Leukemia (Latin leukemia) impairs white blood cells (leukocytes) - mobile health defenders againsttoxins,germs and parasites. As a result of this disease, a large amount of leukocytes appear in the bone marrow with an incorrect appearance and unable to defend the system.
Leukemia pathomechanism
Defective and uncontrollable leukemic cells block the hematopoietic function of the bone marrow. This limits the production of healthy white blood cells and red blood cells and platelets. As a consequence, it leads to the appearance of symptoms of leukemia - weakness, pallor, recurrent severe infections, bleeding tendencies and bruising, purple-red spots on the skin.
Leukemia and blood cells
When a healthy bone marrow produces wholesome white blood cells (so-called leukocytes) - they circulate in the blood in the amount of 4,000. up to 10,000 in 1 milliliter and fight pathogenic bacteria, viruses, parasites, toxins, etc. Leukemia causes pathological neoplastic lesions of leukocytes and their uncontrolled multiplication. (The very name of the disease comes from the whitish color of the blood sample of a person suffering from acute leukemia).
Mechanism of disease development
Rapidly multiplying cancer cells "are pushing" in the medullary cavities, leaving no space for the development of normal blood cells. As a result, the bone marrow is filled with malignant, impaired leukocytes, called blasts, while other blood components such as red blood cells and platelets are produced in insufficient amounts. When defective leukocytes enter the blood, and with it - to the liver, spleen, lymph nodes, cerebrospinal fluid, kidneys - the disease develops.
The most numerous group of leukocytes - granulocytes
The most numerous defensive formation of the immune system, which is gradually eliminated by leukemia, are small granulocytes (neutrophils and eosinophils). Their task is to destroy (phagocytosis) germs, parasites and toxic foreign bodies that have invaded the body. The daily dose of granulocytes introduced from the bone marrow into the blood is about 1 billion granulocytes, for every kilogram of body weight. Granulocytes make up about 55-75% of all leukocytes. The reason for such a large number is their necessity to protect the organism against germs and a short period of life.
Leukemia affects granulocytes and other white blood cells
The disease deprives gradually not only the most important granulocytes of the body, which are the so-called neutrophils, but also monocytes and macrophages, which together destroy (phagocytose) germs (mainly bacteria), as well as eosinophils (so-called eosinophils, 2-4%), which destroy parasites and allergens, etc.
Leukemia interferes with the production of lymphocytes that organize the fight against germs and parasites.
Lymphocytes are another group of white blood cells. Their claim is the lymphatic system (lymphatic) which is a mirror image of the circulatory system. The lymphatic system is fully the role of a biological filter for bacteria, viruses, fungi, dust, etc., cleaning the body of them. Lymphocytes come from various organs (marrow, thymus, lymph nodes, spleen) and are divided into different groups. The basic division is the distinction between T and B lymphocytes. The first one is responsible for cellular immune reactions, i.e. those in which whole cells participate. B lymphocytes, in turn, are responsible for the formation of antibodies and immune reactions of humoral type - an important weapon in the fight against microorganisms.
CAUSES OF PROTEIN
Disruption of control and genetic mechanisms
Like other cancerous diseases, leukemias arise as a result of changes or damage to genes that control growth, development and cell division.Disruption of the control genetic matrix results in the formation of immature or defective leukocytes from bone marrow stem cells as a result of the so-called leukemia transformation. On the other hand, the number of normal blood cells is reduced.
Factors damaging the blood cells
In most cases, no specific cause of leukemia can be found. However, it is widely believed that the reasons for the collapse of control-genetic mechanisms of blood cell production may be several co-operating factors. It may be a retroviral attack, individual predisposition (genes), ionizing radiation, carcinogenic chemicals (from food, environmental pollution), severe systemic infections, etc. These factors facilitate leukemic transformation or weaken the immune system.
The effects of defective leukocytes production
The production of defective leukocytes in the bone marrow results in leukemia. Depending on the pathomechanism, the disease is distinguished by acute leukemia, rapidly wasting the body, which requires intensive treatment with chemotherapy and chronic, usually slow.
The onset of disease symptoms
Acute leukemia appears suddenly and untreated progresses very quickly. Chronic leukemia develops slowly, even if untreated. Often, in patients with leukemia, the spleen and liver are enlarged and painful. Sometimes the lymph nodes are enlarged. There are also frequent serious infections, as degenerated leukemia cells are unable to replace the normal white blood cells that fight germs.
Types of leukemia, due to the type of abnormal blood cells produced
Leukemia is generally divided into myeloid (myeloblastic) and lymphatic (lymphoblastic), and also, as we have already mentioned, acute and chronic. The term bone marrow or lymphatic refers to the type of abnormal cells produced. When we deal with abnormal lymphocytes (or derivatives), we are dealing with lymphoid (or lymphoblastic) leukemia. If the abnormalities concern other white blood cells (granulocytes, monocytes, macrophages, etc.) or also cells from which red blood cells or platelets are formed, we are talking about myeloid leukemia (myeloblastic leukemia).
Prevalence of leukemia
The incidence of leukemia is currently estimated at approximately 7-10 cases per 100,000 people per year. The incidence of deaths for various forms of leukemia is approximately 7 people per 100,000 inhabitants. Attention is drawn to the steady increase in morbidity by around 4% per year. This is probably due to the increase in the number of carcinogenic factors in foods and in the living environment. Leukemia is more common in men than in women (3: 2). Individual types of disease indicate different incidence in different age groups. Acute lymphocytic leukemia occurs mainly in children and young people; chronic lymphatic - usually after the age of 40; marrow - in middle age.
Heredity and leukemia
There is no evidence that any form of blood cancer can be hereditary. However, it was found that in children, genetic damage plays a more important role than in adults. A blood cancer in another child in the family is extremely rare, and the results suggest that children of people who have undergone leukemia do not inherit this disease. However, if the same form of leukemia happens to more than one member of a given family, it is advisable to consult a physician dealing with genetics.
General rules for the treatment of leukemia
Treatment of leukemia depends on its type, severity and general condition of the patient. We distinguish radical therapy aimed at curing or eliminating pathologically changed blood cells from the body and palliative treatment to control the progression of the disease.
Literature:
1. Science about internal diseases - blood diseases in the hematopoietic system - edited by prof. dr hab.med. Witold Orłowski; author - prof. dr hab.med. Julian Blacharski, PZWL, 1990
2. Outline of chemotherapy of organ and systemic tumors - edited by prof. dr hab. med. dr hab. med. Krystyna Orzechowska-Juzwenko; author - prof. dr hab. med. Sabina Kotarek-Haus
3. Small encyclopedia of PWN, 1999 4.
4. Information materials from Schering AG.
