26.2.1. Give the general characteristic of disorders of the leukocyte system:
Pathological changes of leukocytes declare in the disorders of their production in hemolytic tissue and quantitative and qualitative shifts of blood leukocytes. These changes may be the result of primary impairment of granulocytic lymphocytic and monocytic row cells at the disorders of their production, maturation or breaking down in hemolytic tissue and blood stream undergoing various causative factors. Secondary changes in leukocytes develop as response, often protective reaction of the organism to pathological processes running not in the blood system itself but in the organs and tissues of other systems.
The main section of pathogenetic disorders at leukocyte pathology is the change of reactivity of the organism including immunologic and allergic one which is connected with functional particularities of leukocytes ? their participation in the processes of phagocytosis, antibody production, inactivation of biologically active substances (histamine, bradikinin, serotonin). Pathological changes of leukocytes may be followed by trophic disorders of tissues, local microcirculatory disorders. It is mediated by one of the leukocyte functions supplying regenerative tissues by nutritial substances and stimulators of cell division. Granulocytes take part in the development of vascular impairments transmissing vasoactive substances (basophile, eosinophil) or influencing their synthesis and release of tissue (basophiles, neutrophils).
26.2.2. How are leukocytes distributed in the organism?
Leukocytes are stored in the organism in three places: red bone marrow, peripheral blood, peripheral tissues.
1. Red bone marrow. Here leukocytes compose 4 pools:
a) pool of trunk cells, existing at rest. It is not considerable and is a reservoir of hemolysis.
b) mitotic pool. These are cells existing at mitotic division. It takes from 4 till 11 grades to produce maturating cells from a trunk cell.
c) maturating pool contains cells, maturation of which lasts for 3-5 days.
Reserve pool consists of maturated leukocytes which can go into the blood.
2. Peripheral blood:
pool of circulatory leukocytes (about 50%); marginal pool (about 50%).
3. Peripheral tissues:
migrating leukocytes; leukocytes at rest.
It was counted that total mass of leukocytes is about 10 g in peripheral blood, in red bone marrow 500 g, in peripheral tissues ? 600 g.
26.2.3. What indexes are used to characterize the state of leukocyte systems?
The number of leukocytes in the blood unit. Normally it is 4?109/l - 9?109/l. The increased number of leukocytes is called leukocytosis, the decreased leukopenia.
Leukocytic formula ? quantitative correlation of various forms of leukocytes in the peripheral blood. Normally the number of basophiles is 0-1%, eosinophils ? 2-4%, myelocytes ? 0%, metamyelocytes ? 0-1%, stick-nuclear neutrophils ? 3-5%, segment-nuclear neutrophils ? 50-70%, lymphocytes ? 20-35%, monocytes ? 2-8%.
Absolute amount of every leukocyte form in the blood unit. This index is taken into account from the total numbers of leukocytes and leukocytic formula.
Qualitative characteristics of leukocytes. They are detected on the basis of peripheral blood smear research. In case of pathology there may various forms of leukocytes be revealed.
Myelogram, a sign characterizing quantitative and qualitative composition of red bone marrow cells.
26.2.4. What are the qualitative and quantitative changes in leukocytes of pathologic processes in the organism?
Leukocytosis
Leukopenia
Disorders of correlation of maturated and non maturated forms of leukocytes (shift of leukocytic formula)
Degenerative changes of leukocytes
26.2.5. What is leukocytosis? How is it classified?
Leukocytosis is the increased number of leukocytes in the blood unit over 10?109/l. Leukocytosis is just a symptom accompanying many diseases.
Classification of leukocytosis:
1. Due to the causes of its development ? physiological and pathological leukocytosis
2. Leukocytosis may be absolute and relative. For absolute leukocytosis it is characteristic that the absolute number of leukocytes in the blood unit increases. It is said about related leukocytes in the peripheral blood increases.
3. Due to the mechanism of the development leukocytosis may be classified as:
reactive; redistributive; neoplastic.
4. Depending on the type of leukocytes, the number of which in the blood is increased: