Acute leukemia
The content of the article:
- Causes and risk factors
- Forms of the disease
- Disease stages
-
Symptoms of acute leukemia
- Acute myeloid leukemia
- Acute lymphoblastic leukemia
- Features of the course of acute leukemia in children
- Diagnostics of the acute leukemia
- Treatment of acute leukemia
- Possible complications and consequences
- Prognosis for acute leukemia
- Prevention
Acute leukemia is an oncological disease of the hematopoietic system. The tumor substrate in leukemia is blast cells.
All blood cells come from one source - stem cells. Normally, they mature, passing through differentiation and developing along the path of myelopoiesis (leading to the formation of erythrocytes, leukocytes, platelets) or lymphopoiesis (leading to the formation of lymphocytes). In leukemia, the blood stem cell mutates in the bone marrow at the early stages of differentiation and subsequently cannot complete development along one of the physiological pathways. It begins to divide uncontrollably and forms a tumor. Over time, abnormal immature cells displace normal blood cells.
Synonyms: acute leukemia, blood cancer, leukemia.
Causes and risk factors
The exact causes of leukemia are not known, but a number of factors have been established that contribute to its development:
- radiotherapy, radiation exposure (this is evidenced by the massive growth of leukemia in the territories where nuclear weapons were tested or in places of technogenic nuclear disasters);
- viral infections that suppress the immune system (T-lymphotropic virus, Epstein-Barr virus, etc.);
- the influence of aggressive chemical compounds and some medicines;
- smoking;
- stress, depression;
- hereditary predisposition (if one of the family members suffers from an acute form of leukemia, the risk of its manifestation in loved ones increases);
- unfavorable ecological situation.
Forms of the disease
Depending on the rate of multiplication of malignant cells, leukemia is classified into acute and chronic. Unlike other diseases, acute and chronic are different types of leukemia and do not transform one into another (i.e., chronic leukemia is not a continuation of an acute one, but a separate type of disease).
Acute leukemias are divided according to the type of cancer cells into two large groups: lymphoblastic and non-lymphoblastic (myeloid), which are further divided into subgroups.
Lymphoblastic leukemia primarily affects the bone marrow, then the lymph nodes, thymus gland, lymph nodes and spleen.
Depending on which precursor cells of lymphopoiesis prevail, acute lymphoblastic leukemia can take the following forms:
- pre-B-form - precursors of B-lymphoblasts predominate;
- B-form - B-lymphoblasts predominate;
- pre-T-form - precursors of T-lymphoblasts predominate;
- T-form - T-lymphoblasts predominate.
With non-lymphoblastic leukemia, the prognosis is more favorable than with lymphoblastic leukemia. Malignant cells also first affect the bone marrow, and only in the later stages affect the spleen, liver and lymph nodes. Often, with this form of leukemia, the mucous membrane of the gastrointestinal tract also suffers, which leads to serious complications up to ulcerative lesions.
Acute non-lymphoblastic or, as they are also called, myeloid leukemia, are divided into the following forms:
- acute myeloid leukemia - the appearance of a large number of granulocyte precursors is characteristic;
- acute monoblastic and acute myelomonoblastic leukemia - based on active reproduction of monoblasts;
- acute erythroblastic leukemia - characterized by an increase in the level of erythroblasts;
- acute megakaryoblastic leukemia - develops as a result of active multiplication of platelet precursors (megakaryocytes).
Acute undifferentiated leukemias are distinguished into a separate group.
Disease stages
Clinical manifestations are preceded by a primary (latent) period. During this period, leukemia, as a rule, proceeds unnoticed by the patient, without any pronounced symptoms. The primary period can last from several months to several years. During this time, the first reborn cell multiplies to such a volume that it suppresses normal hematopoiesis.
With the appearance of the first clinical manifestations, the disease enters the initial stage. Its symptoms are not specific. At this stage, a bone marrow study is more informative than a blood test, an increased level of blast cells is found.
At the stage of advanced clinical manifestations, the true symptoms of the disease appear, which are caused by the suppression of hematopoiesis and the appearance of a large number of immature cells in the peripheral blood.
At this stage, the following variants of the course of the disease are distinguished:
- the patient does not make complaints, there is no pronounced symptomatology, but signs of leukemia are found in the blood test;
- the patient has a significant deterioration in well-being, but there are no pronounced changes in the peripheral blood;
- both the symptomatology and the blood picture indicate acute leukemia.
Remission (the period of exacerbation subsiding) can be complete and incomplete. Complete remission can be considered in the absence of symptoms of acute leukemia and blast cells in the blood. The level of blast cells in the bone marrow should not exceed 5%.
With incomplete remission, the symptoms subside temporarily, but the level of blast cells in the bone marrow does not decrease.
Recurrences of acute leukemia can occur both in the bone marrow as well as outside it.
The last, most severe stage of the course of acute leukemia is terminal. It is characterized by a large number of immature leukocytes in the peripheral blood and is accompanied by suppression of the functions of all vital organs. At this stage, the disease is practically incurable and most often ends in death.
Symptoms of acute leukemia
Symptoms of acute leukemia are manifested by anemic, hemorrhagic, infectious-toxic and lymphoproliferative syndromes. Each form of the disease has its own characteristics.
Acute myeloid leukemia
Acute myeloid leukemia is characterized by a slight enlargement of the spleen, damage to the internal organs of the body, and increased body temperature.
