Description leukemia
Leukemia can be simply understood as a blood cancer. The essence of this cancer is actually genetic deviation some of the cells, which circulate in the blood and which originate in the bone marrow.
Because the cells and their developmental stages is very much, there are also a number of “leukemia” collectively calledmyeloproliferative and lymphoproliferative diseases (= proliferation multiplication or division, a multiplication of tumor cells).
Many of them have relatively less serious nature, however, can pass in some form of classical leukemia. Examples are myelodysplastic syndrome, polycythemia right (polycythaemia rubra vera), primary thrombocythemia, primary myelofibrosis, and others. Among the most common symptoms include increased bleeding and clotting.
Among lymphoproliferative diseases also include lymphomas,which are cancers arising from blood cells such as leukemia, but, unlike them, are located in the lymph nodes (e.g. the neck, armpit, groin) which swells and the tumor is therefore visible .
Classical leukemia “not seen” because it is in the blood vessel is not increased in any way. In some cases it happens that the so-called lymphoma. Leukemizuje ie. cancer cells get into the blood and vice versa leukemia enters his diseased cells into one body – the lymph nodes (ie has the form lymphoma), spleen or liver and thus locates.
Can not say whether they have a greater chance of cure patients with leukemia or lymphoma, because, first, there are many kinds as leukemias and lymphomas, and prognosis of each patient is governed by histology, generally applies that the cells are mature (most similar to normal adult healthy cell) and the less diseased cells a patient has, the better the prognosis.
In terms of greater clarity you dedicating four basic types of leukemia (ie leukemia in the true sense of the word – not lymphomas, polycythemia, thrombocythemia, etc.), Which you will learn more acute myeloid leukemia, chronic myeloid leukemia, acute lymphocytic leukemia and chronic lymphocytic leukemia.
The word “acute” implies faster progression of the disease, the word “chronic” turn slower, but sometimes even acute leukemia takes longer than chronic, depending of course on treatment.
Some leukemia have other subtypes according to the maturity of cells, this is true particularly in acute myeloid leukemia. To get a glimpse into the medical terminology and to better understand the various leukemias, we will find a brief overview of the blood cells.
blood cells
Blood cells are called cells. We divide them into two main groups – red blood cells (erythrocytes), white cells (leukocytes). Among blood cells sometimes lies and platelets (thrombocytes), which participate in blood coagulation.
White blood cells are more types, the most important are lymphocytes that produce antibodies (B-lymphocytes), and play an essential role in the defense against infections in the immune system and defense against tumors (T lymphocytes).
Another important white blood cells belongs called. Neutrophilic granulocytes (neutrophils for short), which defends the body against bacterial infections in particular.
In bone marrow, which normally takes place hematopoiesis, each person has a certain number called. Stem cells, which are cells capable of totally immature and ferment in any cell red or white line. When the “sick” These stem cells are then affected by the same genetic defect and all of its daughter cells, so it may be both a red and a white blood cell.
More often, however, leads to damage to the cells at a lower level of development – with few mature lymphocytes or neutrophils.
Stem cell establishes two main lines – lymphoid, which is then still separated into T and B (depending on B lymphocytes and T-lymphocytes) and myeloid, which are included precursors of red blood cells, neutrophils, platelets and other cells. Hence derive the names “myeloproliferative” (= myelomonocytic something related to bone marrow) and “lymphoproliferative” syndromes.
The more affected cells mature (more remote from stem cells), the better, because it is not affected by many types of cells and more cells are then healthy – such as “sick” direct precursor B lymphocytes (ie it would be enough one cell division and was by mature B-lymphocyte) are a little better than if “sick” stem cell or a distant ancestor of B-lymphocyte (it would take several more division to produce mature B-lymphocytes), because cells that carry genetic variation are only the descendants of this cell (in our case, the direct ancestor of B-lymphocytes) and other cells are healthy, others also predecessors B-lymphocytes – the same age, but the “sons” and other ancient predecessors of stem cells, which in this case are also healthy .
Acute myeloid leukemia
This is a leukemia that occurs mostly in older age, although it can also occur in children under 15 years. Its incidence is 3-4 cases per 100,000 inhabitants per year over 65 years, however, gets up to 15 cases per 100,000 inhabitants per year.
