BRAC UNIVERSITY
SUMMER 2014
BTE 310: MEDICAL BIOTECHNOLOGY
DATE: 21.08.2014

ASSIGNMENT:
LEUKEMIA

SUBMITTED BY:
Prateem Das
ID: 12136014
BIOTECHNOLOGY, MNS

SUBMITTED TO:
ROMANA SIDDIQUE
LECTURER
MNS

DEPARTMENT OF MATHEMATICS AND NATURAL SCIENCES

Introduction

Leukemia is a type of cancer that results in the body making too many abnormal white blood cells. This uncontrolled production results in an excessive amount of white blood cells that may be immature (acute leukemia) or mature (chronic leukemia). The leukemic cells may not function well to fight infection and may interfere with the production of red blood cells (which carry oxygen) and platelets (which control bleeding).

Normally, white blood cells play an important role in the body's natural defence system. They target and destroy foreign invaders like viruses and bacteria. White blood cells are made in the marrow (the spongy core) of your bones. Without healthy and functioning white blood cells, the body is at risk of developing severe and sometimes fatal infections.

Different types of leukemia
Acute leukemia develops within days to weeks, and large numbers of immature cells called "blasts" build up. These cells can't function as well as normal white blood cells, so people with acute leukemia are at a higher risk of infection. Because the body is so busy producing "blasts," it can't make as many red blood cells or platelets, which can cause anemia and bleeding disorders.
Chronic leukemia, which progresses over the course of months to years, involves overproduction of mature white blood cells that cannot function like normal white blood cells.
There are 4 types of leukemia:
Acute lymphocytic leukemia (ALL) is the most common form of leukemia in children. It is the result of an uncontrolled production of a type of white blood cell called lymphocytes. This causes a buildup of the immature forms of lymphocytes. The high numbers also interfere with the production of red blood cells and platelets.
Chronic lymphocytic leukemia (CLL) most often occurs in people over 55 years of age. It is the most common type of leukemia overall, and occurs about twice as often in men as in women. It develops at a slower rate than ALL. Gradually, leukemic cells outnumber the normal-functioning cells in certain tissues in the body, including the bone marrow where other blood cells are made.
Acute myeloid leukemia (AML) causes uncontrolled production of another type of white blood cell called myelocytes. This causes an overgrowth of their immature cells called myeloblasts. This interferes with the levels of functioning red blood cells, platelets, and normal white blood cells. AML is the most common form of acute leukemia in adults.
Chronic myelogenous leukemia (CML) occurs more slowly than AML and has less effect on the development of other cell types. Chances of getting CML are very low for children but increase with age. CML is associated with the Philadelphia chromosome.

Symptoms and Complications of Leukemia
Leukemia either causes a shortage of functioning white blood cells, which can impair the immune system, or a buildup of extra white blood cells.
In acute leukemias the extra white blood cells are mostly immature, whereas in chronic leukemias the white blood cells are mature but still function poorly. In either case, fewer platelets (the type of blood cells that help stop bleeding) are produced, causing excessive bleeding. Minor injuries can result in hard-to-stop bleeding and large bruises. Tiny red spots may appear just under the skin.
Because the immune system isn't working normally, infections are more frequent. Lymph glands and the spleen may become enlarged, causing pain in the left side of the abdomen.
If abnormal cells accumulate in the brain and spinal cord (as in AML), the symptoms include vomiting and headaches. Occasionally, abnormal cells can accumulate in the skin, causing lumps (chloromas) or skin rashes. A lack of red blood cells causes the skin to look pale. It also results in fatigue and shortness of breath.
Diagnosing Leukemia
Blood and bone marrow are sampled to check the types and numbers of blood cells present. High levels of immature white blood cells (and low red blood cell and platelet counts) indicate acute leukemia.
Special tests such as cytogenetic analysis and flow cytometry can help identify the abnormal cells. Knowing the specific type of leukemia helps the doctor determine the appropriate treatment.

