[Lenalidomid (Revlimid) in the treatment of multiple myeloma--first experience in the Czech Republic]. / Lenalidomid (Revlimid) v lécbe mnohocetného myelomu-- první zkusenosti v Ceské republice.

The prognosis of multiple myeloma (MM) has substantially improved during last decades due to new, so-called targeted drugs--proteasome inhibitor bortezomib and immunomodulatory drugs (ImiDs), thalidomide and lenalidomide. They could be used in various combinations and/or sequentially thanks to different mechanism of action and toxicity. Both bortezomib and thalidomide are widely used in Czech republic, however, lenalidomide was approved for the treatment of MM (and MDS) at the very latest and its usage is limited due to high costs, as well. According to the results of clinical trials lenalidomide is effective in myeloma refractory to various therapy including other new drugs. First time in the Czech republic the combination of lenalidomide and dexamethasone was given in our center to 2 patients with relapsed myeloma as 7th and 10th line of therapy. Acceptable results of treatment with improved clinical status in the first patient enabled to suspend his therapeutic plasmaferesis. Disease stabilization lasting three months was observed also in the second patient.

[Auto- and alloreactivity of T lymphocytes in myelodysplastic syndrome]. / Auto- a aloreaktivita T lymfocytu u myelodysplastického syndromu.

BACKGROUND: Successful therapy with ATG and cyclosporine A in some myelodysplastic syndrome (MDS) patients led us to study the existence of T cells attacking autologous hemopoietic cells. In our study, we attempted to give the direct prove of autoreactive T cells in MDS (autoreactivity analysis). Simultaneously, we analysed the capacity of MDS patients to respond to allogeneic cells from unrelated individuals (alloreactivity analysis). METHODS AND RESULTS: Autoreactive lymphocytes directed against own bone marrow mononuclear cells were analysed using the modification of cell mediated cytotoxic reaction. With one exception we did not confirm the presence of autoreactive T cells among 10 patients examined. Analysis of alloreactivity was performed by means of standard cell mediated cytotoxic reaction and mixed lymphocyte reaction. Surprisingly, the cytotoxic response to allogeneic cells was negative in 11 MDS patients from 16 analysed. When comparing refractory anaemia (RA) and refractory anaemia with ring sideroblasts (RARS) patients, the proportion of negative results was higher in RA (78 %) than in RARS (40 %). In mixed lymphocyte reaction, the response of MDS cells to allogeneic cells of unrelated individual was positive in all tested patients. The preliminary testing of TNF and IFNgamma secretion examined in supernatants of effector cells showed impaired levels of both cytokines in RA and normal levels in RARS in accordance with the findings achieved in alloreactivity analysis. CONCLUSIONS: Autoreactive T cells were not found in MDS patients using our experimental arrangement. Analysis of alloreactivity showed the defect in effector--cytotoxic--phase of cell mediated cytotoxic reaction in the majority of MDS patients. The initial phase of this reaction represented in vitro by mixed lymphocyte reaction gave normal results. The possible reasons of disturbed alloreactivity and its relevance to immunity in MDS are commented in discussion.

[Ubiquitins, proteasomes, sumoylation and application today and in future for cancer and other diseases therapy II. Sumoylation and neddylation as posttranslational modifications of proteins and their ubiquitinylation and its significance]. / Ubikvitiny, proteazomy, sumoylace a pouzití dnes a zítra v terapli nádoru I jiných chorob II. Sumoylace a neddylace jako posttranslacní modifikace proteinu podobné ubikvitinylaci a jelich význam.

Posttranslational protein modifications are effective devices that cells use to control the functions of proteins. Ubiquitin-like protein modifiers (Ubls) are posttranslationally attached to proteins by enzymatic reactions that are similar to ubiquitin conjugation. SUMO (small ubiquitin-related modifier) family proteins are the most intriguing Ubls. Sumoylation is the covalent attachment of SUMO to target proteins. Neddylation is the process that conjugates the ubiquitin-like polypeptide Nedd8 to the conserved lysines of cullins. Cullin family proteins organize ubiquitin ligase complexes to target numerous cellular proteins for polyubiquitinylation and subsequent proteasomal degradation. Despite the similarities in their structure and in enzymatic reactions Ubls and ubiquitin have distinct functions. In contrast with polyubiquitinylation that targets modified proteins to proteasome degradation, the biological consequences of sumoylation include the increase of protein stability. Sumoylation also helps in the protein transport from the cytoplasm to nucleus of cells, regulates transcriptional activities of proteins and mediates the binding of the protein to other proteins. Neddylation has importance for cell cycle control, signal transmission, cell differentiation and DNA repair. Recent studies linked sumoylation and neddylation of several proteins to important diseases (neurodegenerative diseases, acute promyelocytic leukemia, type I diabetes and other disorders). The regulation of these postranslational modifications may provide new targets for therapeutic intervention in several human diseases.