Because of myeloid lineage originates many types of cells (red blood cells, platelets and white blood cells that are primarily neutrophils and monocytes), there are more subtypes of leukemia according to the developmental stages of cells affected. On it, on which type is strongly dependent and prognosis of the patient.
The number of white blood cells varies between individuals. Some patients may be increased tenfold, with other normal or slightly reduced. The more diseased white blood cells, the disease is severe. White blood cells as has been said, although desirable for defending the body against infections, but when they are sick, they are actually broken and the patient is conversely endangered by infections can not resist.
Risk factors for acute myeloid leukemia
The origin of leukemia are probably meaning environmental factors such as various chemicals (benzene, phosgene, alkylating agents etc.), And ionizing radiation. This is evidenced by the higher incidence of this leukemia after the atomic bomb in Japan.
The other has less modifiable factors are viral infections, prior treatment with cytostatic cancer and genetic influences. Some patients have a congenital predisposition for leukemia, which means that the risk of leukemia they are much higher than in people who do not have this genetic predisposition. These are mainly patients with Down syndrome, Klinefelter’s syndrome, Fanconi’s anemia and Recklinghausen disease (neurofibromatosis). All of these patients have been somehow compromised genome and other small deviation is sufficient to produce a leukemia, whereas in otherwise healthy people are required at least two deviation.
People who have myelodysplastic syndrome or polycythemia right, are also at risk of developing leukemia. Myelodysplastic syndrome is sometimes considered directly předstádium for acute myeloid leukemia in polycythemia is a risk of a reversal of leukemia about 1-2%.
Progress and symptoms of acute myeloid leukemia
Symptoms are similar to other leukemia nonspecific and very colorful. The illness may initially look like a flu. Patients are tired, weak, having temperatures.
Nearly half of the patients, the first symptom that brings the patient to the doctor, small subcutaneous haemorrhage is often punctate or in the form of bruises. There may also be a frequent or excessive bleeding from the nose or gums. Severe bleeding is rare Velna.
These symptoms are caused by the oppressed of the bone marrow due to the increasing number of leukemia cells, so blood is then generally less normal red blood cells – anemia (anemia), fewer platelets – caused bleeding (because it violated blood clotting) and neutrophils less – can developinfections against which the body loses its defensive system.
Examination of acute myeloid leukemia
In the diagnosis of leukemia are crucial blood tests and a bone marrow biopsy.
In acute myeloid leukemia is also crucial immunological, and cytogenetic analysis in which recognize different genetic variations, some of which define a good prognosis and others are bad.
Treatment of acute myeloid leukemia
The goal of treatment is up to free the patient leukemic cells, ideally, is completely eradicated.Today, there are various treatment methods and procedures vary somewhat according to the subtype of leukemia. Despite the great popularity and great success of transplantation of cells, it should be emphasized that the essential therapeutic method remains chemotherapy.
Cytostatics are numerous (daunorubicin, cytarabine, hydroxyurea, cytosine arabinoside, …) are administered in different combinations and in different phases.
Acute leukemias are generally better to treat chronic leukemia cytotoxic than having to cytostatics less susceptible cells (cytostatic better engage on leukemias in which the cells proliferate more).
This treatment usually lasts a few weeks together and brings with it unfortunately also a lot of side effects such as vomiting, inflammation of the oral cavity and other bone marrow. They are not only to eradicate leukemic cells, but also of the rest of healthy blood cells, so it is necessary to deliver other medicines to restore hematopoiesis.
In this leukemia is suitable irradiation – first irradiation of the brain as a prevention against ingress of leukemia and there, secondly, the whole body before bone marrow transplantation. It takes place only in some patients prefer it gives to young people between 20 to 25 years, allowing for long-term survival.
When he was a patient with acute myeloid leukemia treated, he would die when weakened immunity (little functional neutrophils) within a few weeks of an infection. Treatment currently brings hope temporary, and sometimes permanent cure. The result of treatment depends on the type of leukemia, the age, and genetic abnormalities and total white blood cell count at diagnosis.
Chronic myelogenous leukemia
This leukemia represents about 25% of all adult leukemias, therefore, only one to two cases per 100,000 people per year. It occurs most often between the 45th-55th year, with a slightly higher frequency in men. For children it is very rare.
