Human Health and Disease Lecture 8

Functions of stem cells

Stem cell/bone marrow transplant It is a procedure that infuses healthy cells, called stem cells, into the body to replace damaged or diseased bone marrow. A bone marrow transplant may also be used to treat certain types of cancer. A bone marrow transplant may be necessary if your bone marrow stops working and doesn't produce enough healthy stem cells. Bone marrow transplants may use cells from your own body (autologous transplant) or from a donor (allogeneic transplant).

Autologous Transplant

Allogeniec transplant

Why it is done? A bone marrow transplant may help you by: Safely allowing treatment of your condition with high doses of chemotherapy or radiation Replacing diseased or damaged marrow with new stem cells Providing new stem cells, which can help kill cancer cells directly

Why it is done? Stem cell transplants can benefit people with a variety of both malignant (cancerous) and nonmalignant (noncancerous) diseases, including: Acute leukemia Adrenoleukodystrophy Aplastic anemia Bone marrow failure syndromes Chronic leukemia Hemoglobinopathies Hodgkin's lymphoma Immune deficiencies Inborn errors of metabolism Multiple myeloma Myelodysplastic syndromes Non-Hodgkin's lymphoma Plasma cell disorders POEMS syndrome Primary amyloidosis

Risks Complications that can arise with a stem cell transplant include: Graft-versus-host disease (allogeneic transplant only) Stem cell (graft) failure Organ damage Infections Cataracts Infertility New cancers Death

Graft-versus-host disease: A potential risk when stem cells come from donors If you receive a transplant that uses stem cells from a donor (allogeneic stem cell transplant), you may be at risk of graft-versus-host disease (GVHD). This disease happens when the donor stem cells that make up your new immune system see your body's tissues and organs as something foreign and attack them. GVHD may happen at any time after your transplant. However, it's more common after your marrow has started to make healthy cells. Many people who have an allogeneic stem cell transplant get GVHD at some point. The risk of GVHD is a bit greater with unrelated donors, but it can happen to anyone who gets a stem cell transplant from a donor.

Types and Symptoms of GVHD There are two kinds of GVHD: acute and chronic. Acute GVHD usually happens earlier, during the first months after your transplant. It typically affects your skin, digestive tract or liver. Chronic GVHD typically develops later and can affect many organs. Mouth sores Abdominal pain Diarrhea Nausea Vomiting Joint or muscle pain Shortness of breath Persistent cough Vision changes, such as dry eyes Skin changes, including scarring under the skin Rash Yellow tint to your skin or the whites of your eyes (jaundice) Dry mouth

Pre-transplant tests and procedures A series of tests and procedures are involved to ensure that the patient is eligible for the transplant. n addition, a surgeon or radiologist will implant a long thin tube (intravenous catheter) into a large vein in the chest or neck. The catheter, often called a central line, usually remains in place for the duration of the treatment. The transplant team will use the central line to infuse the transplanted stem cells and other medications and blood products into your body.

Collecting stem cells for transplant If an autologous stem cell transplant is planned, patient undergoes a procedure called apheresis to collect blood stem cells. Before apheresis, he receives daily injections of growth factor to increase stem cell production and move stem cells into his circulating blood so they can be collected. During apheresis, blood is drawn from a vein and circulated through a machine. The machine separates the blood into different parts, including stem cells. These stem cells are collected and frozen for future use in the transplant. The remaining blood is returned to your body. If an allogeneic stem cell transplant is planned, he will need a donor. Stem cells are gathered from that person for the transplant. This process is often called a stem cell harvest or bone marrow harvest. Stem cells can come from the donor's blood or bone marrow. The transplant team decides which is better for the patient based on his situation.

The conditioning process After the completion of pre-transplant tests and procedures, the conditioning process begins. During conditioning, the patient undergoes chemotherapy and possibly radiation to: Destroy cancer cells if treated for a malignancy Suppress the immune system Prepare the bone marrow for the new stem cells The type of conditioning process depends on a number of factors, including the disease, overall health and the type of transplant planned. The patient may have both chemotherapy and radiation or just one of these treatments as part of the conditioning treatment.

Side effects of conditioning process Nausea and vomiting Diarrhea Hair loss Mouth sores or ulcers Infection Bleeding Infertility or sterility Anemia Fatigue Cataracts Organ complications, such as heart, liver or lung failure

Stem cell transplant procedure On the day of transplant, called day zero, the patient is given the stem cells through his central line using a process known as infusion. The transplant infusion is painless and a patient is awake during the procedure. The transplanted stem cells make their way to the bone marrow, where they begin creating new blood cells. It can take a few weeks for new blood cells to be produced and for the blood counts to begin recovering.

Side effects of DMSO Bone marrow or blood stem cells that have been frozen and thawed contain a preservative called dimethyl sulfoxide (DMSO) that protects the cells. Just before the transplant, the patient may receive medications to reduce the side effects the preservative may cause. He'll also likely be given IV fluids (hydration) before and after the transplant to help rid the body of the preservative. Side effects of DMSO may include: Nausea Fever Diarrhea Chills Hives Red urine

After Stem Cell Transplant When the new stem cells enter the body, they begin to travel to the bone marrow. In time, they multiply and begin to make new, healthy blood cells. This is called engraftment. It usually takes several weeks before the number of blood cells in the body starts to return to normal. In some people, it may take longer. In the days and weeks after the stem cell transplant, the patient will have blood tests and other tests to monitor his condition. He may need medicine to manage complications, such as nausea and diarrhea. After the stem cell transplant, the patient will remain under close medical care. If he is experiencing infections or other complications, he may need to stay in the hospital for several days or sometimes longer. Depending on the type of transplant and the risk of complications, he'll need to remain nearby for several weeks to months to allow close monitoring. He may also need periodic transfusions of red blood cells and platelets until his bone marrow begins producing enough of those cells on its own. He may be at greater risk of infections or other complications for months to years after your transplant.

Case Study: http://www.jhasim.com/files/articlefiles/pdf /ASIN%204_6_NewsPart4_Olsen%20Cas e.pdf