Treatments of lukemia

Lymphoma Treatment
Some form of chemotherapy, radiation therapy, or a combination of the two is typically used to treat Hodgkin lymphoma. Bone marrow or stem cell transplantation may also sometimes be done under special circumstances. Most patients with Hodgkin lymphoma live long and healthy lives following successful treatment.
Many people treated for non-Hodgkin lymphoma will receive some form of chemotherapy, radiation therapy, biologic therapy, or a combination of these. Bone marrow or stem cell transplantation may sometimes be used. Surgery may be used under special circumstances, but primarily to obtain a biopsy for diagnostic purposes.
Although "indolent" forms of non-Hodgkin lymphoma are not currently curable, the prognosis is still very good. Patients may live for 20 years or more following an initial diagnosis. In certain patients with an indolent form of the disease, treatment may not be necessary until there are signs of progression. Response to treatment can also change over time. Treatment that worked initially may be ineffective the next time, making it necessary to always keep abreast of the latest information on new or experimental treatment options.
Approximately 30 to 60 percent of patients with an aggressive form of non-Hodgkin lymphoma can be cured.

Future Treatments of lukemia

* Immunotherapy * Stem Cell Transplantation

Bone Marrow Transplant (BMT) and stem cells
Bone marrow transplant is used to treat several types of cancer and is commonly used for leukemias, lymphomas and other blood cell cancers. The usual doses of chemotherapy drugs can cause serious side effects to quickly dividing tissues such as the bone marrow. Even though higher doses of these drugs might be more effective, they are not given because they could severely damage the bone marrow, which is where new blood cells are formed. This could lead to life-threatening infections, bleeding, and other problems due to low blood cell counts. A stem cell transplant (SCT) allows doctors to use higher doses of chemotherapy (sometimes combined with radiation therapy). After that treatment is finished, the patient receives an infusion of blood-forming stem cells to restore the bone marrow.
Blood-forming stem cells used for a transplant are obtained either from the blood (for a peripheral blood stem cell transplant, or PBSCT) or from the bone marrow (for a bone marrow transplant, or BMT). Sometimes stem cells harvested from a baby’s umbilical cord are used.
Types of transplants
There are 2 main types of stem cell transplants: allogeneic and autologous. They differ with regard to the source of the blood-forming stem cells.
Allogeneic stem cell transplant
This is the most common form of SCT used to treat acute leukemia. In an allogeneic transplant, the stem cells come from someone else – usually a donor whose tissue type is almost identical to the patient’s. Tissue type is based on certain substances on the surface of cells in the body. These substances can cause the immune system to react against the cells. Therefore, the closer a tissue “match” is between the donor and the recipient, the better the chance the transplanted cells will “take” and begin making new blood cells.
The ideal donor is a close relative, such as a brother or sister, if they are a match. If no close relatives match, a matched unrelated donor (MUD) may be an option in some cases, but use of stem cells from a MUD is linked to more complications. The stem cells from an unrelated donor come from volunteers whose tissue type has been stored in a central registry and matched with that of the patient. Sometimes umbilical cord stem cells are used. These stem cells come from blood drained from the umbilical cord and placenta after a baby is born and the umbilical cord is cut.
Using donor cells for SCT for acute myeloid leukemia (AML) is preferred because leukemia is a disease of the blood and bone marrow, so giving the patient his or her own cells back may mean giving leukemia cells. Donor cells are also helpful because of the “graft versus leukemia” effect. When the donor immune cells are infused into the body, they may recognize any remaining leukemia cells as being foreign to them and will attack them. This effect doesn’t happen with autologous stem cell transplants
An allogeneic transplant is often the preferred type of transplant for AML when it is available, but its use is limited by the need for a matched donor. It is also limited by its side effects, which are too severe for most older people.
Non-myeloablative transplant (mini-transplant): Many older people can’t tolerate a standard allogeneic transplant that uses high doses of chemotherapy. Some may be able to have a non-myeloablative transplant (also known as a mini-transplant or reduced-intensity transplant), where they receive lower doses of chemotherapy and radiation that do not completely destroy the cells in their bone marrow. They then receive the allogeneic (donor) stem cells. These cells enter the body and establish a new immune system, which sees the leukemia cells as foreign and attacks them (a “graft-versus-leukemia” effect).

