Chronic Lymphocytic (CLL) and Myelogenous (CML)

Hello readers,

In my previous two posts, I discussed acute lymphoblastic and myeloid leukemia, however, there are two other types of leukemia that are labelled as chronic. Usually in medical terms, the word chronic means to be continuing for a long time, or recurring, therefore a disease labelled chronic would be continuing for a long duration. On the other hand, an acute disease would have a rapid onset or last for a short course. Therefore, chronic lymphocytic and myelogenous leukemia tends to progress slowly over the course of many years. I'll be discussing the two diseases in more detail below.

Chronic Lymphocytic Leukemia

In the UK, around 8,600 cases of leukaemia are diagnosed and about 3,200 (37 percent) of these are chronic lymphocytic leukaemia. It is more common in older people, most cases occurring in people over 60 and is rare in people under 40. Men are more likely to develop chronic lymphocytic leukaemia than women, however it is not known why. Although in its early stages, there are usually no noticeable symptoms, as the condition develops, symptoms can include repeated infections occurring over a short space of time, tiredness due to a lack of red blood cells, unusual bleeding and bruising, fever, night sweats, bone pain, weight loss, swollen spleen and swollen lymph nodes.

Classified according to the type of white blood cells affected, lymphocytic leukaemia affects the type of white blood cells called lymphocytes. In the bone marrow where stem cells are produced that can mature into red blood cells, white blood cells and platelets, stem cells start overproducing white blood cells that are not fully developed which are lymphocytes. The overproduction of lymphcytes is at the expense of other blood cells, resulting in a lack of red blood cells and platelets that cause tiredness and increasing the likelihood of excessive bleeding. In some people with chronic lymphocytic leukaemia, the body's immune system can start attacking red blood cells and cause haemolytic anemia. As white blood cells are not properly formed, immature lymphcytes are much less effective at fighting bacteria and viruses.

It is not known what causes leukaemia, however, there are several risk factors that may increase your chances of developing chronic leukaemia which include having a family history of the condition, being of European, American or Australian origin, having certain medical conditions such as pneumonia, sinusitis or shingles, and being male.

Some people can live or years or decades with chronic lymphocytic leukaemia without developing systems or needing treatment and so it may not necessarily always be required. In such cases, a policy of watchful waiting will be employed, involving regular visits to the doctor and blood tests to closely monitor the patient's condition. If treatment is required, chemotherapy will usually be recommended and radiotherapy may be needed to shrink swollen lymph nodes. Treatment cannot cure chronic lymphocytic leukaemia completely but can slow its progression and lead to remission.

Chronic Myelogenous Leukemia

A rare type of cancer, chronic myelogenous leukemia affected around 680 people in the UK in 2001 out of the 8,600 people diagnosed with leukaemia. It can affect people of any age, but is more common in people aged 40-60. Classified according to the type of white blood cell affected by the cancer, chronic myelogenous leukemia affects the myeloid cells. A genetic mutation causes the stem cells in bone marrow to over-produce white blood cells that correspond to the drop in levels of red blood cells and platelets which causes symptoms of anemia such as tiredness and excessive bleeding. As the condition develops, symptoms include tiredness, weight loss, night sweats, feeling of bloating, bruising, and bone pain. The outlook depends on how well a person responds to medication; most patients, numbering 60 to 65 percent, do well on imatinib tablets which taken daily for life. For those who do not, more than half respond to one of the alternative drugs: nilotinib, for example. For those who fail these drugs or cannot tolerate them, they may be offered a bone marrow transplant if it is suitable treatment. If diagnosed early, the outlook is excellent, with almost 90 percent of people living at least five years after diagnosis.

Cells affected:

Lymphocytes



It is any of the three types of white blood cells responsible for immune responses. There are two main types of lymphocytes: B-cells and T-cells, as well as natural killer cells. B-cells make antibodies that attack bacteria and toxins while the T-cells attack body cells themselves when they are taken over by viruses or have become cancerous. Lymphocytes secrete products (lymphokines) that modulate functional activities of many other types of cells and are often present at sites of chronic inflammation. Natural killer cells play a major role in defending the host from tumors and virally infected cells, distinguishing infected cells and tumors and when activated in response, release cytotoxic granules that destroy the altered cells.