With the development of leukemic pneumonitis, the focus of inflammation is in the lungs, the main symptoms in this case are cough, shortness of breath and fever. A quarter of patients with myeloid leukemia have leukemic meningitis with fever, headache, and chills.
At a later stage, renal failure may develop, up to complete urinary retention. In the terminal stage of the disease, pink or light brown formations appear on the skin - leukemides (skin leukemias), and the liver becomes denser and larger. If leukemia has affected the organs of the gastrointestinal tract, severe abdominal pain, bloating, and loose stools are observed. Ulcers may form.
Acute lymphoblastic leukemia
The lymphoblastic form of acute leukemia is characterized by a significant increase in the spleen and lymph nodes. Enlarged lymph nodes become noticeable in the supraclavicular region, first on one side, and then on both. Lymph nodes thicken, do not cause pain, but can affect adjacent organs.
With an increase in the lymph nodes located in the region of the lungs, cough and shortness of breath appear. The involvement of the mesenteric lymph nodes in the abdominal cavity can cause severe abdominal pain. Women may experience induration and pain in the ovaries, more often on one side.
In acute erythromyeloblastic leukemia, anemic syndrome comes to the fore, which is characterized by a decrease in hemoglobin and erythrocytes in the blood, as well as increased fatigue, pallor and weakness.
Features of the course of acute leukemia in children
In children, acute leukemia accounts for 50% of all malignant diseases, and they are the most common cause of infant mortality.
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The prognosis of acute leukemia in children depends on several factors:
- the age of the child at the time of the onset of leukemia (the most favorable in children from two to ten years);
- the stage of the disease at the time of diagnosis;
- form of leukemia;
- gender of the child (girls have a more favorable prognosis).
If the child does not receive specific treatment, death is likely. Modern treatment with chemotherapy provides 5 years without relapse in children in 50-80% of cases. If there is no relapse within 7 years, there is a chance for a complete cure.
To prevent recurrence, it is undesirable for children with acute leukemia to carry out physiotherapeutic procedures, to be exposed to intense insolation and to change the climatic conditions of residence.
Diagnostics of the acute leukemia
Often, acute leukemia is detected according to the results of a blood test when the patient applies for another reason - the so-called blast crisis, or leukocyte failure (absence of intermediate cell forms) is found in the leukocyte formula. Changes in the peripheral blood are also observed: in most cases, patients with acute leukemia develop anemia with a sharp decrease in erythrocytes and hemoglobin. There is a drop in platelet count.
As for leukocytes, two options can be observed here: both leukopenia (a decrease in the level of leukocytes in the peripheral blood) and leukocytosis (an increase in the level of these cells). As a rule, pathological immature cells are also found in the blood, however, they may be absent, their absence cannot be a reason to exclude the diagnosis of acute leukemia. Leukemia, in which a large number of blast cells are found in the blood, is called leukemic, and leukemia with the absence of blast cells is called aleukemic.
The study of the red bone marrow is the most important and accurate method for diagnosing acute leukemia. The disease is characterized by a specific picture - an increase in the level of blast cells and inhibition of the formation of erythrocytes.
Another important diagnostic method is bone trephine biopsy. Bone sections are sent for biopsy, which reveals blast hyperplasia of the red bone marrow and thus confirms the disease.
Treatment of acute leukemia
Treatment of acute leukemia depends on several criteria: on the patient's age, condition, stage of the disease. A treatment plan is drawn up for each patient individually.
Most of the disease is treated with chemotherapy. If it is ineffective, they resort to bone marrow transplantation.
Chemotherapy consists of two sequential steps:
- stage of induction of remission - achieve a decrease in blast cells in the blood;
- consolidation stage - necessary to destroy the remaining cancer cells.
This may be followed by re-induction of the first step.
The average duration of treatment for acute leukemia is two years.
Bone marrow transplant provides the patient with healthy stem cells. Transplantation consists of several stages.
- Search for a compatible donor, bone marrow collection.
- Patient preparation. In the course of preparation, immunosuppressive therapy is carried out. Its goal is to destroy leukemic cells and suppress the body's defenses so that the risk of transplant rejection is minimal.
- The actual transplantation. The procedure resembles a blood transfusion.
- Bone marrow engraftment.
It takes about a year for the transplanted bone marrow to fully engraft and begin to perform all its functions.
According to statistics, disease-free survival after bone marrow transplantation ranges from 29 to 67%, depending on the type of leukemia and some other factors.
Possible complications and consequences
Acute leukemia can provoke the growth of cancerous tumors in places of lymph node accumulation, hemorrhagic syndrome and anemia. Complications of acute leukemia are dangerous and often fatal.
Prognosis for acute leukemia
In children, the prognosis for acute leukemia is more favorable than in adults, which is confirmed by statistics.
With lymphoblastic leukemia, the five-year survival rate in children is 65-85%, in adults - from 20 to 40%.
Acute myelogenous leukemia is more dangerous, the five-year survival rate in young patients is 40-60%, and in adults - only 20%.
Prevention
There is no specific prophylaxis for acute leukemia. It is necessary to visit a doctor regularly and undergo all necessary examinations in a timely manner in case of suspicious symptoms.
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Anna Aksenova Medical journalist About the author
Education: 2004-2007 "First Kiev Medical College" specialty "Laboratory Diagnostics".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
