Oncology, cancer - these terms cause unpleasant, bordering on fear associations in many of us. When a malignant tumor occurs in any organ, it is removed. And what about blood cancer, which continuously moves throughout the body and visits each organ dozens of times a day. Many people consider this disease to be 100% fatal, but, meanwhile, it can be treated like any oncology. Its correct name is leukemia or leukemia. What it is? What factors cause it? Are there any remedies that can cure him? Is leukemia inherited? Why do small children get sick? Let's try to answer all these questions.
Blood factories
It is impossible to explain what leukemia is without telling more about blood. It seems to be a homogeneous fluid, but in fact it contains thousands of microscopic elements - red blood cells, platelets, and white blood cells. All of them, in the time allotted to them, age and die. The place of the dead is immediately occupied by new ones. They are produced by the so-called "factories" of hematopoiesis, located in the thymus, spleen, lymph nodes, bone marrow of the tubular and hip bones. In any production, raw materials are required to produce the final product. In hematopoietic "factories", stem cells are the raw material. As necessary, they mutate (differentiate), turning into particles necessary for blood. This process is called cell maturation. A certain system behind him exercises strict control. Scientists so far do not know much about this hematopoietic “controller”, it is only known that during maturation, stem cells undergo multiple metamorphoses, gradually turning into myelocytes, normocytes, prolymphocytes and others, until they reach the last stage in which the changes end. For example, a lymphocyte goes through the stages of a lymphoblast and a pro-lymphocyte, and a red blood cell passes through a stage of an erythrocytoblast, pronormocyte, normocyte, and reticulocyte. When this complex “conveyor” malfunctions, unripe cells from intermediate stages begin to massively divide, the chain of further transformations breaks. For example, it does not come to lymphocytes, but stops at lymphoblasts. It turns out an excess of unnecessary useless cells, which accumulate so much that they displace normal hematopoietic sprouts. So leukemia occurs. What it is? This is a malignant disease of the hematopoietic system.
Chronic form
Leukemia is classified according to various characteristics. By the nature of the course of tumor processes , their acute and chronic forms are distinguished. In this case, these definitions are conditional and do not correspond to generally accepted ones. So, the forms of leukemia do not depend on the duration of the disease and never turn into one another, but each has a stage of remission and relapse. A dangerous feature of leukemia is the rapid transport of mutant cells by blood to any organs, which causes the onset of the tumor process in them.
Consider chronic leukemia in more detail. What is it and why is it called that? This type of disease is caused by mutations of already formed, ready-to-work blood cells (red blood cells, white blood cells and platelets). More often it manifests itself at the age of 50 years and older. Forms of chronic leukemia:
- myelocytic;
- neutrophilic;
- myelosclerosis;
- basophilic;
- myelomonocytic;
- monocytic;
- erythromyelosis;
- lymphocytic leukemia;
- hairy cell leukemia;
- lymphomatosis
- histocytosis;
- areretrimia;
- thrombocythemia.
Each of them has its own characteristic symptoms. For example, with myelocytic leukemia, the only signs of the onset of the disease are weakness, sweating, fatigue. The spleen is not enlarged, the blood composition is normal. The only thing that may alert is an increased number of neutrophils in the blood, although this is observed in any infectious processes.
Common features of progressive chronic leukemia are:
- weakness;
- excessive sweating;
- enlarged spleen;
- enlarged lymph nodes;
- rash on the skin and mucous membranes;
- necrotic processes of the skin and organs;
- with exacerbation, blast crisis in the blood and bone marrow;
- infectious diseases;
- increase in blood white blood cell count;
- leukocyte infiltrates in the bone marrow;
- decreased immunity.
Chronic lymphocytic leukemia
This disease causes mutations in mature lymphocytes, with 90-98% of them in group “B”. Here, benign and malignant stages are distinguished. The latter very quickly passes into lymphosarcoma. The onset of the disease is almost indefinable, since the patient does not feel any suspicious symptoms at all, and all blood tests show the norm, including the number of leukocytes. Over time, a sick person begins to tire more quickly, sweating appears, and the lymph nodes and spleen increase slightly. Chronic lymphocytic leukemia has an independent form called hairy cell leukemia, characterized by villous outgrowths of the cytoplasm, moreover, it contains a lot of phosphatase and is resistant to tartaric acids. With this form, not the lymph nodes increase, but the spleen. Its second sign is cytopenia, that is, a decrease in the blood of one or all of the immediately formed elements.