Myeloid cells



The name refers to the granulocyte precursor cell in the bone marrow or spinal cord stem cells. They are controlled by distinct transcription factors that follow on by a terminal differentiation in response to specific stimulating factors and release into the circulation. When pathogens invade cells, myeloid cells go into local tissues via chemokine receptors, where they are then activated for phagocytosis and secretion of inflammatory cytokines, therefore, plays a major role in immunity. Phagocytosis is the process in which a cell engulfs a solid particle to form an internal vesicle known as a phagosome.

Acute Myeloid Leukemia (AML)

Another leukemia cancer, called Acute Myeloid (AML), is a rare cancer that can affect people at any age but is more common in people over 65. Around 2.500 people are diagnosed with AML each year in the UK. People with AML suffer from the occurrence of many abnormal leukemia cells being made and immature cells unable to develop into normal functioning blood cells.

To understand more about AML, it helps to know about blood in our bodies and the process it goes through. Blood, made up of blood cells that flout in a liquid called plasma, is a constantly circulating fluid that provides the body with nutrition, oxygen and waste removal. It is a mostly liquid fluid with numerous cells and proteins suspended in it, making blood thicker than pure water. A liquid called plasma makes up about half of the content of blood containing proteins that help blood to clot, transport substances through the blood, and perform other functions. Blood plasma also contains glucose and other dissolved nutrients. It is conducted through blood vessels, arteries and veins.

Blood cells are made in the bone marrow, a spongy material found in the middle of our bones, particularly in our pelvis and backbone. 

Normally, millions of blood cells would be made every day to replace old and worn-out blood cells. All blood cells come from two different types of stem cells: lymphoid stem cells and myeloid stem cells. In the bone marrow, stem cells go through the process of dividing and starting off immature and then growing to form fully mature red blood cells, platelets and white blood cells. Immature cells are known as blast cells that stay in the bone marrow until they have matured. Once they mature, they are released into the body to provide certain functions:

Red blood cells contain haemoglobin which carries oxygen from your lungs to all the cells in your body

Platelets are very small cells that help blood to clot and prevent bleeding and bruising

White blood cells fight and prevent infection. There are two types: neutrophils and lymphocytes

In AML, too many early myeloid cells and abnormal leukaemia cells are made. These immature cells cannot develop into normal functioning blood cells and fill up the bone marrow, taking up the space needed to make normal blood cells. Some of the leukaemia cells 'spill over' into the bloodstream and circulate the body. This leads to an increased risk of infection, anemia symptoms and bruising caused by fewer healthy red blood cells and platelets being made. 

Symptoms 

Most symptoms develop due to the effects of the leukaemia cells in the bone marrow, leaving it unable to produce enough normal blood cells. This results in symptoms such as looking pale and feeling tired and breathless, having more infections, unusual bleeding, feeling generally unwell and run down, and having a fever and sweats. Other less common symptoms may be caused by a build-up of leukaemia cells in a particular area of the body, causing bones to ache due to the pressure from a build-up of immature cells in the bone marrow. Raised, bluish-purple areas under the skin may occur due to leukaemia cells in the skin, or swollen gums caused by leukaemia cells in the gums.  

Treatment

The aim of treatment for AML is the destroy the leukaemia cells and allow the bone marrow to work normally again. When there is no sign of the leukaemia and bone marrow is working normal, the patient would be at remission. Chemotherapy is the main treatment used and research has shown that certain types of chemotherapy drugs can be very effective in treating AML. However, in some situations, high dose treatment and a stem cell or bone marrow transplant are used to improve the chances of curing leukaemia.

New treatments

While they are not currently licensed for use in the UK, patients may be offered one or more of these newly developed drugs as part of their treatment if they take part in a research trial.

Clofarabine is similar to another drug commonly used to treat people with AML, however, it has fewer side effects and thought to be more suitable for older people who are less able to have intensive chemotherapy. It is given as a drip into the vein and only available for people with AML as part of research trials.

Gemtuzumab is made up of a combination of a monoclonal antibody and chemotherapy drug. The monoclonal antibody attaches itself to a protein found on the surface of leukaemia cells, carrying the chemotherapy directly to the leukaemia cells. It is hoped that this drug will target the chemotherapy against leukemia cells and cause less damage to healthy cells.

