CD 34 Immunotyping of blasts in myelodysplasia

Summary We studied the expression of the hematopoietic progenitor cell antigen CD 34 in six patients with refractory anemia with excess of blasts (RAEB), five patients with RAEB in transformation (RAEB-T), and seven patients with chronic myelomonocytic leukemia (CMML). Immunocytochemical labeling of bone marrow cells was performed by an indirect immunoperoxidase method with preservation of morphological details. The cells were stained with May-Grünwald-Giemsa, photographed, destained, and immunolabeled by the immunoperoxidase technique. We found 1.5±0.5% blasts and 0.8±0.4% CD 34⁺ blasts in normal bone marrow. The CD 34 positivity of blasts was 53±9%. The patients with RAEB showed 1.7±1.4% CD 34⁺ blasts. The CD 34 positivity of blasts (11.8±5.6%) was lower than in normal bone marrow. The patients with RAEB-T had a higher percentage of CD 34⁺ blasts (7.33.4) and a higher CD 34 positivity of blasts (28.2±14.6%) than patients with RAEB. The CMML patients showed a percentage of CD 34⁺ blasts and a CD 34 positivity of blasts in the range of RAEB. We found an increase of promonocytes (PMC) in 5/7 patients. In some patients the PMC were CD 34 positive. Our results indicate that the increase of blasts in REAB is related to CD 34-negative blasts. With progression to RAEB-T the percentage of CD 34-positive blasts increased. Some of the CMML patients also showed a population of CD 34-positive PMC. A clone of undifferentiated CD 34-positive cells is characteristic for patients with these types of myelodysplasia.This work was presented at the Annual Congress of the German and the Austrian Society of Hematology and Oncology, Essen, 10–13 October 1993     

Prognostic relevance of serum thymidine kinase in primary myelodysplastic syndromes: relationship to development of acute myeloid leukaemia

The aim of this study was to evaluate the possible prognostic relevance of thymidine kinase serum levels (s-TK), an indirect marker of proliferative activity, in myelodysplastic syndromes (MDS). S-TK levels were monitored by means of a radioenzyme assay in 90 patients affected by MDS (22 refractory anaemia, RA; 17 RA with ring sideroblasts, RARS; 21 RA with blast excess, RAEB; 15 RAEB in transformation, RAEB-T; 15 chronic myelomono-cytic leukaemia, CMMoL). Mean s-TK levels (U//tl) measured at diagnosis were 11–9 –12–6 for RA, 11–4–13'6 for RARS, 19–9 – 28–4 for RAEB, 39–6 – 34–3 for RAEB-T and 77–7 – 69–7 for CMMoL (normal values <5U//LI1). With the only exception of a weak relationship with lactate dehydrogenase, no correlation was found between initial s-TK values and other clinical or laboratory parameters, such as age, haemoglobin, white blood cell or platelet count, percentage of bone marrow blasts. MDS patients with s-TK >38 V/fA , a cut-off level selected by means of ROC statistical analysis, showed a significantly shorter survival than those with s-TK <38U//xl (8–2 v 37–4 months, respectively; P < 0–0001). In particular, transformation in acute myeloid leukaemia (AML) occurred in 17/21 (81%) of patients with s-TK >38U//d and 9/69 (13%) of those with lower levels at diagnosis (P < 00001), independently of FAB subtype. High s-TK levels were also useful to predict evolution in AML during the course of the disease in patients with normal initial values. Multivariate analysis confirmed the independent prognostic value of s-TK on both overall survival and risk of acute transformation. We conclude that s-TK may be an important prognostic factor in MDS, strongly correlated with development of AML.     

