LEUKAEMIA
Leukemia (American English) or Leukaemia (British English) from the Greek word “Leukos –white” and “Haima – blood” is a type of cancer of the blood or blood marrow characterized by the abnormal increase of white blood cells. Leukemia is a broad term covering a spectrum of diseases. In turn, it is part of the even broader group of diseases called haematological neoplasm (derived from haematology i.e. the study of blood).
Worldwide around 350,000 people are diagnosed with leukaemia in 2008. About 90% of all leukaemia are diagnosed in adults.
Contents
1. Classification
2. Signs and symptoms
3. Causes
4. Diagnosis
5. Treatment
5.1 Acute lymphoblastic
5.2 Chronic lymphocytic
5.2.1 Decision to treat
5.2.2 Typical treatment approach
5.3 Acute myelogenous
5.4 Chromic myelogenous
5.5 Hairy cell
5.6 T-cell prolymphocytic
5.7 Juvenile myelomonocytic
6. Epidemiology
7. History
8. Research
9. Society and culture
10. See also
11. References
12. External links
Classification
Four major kinds of leukaemia;
Cell type: Acute and Chronic
Lymphocytic leukaemia (or “lymphoblastic)
Acute lymphoblastic leukaemia (ALL) Chronic lymphocytic leukaemia (CLL)
Myelogenous leukaemia ( also “myeloid” or “nonlymphocytic”)
Acute myelogenous leukaemia (AML) Chronic myelogenous leukaemia (CML)
Acute leukaemia is characterized by a rapid increase in the numbers of immature blood cells. Crowding due to such cells makes the bone marrow unable to produce healthy blood cells. Immediate treatment is required in acute leukaemia due to the rapid progression and accumulation of the malignant cells which the spills over into the bloodstream and spread to other organs of the body. Acute forms of leukaemia are the most common forms of leukaemia in children.
Chronic leukaemia is characterized by the excessive build up of relatively mature, but till abnormal white blood cells. Typically taking months or years to progress. The cells are produced at a much higher rate than normal cells resulting in many abnormal white blood cells in the blood. Whereas acute leukaemia must be treated immediately. Chronic forms are sometimes monitored for some time before treatment to ensure maximum effectiveness of therapy. Chronic leukaemia mostly occurs in older people but can theoretically occur in any age group.
Additionally, the diseases are subdivided according to which kind of blood cell is affected. This split divides leukaemias into lymphoblastic or lymphocytic leukaemias and myeloid or myelogenous leukaemias.
In lymphocytic or lymphocytic leukaemia the cancerous change takes place in a type of marrow cell that normally goes on to form lymphocytes, which are infection fighting immune system cells. Most lymphocytic leukaemia involves a specific subtype of lymphocyte the B cell.
In myeloid or myelogenous leukaemias the cancerous change take place in a type of marrow cell that normally goes on to form red blood cells.
Some other types of white cells and platelets.
Combining these two classifications provided a total of four main categories. Within these main categories there are typically eight subcategories. Finally, some rarer types are usually considered to be outside of this classification scheme.
Acute lymphoblastic leukaemia (ALL) is the most common type of leukaemia in young children. This diseases also affects adults especially those age 65 and older. Standard treatments involve chemotherapy and radiation. The survival rates vary by 85% in children and 50% in adults.
Subtypes include precursor B acute lymphoblastic leukaemia, precursor T acute lymphoblastic leukaemia. Burkitt’s leukaemia and acute biphenotypic leukaemia.
Chronic lymphocytic leukaemia (CLL) most often affects adults over the age of 55. It sometimes occurs in younger adults but it almost never affects children. Two-thirds of affected people are men. The five year survival rate is 75%. It is incurable but there are many effective treatments. One subtype is B-cell prolymphocytic leukaemia, a more aggressive disease.
Acute myelogenous leukaemia (AML) occurs more commonly in adults than in children, and more commonly in men than women. AML is treated with chemotherapy. The five-year survival rate is 40%.
Subtypes of AML include acute promyelocytic leukaemia, acute myeloblastic leukaemia and monocytic leukaemia.
Hairy cell leukaemia (HCL) is sometimes considered a subset of CLL, but does not fit neatly into this pattern. About 80% of affected people are adult men. There are no reported cases in young children. HCL is incurable but easily treatable survival is 90% to 100% at ten years.
T-cell prolymphocytic leukaemia (T-PLL) is a very rare and aggressive leukaemia affecting adults somewhat more men than woman are diagnosed with this disease.