At the initial stages, the diagnosis of all forms of lymphocytic leukemia is difficult even when performing blood tests, since their results are similar for any infectious ailments. Also, inflammatory processes in the lymph nodes, which may not be associated with leukemia, are prevented from correctly diagnosing. The patient is first given a course of antibiotic treatment, and then the diagnosis is clarified by the methods of histological and
cytological studies, an x-ray is performed (with leukemia in the lungs, lymphocyte infiltrates are formed, chest lymph nodes are enlarged).
Acute form of leukemia
In childhood and adolescence, acute leukemia is more often observed. What is it and why is it dangerous? This type of disease is caused by mutations in blood cells in an immature, primary (blast) state. Depending on which forms of the primary cells have mutated, the following types of acute leukemia are distinguished:
- monoblastic;
- myeloblastic;
- erythromyeloblastic;
- myelomonoblastic;
- acute lymphoblastic leukemia;
- undifferentiated.
Since during acute leukemia in the blood, useful working particles are replaced by immature ones, the blood gradually loses its functions, namely supplying organs with oxygen and nutrients. Also, the work of white blood cells to protect the body from foreign microorganisms is significantly reduced or completely lost.
Symptoms of Acute Leukemia
All types of this disease have a first stage (attack), remission, relapses. It should be noted that both primary and repeated relapse of acute leukemia are possible. The general symptomatology of the disease is as follows:
- tumor growths in the bone marrow;
- severe forms of anemia;
- general weakness with shortness of breath and dizziness;
- bleeding and ulceration of the mucous membranes (stomatitis, tonsillitis, ulcers in the esophagus and intestines are common);
- skin rash;
- enlargement of the liver, spleen, lymph nodes;
- pneumonia;
- pain in the bones when they are beaten (cause the growth of mutant cells in them);
- sepsis and other infectious complications.
The stage of remission occurs when immature cells are no longer detected in the blood, no more than 5% in the bone marrow, and there are no leukemic growths outside the bone marrow.
The most dangerous and common among children in the age group 1-6 years is acute lymphoblastic leukemia. More often they get sick boys.
Since lymphocytes exist in the forms “B” (responsible for the production of antibodies) and “T” (fighting foreign particles), lymphoblastic leukemia is divided into several types, in each of which certain forms of white blood cells mutate. In percentage terms, the "B" form is the leader, the share of which is 85%. The peak incidence occurs in children from 3 years, since it is at this age that the body actively produces “B” leukocytes. The “T” form takes the lead among adolescents aged 14-15, when the thymus gland reaches its maximum size. At the stage of remission with this type of leukemia, cerebrospinal fluid must be normal. A child whose remission lasts 5 years or more is considered to be recovered. The survival rate of children with timely and proper treatment of acute leukemia is 80-85%.
Reasons and diagnosis
Leukemia in adults and children causes abnormalities in the structure of chromosomes, which may be due to hereditary defects or external influences. These include:
- radiation (radiation);
- carcinogens (drugs, food, chemicals);
- nicotine;
- chemotherapy for tumors.
The theory of the viral etiology of leukemia has not yet been proven.
Among hereditary factors, there is a significant increase in leukemia diseases among those suffering from Down, Bloom, and Turner syndromes.
Diagnosis of leukemia includes:
- external examination (palpation of the lymph nodes, detection of changes in the mucous membranes);
- laboratory blood tests for the quantitative composition of red blood cells, lymphocytes, red blood cells, platelets;
- bone marrow biopsy;
- PCR (allows you to detect the Philadelphia chromosome, if any);
- FISH analysis (shows changes in chromosomes);
- IFT (identifies cells using markers and antigens).
Treatment
Patients with leukemia are required to undergo chemotherapy (tablets, injections of drugs). This treatment method allows you to kill all mutated cells. Chemotherapy courses, as a rule, are at least two - the main, at the stage of the acute form of the course of the disease, and prophylactic, at the stage of remission. At the end of the first stage of treatment and when 100% of the result is achieved, bone marrow cells are transplanted. If relapse occurs after all the work done, this indicates the ineffectiveness of the medications used. In such cases, the treatment regimen is changed. Relapse of leukemia always reduces the survival rate. Doctors distinguish several types of disease return:
1. By timing
- super early (survival rate of only 10%);
- early;
- late (success is achieved in 38% of cases).