Evaluation of apoptosis as a prognostic factor in myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a group of disorders characterized by peripheral pancytopenia despite normo- or hypercellular bone marrow. This is thought to be as a result of the apoptosis of haematopoietic bone marrow cells resulting in ineffective haematopoiesis. To clarify the relationship between prognosis and apoptosis and/or cell proliferation in the bone marrow, we studied 51 cases with MDS. Bone marrow biopsies were stained immunohistochemically for MIB-1 (marker for proliferating cells) and CD34 (marker for stem cells). Apoptosis was visualized by detection of DNA fragmentation using TdT incorporation of nucleotides on 3' ends of DNA (TUNEL technique) and expressed as the apoptotic rate. MDS patients included 32 with refractory anaemia (RA), one RA with ringed sideroblasts (RARS) patient, seven RA with excess of blasts (RAEB) patients, eight patients with RAEB in transformation (RAEB-t) and three patients with chronic myelomonocytic leukaemia (CMMoL). In addition, we also studied six cases with acute myeloid leukaemia (AML) arising from MDS (AML-MDS) and ten control subjects. Fatal pancytopenia was the cause of death in 19 out of 51 patients. The apoptotic rate was higher in MDS patients (5.5%) than in control subjects (0.6%) and AML-MDS patients (0.4%). The percentage of MIB-1 positive cells was higher in MDS and AML-MDS than in control. The percentage of CD34-positive cells was higher in AML-MDS, RAEB, RAEB-t and CMMoL patients than control subjects and RA patients. Our findings indicate the activation of both the proliferative and apoptotic rates in MDS. Poor prognosis correlated significantly with higher apoptotic rates, but not with percentages of MIB-1 and CD34-positive cells. Our results suggest that apoptosis might be a useful prognostic factor and inhibition of apoptotic mechanisms may induce leukaemic transformation in MDS.     

Bmi-1 is useful as a novel molecular marker for predicting progression of myelodysplastic syndrome and patient prognosis

The International Prognostic Scoring System (IPSS) has been widely used to predict the prognosis of patients with myelodysplastic syndrome (MDS). However, IPSS does not always provide a sufficiently precise evaluation of patients to allow the appropriate choice of clinical interventions. Here, we analyzed the expression of Bmi-1, which is required to regulate the self-renewal in CD34+ cells from 51 patients with cases of MDS and acute myeloid leukemia preceded by MDS (MDS-AML). Higher positivity rate of Bmi-1 was preferentially seen in refractory anemia with excess blasts (RAEB), RAEB in transformation (RAEB-T), and MDS-AML compared with refractory anemia (RA) and RA with ringed sideroblasts (RARS). IPSS score was positively correlated with the percentage of Bmi-1 expression. Patients with RA and RARS with a higher percentage of Bmi-1+ cells showed disease progression to RAEB. Here, we propose Bmi-1 as a novel molecular marker to predict the progression and prognosis of MDS.     

Clinical significance of phenotypic features of blasts in patients with myelodysplastic syndrome

Knowledge of the blast phenotype in myelodysplastic syndrome (MDS) would be valuable, as in other malignancies, but remains sparse. This is mainly because MDS blasts are a minor population in clinical samples, making analysis difficult. Thus, for this blast phenotype study, we prepared blast-rich specimens (using a new density centrifugation reagent for harvesting blasts) from blood and marrow samples of 95 patients with various MDS subtypes and 21 patients with acute leukemia transformed from MDS (AL-MDS). Flow cytometry revealed that a high proportion of the enriched blast cells (EBCs) from almost all patients showed an immunophenotype of committed myeloid precursors (CD34(+)CD38(+)HLA-DR(+)CD13(+)CD33(+)), regardless of the disease subtype. The cytochemical reaction for myeloperoxidase was negative in 58% of the cases. Thus, the EBC phenotype is more immature in MDS than in de novo acute myeloid leukemia. MDS EBCs often coexpressed stem cell antigens and late-stage myeloid antigens asynchronously, but rarely expressed T- and B-lymphoid cell-specific antigens. Markers for myeloid cell maturation (CD10 and CD15) were more prevalent on EBCs from low-risk MDS (refractory anemia [RA] and RA with ringed sideroblasts), whereas markers for myeloid cell immaturity (CD7 and CD117) were more prevalent on EBCs from high-risk MDS (chronic myelomonocytic leukemia, RA with excess blasts [RAEB], and RAEB in transformation) and AL-MDS. A shift to a more immature phenotype of EBCs, accompanying disease progression, was also documented by sequential phenotyping of the same patients. Further, CD7 positivity of EBCs was an independent variable for a poor prognosis in MDS. These data represent new, valuable information regarding MDS.     

