Beginning >> Diseases >> Tumors >> Hemoblastoses


Hemoblastoses — the new growths developing from cells of the hemopoietic fabric. They are subdivided into two groups:
1) leukoses — system processes with primary tumoral damage of marrow;
2) gematosarkoma — extra marrowy originally local tumors (mainly in lymph nodes) with their possible generation in the hemopoietic bodies, including marrow.

Incidence of hemoblastoses is rather low (about 10 on 100 000 population a year) and borrows 6 — the 8th place among new growths, making 6 — 7% of them. In the developed countries hemoblastoses make about 1% of all reasons of mortality of the population. From 6 to 10% of all cases of death of malignant new growths, and among patients aged till 30 flyings — 50% fall to their share. In the majority of the countries the ratio of incidence of leukoses and lymphoma makes 1:1. In Great Britain, Germany, Poland, Finland leukoses, in the USA, Canada, Cuba, Australia, Israel — lymphoma prevail a little.

Among the population Severnoy and Northwest Europe (Norway, Sweden, Finland, Denmark), the indicators of incidence of hemoblastoses of the man's population in Canada, the USA, Israel standardized make 7 — 10,7 cases, and female — 5 — 7 cases on 100 000 people.
Among hemoblastoses first place is won by acute leukoses (29,1%).

The chronic lymphoid leukosis often occurs among the population of the European countries, Canada, the USA (from 15 to 40% of all cases of leukoses), is very seldom observed in the countries of Southeast and East Asia.

Etiology and pathogeny
Influence of ionizing radiation on the frequency of developing of leukoses is established in the analysis of effects of atomic bombing of Hiroshima and Nagasaki, and also at patients, treated by radiation. The ionizing radiation causes generally acute leukoses and a myelosis, is much more rare - lymphoma. Effects of atomic bombing in Japan showed that the frequency of developing of leukoses is directly proportional to an exposure dose. The small doses of radiations applied in medicine with the diagnostic purpose do not influence the frequency of development of leukoses. Data on possible leykozogenny effect of some chemicals and medical drugs are saved up: benzene, flying organic solvents, Butadionum, levomycetinum, about increase of cases of an acute miyeloblastny leukosis at patients with a multiple myeloma, Valdenstrem's macroglobulinemia, chronic lymphoid leukosis, treated Melphalanum, Myelosanum, leukeranum, Azathioprinum, Cyclophosphanum.

Now the virus origin of leukoses and lymphoma at many animal species is confirmed. Indirect data on an etiological role of a virus of Epstein — Barre (VEB) in emergence of a malignant lymphoma of Berkitt are obtained.

The new exogenous retrovirus C from cells of the T-cellular leukosis of adults and from T-cells of fungoid mycosis is got. It is designated by the term "virus of T-cellular leukemia — a lymphoma of the person". At the T-cellular leukosis of adults the method of molecular hybridization revealed implementation of a pro-virus genome of HTLV in the leukemic T-cells having a monoclonal origin.
A certain role in emergence of a lymphoma of Berkitt is given to a malarial infection" by followed oppression of immunity and stimulation of proliferation of the V-lymphocytes infected with VEB. Point out possible value in development of the T-cellular leukosis of adults of a filariosis.

In experiment high blastomogenic (leykozogenny) activity of a number of metabolites of tryptophane and tyrosine" these amino acids arising at deep disturbances of an exchange, their ability to induce chromosome mutations, to exert immunodepressive impact is established.
The role of genetic factors in development of leukoses is confirmed by messages on diseases of members of one family, is more often than brothers and sisters (about 60% of all supervision) that does not exclude possibility of a leukosis under the influence of the general environmental factors.

The essential difference in the frequency of emergence of a chronic lymphoid leukosis among various national ethnic groups also indicates a role of genetic factors in development of a disease. There are proofs of increase of risk of a disease of leukoses at congenital chromosomal anomalies (a Down syndrome, Blum's syndrome, Fankoni's syndrome, Klaynfelter's syndrome).
Noticeable increase in incidence of hemoblastoses in the senior age groups indicates a role of the immune status in their development" also higher frequency of emergence of lymphoma and leukoses of a lymphoid origin at immunodeficiency testifies to it. Data on possible interrelation of histocompatibility antigens (HLA) with certain forms of hemoblastoses are saved up.

The tumoral progression at hemoblastoses is characterized by a clonal origin and the increased variability, the properties of a tumor defining variability.

The clonal nature of hemoblastoses is confirmed by many researches. At not lymphoblastoid acute leukoses at uncured patients more than in 90% of cases chromosomal changes of clonal type come to light. Clones of cells with aneuploid chromosome number or structurally changed chromosomes disappear during remission and again are found at recurrence of a disease.
Acute leukoses with chromosomal changes proceed less favorably, than cases with a normal karyotype. An exception are acute leukoses with a translocation 8; 21 (q22; q22), coming to light in 10% of cases, mainly at a miyeloblastny form, in these cases note development of remission more than at 70% of patients. At 5% of patients with an acute lymphoblastoid leukosis hyper diploid clones meet chromosome number more than 50 that is regarded as an advantage predictive factor.

There is an accurate communication of the observed reorganizations of chromosomes with a form of an acute leukosis: translocations 8; 21 and 6; 9 (r21 — 23; q33 — 34) meet at a miyeloblastny leukosis; t (15; 17) (q25; q22) — at promiyelotsitarny; t (9; 11) (r21 — 22; q22 — 24) — at acute monoblast; t (4; 11) (q21; q23) — at a lymphoblastoid leukosis.

At the chronic V-cellular lymphoid leukosis which is found approximately at 90% of patients with a chronic lymphoid leukosis, anomalies of chromosomes are found in 50% of cases, is more often in the form of a trisomy of a chromosome 12 (+12). Surface membrane markers are noted on the prevailing part of lymphocytes, blood cells, marrow and lymph nodes, bear monoclonal surface immunoglobulins, S3-and Fc-petseptora, in some cases monoclonal immunoglobulin with light chains comes to light (x or a lambda).

At 80 — 90% of patients with a myelosis reveal existence abnormal Philadelphian (Ph') the chromosome called in honor of the city in the USA where it was for the first time revealed. Ph '-a chromosome is identified as the 22nd chromosome with partial deletion of a long shoulder (22q-). It is established also that a deletirovanny segment of a chromosome 22 translotsirovan on a long limb 9: t (9; 22) (q34; qll). Translocation 9; 22 it is found in 92% of patients with a myelosis. Ph' - a chromosome comes to light in cells of granulotsitarny, erythroidal and megakariotsitarny sprouts.
At lymphoma of the V-cellular nature of the most frequent reorganization of a chromosome 14 is. It can arise also in chromosomes 1, 8, 10, 11 and 18.

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