 respectively). For RAC2, no difference existed between AML and control groups, while both these two groups demonstrated significant difference compared with RA, RAEB and REABt groups. The RA group had the highest expression level, AML the lowest; and RAEB in between. For RhoBTB3, a significant difference could be seen between RAEBt and other groups, RAEBt had the highest level of RhoBTB3. There was no difference in SPA-1 expression level determined between each two groups. However, an increasing tendency from control group to RA, RAEB, and REABt could be observed, whereas the expression of SPA-1 dramatically dropped to the lowest level in AML. For Rap1GAP, differences were found between AML and other group; These results were validated by qRT-PCR, and the data obtained by each method had close linear correlation, the Pearson correlation coefficient was 0.930, 0.946, 0.945 and 0.921 for RAC2, RhoBTB3, SPA-1 and Rap1GAP respectively (P<0.001 for all four).Based on these preliminary results, A liquid bead-based flow-cytometric multiplex assay for a rapid assessment of gene expression profile had been successfully developed and validated by qRT-PCR. This method will facilitates the clinical usage of a certain group of Rho GTPase family genes as well as other appropriate genes as useful biomarkers in the diagnosis of MDS patients and provide interesting clues to further explore the pathogenesis of MDS. Disclosures:No relevant conflicts of interest to declare.

Analysis the Expression of Rho Family GTPases and Its regulator's in Myelodysplastic Syndrome.

Abstract 2779Poster Board II-755The myelodysplastic syndrome (MDS) is a group of clonal hematological disorders characterized by some shared features of refractory cytopenia, dysplastic cellular morphology, and a propensity toward malignant transformation. The variable manifestations and clinical courses are reflected in evolving classification schemes based largely on the morphology of BM cells in aspirate smears and in biopsies. The diagnosis of MDS based on morphology of BM cells is somehow difficult due to the lack of “golden standard”. However, dysplasia is one of the most distinct features of MDS, which may be closely related to cytoskeleton. Rho family GTPases are important network which regulate cytoskeleton. Study on the expression of Rho family GTPases members including RAC1, RAC2, RhoH, RhoBTB3 and its regulator of SPA-1, Rap1GAP in MDS cells may help to explore the mechanism of MDS, and to provide possible biomarkers for differential diagnosis of MDS. To approach this issue, 111 BM specimens were collected and classified into five groups consisting of RA(22), RAEB(22), RAEBt(9), AML(33), and control group (22, including hyperplastic anemia , iron deficiency anemia, leukocytopenia and thrombocytopenia etc ). The mononuclear cells were isolated by Ficoll density gradient centrifugation, and the relative expression level of RAC1, RAC2, RhoH, RhoBTB3, SPA-1 and Rap1GAP compared with GAPDH were detected by quantitative real time reverse transcription PCR. Wilcoxon non-parametric test and SNK method were used to analyze the expression level of these genes among different groups. No difference could be found in expression of RAC1 and RhoH among five groups, while the expression of RAC2, Rap1GAP and SPA-1 showed significant difference among groups (P=0.0002, P<0.0001 and P=0.0182 respectively). For RAC2, The highest expression level was found in RA group and the lowest level in AML with RAEB in between. Significant difference were found between RA and control group, RA and AML, RAEB and AML, respectively. The expression of Rap1GAP differed between AML and MDS, and among the MDS groups, the expression level sequentially decreased from RA to REAB, RAEBt, control and AML. There were no difference in SPA-1 expression compared within each pair of groups However, an elevated tendency could be seen from control group to RA, RAEB, REABt, and the expression decreased dramatically to the lowest expression level in AML. For RhoBTB3, there were no difference among groups if the significant level was set at 0.05(P=0.0620), but when it was compared between two groups, a significant difference could be seen between RAEBt and others, and RAEBt had the highest expression level. The study on expression profile of Rho family GTPases in MDS had not been reported so far. Their effects on the cell morphology focused primly on some fibroblasts. The results of our present study suggested that the expression and function of Rho family GTPases, especially RAC2, Rap1GAP and RhoBTB3, may play important roles in the development and progression of MDS. Their altered expression pattern could provide valuable biomarkers to help the diagnosis and stratification of MDS and to understand its pathogenesis. Disclosures:No relevant conflicts of interest to declare.