Immunotyping of blasts in human bone marrow

 The diagnostic potential of immunocytochemical investigation of human bone marrow has not been fully realized due to difficulties in morphological identifying of immunostained cells. We used an indirect immunoperoxidase technique after May-Grünwald-Giemsa staining for simultaneous morphological and immunocytochemical analysis of blasts in human bone marrow. Six healthy bone marrow donors were investigated. Most blasts I expressed CD34 ,CD38 and HLA-DR. Expression of c-kit (CD117) was observed on 42±9% of blasts I. Granulocytomonocytopoietic character was demonstrated by expression of CD13 (33±15%) and CD45RA (23±10%) and erythropoietic character was demonstrated by expression of CD36 (22±8%) and CD45RO (30±11%). A very low proportion of blasts I were Thy-1 and CD61 positive; 34±6% of blasts I expressed CD22, representing B lymphoid committed progenitors. CD3, CD15, and glycophorin A expression was not detected. Blasts II and III and proerythroblasts did not show CD34 positivity. We conclude that blasts I are morphologically identifiable cells with a high percentage of CD34, CD38, and HLA-DR positivity. They are a pool of committed progenitor cells for erythropoiesis, granulocytomonocytopoiesis, megakaryocytopoiesis, and B cell development. Blast II and proerythroblast represent the first morphologically identifiable cells of granulocytopoiesis and erythropoiesis. Received: 14 September 1995 / Accepted: 29 September 1995     

Allogeneic bone marrow transplantation for secondary leukemia or myelodysplasia

BACKGROUND AND OBJECTIVE: Marrow transplantation results in disease-free survival for less than one-third of patients treated for secondary leukemia. The objective of this report is to review results following allogeneic marrow transplantation for treatment of secondary leukemia or myelodysplasia at a single tertiary referral center to determine the patient characteristics which lead to better survival and lower relapse. DESIGN AND METHODS: The medical records of 99 patients with secondary leukemia or myelodysplasia transplanted consecutively at the Fred Hutchinson Cancer Research Center between 1971 and 1997 were reviewed. Prior to development of secondary leukemia or myelodysplasia, the patients' original diagnoses were hematopoietic malignancies, solid tumors, aplastic anemia, or miscellaneous individual disorders previously treated by chemotherapy alone, radiation alone, chemoradiotherapy, or immunosuppressive therapy. At the time of transplantation, at each stage of myelodysplasia the numbers of patients were 52 with acute myelogenous leukemia (AML), 15 with refractory anemia with excess blasts in transition (RAEB-T), 18 with refractory anemia with excess blasts (RAEB), 11 with refractory anemia (RA), 1 with refractory anemia with ringed sideroblasts (RARS), and 2 with hypoplastic unclassifiable hematologic disorders. Sixty-five patients received marrow from an HLA identical or partially identical family member, and 34 received marrow from an HLA identical unrelated donor after conditioning with chemotherapy and total body irradiation or chemotherapy alone. RESULTS: The Kaplan-Meier probability of survival after transplantation for all patients was 13%, and by stage of disease was 33% for RA/RARS, 20% for RAEB, and 8% for RAEB-T/AML. The probability of relapse for all patients was 47%, was 34% for RAEB, and 58% for RAEB-T/AML. None of the patients with RA/RARS has relapsed. The overall probability of non-relapse mortality was 78%, divided equally among infection or organ failure-related causes of death. INTERPRETATION AND CONCLUSIONS: The main impediments to long-term survival after transplantation for secondary leukemia or myelodysplasia are relapse and mortality from infections or organ failure. The survival is better when transplantation is done during the early stages of myelodysplasia because it is then associated with a lower relapse rate. These data suggest that patients at risk of secondary myelodysplasia should be followed prospectively to detect the early stages of myelodysplasia, and be considered for transplantation at that time.     

Chronic myelodysplastic syndrome: short survival with or without evolution to acute leukaemia

The myelodysplastic syndromes represent a prognostically diverse group of disorders. Their study has recently been facilitated by the classification proposed by the French-American-British (FAB) Cooperative Group. Using this scheme it is now possible to define more precisely their natural history and clinical relationship to acute leukaemia. Using the longitudinal case control technique, we reviewed the clinical data and morphology of 69 patients (all elderly males) with chronic irreversible haematological cytopenia and dysplasia. Applying FAB criteria we found: refractory anaemia (RA) in 43%; sideroblastic anaemia (RA-S) in 33%; refractory anaemia with excess blasts (RAEB) in 13%; RAEB in transformation (RAEB-T) in 9% and chronic myelomonocytic leukaemia (CMML) in 1%. The median survival for the entire group was 27 months (RA, 52; RA-S, 29; RAEB, 12; RAEB-T 11; and CMML, 2 months). Short survival was predicted by transfusion requirement and other manifestations of severe cytopenia, as well as by myeloid immaturity. The presence or absence of sideroblastosis did not correlate with survival. Acute leukaemia developed in only eight patients (12%), six of whom initially had RA. Leukaemic transformation was not predicted by progressive cytological immaturity. This study demonstrates that even in the absence of leukaemic transformation, chronic myelodysplasia is a lethal haematological disorder.     