[Ubiquitins, proteasomes, sumoylation and therapeutic application today and in future for cancer and other diseases. I. Ubiquitin-proteasome system and the transcription factor NF-kappaB]. / Ubikvitiny, proteazomy, sumoylace a pouzití dnes a zítra v terapii nádoru i jiných chorob I. Ubikvitin-proteazomový system a transkripcní faktor NF-kappaB.

Proteasome is protein complex with proteolytic activity. Proteasomes are in addition to lysosomes the main proteolytic machinery of the eukaryotic cell. Proteins destined for degradation in proteasomes are marked by ubiquitinylation, which consists in attachment of polyubiquitin to relevant protein. The transport of polyubiquitinylated protein follows to proteasome, where protein is cleaved into small peptides. Besides polyubiquitin attachment to protein, monoubiquitinylation of proteins exists and has an important role in DNA repair, transcription of genes, endocytosis and signal transduction. The function of an important transcription factor NF-kappaB is connected with proteasome. NF-kappaB is activated after the proteolysis of its inhibitor IkappaB in proteasome. Ubiqutinylation and degradation of protein in proteasome and the activation of NF-kappaB play significant roles in taking proteins away and in expression of great numbers of genes important for the regulation of the cell cycle and apoptosis of cells. The inhibition of proteasomes has antiproliferative and antiinflammatory effects and opens new therapeutic approaches to a treatment of cancer and some inflammatory diseases. We divided the review into three parts: I. Ubiquitin-proteasome system and the transcription factor NF-kappaB, II. Sumoylation and neddylation as post-translational modification of proteins similar to ubiquitinylation and their significance and lastly III. Using of the knowledge of ubiquitin-proteasome system in cancer and other diseases therapy.

Low-dose cytosine arabinoside (LD-AraC) vs LD-AraC plus granulocyte/macrophage colony stimulating factor vs LD-AraC plus Interleukin-3 for myelodysplastic syndrome patients with a high risk of developing acute leukemia: final results of a randomized phase III study (06903) of the EORTC Leukemia Cooperative Group.

In this randomized phase III study of the EORTC Leukemia Cooperative Group, patients with myelodysplastic syndromes (MDS) with 10-30% bone marrow blasts and hematopoietic failure were treated with low-dose cytosine arabinoside (LD-AraC) (2 x 10 mg/m2/day subcutaneously (s.c.) days 1-14) either alone or in combination with rhGM-CSF or interleukin-3 (IL-3) both given s.c. at a dose of 150 microg/day from day 8 to 21. A total of 180 evaluable patients with a median age of 65 years and refractory anemia with an excess of blasts (RAEB, n = 107) or RAEB in transformation (RAEBt, n = 73) were randomized. There were no differences among the three treatment regimens with respect to numbers of courses applied or treatment delays. Hemorrhage occurred in approximately 40% in all arms, whereas infection rates were higher in the granulocyte/macrophage colony stimulating factor (GM-CSF)- or IL3-containing arm. The overall response rate was 38.6% with no statistically significant difference among the three arms. In summary, a substantial proportion of patients had achieved relatively durable responses in all the three arms. No influence of either growth factor was detected on the grade of cytopenia. Thus, the combination of LD-AraC with GM-CSF or IL-3 cannot be recommended for routine use in a high-risk MDS population.

Accumulation of homoplasmic mtDNA point mutations in erythroblasts isolated from the bone marrow of patients with refractory anemia with ring sideroblasts (RARS).

It was hypothesised that mitochondrial iron overload in patients with refractory anemia with ring sideroblasts (RARS) results from mitochondrial DNA (mtDNA) mutations. To analyse the mtDNA sequence of iron storing mitochondria sensitively, we developed new protocols for selective erythroblasts isolation, mtDNA PCR amplification and sequencing. Using this approach, we found in each of the three RARS patients examined a unique spectrum of homoplasmic mtDNA point mutations affecting several mtDNA genes. Prediction analyses suggest that identified mutations do not result in major perturbations of mitochondrial functions and are tolerated. We discuss a mechanism explaining how the mutations identified may contribute to RARS pathogenesis.