Clinical significance of regulatory T cells in patients with myelodysplastic syndrome

Foxp3(+) regulatory T cells (Tregs) play a central role in maintaining immune tolerance. Their expansion in malignant diseases leads to the suppression of host anti-tumour responses. In this study, we evaluated the clinical significance of Tregs in patients with myelodysplastic syndrome (MDS). We analysed the number of CD4(+) CD25(+) Foxp3(+) Tregs using three-colour flow cytometry in the peripheral blood of 26 patients with MDS classified according to the World Health Organization classification method into four cases of refractory anaemia and refractory anaemia with ringed sideroblasts (RA/RARS), 15 cases of refractory cytopenia with multilineage dysplasia (RCMD), three cases of refractory anaemia with excess blast-1 (RAEB-1) and four cases of refractory anaemia with excess blast-2 (RAEB-2). Eighteen healthy volunteers were included as the control group. The mean absolute numbers of Tregs in the RA/RARS group (0.06 x 10(9)/L; 95% CI, 0.02-0.10 x 10(9)/L) and RAEB group (0.06 x 10(9)/L; 95% CI, 0.02-0.10 x 10(9)/L) were significantly higher than that of the control group (0.03 x 10(9)/L; 95% CI, 0.02-0.03 x 10(9)/L) (P < 0.05). However, in the RCMD group, there was no significant difference in the mean absolute number of Tregs (0.03 x 10(9)/L; 95% CI, 0.02-0.04 x 10(9)/L) compared with the control group. Regarding the mean level of the CD8/Foxp3 ratio, there were significant decreases in the RA/RARS group (2.8; 95% CI, 0.7-4.9; P < 0.01), RCMD group (3.4; 95% CI, 2.0-4.4; P < 0.001) and RAEB group (2.1; 95% CI, 1.7-2.5; P < 0.001) compared with the control group (6.1; 95% CI, 5.1-7.0). The expansion of natural CD4(+) Tregs may contribute to the suppression of CD8 through the Th1-mediated immune response in MDS. The low CD8/Foxp3 ratio is a characteristic feature in MDS. To determine whether the expansion of CD4(+) Tregs contributes to the progression of MDS subtypes into more aggressive subtypes, more MDS cases and further follow-up are required.

Gene Expression Profiles of CD34+ Cells in Myelodysplastic Syndrome

Myelodysplatic syndrome (MDS) represents a heterogeneous group of clonal disorders with ineffective hematopoiesis that is characterized by dysplasia and peripheral cytopenia of one or more cell lineages. We studied gene expression profiles in CD34+ cells of 42 MDS patients and 6 healthy controls using Illumina cDNA microarray technology. Nine patients had RA, 7 patients had RCMD, 17 patients had RAEB and 9 had RAEB-T. CD34+ cells were isolated from bone marrow samples using MACS magnetic columns. The quality of total extracted RNA was confirmed with the Agilent Bioanalyzer 2100. 200ng of total RNA was amplified using Illumina RNA amplification kit. cRNA targets were hybridized on the Sentrix HumanRef-8 BeadChips (> 24 000 probes), which were scanned on the Illumina BeadStation 500. The data were pre-processed and normalized by lumi R package designed to preprocess the Illumina microarray data. Normalized data were filtered by detection p-value <0.01, resulting in total number of 10 091 genes. This gene set was tested for differential expression between clinical groups and control group. For this purpose, statistical testing by ANOVA with correction for multiple testing problem by Bayesian thresholding was performed. Additionally, analysis by random-forests (RAFT) was performed. Significant genes from both analyses were merged resulting in 332 differentially expressed genes detected. Out of these, 79 genes showed ≥2.5 fold changes in gene expression between controls and all MDS groups (22 up-regulated and 57 down-regulated). Our findings were confirmed by real-time quantitative PCR for several genes (TaqMan Gene Expression Assays). We used DAVID database to annotate 79 selected genes: 8 of 22 up-regulated genes in MDS patients were recognized to play a role in regulation of transcription (LEO1, E2F6 and several zing finger proteins). A half of these over-expressed genes could not be annotated due to still unknown biological function. Within the set of the down-regulated genes in MDS patients those biological processes were predominantly detected: cell differentiation (KLF4, FOSL2, STK17B, BCL3, SNF1LK, ID2 etc.), response to stress (CXCL12, SMAD7, CYGB, etc.) and cell proliferation (MXD1, OSM, FTH1, KLF10 etc.). In the set of 31 genes with 5 fold decreased expression, we identified 8 genes involved in B-cell development. (VPREB1, VPREB3, CD79A, EBI2, LEF1, CXCL12, CTGF, GALNAC4S-6ST). RAFT analysis was performed also in the set of 332 statistically differentially expressed genes in order to evaluate accuracy of grouping the patients according their diagnosis. We detected strong heterogeneity in gene expression patterns within the MDS patients, especially in the RAEB group reflecting clinical diversity of MDS. Clustering analysis (Spearman correlation) showed that most of the RAEB-2 patients (7 out of 9) were clustered together with REAB-T whereas RAEB-1 clustered with RCMD or RA. These results underline the need of distinguishing RAEB-1 and RAEB-2 diagnosis according to WHO classification system, since their expression profiles are significantly different.