Expression of EVI1 in myelodysplastic syndromes and other hematologic malignancies without 3q26 translocations

The EVI1 gene encodes a zinc-finger, DNA-binding protein originally described as the transforming gene associated with a common ecotropic viral insertion site in myeloid leukemias. Previous studies demonstrated EVI1 expression in human leukemias in cases with 3q26 translocations, but not in normal blood or bone marrow. These studies also suggested an association between EVI1 expression and chromosome 7 deletion (del). Because of this association, we examined expression of EVI1 using RNA polymerase chain reaction (PCR) in patients with myelodysplastic syndromes (MDS) and acute leukemia with and without 3q26 translocations. EVI1 RNA was expressed in 29% of 34 (95% confidence interval, 20% to 50%) patients with the MDS subtypes refractory anemia (RA), refractory anemia with excess blasts (RAEB), or refractory anemia with excess blasts in transformation (RAEB-T). The vast majority of these cases occurred in patients with RAEB and RAEB-T. EVI1 expression was not detected in patients with chronic myelomonocytic leukemia (CMML), normal bone marrow or cord blood, or a variety of other hematologic malignancies. EVI1 RNA was detected in three of 18 patients with acute myelogenous leukemia (AML) and in two of four patients with acute promyelocytic leukemia (APL). Karyotypes showed that only one AML patient had karyotype 3q26 abnormalities, indicating that EVI1 expression is associated with cases that do not have structural abnormalities involving chromosome 3q26. These studies document for the first time the abnormal expression of EVI1 RNA by patients with MDS, and suggest an important role for EVI1 in the pathogenesis or progression of some myeloid malignancies.     

Expression of Fas antigen in acute myeloid leukaemia is associated with therapeutic response to chemotherapy

Flow cytometric immunofluorescent analysis was used to assess Fas antigen (CD95) expression in blasts obtained from the bone marrow of 30 patients with acute myeloid leukaemia. The percentage of positive cells in each sample was highly variable. Fas antigen expression did not correlate with age, FAB subtype, white blood cell counts, or CD34 expression. Low expression of Fas was associated with a low complete remission rate after induction chemotherapy (62.5% in cases with <20% positive cells v 92.9% in cases with ≥ 20% positive cells, P <0.01). The main cause for not achieving remission was resistant disease. Our results suggest that the quantitation of Fas expression can be predictive of treatment outcome in acute myeloid leukaemia.     

Granulocytic sarcoma presenting as a right atrial mass

We describe a 48-year-old male who developed acute myelogenous leukaemia (AML) associated with a right atrial mass. The patient was admitted with fatigue, positional dyspnoea and headache. Transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE) revealed that the right atrium was filled with a mass. Peripheral blood smear revealed 85% blasts, and bone marrow examination showed 74% myeloid blasts and 27% monocytoid cells (monoblast and promonocytes). Immunophenotypic analysis of the bone marrow aspirates showed CD13, CD14 and CD33 positivity, consistent with acute myeloid leukaemia of M4 Fab subtype.The patient achieved remission (but not cure) accompanied by near resolution of the right atrial mass following intensive chemotherapy.     

Treatment of myelodysplastic syndromes with all-trans retinoic acid. Leukemia Study Group of the Ministry of Health and Welfare

We treated 23 patients with myelodysplastic syndromes (MDS); 2 refractory anemia (RA) with prior therapy, 11 RA with excess of blasts (RAEB), and 10 RAEB in transformation (RAEB-T), with daily oral 45 mg/m2 all-trans retinoic acid (ATRA) in a multiinstitutional prospective study. In two patients with RAEB and one with RAEB-T, a more than 1,000/microL increase of peripheral neutrophil counts was observed with some reduction of blast percentage in the bone marrow 2 to 9 weeks after the start of ATRA. However, the effect was transient and did not last for more than 5 weeks despite the continuation of ATRA therapy. In one other patient with RA, one patient with RAEB, and one patient with RAEB-T, slight increase of hemoglobin levels or reduction of blast percentage in bone marrow was noted. Toxicities attributable to ATRA were minimal and included cheilitis, xerosis, dermatitis, gastrointestinal disorders, abnormal liver function tests, and high serum triglyceridemia. Although ATRA works remarkably as a differentiation therapy in acute promyelocytic leukemia, its effect in MDS included in this study was modest. Further study of this agent alone or in combination may be warranted in less advanced stages of this disease.     