Doctors have learned that if they use small doses of certain chemotherapy drugs and low doses of total body radiation, an allogeneic transplant can still sometimes work with much less toxicity. In fact, a patient can receive a non-myeloablative transplant as an outpatient. The major complication is graft-versus-host disease.
Many doctors still consider this an experimental procedure for AML, and studies are under way to determine how useful it may be.
Autologous stem cell transplant: In an autologous transplant, a patient’s own stem cells are removed from his or her bone marrow or peripheral blood. They are frozen and stored while the person gets treatment (high-dose chemotherapy and/or radiation). A process called purging may be used to try to remove any leukemia cells in the samples. The stem cells are then put back (reinfused) into the patient’s blood after treatment.
Autologous transplants are sometimes used for people with AML who are in remission after initial treatment and who don’t have a matched donor for an allogeneic transplant. Some doctors feel that it is better than standard “consolidation” chemotherapy (see section called “Typical treatment of acute myeloid leukemia”) for these people, but not all doctors agree with this.
Autologous transplants are generally easier to tolerate than allogeneic transplants, but the high-dose chemotherapy can still cause major side effects. The patient is getting his or her own cells back, so the risk of some complications is smaller. This type of transplant can be done in any otherwise healthy person, although very old patients might not be suitable.
One problem with autologous transplants is that it is hard to separate normal stem cells from leukemia cells in the bone marrow or blood samples. Even after purging (treating the stem cells in the lab to try to kill or remove any remaining leukemia cells), there is the risk of returning some leukemia cells with the stem cell transplant.
Immunotherapy

What is immunotherapy?
Cancer may develop when the immune system breaks down or is not functioning adequately. Immunotherapy (also called biological therapy and biotherapy) uses the body's immune system to fight cancer. Immunotherapy works by either stimulating your immune system to attack cancer cells or providing your immune system with what it needs, such as antibodies, to fight cancer.
Common types of immunotherapy include:
Monoclonal antibodies: These are man-made versions of immune system proteins. Antibodies can be useful in treating cancer because they can be designed to attack a very specific part of a cancer cell.
Cancer vaccines: Vaccines are substances designed to trigger an immune response in the body against certain diseases.
Non-specific immunotherapies: These treatments stimulate the immune system in a general way to increase activity against cancer cells. Some examples include man-made versions of cytokines, a chemical in immune cells, such as interleukins and interferons.

Nutrition therapy for lukemia

Many leukemia patients experience symptoms that can impact their nutrition intake and ability to tolerate treatment. Dietitian will work closely with the other members of your care team, including gastroenterologist and naturopathic clinician, throughout treatment. Together, they will recommend supplements and other therapies to support optimal digestion and nutrition, and help manage side effects.
For example, since Vitamin D is important for leukemia patients, your dietitian may work with your doctor to have your Vitamin D levels checked and may recommend supplementation with Vitamin D if needed.
For leukemia patients who undergo a stem cell transplant, nutrition plays an essential role. After the transplant, your blood cell counts, including infection-fighting white blood cells, will be lower, making one more susceptible to infection. A strict adherence to food safety is important at this time. For a period of time following the transplant, nutrition therapy plan may include a neutropenic diet. Diet recommendations may include avoiding raw/undercooked foods (e.g., meats, seafood, eggs, vegetables or unpeeled fruits) or unpasteurized dairy products.
Leukemia treatments can cause side effects, such as weight loss, fatigue, nausea, diarrhea, constipation, low blood counts and increased risk of infection. By providing proper nutrition for cancer patients, one can minimize these side effects and avoid delays or interruptions in treatment. dietitian may use the following leukemia nutrition interventions to combat side effects throughout treatment:
Weight loss: dietitian will monitor you closely to ensure you are maintaining a healthy weight, since weight loss can delay or interrupt your leukemia treatment.
Fatigue: dietitian may recommend small, frequent meals and nutrient-dense foods to give more energy.
Nausea: dietitian may recommend a low-fat, bland diet of cold foods, ginger products, peppermint or sea bands to combat nausea. An hour before treatment, he/she may suggest you eat a high-protein, bland meal.
Anemia: dietitian may recommend iron and folic acid supplements to boost red blood cell count.
Low blood counts: dietitian may recommend a well-balanced, protein-rich diet to help blood counts return to a safe level.
Constipation: dietitian may recommend increase fiber intake and stay hydrated to relieve constipation.
Reference
* http://chealth.canoe.ca/ * Google * Google Scholar * http://www.cancer.org/