A characteristic feature of chronic myelogenous leukemia is the presence of so-called. Philadelphia chromosome. Chromosome is a component of the cell nucleus and are stored as individual genes dimension (ie DNA) .In the cell is several chromosomes, and in this leukemia is currently the 22ndtruncated chromosome and are connected to it two genes that otherwise belong each to a different chromosome, so that when they are together on one, make the “mischief” which consists in the excessive proliferation of leukaemic cells and also increased resistance to their demise.Nevertheless, patients with Philadelphia-chromosome better prognosis compared to patients lacking (5% of chronic myeloid leukemia).
Patients usually have a significantly higher number of white blood cells when the blood becomes more viscous, it slows the flow of blood and can develop thrombosis (excessive clotting).
Other times may occur as bleeding from a lack of platelets, although their number is usually normal if not higher. Leukemic cells are much more mature than in acute leukemia, therefore prognosis slightly better.
Risk factors for chronic myelogenous leukemia
As with acute myeloid leukemia may contribute to disease onset environmental factors – ionizing radiation and chemicals.
A risk factor is also already mentioned Philadelphia chromosome.
Symptoms and course of chronic myeloid leukemia
The beginning of the disease can be subtle, so the diagnosis is often determined based on random blood count. Other times leukemia reflected pressure in the left upper quadrant tenderness andfullness in the upper abdomen. This is caused by an enlarged spleen, where they also get leukemia cells. Sometimes it may be spleen and inflamed and it shows severe pain spreading to the left shoulder.
For non-specific symptoms of patients have fevers, sweats, weight loss, sometimes have a pain in the bones, which indicates increased breakdown of bone (osteoporosis) during expansion of leukemic cells in bone marrow.
Patients are anemic (anemia), a shortage of red blood cells and thus are Dušní – harder to breathe them. Furthermore, there may be an infectious disease, neurological disorders, such as visual disturbances.
Disease goes untreated in three phases – chronic (3-4 years), accelerated (1-1.5 years) andmalignant (ie. Metamorphosis). Recent moves in acute leukemia and takes approximately 3-6 months.
Examination of chronic myeloid leukemia
Investigations are practically the same as in acute myeloid leukemia. From laboratory tests in addition to data of blood cells in blood and bone marrow can be read increased concentration of vitamin B12 and elevated levels of calcium, which is related to the degradation of bone (osteoporosis), and also to the disappearance of leukemic cells.
What is important is the lack of certain enzymes and cytogenetic analysis that demonstrates Philadelphia chromosome.
Treatment of chronic myeloid leukemia
Originally fatal disease is now curable in some patients or treatment can be achieved variously long-lasting temporary recovery (remission), which normalizes blood count and symptoms of the disease disappear.
The only method that can really lead to a complete cure is stem cell transplantation. Cell transplantation from unrelated donors are always risky, because they are better known. Autologous transplantation (after removal of cells from their own body), but these are only performed at selected sites.
In the pharmacological treatment does not play the role of a classical cytostatic, as more different substances that somehow interfere with the genetic and immune mechanisms. , Antibodies(Glivec), plant extracts (berbamin of plants Berberis amurensis), or interferon.
Is tested and new cytostatics (decitabine troxacitabine …) and vaccine therapy.
Thanks to frequent transplantation and antibody imatinib (Glivec), the prospects of leukemia have improved substantially.
Acute lymphocytic leukemia
Sometimes we encounter as acute lymphoblastic leukemia, which means the same thing.
It is the most common leukemia in children and even the most common childhood cancer around 4 years. In adults it is scarce even increasing also in people over 50 years. Total is reported 5-7 cases per 100 000 population.
The leukemia can be derived from either B cell (often) or T-lymphocytes. In any case, the bone marrow is these cells are massively crowded, so oppresses the original hematopoiesis and sick again have anemia and are prone to bleeding.
There are several known subtypes according to the maturity of cells influencing prognosis similar to acute myeloid leukemia, although to a lesser extent.
Risk factors for acute lymphocytic leukemia
Some rare forms of leukemia undoubtedly relates to viral infection – virus HTLV-1, which causes leukemia young adults in southern Japan, Africa and the Caribbean, and Epstein-Barr virus (EBV virus), which is the cause of mononucleosis.