Patients with high-risk myelodysplastic syndrome can have polyclonal or clonal haemopoiesis in complete haematological remission

The clonality of mature peripheral blood-derived myeloid and lymphoid cells and bone marrow haemopoietic progenitors from 18 females with myelodysplasia (MDS) (five refractory anaemia, RA; one RA with ringed sideroblasts, RARS; three chronic myelomonocytic leukaemia, CMML; four RA with excess of blasts, RAEB; five RAEB in transformation, RAEB-t) was studied by X-chromosome inactivation analysis. Using the human androgen-receptor (HUMARA) assay, we analysed the clonal patterns of highly purified immature CD34⁺38^? and committed CD34⁺38⁺ marrow-derived progenitors, and CD16⁺14^? granulocytes, CD14⁺ monocytes, CD3⁺ T and CD19⁺ B lymphocytes from peripheral blood. In high-risk patients (RAEB, RAEB-t), clonality analysis was performed before and after intensive remission-induction treatment. All patients, except one with RA, had predominance of a single clone in their granulocytes and monocytes. The same clonal pattern was found in CD34⁺ progenitor cells. In contrast, CD3⁺ T lymphocytes were polyclonal or oligoclonal in 14/18 patients. X-chromosome inactivation patterns of CD19⁺B cells were highly concordant with CD3⁺ T cells except for two patients (one RA, one CMML) with monoclonal B and polyclonal T lymphocytes, therefore suggesting a clonal mutation in a progenitor common to the myeloid and B-lymphoid lineages or the coexistence of MDS and a B-cell disorder in these particular patients. After high-dose non-myeloablative chemotherapy, polyclonal haemopoiesis was reinstalled in the mature myeloid cells and immature and committed marrow progenitors in three of four patients achieving complete haematological remission. Therefore we conclude that most haematological remissions in MDS are associated with restoration of polyclonal haemopoiesis.     

骨髓增生异常综合征免疫表型分析

目的：探讨免疫表型测定在骨髓增生异常综合征（MDS）诊断及分型中的价值。方法：采用一组系列相关单克隆抗体和流式细胞术对19例MDS患者免疫表型进行检测，并对其中的10例进行了细胞遗传学检查。结果：MDS患者骨髓单个核细胞（MNC）CD13，CD33抗原表达率平均分别为36．69％和41．86％，而T淋巴系抗原CD3的表达平均仅为14．49％，且随着低危的难治性贫血（RA）向高危的难治笥贫血伴原始细胞增多（RAEB）或难治性贫血伴原始细胞增多－转变型（RAEB-t)的进展，较早期的髓系抗原CD13，CD33及干（祖）细胞抗原CD34的表达升高，并伴有T淋巴系抗原CD3的表达降低。10例进行了细胞遗传学检查的患者中，5例有染色体核型异常，染色体核型异常的患者与染色体核型正常的患者在抗原表达上存在区别。结论：对MDS患者进行免疫表型检查有助于MDS的诊断分型研究。     

Non-specific esterase positive neutrophils in a case of refractory anemia with excess of blasts

A 61-year-old woman was admitted with complaint of fever. The peripheral blood showed pancytopenia and bone marrow aspirate showed dysplasia in trilineage blood cells with increased blasts (18.2%). Bone marrow chromosome study revealed a karyotype of 46XX, -6, 3q-, +mar in 19 cells of 20 analyzed. She was diagnosed as refractory anemia with excess of blasts (RAEB). 95% of neutrophils in the bone marrow and 84% of that in the peripheral blood were stained with non-specific esterase using alpha-naphthyl acetate as substrate. On the other hand, the positivity of neutrophils for peroxidase. Sudan black B or chloroacetate esterase was markedly decreased. The phagocytotic activity of neutrophils was increased in comparison with normal control cells. Surface marker analysis of peripheral blood myeloid cells revealed increased expression of monocyte specific markers. These findings suggested that the patient's neutrophils, which were surely neutrophils in morphology, shared also monocyte-specific characters. After treatment with low dose Ara-C, pancytopenia was recovered and blasts in the bone marrow were reduced. Also was decreased non-specific esterase positive neutrophils, indicating that the neutrophils were derived from abnormal myeloid clone.     