TRAIL (Apo2L) suppresses growth of primary human leukemia and myelodysplasia progenitors.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL, APO2L) has been shown to induce apoptosis in a number of tumor cell lines as well as in some primary tumors whereas cells from most normal tissues are highly resistant to TRAIL-induced apoptosis. We have studied the susceptibility of primary malignant and normal bone marrow hematopoietic progenitors to TRAIL-induced apoptosis. Extracellular domain of human TRAIL with N-terminal His(6) tag (His-TRAIL, amino acids 95-281) was produced in E. coli and its apoptosis-inducing ability was compared with the leucine-zipper containing TRAIL, LZ-TRAIL. Both variants of TRAIL had the same apoptosis-inducing ability. Clonogenic progenitor assays showed that His-TRAIL significantly reduced the number of myeloid colonies (CFU-GM) and clusters from patients with acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and myelodysplastic syndromes (MDS). His-TRAIL had no negative effect on the number of CFU-GM colonies and clusters derived from bone marrow cells of AML patients in complete remission, and lymphoma patients without bone marrow involvement, as well as those derived from normal cord blood cells. Moreover, we found that normal human stem cells treated with high doses of His-TRAIL maintain a repopulating potential when transplanted into NOD/SCID mice. To conclude, our data document that TRAIL does not affect normal human hematopoiesis but suppresses the growth of early primary leukemia and myelodysplasia progenitors.

[The International Prognostic Scoring System for primary myelodysplastic syndrome]. / Mezinárodní prognostický bodovací systém u pacientu s primárním myelodysplastickým syndromem.

A number of prognostic scoring systems for patients with myelodysplastic syndrome (MDS) have been introduced since FAB classification of the MDS in 1982. Recently, the International Prognostic Scoring System (IPSS), published in 1997 by Greenberg et al. [9] is based on the percentage of bone marrow (BM) blasts, cytogenetic abnormalities and number of cytopenias. We applied criteria of the IPSS on 205 patients (pts) with primary MDS (RA = 82, RARS = 49, RAEB = 42, RAEB-t = 8, CMML = 24 pts). IPSS discriminated within each of the FAB-subgroups: RA pts were present in low risk and intermediate (Int) I and II risk subgroups, RARS pts were separated into low and Int I, RAEB were distributed predominantly between Int I and Int II risk groups, RAEB-t in high-risk group, and CMML pts were distributed in all groups. In contrary to Greenberg's group of the MDS patients there are only three risk-groups in our study: low risk (score 0-0.5), intermediate (1-2) and high risk (> 2); the median survival and the risk of the evolution to the acute leukemia (p = 0.0001) are significantly different.

[Cell clonality in myelodysplastic syndrome]. / Bunecná klonalita u myelodysplastického syndromu.

INTRODUCTION: Myelodysplastic syndromes (MDS) are classified as oncohematologic, clonal diseases. However, some MDS subtypes lack malignant clinical features. Literary data on the clonality of blood cells in MDS are controversial. Therefore we examined the clonality in the group of our own MDS patients. We were especially interested in the comparison of the clonality of myeloid and lymphoid cell line-ages. METHODS AND MATERIAL: Using X-chromosome inactivation methods based on polymorphism in human androgen receptor gene (HUMARA), iduronate sulphatase gene (IDS) and protein p55 gene, we assessed the clonality of granulocytes, monocytes and T-lymphocytes of 49 female patients with MDS and 12 control women of various ages. RESULTS: Though the results were heterogeneous, certain trends were observed: most frequently monoclonality of monocytes was found (51%), granulocytes were monoclonal in 33% of cases, monoclonal T lymphocytes only in 8% of cases. There was no case with monoclonal T lymphocytes and simultaneously polyclonal myeloid cell fractions. Results differ in relation to the subtypes of MDS. Among controls we observed monoclonality of myeloid cells in one case of an old lady. WE CONCLUDE: The results confirm the presence of malignant clone of myeloid cells in MDS, which can be of variable size. The examination of the clonality in MDS can be significant for the therapy decision. Monoclonal myeloid cells are found least frequently in refractory anemia, most frequently in RAEB-T. Monoclonality of cells in sideroblastic anemia is interesting. The prevailing polyclonality of T lymphocytes in MDS can be explained by the presence of a long-lived cell population originating from the period before the development of MDS. The role of the polyclonal memory T cells in the antitumor immunity in MDS is discussed.