2. By localization
- outside the bone marrow;
- bone marrow (the most dangerous);
- combined.
A very serious and, in most cases, unpredictable disease is leukemia. What is it dangerous in addition to impaired blood function? Firstly, the fact that cancer cells spread easily and quickly throughout the body. Secondly, the most serious complications of the course of the disease, in which mutant cells can penetrate the lining of the brain. Thirdly, the side effects caused by all types of treatment for leukemia.
Leukemia cattle (cattle)
All animals, including reptiles, also suffer from leukemia, the second name of which is hemoblastosis. It was described back in 1858. At first, it was believed that this disease is not dangerous for humans. Now, thanks to new studies, it has been proven that animal leukemia is a significant threat to humans. To date, the disease has been well studied, but treatment has not yet been developed. As in humans, leukemia in animals is manifested in tumor proliferation (proliferation) of hematopoietic tissue cells with the release of a large number of unripe lymphoblasts and myeloblasts into the blood. The bovine leukemia virus causes such mutations. A certain optimism instills its instability to high temperatures and chemicals. So, in meat it dies in a minute already at a temperature of 60 ° C, and in milk, at a temperature of 75 ° C, in 20 seconds. Solutions of formaldehyde, chlorine, caustic soda are easily eliminated from the virus. But in living animals it is impossible to destroy it. The fact is that it affects lymphocytes. Any type of therapy aimed at the destruction of the leukemia virus, at the same time destroys the white blood cells, without which the animal dies.
Symptoms and course of the disease
Leukemia of cattle can be asymptomatic for up to 6 years. All this time, the animal is a virus carrier that can infect other animals and humans, as well as reproduce sick offspring, thereby spreading the disease to livestock farms. There are 4 stages of the course of the disease:
- subleukemic;
- initial;
- detailed;
- terminal.
At the first stage, routine blood tests show the norm. Only specific blood tests (serological tests, virological tests) can detect the disease. In state farms they are carried out as planned, and in private people often do not suspect that his beloved burenka is terminally ill.
The second stage is characterized by an increase in the number of leukocytes and lymphocytes in the blood, and a large percentage of their immature forms appears. However, there are still no external signs of the disease.
Only in the third stage, cattle leukemia begins to show clinical symptoms. These include:
- animal fatigue;
- general deterioration, exhaustion;
- reduction in milk yield;
- problems with the digestive tract (diarrhea or constipation, difficulty in chewing);
- yellowing of the mucous membranes;
- worsening heart function;
- numerous edema (in the area of the udder, chest, abdomen);
- falling on hind limbs;
- eyeballs;
- enlarged lymph nodes (sometimes they reach the size of the child’s head).
The final stage does not last long. In this case, all clinical symptoms are pronounced, a high percentage of mutated white blood cells is found in the blood with a tendency to their overall quantitative decrease. The animal loses its ability to fight the disease and dies.
In young animals, all stages quickly pass, and an adult animal sometimes dies instantly, from a rupture of the spleen. This can happen before the onset of symptoms of the disease.
Prevention
Since treatment of animal leukemia is impossible, prevention is of great importance in the fight against the disease. First of all, it consists in conducting timely analyzes. In large farms they are performed every year 1 time for all animals and 2 times for bulls. If more than 2 virus carriers are detected in the herd, the economy is considered to be dysfunctional. Correction of the situation is carried out in two ways - culling sick animals and replacing the entire population. At the same time, cowsheds are disinfected without fail.
Of great importance is also the prevention of the importation of young animals to an existing livestock. All imported animals must be checked for oncornavirus.
Is there leukemia of milk and meat obtained from sick animals? Unfortunately yes. Milk obtained from patients with leukemia of cows is strictly forbidden to drink fresh. Such milk should be delivered to dairies, where it is subjected to prolonged pasteurization. At home, you can drink it after a long (at least 5 minutes) boiling. Many doctors recommend using this milk only for animal feed.
Meat, if there is no lesion of muscle leukemia, can also be eaten after thorough heat treatment. If organs or skeletal muscles are affected in a slaughtered or dead animal, then its carcass must be disposed of.