As with acute myeloid leukemia risk group consists of patients with certain hereditary syndromes– with Down syndrome, neurofibromatosis and Fanconi’s anemia, are up to 20 times more leukemia patients than the healthy population.
More than 85% of leukemia patients are detected some defects in chromosomes that is closely related to their prognosis. For example, presence of Philadelphia chromosome (see. Chronic myeloid leukemia) which thus arises called. Hybrid leukemia, because it comes from both myeloid and lymphoid lines, indicative of a worse prognosis (against the chronic myelogenous, where on the contrary this modified chromosome is prognosis better ).
Progress and symptoms of acute lymphocytic leukemia
General symptoms such as fatigue, weakness, anemia and bleeding symptoms are similar to acute myeloid leukemia. Compared to her, but patients are often pain in the joints and bones, because there penetrate the bone marrow leukemic cells.
Patients also have enlarged lymph nodes and spleen slightly, which can cause pressure in the left upper quadrant, rarely are magnified and liver. In 5-13% of patients penetrate leukemic cells also in meningitis, patients can then have some of the neurological symptoms – visual disturbances, headache, and others. 10-15% of men having unhealthy cell affected and testes, which can therefore be increased.
Examination acute lymphocytic leukemia
They are important for proper diagnosis mainly auxiliary laboratory immunological andcytogenetic testing of blood.
The obligate procedures include the testing of spinal fluid (from lumbar puncture – from the back), and examined by an ophthalmologist to determine whether leukemic cells and in the brain.
The doctor must rule out lymphoma, which leukemizovaly and some infections – mononucleosis and others. Of course, it is his task to determine the correct type of leukemia and distinguish this acute to chronic.
Treatment of acute lymphocytic leukemia
The basic therapy, as with acute myeloid leukemia chemotherapy. Used especially vincristine, daunorubicin, asparaginase, cyclophosphamide and corticosteroids (prednisone). Usually they administered intravenously.
Cytostatics to give even through the spinal canal to the brain in combination with radiation skull.It is an effective prevention against leukemia cells to reach the brain.
Unfortunately sometimes encountered even with side effects of cytostatics – vincristine is toxic to the nervous and digestive systems and buzz mischief when administered outside the vein.Daunorubicin may rarely negative effects on the heart. Asparaginase again somewhat detrimental to the liver and causes coagulation disorders, possible they are also allergic reactions and toxic effect on the nervous system. Cyclophosphamide is known for bloody inflammation of the bladder. As a precaution, therefore, serves mesna, to prevent such inflammations. Despite all these negatives, it is good to undergo treatment, because only then can we win the fight with this cancer.
After recovery (remission) at high-risk patients makes cell transplantation (such as those who have the Philadelphia chromosome).
Otherwise, the standard of maintenance therapy with low-dose chemotherapy (methotrexate, mercaptopurine) for up to one year.
Is tested and a number of new products, the T-leukemia is, for example nelarubin (Arranon) orantibody (rituximab).
Among the favorable prognostic factors include age – children are often achieves a cure than in adults (who tend to have more Philadelphia chromosome), it is around 30-40%. Furthermore, a smaller number of white blood cells at diagnosis also plays a positive role. When remission is achieved later than 4-6 weeks of intensive therapy are the chances of recovery worse.
Chronic lymphocytic leukemia
It is the most common type of leukemia, and all of them have also, fortunately, the best prognosis. Occur annually 30 cases per 100 000 population. Predominantly affects men over 50 years.
As with previous acute leukemia mostly based on B-lymphocytes. However, there are T-leukemia, some of which have rarely cutaneous localization (Sézary syndrome). Rare are also B-leukemia, based on the so-called. Hairy cell (hairy cell leukemia), with hair that has nothing to do, these are microscopic hairs that are on the surface of leukemic cells.
The blood and bone marrow are mostly moderately ill mature B lymphocytes. Their superiority lies in the failure of cell death, so that they survive excessively long compared to healthy cells and longer maturate, so do not work as they should. Interestingly, even so not reproduce other leukemias, in short they need to survive and thus exceeds the number of healthy cells.
Risk factors for chronic lymphocytic leukemia
Unlike other leukemia have not been linked with exposure to ionizing radiation. The origins of this leukemia is probably therefore purely genetic (note – not the same as genetic hereditary! Leukemia is generally not hereditary disorder in DNA not from her parents, but originates with the individual throughout life randomly and again does not pass other descendants).