[Will knowledge of the mechanisms of apoptosis lead to new therapeutic procedures?]. / Povede poznávání mechanizmu apoptózy k novým terapeutickým postupum?

Apoptosis (programmed cell death) ensures under physiological conditions cell homeostasis. Under pathological conditions excessive apoptosis, premature apoptosis or delayed or infinite apoptosis of cell is a sign of various serious diseases. Due to intensive research in this field it proved possible to assess nowadays at a molecular level a number of pro- and anti-apoptotic factors and their function in the process of apoptosis. Apoptosis proceeds by external as well as internal pathway. Factors involved in apoptosis are studied from the aspect of their possible therapeutic application in tissue cultures, experimental animals, and there are already some initial reports from human pathology. Delayed or infinite apoptosis is a typical property of tumor cells. So far most attention was paid to two ways of apoptosis induction of tumor cells: suppressed translation of the antiapoptic factor Bcl 2 by means of an antisense nucleotide and induction of apoptosis by TRAIL (TNF related apoptosis inducing ligand). Conversely a delay of premature apoptosis gives hope for hitherto untreatable neurodegenerative diseases, myelodysplastic syndromes, ischaemic events and some severe infections. This is achieved by means of peptides inhibiting caspases. Provided that modulation of cell apoptosis will not be associated with unacceptable side-effects, it will become a new therapeutic approach in hitherto inadequately curable diseases.

Myelodysplastic and myeloproliferative type of chronic myelomonocytic leukemia--distinct subgroups or two stages of the same disease?

Several authors have tried to solve the problems in the classification of CMML. A fully suitable classification does not exist. The goal of our study was to determine common and different signs of MD and MP type of CMML and to observe frequency of shifts from MD to MP-CMML. Sixty nine CMML patients were divided according to FAB proposal into two groups: 31 patients into the MD group (WBC < or = 13 x 10(9)/l) and 38 patients into the MP group (WBC < or = 13 x 10(9)/l). Presenting features and the course of the disease in both groups were evaluated. The median age of patients was not different in both groups (71.5 and 74 years, respectively), male/female ratio was 1.1 and 2.4, respectively. The median follow-up time was 15.5 months (1-58.8) in MP group and 24 months (2-118) in MD group. In MP group splenomegaly, hepatomegaly, lymphadenopathy, abnormal karyotype and skin involvement were found more often than in MD group. Median LDH value was higher in MP group. Probability of survival was higher in the MD group than in MP group (median 30 and 11 months, respectively). Leukaemia transformation frequency was similar in both groups. In 12 out of 24 (50%) MD group patients WBC increased during the course of the disease over 13 x 10(9)/l. Oscillation of WBC values below and over 13 x 10(9)/l was observed in three patients. During the follow-up time number of patients with splenomegaly and/or immature granulocytes in the PB increased. After inclusion of 12 patients who shifted from MD to MP group a new CMML group resulted characterised by longer median survival (17 months) due to a higher number of patients in an earlier stage of the disease. Failure of evolution of myeloproliferative signs and lower frequency of AL in the remaining group might be explained by an early stage of CMML, untimely deaths due to unrelated causes and/or by patients suffering of RA with monocytosis rather than of CMML. In summary, our data suggest, that evolution from MD-CMML to MP-CMML is a frequent event and that MD-CMML could be the early stage of CMML in most of cases. The WBC at diagnosis as the single criterion for subclassification of CMML does not seem to be fully justified. We propose that CMML should not be divided in MD and MP types and that monitoring of patients and search for other signs of myeloproliferation such as PB immature granulocytes, splenomegaly, lymphadenopathy, skin involvement, pleural or peritoneal effusions, spontaneous growth of CFU-GM in vitro should be taken in consideration for a better classification of CMML, which would have an impact on the therapeutic approach.

[The comet assay: principles of the method and clinical utilization]. / Kometový test: princip metody a klinické aplikace.

