Stem cell and bone marrow transplants

Stem cell transplantation or bone marrow donation is a complicated and lengthy process that includes five main stages.

These are the stages:

1. To assess your general health, you may need to have tests and examinations.

2. Harvesting is the process of harvesting stem cells from a donor or you.

3. Conditioning - preparation for the transplant.

4. Transplantation of stem cells

5. Recovery - You will need to remain in the hospital at least for a few weeks before the transplant can take effect.

Below are more details about the stages.

Exams and tests

A series of tests and examinations will be required before a stem-cell transplant can be performed.

People in good health tend to have greater success with transplants, regardless of their underlying conditions.

These are some of the possible tests that you may have to pass:

• An electrocardiogram (ECG), a simple test that checks your heart rhythm and electrical activity, is available.

• An echocardiogram is a scan that looks at the heart and blood vessels nearby.

• A CT scan and X-rays are used to assess the health of organs like the liver and lungs.

• Blood tests are used to determine the number of blood cells present and how well the kidneys and liver function.

A biopsy may be required if you are diagnosed with cancer. A biopsy is a procedure that involves the removal of small amounts of cancerous cells and their analysis. This can tell you if your cancer is under control (in recovery) or if there is a high chance of it returning following a transplant.

Stem cells can be harvested

After your health has been checked, you will need to have the stem cells for the transplant removed and stored.

Three main methods stem cells can be obtained are:

• From blood - This is where stem cells are taken from your blood using an automated machine (see below).

• From bone marrow - A procedure to remove a small amount of bone marrow (see below).

• Cord blood - This is where cord blood is taken from the umbilical cord and placenta of a newborn baby to obtain stem cells

You may be able to take stem cells from your bone marrow or blood and transplant them later after any cancerous or damaged cells have been removed.

If this is not possible, then stem cells from a donor's bone marrow or blood will be used.

Stem cells are removed from the blood.

Most people harvest stem cells by temporarily removing blood from their bodies, then separating the stem cells and returning the blood back to the body.

A medication that stimulates the production of stem cells will be administered approximately 4 days before. A blood test will be done on the fifth day to ensure that there are sufficient stem cells in circulation.

Each arm's veins will be connected to a cell separator machine if there are enough cells. The blood is taken from one arm and then passed through a filter before being returned to the rest of the body via the other arm.

The procedure is painless and can be done while you are awake. If not enough cells have been removed, it may take around three hours.

Remove a bone marrow sample

Another method to collect stem cells is to take around a liter from your hip bone with a needle and inject it into your veins.

To ensure sufficient bone marrow, the needle may be needed to be inserted in multiple parts of your hip. The procedure is performed under general anesthesia, meaning you won't feel any pain and will fall asleep.

The needles may cause pain in the area you are inserting them. You'll also have marks on your skin from where they were inserted (usually one per side).

Conditioning treatment

Before stem cells can be transferred to the right place, they will need to be treated with radiotherapy and high doses of chemotherapy.

• To make space for transplanted tissue, it is necessary to destroy bone marrow cells.

• Any existing cancer cells must be destroyed

• This will stop your immune system from working, which reduces the chance of the transplant being rejected.

A variety of medications will be administered to you as part of the conditioning procedure. A tube known as a central line is usually inserted into a large vein close to your heart. This allows the medication to be injected directly into your body, without the need for many injections.

The conditioning process can last up to one week. During the treatment, you will likely need to remain in the hospital.

Some side effects of conditioning can include fatigue, hair loss, and sickness. These side effects are usually temporary. The risks associated with treatment will be discussed beforehand by your treatment team.

The transplant

The transplant is usually performed within a few days after the conditioning has ended.

Through the central line, stem cells are slowly introduced to your body. This can take up to an hour.

You won't feel any pain and will be awake all the time.

Recovery

After the transplant is complete, you will need to remain in the hospital for several weeks to allow the stem cells to settle in the bone marrow. Then you can start making new blood cells.

You may also:

• Feel weak and may feel nauseated, vomiting, diarrhea, or loss of appetite.

• To prevent malnutrition, fluids can be administered by mouth or via a tube that runs from your nose to the stomach (a Nasogastric tube).

• Regular blood transfusions are recommended as you will have a lower number of red blood cells.

• Regular platelet transfusions are recommended as you will have a lower number of platelets.

• You'll be in a germ-free area and visitors will need to wear protective clothing to avoid infection.

Most people can leave the hospital within 1 to 3 months of receiving a transplant. If you have complications, such as infection, it is possible to stay in the hospital longer.

You'll still be susceptible to infections even after you return home. It can take up to a year for your immune system and brain to recover fully.

You will need to take medications to stop your immune system from working as hard if you have transplanted stem cells from donors. This is to decrease the chance of your body attacking the transplanted cell (immunosuppressants) or the risk of other cells being attacked by the transplanted cells.