Some people with AML have a mutation in the leukaemia cells called FLT3 which can increase the risk of leukaemia coming back in the future. AC220 is an experimental new treatment designed to act against cels with this mutation 

Arsenic trioxide is licensed to treat people who have acute promyelocytic leukaemia that has reoccured after treatment or has not gone into remission with treatment. Made from the poison arsenic, it is given at low, safe doses.

Acute Lymphoblastic Leukemia

Hello readers,

The next cancer that I will be discussing is acute lymphoblastic leukemia, one of the few types of leukemia cancers. Also known by its shorthand ALL or acute lymphoid leukemia, this cancer is an acute form of leukemia, a cancer of the white blood cells, causing the overproduction of cancerous, immature white blood cells that are known as lymphoblasts. When these lymphoblasts are overproduced in the bone marrow, they continually multiply, which in turn causes damage and death by inhibiting the production of normal cells such as red and white blood cells and platelets in the bone marrow and by spreading to other organs. ALL is most common in childhood.

It is classified according to the type of the white blood cells affected. There are two types: lymphocytes which are mostly used to fight viral infections, and neutrophils, which have multiple functions, such as fighting bacterial infections, defense against parasites and prevention of the spread of tissue damage. Lymphoblastic leukaemia is a cancer of the lymphocytes.

All the blood cells in the body are produced by the bone marrow, a spongy material found inside bones. The bone marrow produces specialized cells called stem cells which have the ability to develop into three blood cells: red blood cells which carry oxygen around the body, white blood cells that fight injections and platelets which act as coagulants so help stop bleeding. Stem cells would fully develop before being released into the blood. However, in acute leukemia, bone marrow releases large numbers of immature white blood cells. As the number of these immature white blood cells increase, there is a drop in the number of red blood and platelet cells. This causes symptoms of anemia, such as tiredness, and increases the risk of excessive bleeding. The immature white blood cells are less effective at fighting bacteria and viruses, which results in increased vulnerability to infection.

Symptoms

The cause of leukemia are uncertain, but there are known risk factors which include exposure to high levels of radiation or exposure to benzene, a chemical used in manufacturing that is also found in cigarettes. The symptoms are usually slow to begin with before getting rapidly severe as the number of immature of white blood cells in blood increase. They include pale skin, tiredness, breathlessness, repeating infections over a short space of time and unusual and frequent bleeding.

Treatment

Acute lymphoblastic leukemia is treated usually by a combination of chemotherapy and radiotherapy, however, in some cases, treatment may also include a bone marrow transplant as a cure. Without treatment, there is a risk that the lack of healthy blood cells can make the person vulnerable to life-threatening infections due to the lack of white blood cells or uncontrolled and serious bleeding due to the lack of platelets. For children, the outlook is usually good - almost all children will be in remission and 85% completely cured. However, the outlook for adults are not as good, as only 40% of people with the condition will be completely cured.

Hodgkin's Lymphoma

Hello readers,

I hope you all had a merry Christmas and wonderful holiday! It may not be the a very festive post today but since I heard some sad news that a very dear friend of mine was diagnosed with Hodgkin's Lymphoma, and never hearing of it before, I thought that it would be a good idea to spend some time writing on the disease to shed some light on for those who may want to learn more about it.

To understand Hodgin's, it is helpful to have a basic understanding of the lymphatic system. It is a system that is one of the body's defenses against infections and diseases made up of lymphatic organs such as bone marrow, tonsils, thymus, spleen and lymph nodes. Lymph nodes are throughout the body, although are mainly found in the neck, armpit and groin, and are connected by a network of tiny lymphatic tubes. Circulating in the lymphatic vessels are a fluid called lymph that contains something called lymphocytes which are also known as white blood cells. They are a significant part of our immune system, essential at fighting viruses, bacteria and other foreign bodies that threaten our health. They are produced inside the bone marrow and stored in our blood and lymphatic tissues.