Activity of the caspase-3/CPP32 enzyme is increased in "early stage" myelodysplastic syndromes with excessive apoptosis, but caspase inhibition does not enhance colony formation in vitro

OBJECTIVE: Excessive apoptosis may have a role in the ineffective hematopoiesis and cytopenias observed in myelodysplastic syndromes. The goals of this study were 1) to quantify apoptosis in patients with "early stage" myelodysplasia [including patients with refractory anemia (RA), RA with ringed sideroblasts (RARS), RA with excess blasts and with less than 10% blasts (RAEB(<10))], and in patients with "late stage" myelodysplasia [including RAEB with more than 10% blasts (RAEB(>10)), RAEB in transformation (RAEB-t), and acute myeloid leukemia secondary to myelodysplasia (LAM2)]; 2) to study the activation of the caspase-3/CPP32 enzyme, a major "effector" caspase in hematopoiesis, in patients with "early stage" myelodysplasia, and 3) to evaluate the effect of caspase inhibition on the apoptotic phenotype and clonogenicity of hematopoietic progenitors in vitro in these patients. MATERIALS AND METHODS: Patients: Fifty-four patients with myelodysplastic syndromes, including 30 with "early stage" myelodysplasia and 24 with "late stage" myelodysplasia were studied. Study of apoptosis: TUNEL assay performed on bone marrow smears and/or quantification of annexin V positive bone marrow mononuclear cells by flow cytometric analysis. Caspacse-3/CPP32 activity: Quantitative measurement of caspase-3/CPP32 activity on total bone marrow mononuclear cells using a fluorogenic substrate. Effect of the caspase-inhibitor Z-VAD-FMK: 1) on the apoptotic phenotype of total bone marrow mononuclear cells and 2) on the clonogenicity of hematopoietic progenitor cells. RESULTS: The group of 30 patients with "early stage" myelodysplasia had statistically increased apoptosis compared to the group of 24 patients with "late stage" myelodysplasia (44.1% +/- 4.8 vs 21.8% +/- 3.6; p = 0.02) using the TDT-mediated dUTP nick-end labeling (TUNEL) assay. In the group of patients with RAEB, those with MDS(RAEB<10) had excessive apoptosis compared to those with MDS(RAEB>10) (44.0% +/- 3.5% vs 29.5% +/- 3.6%;p = 0.042) The median caspase-3 activity in 20 "early stage" myelodysplasia patients was 19,000 U (range 3,460-41,000) and significantly increased compared to normal individuals (4,256 U, range 3,200-5,200; p = 0.032) Bone marrow mononuclear cells from 12 "early stage" MDS patients (including 11 from the 20 studied for caspase-3 activity) were incubated with or without the broad-spectrum caspase inhibitor Z-VAD-FMK. In 4 of 9 evaluable patients (44.4%) with excessive apoptosis, the number of annexin V positive cells decreased in a dose-dependent manner in the presence of Z-VAD-FMK. However, in none of these patients was caspase inhibition with Z-VAD-FMK able to enhance colony formation in vitro. CONCLUSION: These results confirm that a major characteristic of patients with "early stage" myelodysplasia is increased apoptosis. The results also indicate that excessive apoptosis in these patients is accompanied by increased caspase-3/CPP32 activity. However, caspase inhibition with the broad-spectrum inhibitor Z-VAD-FMK cannot improve hematopoiesis in this group of patients, even when apoptosis is attenuated.     

Advances in the prognostication and management of advanced MDS in children

Advanced myelodysplastic syndrome (MDS) in children includes refractory anaemia with excess blasts (RAEB) and RAEB in transformation (RAEB-T) according to the paediatric modification of the World Health Organization classification. Clinical features and cytogenetics are essential to make a diagnosis because blast count alone is insufficient to differentiate MDS from acute myeloid leukaemia (AML). Little is known about molecular genetics in paediatric MDS but hypermethylation seem to be frequent. Monosomy 7 is the most common cytogenetic aberration but prognostic neutral whereas those with structural complex karyotype have a very poor outcome. Haematopoietic stem cell transplantation (HSCT) is the treatment of choice and results in cure rates of around 60%. Intensive chemotherapy prior to HSCT provides no survival benefit for children with RAEB and RAEB-T and can generally not be recommended. Intensive chemotherapy before HSCT should be considered in patients with myelodysplasia-related-AML (MDR-AML).     