BACKGROUND: Single cell gel electrophoresis or comet assay is used at present in the world to study of DNA damage, DNA repair and apoptosis. The aim of the work is to introduce the principle of comet assay to the medical community and to give a basic survey of its possible clinical applications. The article includes our first experience with this method in detection of apoptosis in bone marrow cells of patients with myelodysplastic syndrome (MDS). METHODS AND RESULTS: The whole bone marrow aspirates from 6 patients with MDS and 7 control persons were processed by alkaline version of comet assay and the degree of DNA fragmentation in individual cells was quantified using Image Analysis System. In comparison with controls, the patients with diagnosis RA and RARS exhibited in bone marrow significantly elevated number of cells with high level of DNA breaks, reflecting most probably the apoptotic cleavage of DNA. In contrast, the patient in proliferative stage of the disease (MDS-CMML-->AML) exhibited decreased frequency of apoptotic cells, well below the control level. CONCLUSION: Our results correspond with the data published on the occurrence of apoptosis in particular types of MDS. Comet assay represents a simple and cheap technique, applicable in clinical hematology to specify the diagnosis, to monitor the disease progress and efficacy of therapy not only in patients with MDS but also in other diseases resulting from an imbalance between proliferation and apoptosis.

Cyclosporin A combined with vincristine, doxorubicin and dexamethasone (VAD) compared with VAD alone in patients with advanced refractory multiple myeloma: an EORTC-HOVON randomized phase III study (06914).

Patients with multiple myeloma (MM) refractory to alkylating agents frequently express P-glycoprotein (Pgp), which is associated with the multidrug resistance (MDR) phenotype. We have conducted a randomized phase II/III study of the MDR reversal agent cyclosporin A combined with VAD (vincristine, doxorubicin, dexamethasone) compared with standard VAD in patients with MM stage IIA/IIIA who were refractory to or progressive after treatment with alkylating agents. Out of 81 patients who were randomized, 75 were eligible and evaluable: 34 in the VAD + cyclosporin A arm versus 41 in the VAD arm. Toxicities of grade 2-3 were observed more often with VAD + cyclosporin A than with VAD only: nausea (30% versus 8%, P = 0.015), mucositis (18% versus 5%, P = 0.13), infection (45% versus 35%, P = 0.50). The treatment results were similar in the two arms: 53% versus 49% responded [95% CI (-18.5%, 26.9%)]. The median progression-free survival (PFS) was 8.6 months (VAD + cyclosporin A) versus 5.8 months (VAD): [log rank P = 0.16, hazard ratio = 0.71, 95% CI (0.44, 1.15)], and median overall survival was 13 months versus 14.6 months [log rank P = 0.89, hazard ratio = 0.96, 95% CI (0.62, 1.72)]. The cause of death was progressive disease (85%), toxicity (10%) or other (5%). Bone marrow analysis performed in 23 patients showed that the response rate was 67% in Pgp-positive versus 55% in Pgp-negative patients. Cyclosporin A combined with VAD is relatively well tolerated. There is no effect of cyclosporin A on the overall response rate, PFS and overall survival with VAD.

[Use of cyclosporin A in hematology]. / Pouzití cyklosporinu A v hematologii.

We present an overview of clinical conditions where cyclosporin A (CyA) could be used in the treatment of hematological diseases. CyA is an effective immunosuppressive agent. It has long been successfully used in organ transplants and bone marrow transplants. The strong immunosuppressive effect of CyA makes this agent useful in various autoimmune diseases. The indication of CyA in certain hematological diseases has recently been steadily expanding. Based on the influence of CyA on cell immunity, the creation of cytokines and subsequently on humoral immunity we try to elucidate or justify its use in specific hematological diseases with regards to their pathophysiology. The common denominator to the diseases discussed below is a certain form of autoaggression. We include for example idiopathic autoimmune hemolytic anemia (AIHA) idiopathic thrombocytopenic (ITP), Evans syndrome, pure red cell aplasia. In certain sense we can include here even aplastic anemia (AA) and myelodysplastic syndrome (MDS). Furthermore, it is possible to use CyA for its ingerence to the proliferation and activation of T-cells in some T-lymphoproliferations and in histiocytoses. In B-lymphoproliferation the use of CyA will probably require further studies. We briefly note the possibility of influencing multiple drug resistance (MDR) with CyA.

Cyclosporin A therapy in hypoplastic MDS patients and certain refractory anaemias without hypoplastic bone marrow.

