Collecting stem cells

Your stems cells will be collected and stored before you have high-dose treatment. This happens a few days or weeks before the treatment.

Stem cells are usually collected from the blood. You will have daily injections of a growth factor (G-CSF). This encourages the stem cells to move (mobilise) from the bone marrow into the blood. Once mobilised, the stem cells will be collected. This takes between 3-4 hours using a cell-separator machine. Stem cells may be collected a second time if not enough are collected at first.

In some cases, stem cells may be collected from the bone marrow. This is done under an anaesthetic. The stem cells are usually collected from the bone marrow in the pelvis.

The collected stem cells are counted to make sure there are enough. They are then are frozen and stored in the laboratory until you need them.

Any blood or platelet transfusions you have before or after the collection will be treated with radiation (irradiated). This is to prevent problems caused by white blood cells in the donation.

Collecting your stem cells

Stem cells are usually collected from the blood. Occasionally, they may be collected from the bone marrow.

You will usually have your stem cells collected a few days or weeks before the high-dose treatment. You can normally have them collected as a day patient. It takes 3–4 hours. You will be sitting or lying down, so it can help to wear loose, comfortable clothing. You may want to take some books, magazines or music to help pass the time.

The first part of collecting stem cells from the blood is making them move from the bone marrow into the blood. This is called mobilising the stem cells.


Mobilising stem cells

You may be given chemotherapy followed by daily injections of a drug called a growth factor (G-CSF). Or, you may have only G-CSF injections.

Growth factors are natural substances. They stimulate the bone marrow and increase the number of stem cells and white blood cells in the blood. The growth factor is given as an injection under the skin (subcutaneously). People with lymphoma and myeloma may also be given a drug called plerixafor (Mozobil®) to help increase the number of stem cells. It’s given with the G-CSF as an injection under the skin.

You or a relative can be taught to give these injections, or you can go to your GP, district nurse or the hospital to have them.

Your blood will be tested regularly to check the level of stem cells.

Once there are enough stem cells in the blood, they will be collected. In a small number of people, not enough stem cells move into their blood for collection.


Collecting stem cells from the blood

A nurse will make sure you are comfortable on a chair or bed. They will put a short, thin tube (cannula) into a vein in each arm. Sometimes a vein at the top of your leg is used. If you have a central line or implantable port, this will be used instead.

Each cannula is connected by tubing to a machine called a cell separator. Blood goes from one of your arms through the tubing into the cell separator.

As the blood travels through the cell separator, it’s spun to separate out the stem cells, which are collected in a bag. The rest of your blood and blood cells are then returned to you through the cannula in your other arm.

You won’t usually feel anything while you are having your stem cells collected, but occasionally people feel dizzy or light-headed. Some people may experience muscle cramps or a tingling, numb or cold feeling in their lips, fingers or toes. This is caused by a drug called citrate, which is added to prevent the blood from clotting while it’s out of the body. You may be given a calcium tablet to chew, which can treat or prevent this side effect.

You may feel very tired afterwards, so it’s a good idea to arrange for a family member or friend to take you home.


Collecting stem cells from the bone marrow

Although it’s more common to collect stem cells from the blood, sometimes they are collected from the bone marrow. These are usually collected a few days or weeks before you have the transplant. You will have a general anaesthetic or an anaesthetic given into the spine, so you won’t feel any pain. Usually, bone marrow is taken from the back of the hip bones (pelvis).

Rarely, bone marrow is taken from the breastbone (sternum) or the front of the pelvis. If this needs to be done, the doctor will explain more about it to you.

The doctor inserts a needle through the skin and into the bone. Bone marrow is then drawn into a syringe and placed in a sterile container. The doctor may do this a number of times during the collection, taking bone marrow from more than one area of the pelvis.

For an adult, about one litre of bone marrow is removed – only about 10–15% of the body’s total. This leaves plenty for your body’s needs. The body quickly replaces the bone marrow that’s been removed.

You may have to stay in hospital overnight after the collection.

It’s common to feel sore for a few days, but regular painkillers can help. You’ll be given a supply to take home if you need it. There may also be some bruising from where the bone marrow was taken, which may last for a few weeks.


After the collection

Counting and storing stem cells

The collected stem cells are counted to make sure there are enough. Some people need to come back over two or three days to collect enough stem cells. Collected stem cells are frozen and stored in the laboratory until you need them.

Sometimes, not enough stem cells are collected over this period. If this happens, doctors can arrange for you to try again using another course of chemotherapy and G-CSF, or G-CSF on its own.

Irradiated blood

For at least two weeks before stem cells are collected, any blood or platelet transfusions you have will be treated with radiation (irradiated). This is to prevent any problems caused by white blood cells in the donated blood. Any transfusions you need in the future will also need to be irradiated.


Back to Being treated with high-dose treatment with stem cell support

What's involved in high dose treatment?

You’ll be given high doses of chemotherapy to remove any cancer cells that remain in your body after initial treatment.

Making your decision about treatment

Make sure you have all the information you need about the benefits, risks and possible side effects of high-dose treatment.