As lymph circulates the body, the fluid passes through the lymph nodes which filter out bacteria that cause infection. Sometimes, if you have a cold, the lymph nodes in your neck may get larger which is a sign that your body is fighting the infection. There are two main types of white blood cells (lymphocyte) - T-cells and B-cells. While both types develop in the bone marrow from immature cells to stem cells, T-cells mature in the thymus gland and B-cells mature in the bone marrow or lymphatic organs.

Here is a diagram showing the lymphatic system is green all over the body.

In summary, the lymphatic system is composed of a series of vessels that are all over the body which drain fluid from tissues. Bacteria and other microbes are picked up in the lymphatic fluid and trapped inside lymph nodes where they are attacked and destroyed by white blood cells.

Hodgkin's Lymphoma
It is a cancer of the lymphatic system and can be divided into two main types:
Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Its cause is unknown, however, there are some risk factors that may contribute to its development including poor immunity and previous exposure to the Epstein Barr virus which causes glandular fever. It is most common in younger people aged 20-34 and older people aged 70-79. Having a member of the family with Hodgkin lymphoma may slightly increase someone's risk of getting it, but it is not known whether this is caused by an inherited faulty genes or because families may have similar lifestyle factors that affect their risk.

Symptoms
The first is usually a swelling in the neck, armpit or groin which are usually painless but some find that they ache. Other symptoms may include frequent sweats, especially at night, unexplained high temperatures, weight loss, tiredness, a cough or breathlessness or a persistent itch all over the body. A few people with Hodgkin lymphoma have abnormal cells in their bone marrow when diagnosed which can lower the number of healthy blood cells in the blood which in turn, can cause breathlessness and tiredness, increased risk of infection and/or excessive bleeding. When diagnosing a patient, the doctor may take blood tests and a chest x-ray and a definite diagnosis is made by a biopsy where the removal of an enlarged lymph node or part of it is examined under a microscope.

Staging

• Stage 1: one group of lymph nodes is affected
• Stage 2: two or more groups of lymph nodes are affected on the same side of the diaphragm 
• Stage 3: lymph nodes above and below the diaphragm are affected
• Stage 4: the lymphoma has spread outside the lymph nodes to organs such as the liver, bones or lungs

If the Hodgkin lymphoma comes back after initial treatment, this is known as recurrent lymphoma. As well as a stage, doctors use a letter: A or B, to show whether or not you have certain symptoms (unexplained high temperatures, drenching night sweats, for example). If the patient doesn't have these symptoms, the doctor will prescribe the letter A next to the stage. If the patient has one or more of these symptoms, the letter B is prescribed next to the stage.  

Treatment

Luckily, with current treatment the majority of people with Hodgkin's lymphoma can be cured. The main types of treatment are chemotherapy and radiotherapy and a treatment plan would be decided based on the results of the staging tests and other factors such as age, general health, what parts of the body is affected and specific type of Hodgkin lymphoma. 

Chemotherapy involves the use of anti-cancer, also known as cytotoxic, drugs to destroy the lymphoma cells by disrupting their growth and can reach lymphoma cells anywhere in the body through the bloodstream. The drugs can be administered as tablets or capsules or by injection into a vein in your arm which is called intravenously. A combination of several drugs is normally given over a few days followed by a break and would continue from 2 to 6 months depending on the stage of lymphoma.

Radiotherapy treats cancer by the use of high-energy rays that destroy the cancer cells while doing as little harm as possible to normal cells because it only treats the area of the body it is aimed at. This is usually provided after a course of chemotherapy for early-stage disease as part of the overall treatment. In more advanced stage disease, it may be used after after chemotherapy to treat areas where there may still be cancer. 

Another treatment is called high-dose treatment with stem cell support for Hodgkin lymphoma. This is a high-dose chemotherapy treatment if the standard chemotherapy had not completely gotten rid of the disease and may also be used if the lymphoma reoccurs. High doses of chemotherapy destroy the bone marrow where blood cells are usually made which means stem cells must be collected from your body at a time when you are well - this is called stem cell harvest. The stem cells are collected by a process where blood is removed through a needle in your arm and it is then passed through a machine called a cell separator where stem cells are separated from the rest of your blood. Alternatively, stem cells can be collected from your bone marrow. Stem cells are then frozen and kept in storage until the patient receives high-dose treatment and once it is administered, stem cells are thawed and given back through a drip to support their immune system.