Despite its overall rarity, it is also the most common type of mature leukaemia nearly all other leukaemia involve B-cells. It is difficult to treat and the median survival is measured in months.
Large granular lymphocytic leukaemia may involve either T-cell or NK cells like hairy leukaemia which involves solely B-cells. It is a rare and indolent (not aggressive) leukaemia.
Adult T-cell leukaemia is caused by human T-lymphotropic virus (HTLV) a virus similar to HIV. Like HIV, HTLV infects CD4+ T-cells and replicates within them. However, unlike HIV, it does not destroy them instead, HTLV “immortalizes” the infected T-cells giving them the ability to proliferate abnormally.
In summary, leukaemia is gotten from the Greek word “Leukos (white) and Haima (blood). It is the cancer of the blood or bone marrow characterized by abnormal increase of white blood cells. In 2008, about 350,000 people were diagnosed with leukaemia and 90% were adults.
Leukaemia can be classified according to cell types: Acute and Chronic
Acute: Acute lymphoblastic leukaemia and Acute myelogenous leukaemia
Chronic: Chronic lymphoblastic leukaemia and Chronic myelogenous leukaemia
v Acute leukaemia is caused by rapid increase in the number of immature blood cells thereby crowding occurs making the marrow unable to produce healthy blood cells. If not treated in time, it will spill over into the bloodstream and affect other organs. It is mostly common in children.
v Chronic leukaemia is caused by the excessive build-up of mature but abnormal white blood cells. It takes months or years to progress and cells are produced at a much higher rate than normal cells causing abnormal white blood cell in the blood. It is common in older people.
NOTE: Acute leukaemia can be treated immediately but Chronic leukaemia are for sometimes monitored to ensure maximum effectiveness of therapy.
LEUKAEMIA
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FOUND IN
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AGE BRACKET
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TREATMENT
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SURVIVAL CHANCE
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Acute lymphoblastic leukaemia (A.L.L)
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It is common in young children and affects adults.
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65 and above
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Chemotherapy and radiation
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85% in children
50% in adults
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Chronic lymphoblastic leukaemia (C.L.L)
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Most often affects adults and sometimes in younger adults. It almost never affect chidren.2/3 are men.
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55 and above
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It is incurable
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75% survival
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Acute myelogenous leukaemia (A.M.L)
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Common in adults but mostly found in men than women.
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Adults
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Chemotherapy
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40% survival
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Chronic myelogenous leukaemia (C.M.L)
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Occurs mainly in adults. Very small amount of children develop this disease.
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Adults
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Imatinib
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90% survival
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SIGNS AND SYMPTOMS
1. Inability of the body to clot.
2. Frequent infections e.g. sores in mouth, diarrhoea
3. Fever
4. Chills
5. Fatigue
6. Night sweat
7. Weight loss
CAUSES
1. Somatic mutation in the deoxyribonucleic acid (DNA).
2. Exposure to radiation or carcinogenic substance e.g. asbestos.
3. Inheritance from parents.
4. Chromosomal abnormalities.
DIAGNOSIS
Three tests are carried out to check the part affected and they are: X-ray, MRI or ultrasound
v X-ray used to test the bones.
v MRI used to test the brain and kidney.
v Ultra-sound used to test the liver.
TREATMENT
v Pharmaceutical medication combined with multi drug chemotherapy regimen.
v Radiotherapy
v Surgically by the transplant of the bone marrow.
HISTROY
Leukaemia was first observed by pathologist Rudolf Virchow and John Hughes Bennet in 1845. They observed an abnormal large number of white blood cells in a blood sample from a patient. Virchow called the condition Leukamie in German which was from two Greek words Leukos(white) aima(blood). After 10 years, a pathologist Franz Ernst Christian Neumann found that one deceased leukaemia victim’s bone marrow was coloured dirty greenish yellow as opposed to the normal red which made him conclude that a bone marrow problem was responsible.
RESEARCH
By 1947, Boston Sydney Farber believed from past experiments that amino-pterin, a folic acid mimic could potentially cure leukaemia in children. Majority of the children with acute lymphoblastic leukaemia (A.L.L) tested showed signs of improvement but none was actually cured.
Qin 1962, researches were done by Emil. Freireich (Jnr) and Emil Frei III using combination chemotherapy to attempt curing leukaemia. The test was successful with some patients surviving long after the test.
