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Miyelodisplastichesky syndromes

Miyelodisplastichesky syndromes — heterogeneous group of diseases which cornerstone pathology of a haematopoietic stem cell is. Their main manifestations is the complex of various quantitative, high-quality, morphological and kinetic disturbances in the hemopoiesis cells (disgemopoez) which are often combined with unmotivated fever, increase in a spleen, liver, a micropolyadenia, an infection.
Idiopathic miyelodisplastichesky syndromes are quite often called a preleykemiya, oligoblastny forms of leukoses.

Epidemiology
Many years considered that miyelodisplastichesky syndromes meet seldom and are diagnosed only retrospectively.

Thanks to the developed complex of kliniko-hematologic signs their diagnosis became possible recently; data on prevalence of miyelodisplastichesky syndromes are absent.

Etiology and pathogeny
The etiology of miyelodisplastichesky syndromes is not established. Believe that their genesis is connected with changes of a haematopoietic stem cell and its environment. Thereof morphological defects of cells of the erythrocyte, granulotsitarny, lymphocytic and megakariotsitarny line of a hemogenesis, increase in quantity of blast cells in peripheral blood and marrow come to light. These changes meet various frequency and in different combinations. The most constant are dizgemopoez, refractory anemia, a cytopenia (1 - 2-, 3-rostkovy) and/or a hypoplasia of the hemopoietic fabric. Miyelodisplastichesky syndromes usually proceed in two phases: haemo depressions and clinics of an acute leukosis (is more rare — a chronic leukosis or other form of hemoblastoses). There are data on kariologichesky, immunological disturbances, changes of an antigenic structure of cells, as a rule, having mosaic and nonspecific character.

Classification
Miyelodisplastichesky syndromes can be idiopathic (primary) or accompany the course of other diseases. On FAB classification it is possible to carry the refractory anemia (RA) to the most often found forms of miyelodisplastichesky syndromes, RA with ring sideroblasts or the sideroblastny anemia (SA) and RA is a lot of blasts (RAIB). Besides, according to FAB classification, still RAIB in transformation are allocated (RAIB a trance.) and chronic miyelomonotsitarny leukemia (HMML) or RA with monocytes.

Approximate formulation of the diagnosis:
1. The Miyelodisplastichesky syndrome in the form of refractory anemia.
2. The Miyelodisplastichesky syndrome in the form of refractory anemia with ring sideroblasts, a moderate leukopenia, thrombocytopenia and morphological anomalies of two cellular lines, small increase in a spleen.
3. The Miyelodisplastichesky syndrome in the form of a hemogenesis depression, generally an erythrogenesis with megaloblastny lines at part of cells, slowly accruing blastozy in a gemogramma and a miyelogramma; leykotsitopeniya and trombotsitopeiichesky hemorrhages, morphological anomalies of three cellular lines.

Clinic
At miyelodisplastichesky syndromes all cellular lines suffer, but it is the most constant — erythrocyte. The anemic syndrome is usually expressed as RA, sometimes with detection in marrow of ring forms of sideroblasts, aplastic anemia, a partial krasnokletochny aplasia (eritro-blastoftiz). As a rule, the part of cells of an erythrogenesis carries megaloblastny lines; sometimes there can temporarily be a positive test of Koombs, Ham's test, the saccharose test, simulating autoimmune hemolitic anemia or a paroxysmal night haemoglobinuria.

In erythropoietic elements find various qualitative anomalies: decrease of the activity of some enzymes, especially pyruvatekinases and glyutationreduktaza, PAS positive reaction in erythroblasts, changes of erythrocyte antigens, increase of level of fetalis hemoglobin (HbF), proto - and coproporphyrins. In peripheral blood yadrosoderzhashchy predecessors of erythrocytes can meet, the macrocytosis is noted. The number of reticulocytes is reduced or increased. Level of transport iron of serum can be raised or normal. These studying of the test with 59Fe indicate reduced utilization and excess accumulation it in bodies and fabrics.

One of frequent hematologic syndromes of miyelodisplastichesky syndromes is the watering can and/or thrombocytopenia. The isolated leukopenia meets seldom, is even more rare — the thrombocytopenia which is usually not followed by hemorrhages. Degree of a cytopenia is various, but can reach very low level. At some patients the quantity of monocytes increases.

In cells of these lines also high-quality disturbances are noted. So, in segmentoyaderny neutrophils false pelgerovsky anomaly, increase or decrease in maintenance of an alkaline phosphatase sometimes comes to light. In megacaryocytes polyploid changes are found, the sizes of cells are reduced, among them cells meet 1 — 2 oval kernels and mature cytoplasm, in thrombocytes decrease of the activity of ADF/ATF+AMF is found.

However the most demonstrative sign of miyelodisplastichesky syndromes is increase in number of morphologically defective cells of a hemogenesis, especially a neytropoeza, both in marrow, and in peripheral blood. Contents them can increase to 30% with the subsequent increase in process of progressing of an illness.

The main signs of RAIB are: anemia, a leykotsitopeniya and/or thrombocytopenia, morphological anomalies in all cellular lines (such cells in granulotsitarny and erythroidal ranks there are about 30% and more), quantity of blasts in a gemogramma — to 5%, in a leykokontsentrata of peripheral blood — 0,5 — 9%, in a miyelogramma — 5 — 20%, marrow can be both normokletochny, and hyper - and hypocellular. At RAIB the trance, in peripheral blood of blasts is more (5%), in marrow — to 20 — 30%.

In cases of development of leukoses, a thicket acute, in marrow cells structural and quantitative disturbances of chromosomes quite often are found, colony-forming ability of cells predecessors of a granulocytopoiesis is reduced or is absent.

At histologic studying of marrow against its polymorphic structure focal accumulations of blast cells can come to light.

At idiopathic miyelodisplastichesky syndromes at part of patients small increase in a spleen, sometimes a liver is noted and/or peripheral lymph nodes, quite often there are infectious complications caused by defects in immune system (a neutropenia, functional inferiority of neutrophils, lymphocytes, etc.).

Duration of a phase of a haemo depression fluctuates in quite big limits — of 9 days to 11 — 13 and even 20 years, then miyeloblastny, miyelomonoblastny or nondifferentiable acute leukoses usually develop. Isolated cases of developing of an acute lymphoblastoid leukosis, the myelosis proceeding with existence or lack of Ph' - chromosomes are described.

Verification of the diagnosis
It is based on detection of morphological defects of cells of various lines of a hemogenesis, features of their qualitative characteristic, detection of blast cells in marrow, peripheral blood and a leykokontsentrata, on changes, inherent refractory or aplastic anemia, to an eritroblastoftiz. Signs of the raised intracellular or intravascular hemolysis are periodically observed, insignificant increase in a spleen, liver sometimes meets.

Treatment
Use of medical actions both in a haemo depression phase, and during formation and development of an acute leukosis ineffectively. There are attempts to use small doses of Cytosarum, immunoproofreaders, transfusions of eritrotsitny weight, a plasma exchange, a splenectomy.

 
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