Prognostic factors in adult de novo myelodysplastic syndromes treated by intensive chemotherapy

We treated 47 adult patients with de novo myelodysplastic syndrome (MDS) by an anthracycline-AraC regimen. Median age was 54, and M/F 1.3. At diagnosis, 26 patients had refractory anaemia with an excess of blasts in transformation (RAEB-T) three had refractory anaemia (RA), 11 had refractory anaemia with excessive blasts (RAEB) and seven had chronic myelomonocytic leukaemia (CMML). Treatment was started within 3 months of diagnosis in 30 patients, and after more than 3 months in the 17 remaining patients. At the onset of treatment, 16 patients had progressed to acute myeloid leukaemia (AML). Twenty-two patients (47%) reached complete remission (CR), 10 (21%) had hypoplastic death and 15 (32%) had resistant disease. Median actuarial disease-free interval was 11 months. Median actuarial survival was 14 months from diagnosis and 10 months from the onset of treatment. A significantly higher CR rate was found in patients with RAEB-T at diagnosis (69% v 19% in patients with other FAB subtypes: P = 0.008), and in patients treated within 3 months of diagnosis. Using multivariate analysis, RAEB-T at diagnosis emerged as the most powerful prognostic factor of CR achievement. Karyotype was the only significant prognostic factor of disease-free interval, with a median of 16.5 months in patients with normal karyotype versus 4 months in patients with normal findings (P = 0.018). A subgroup of 15 patients with RAEB-T at diagnosis and normal karyotype, who had a CR rate of 80% and a median actuarial disease-free interval of 18 months, could be identified. Our results confirm that, overall, intensive chemotherapy has limited efficacy in MDS, especially when compared with allogeneic bone marrow transplantation (BMT). Relatively favourable results were obtained in our patients with RAEB-T at diagnosis, however, particularly those with normal karyotype. In that subgroup, intensive chemotherapy may be recommended, especially before BMT, as a high risk of relapse after BMT in patients with RAEB-T allografted as first line therapy has been reported.     

Prognostic implications of morphology and karyotype in primary myelodysplastic syndromes

Forty-nine patients with primary myelodysplastic syndromes (MDS) were subclassified according to French-American-British (FAB) Cooperative Group criteria. Eight patients had acquired idiopathic sideroblastic anemia (AISA), ten had chronic myelomonocytic leukemia (CMMoL), 14 had refractory anemia (RA), nine had refractory anemia with excess blasts (RAEB), and five had refractory anemia with excess blasts in transformation (RAEB-T); three patients could not be subclassified. The actuarial median survival for patients with AISA or with RA had not been reached at 60 months of follow-up. The median survival times for patients with CMMoL, RAEB, and RAEB-T were 25, 21, and 16 months, respectively. The percentages of patients with each subtype who developed ANLL were none in AISA, 20% in CMMoL, 7% in RA, 56% in RAEB, and 40% in RAEB-T. Patients with CMMoL had a poor prognosis independent of transformation to acute nonlymphocytic leukemia (ANLL), whereas patients with RAEB and RAEB-T had a high incidence of transformation and short survival times. Clonal chromosomal abnormalities were present in bone marrow cells from 19 patients at the time of diagnosis, and two others developed an abnormal karyotype at the time of leukemic transformation. The most frequent abnormalities, including initial and evolutionary changes, were trisomy 8 (9 patients), deletion of 5q (4 patients), and deletion of 20q (4 patients). The median survival times were 32 months for patients with an abnormal karyotype, and 48 months for those with a normal karyotype (P = 0.2). Specific chromosomal abnormalities were not associated with particular histologic subtypes; however, a high percentage of patients with RAEB and RAEB-T had an abnormal clone (89% and 80%, respectively). The percentages of patients with clonal abnormalities were 13% for AISA, 20% for CMMoL, and 29% for RA. The MDS transformed to ANLL in 42% of patients with an abnormal karyotype, compared to 10% of those with an initially normal karyotype (P less than .01). Among patients with RA, RAEB, and RAEB-T, the risk of leukemic transformation was confined to those with an abnormal karyotype (P less than .01). Thus, in the present study, morphology and karyotype combined were the best indicators of outcome in patients with MDS.