Steroid therapy involves steroids, such as prednisolone or dexamethasone, which are drugs that are often given with chemotherapy to help treat Hodgkin lymphoma which may help the patient feel better and reduce nausea.

Possible long-term effects from the treatment may be permanent infertility from some chemotherapy drugs. Both chemotherapy and radiotherapy can also lead to a slightly increased risk of developing another cancer later in life. 

Hope this has been informative and, as always, thanks for reading  

Plans for Mars

Hello readers!

Recent reports on Mars have been discussing the speculation of possible form of life on the red planet due to Nasa's rover, Curiosity's detection of fluctuating wafts of methane. These unexplained spikes of methane levels detected, unable to be easily correlated by geology or transportation of organic material by comets or asteroids, has resulted in a few hypotheses including the suggestion that these spikes offer evidence of life on Mars.

Only last year the US space agency reported that Gale Crater, located on the Martian equator when a meteor hit the planet, contained the remains of an ancient freshwater lake that may have once been a hospitable environment for life in the past. The latest discovery adds to the possibility of gathered evidence of life on Mars. Curiosity recorded a 10-fold increase in methane in the atmosphere, additionally detecting other organic molecules in powdered rock that was obtained by the rover's drill, becoming the first definitive detection of organics in surface materials on Mars. These could have formed either on Mars or landed on Mars by meteorites. The spikes in methane are provoked interest as life is the main producer of methane on Earth, however, many non-biological processes can also generate the gas. Speculation on the methane fluctuations have included the idea of the Sun's rays degrading organic material deposited by meteors and methane being formed by microbial bugs that are known as methanogens.   

Named after the Roman god of war and dubbed the red planet due to its iron-rich minerals that cover the surface that give it a rusty red color, Mars is the fourth planet from the Sun that has the largest volcanoes in the solar system as well as the highest mountain and deepest valley. It has a cold, thin atmosphere which means that liquid water cannot currently exist on the Martian surface for any length of time, resulting in the desert planet having the same amount of dry land as Earth despite being half in diameter. With channels, valleys and gullies discovered across Mars, this suggests that liquid water may have flowed across the planet's surface in recent times and may still lie in cracks and pores in underground rock. Cooler than Earth, its average temperature is roughly minus 80 degrees Fahrenheit, however, it can vary depending on time and season. Its carbon-dioxide-rich atmosphere means that it is dense enough to support weather, clouds and winds. NASA's detection of carbon-dioxide snow clouds makes Mars the only body in the solar system known to host winter weather. However, dust storms also occupy the planet, capable of lasting for months resulting in blanketing the entire planet.   

The possibility of life on Mars was first considered in 1996 when Geologist David McKay and his colleagues discovered in the rocks blasted from the surface of Mars grains of a mineral called magnetite that can form within certain kinds of bacteria and tiny structures that resembled fossilized microbes. The hypothesis that Mars may have once possessed oceans on its surface offer the opinion that it provided an environment where life can develop, a hypothesis further established with the discovery of the lake when beforehand establishing the planet had key ingredients present for life to evolve.   

Currently in process is an important development in space exploration; the Mars One Mission that aims to establish a human settlement on Mars. This project involves firstly building Earth-based simulation outposts for training, technology, try-outs and evaluation and the construction of rocket launches that would take payloads into Earth orbit and then onto Mars that include satellites, rovers, cargo or humans. Other necessities would include the Mars Transit Vehicle that would ensure the travel of human crew in space and a landing capsule that would carry life support unites, living units, rovers and mars suits. People are currently going through a vigorous process to be one of the chosen humans to be a part of the Mars One crew, who would have to go through eight years of training isolated from the world for several months every two years before being considered to settle permanently on Mars. So it seems that while we have yet to know whether life was or is on Mars for certain, the future ahead is dedicated to the emigration of humans to live on the red planet.

Thank you for reading!

Sources

http://www.space.com/47-mars-the-red-planet-fourth-planet-from-the-sun.html
http://www.mars-one.com/mission/humankind-on-mars
http://www.theguardian.com/science/2014/dec/16/methane-spikes-mars-fuel-speculation-life-nasa-curiosity