We report 17 cytopenic patients with myelodysplastic syndrome (MDS) of refractory anaemia (RA) subtype with hyper-, normo- or hypo-cellular bone marrow (BM), who were treated with cyclosporin A (CyA). Substantial haematological response was observed in 14 patients (82%): their anaemia improved and all transfusion-dependent patients achieved transfusion independence. Complete trilineage recovery was observed in four patients (23%). The CyA therapy has not yet failed in any of the 14 successfully treated patients during follow-up times ranging from 5 to 30 months. CyA was well tolerated in 14 patients; serious side-effects required termination of the therapy in three patients in whom the blood count rapidly deteriorated to former levels upon cessation of therapy. Two patients benefited from a combination therapy of CyA and erythropoietin. Six patients experienced various autoimmune phenomena. CyA could thus offer an alternative treatment for certain MDS patients with RA regardless of hyper-, normo- or hypo-cellularity of bone marrow (BM). The mechanism of the beneficial effect of CyA is discussed and remains the subject of an ongoing study.

[Mixed myelodysplastic and myeloproliferative syndromes]. / Smísené myelodysplastické a myeloproliferativní syndromy.

BACKGROUND: An injury to the hemopoietic stem cell may lead to the aplasia of hemopoiesis, myelodysplasia and to an unregulated myeloproliferation. There is not a strict demarcation of them, so that mixed syndromes can develop as are hypoplastic syndromes on one side and mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) on the other side. METHODS AND RESULTS: Among our 616 pts with MDS we looked for those cases, who had beside myelodysplasia signs of myeloproliferation with increased number of blood cells. They were examined in detail including bone-marrow histology, bone marrow cultivation, cytogenetics and bcr-abl gen. Signs of MDS-MPS were found in 22 patients at the first contact with the patient (13 patients had thrombocytemia and 9 patients had leukocytosis). Further 7 patients were diagnosed as MDS, proliferative syndrome developed after several months (MDS-MPS in evolution). The level of thrombocytemia was relatively stable, the number of leukocytes was progressive. All subtypes of MDS were found. All subjects had variable degree of anemia. Ring-sideroblasts and myelofibrosis were frequent finding in MDS-MPS. Men prevailed in patients with leukocytosis. Cytogenetic and cultivation findings were similar to MDS cases, deletion of long arm of chromosome 20 was present in 3 patients. Five patients transformed to acute myeloid leukemia. CONCLUSIONS: Sings of myelodysplasia and myeloproliferation were found in 4% of our MDS patients, designated as mixed myelodysplastic and myeloproliferative syndrome (MDS-MPS). In this syndrome beside evident signs of myelodysplasia thrombocythemia or leukocytosis with the release of bone marrow precursors are present. In only one case polycythemia was encountered.

Mixed myelodysplastic and myeloproliferative syndromes.

Aplastic anemia, myelodysplastic syndromes (MDS) and chronic myeloproliferative diseases (MPD) are stem cell disorders. There is no clear-cut demarcation of them. Hypoplastic MDS displays features of aplastic anemia and MDS, on the other side mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) develop. In our collection of 566 MDS patients, features of myelodysplasia as well as myeloproliferation, MDS-MPS, were present in 25 patients (4.4%). Twelve patients had at the time of diagnosis megakaryocytic proliferation and thrombocythemia beside signs of MDS, and seven had myelodysplasia with granulocytic proliferation and leukocytosis. In another six patients, MDS was the first diagnosis and the proliferative phase developed later during the course of the disease. These patients can be characterized as MDS-MPS in evolution. All subjects had a variable degree of anemia. While the level of thrombocythemia has been relatively stable, the number of leukocytes has been progressive, but rarely extended beyond 100 x 10(9)/l. Ring-sideroblasts and myelofibrosis were frequent findings. Two more homogeneous MDS-MPS groups emerged in our analysis: sideroblastic anemia with thrombocythemia and a group fulfilling the criteria of Philadelphia chromosome negative and bcr-abl negative "atypical chronic myeloid leukemia (aCML)'. One patient with thrombocythemia and three with leukocytosis (23%) transformed to acute myeloid leukemia (AML). Men prevailed (12/13) in patients with leukocytosis and MDS-MPS in evolution. Of the 46% MDS-MPS patients with chromosomal aberrations, del(20)(q) is of interest.