Progress and symptoms of chronic lymphocytic leukemia
The course of the disease is chronic, ie usually lasts much longer compared to acute leukemia, obviously correlates with a greater chance of a long life.
Initially, the disease occurs mostly without symptoms, diagnosis is determined based on random blood count. In advanced stages, patients have enlarged lymph nodes (submandibular, cervical, supraclavicular, armpit or groin). They may be small, but also reach a size tangerines. Not unlikepainful inflammation, such as tonsillitis.
Enlarged spleen also.
Oppression normal hematopoiesis is reflected back from anemia, lack of neutrophils – theincreased susceptibility to infections and also the lack of platelets – thus increased bleeding.
Investigations of chronic lymphocytic leukemia
As always makes the blood and bone marrow. Of particular importance is in this leukemiacytogenetic test that shows the presence or absence of certain “bad genes”. Accordingly, then selects and treatment.
Treatment of chronic lymphocytic leukemia
The disease can be their course divided into five stages.
In the first stage, the patient has only leukemic cells in the blood, resulting in increased numbers of white blood cells in the blood.
In the second stage, the addition and enlarged lymph nodes in both the third and the spleen or liver.
The fourth stage is characterized by increased blood thinners and fifth lack of platelets (both from the oppression of the bone marrow and its hematopoiesis).
The first three stages are mostly treat only the case when enlarged nodes is subjective patient discomfort or oppresses the surrounding structure – the neck, for example, respiratory or digestive tract.
In the fourth and fifth stages, treatment is initiated immediately. The therapy is based cytostatics – fludarabine (Fludara) and cyclophosphamide or chlorambucil (Leukeran).
Corticosteroids are reserved for the treatment of complications (see. Below). They are used inantibody transplantation is still “in its infancy”.
Can induce long-term remission of total body irradiation. Irradiated spleen also separately only to decrease its volume, as well as sometimes isolated irradiation affected nodes to oppress surroundings. In some cases, the patient awaits surgery spleen.
Complications and prognosis of chronic lymphocytic leukemia
The most common complication is infection, usually bacterial. Linked with immune deficiencies and the lack of certain white blood cells – neutrophils. Of the viral infection is a common herpes (chickenpox and shingles). Often it is otherwise quite common infection, but the patient’s immune system can not handle.
Except neither exaggerated response of patients to any vaccination – vaccination. Because are often ill B cells is impaired and formation of antibodies. They may be present, but do not work properly and operates rather then damaging – are directed against cells own body, for example against red blood cells and also the mechanism actually cause anemia (ie. Haemolytic anemia, which is itself complications)., Or are directed against platelets and thereby bleeding (ie. thrombocytopenic purpura).
The disease can also complicate some other tumor diseases, as well as the immune system is important in fighting infections, they play an important role in the defense against tumors and if does not work, does not work defense.
Despite all these difficulties has chronic lymphocytic leukemia best prognosis, patients live with it for ten or twenty years, sometimes more.
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Future treatment of leukemia
Leukemia is clearly one of a very serious disease, which we know from a number of films (Love Story, Dying Young, Day for My Love, My Life Without Me, Lost and Found, Something for Joey, Last good guy and more), where the main heroes of leukemia They are dying. We must realize that, like most of these films is already old, a time when leukemia was totally incurable, it is also gone.
Medical progress goes forward unimaginably along with genetics and other disciplines. In the seventies, yet it did not know under what mechanisms leukemia occur. Some viruses causing certain types of leukemia, have been found only in the eighties. Today examines lot of genes that can cause leukemia while already tested full spectrum of new drugs on the basis of already identified some genetic processes.
The aim of progress in treatment is to move from cytostatic drugs and their side effects to a treatment that would clearly interfere in the mechanism and affected so other healthy cells.Therefore, we mindlessly kill leukemia cells, but we treated the specific cause of the leukemia.
Doctors and scientists are therefore doing everything in their power.
Other Names: blood cancer, myeloproliferative disease, lymphoproliferative disease, malignant blood diseases, acute myeloid leukemia, AML, chronic myelogenous leukemia, CML, acute lymphocytic leukemia, ALL, chronic lymphocytic leukemia, CLL
