G-CSF is a type of protein called a growth factor. It is used to help your body make more white blood cells.
How G-CSF works
G-CSF is made naturally in the body, but it can also be made as a drug. G-CSF stimulates the bone marrow to make more blood cells. Bone marrow is a spongy material inside bones. It is where blood cells are made.G-CSF is used in two ways. It is given:
- during treatment with chemotherapy, to stimulate the bone marrow to make white blood cells. These cells are called neutrophils. They help to fight infection.
- before a stem cell transplant, to encourage the bone marrow to release stem cells into the blood. The stem cells can then be collected for use in a stem cell transplant. Stem cells are blood cells at their earliest stage.
When G-CSF is used
With chemotherapy
Chemotherapy can lower the number of white blood cells in the blood. The main white blood cells that fight infection are called neutrophils. When they are low, you are neutropenic. This means you are more likely to get an infection.You may have G-CSF during treatment with chemotherapy so that you are neutropenic for a shorter time. G-CSF is not needed with all types of chemotherapy.
The number of white blood cells usually goes back to a normal level between cycles of chemotherapy. But if white blood cell levels are too low, chemotherapy may have to be delayed or given in a lower dose. G-CSF encourages the bone marrow to make white blood cells. This helps to reduce the risk of infection. It also allows chemotherapy treatments to be given on time and at the planned dose.
Collection for a stem cell transplant
Usually, stem cells stay in the bone marrow while they develop into blood cells. G-CSF encourages the bone marrow to make more stem cells. These cells then move (mobilise) from the bone marrow into the bloodstream. They can then be collected, stored and given back to you when you need them. This is called a stem cell transplant.You usually have a stem cell transplant as part of high-dose chemotherapy treatment. You have G-CSF before the stem cells are collected from your bloodstream. The cells can then be given back to you after your treatment. They will make new blood cells to replace those you have lost. This is sometimes called high-dose chemotherapy with stem cell support.
You may also have G-CSF after a stem cell transplant. It helps the new stem cells in the bone marrow to recover quicker.
If you are donating stem cells to another person, you will have daily injections of G-CSF for several days. These injections encourage your bone marrow to make stem cells and increase the number of stem cells in the blood.