Angiogenesis in relation to clinical stage, apoptosis and prognostic score in myelodysplastic syndromes

The International Prognostic Scoring System (IPSS), based on the number of cytopenias, percentage of bone marrow blasts and cytogenetics, is an important prognostic tool for patients with myelodysplastic syndrome (MDS). In addition, factors such as high bone marrow cellularity and lactate dehydrogenase levels have been associated with an adverse outcome, spontaneously and after chemotherapy. Recently, increased bone marrow angiogenesis, measured as, e.g. microvascular density (MVD), was reported to be more intense in high-risk than in low-risk MDS. To assess the prognostic role of MVD in MDS, a cohort of 56 patients, thoroughly investigated for various clinical and morphological parameters, were followed-up for survival ≥60 months after the diagnostic analysis. As a group MDS patients had higher MVD compared to healthy controls (p<0.02). The highest median MVD value was observed in the RAEB group, but there was no overall significant difference between the FAB groups. No significant correlations were observed between MVD and peripheral blood counts, bone marrow cellularity, percentage of bone marrow blasts and CD34 positive cells, apoptotic index (TUNEL), proliferation index (MIB-1), erythroid index, FAB group and IPSS score. MVD was not correlated to overall survival. In contrast, bone marrow blast count <5%, low or normal cellularity, as well as a high erythroid index, indicated a favorable survival. Thus, our data do not support an important prognostic role of angiogenesis, reflected by microvessel density, in the myelodysplastic syndromes.

Refractory anemia with severe dysplasia: clinical significance of morphological features in refractory anemia.

Refractory anemia (RA) in myelodysplastic syndromes (MDS) are very heterogeneous diseases regarding their morphology, clinical features and survival. We proposed the new designations 'RA with severe dysplasia (RASD)' and 'RA with minimal dysplasia (RAminiD)'. In our criteria, RASD is considered present if a bone marrow (BM) examination shows Pseudo-Pelger-Huet anomalies of mature neutrophils > or =3% and/or micromegakaryocytes (mMgk) of megakaryocytes > or =10% in RA patients. RAminiD is defined as RA cases other than RASD. After the reclassification of 58 primary RA patients, the group was composed of 45 RAminiD and 13 RASD patients. The blast percentage in the BM and the frequency of cytogenetic abnormalities observed in the RASD patients were intermediate between those in the RAminiD and RAEB patients. The analysis of survival curves revealed differences among the three groups; the RASD patients had lower survival probabilities than those of the RAminiD group, and significantly higher probabilities than those of the RAEB group. (RAminiD vs RASD, P=0.06; RASD vs RAEB, P=0.004.) Our data indicate that in RA patients, RASD is a distinct subset of RA with an unfavorable clinical outcome.