What are stem cells?

Stem cells are the building blocks of all our body cells. Stem cells have the potential to develop into many different cell types. When a stem cell multiplies, the resulting cells either remain as stem cells or can develop into more specialised cells such as a blood cell, a brain cell or a muscle cell.

What is a stem cell transplant?

Stem cell transplant is a treatment which allows very high doses of anti-lymphoma therapy (usually high-dose chemotherapy or high-dose chemotherapy plus radiotherapy) therapy.

Where do the transplanted stem cells come from?

Stem cells are transplanted into a person after myeloablative therapy (chemotherapy or radiation therapy that destroys the stem cells in the bone marrow).

The transplanted stem cells can come from two sources:

• Autologous stem cell transplant: the person themselves provides the stem cells before they receive the myeloablative (high dose) treatment.
• Allogeneic stem cell transplant: stem cells are provided by a compatible donor, such as a sibling.

Autologous stem cell transplants are more commonly performed in the management of lymphoma as they are better tolerated by the person with cancer.

How is the transplant performed?

Transplant is performed in the following stages,

• Harvesting stem cells or bone marrow: It is  the procedure by which the bone marrow or stem cells are obtained in preparation for the transplant
• Processing/preserving the stem cells or bone marrow: Stem cells or bone marrow harvested from the person (autologous transplant) are usually stored in a freezer until ready for use. Stem cells or bone marrow derived from a donor (allogeneic transplant) are usually collected immediately before use and not stored for any length of time.
• Administering myeloablative therapy: High-dose chemotherapy, with or without myeloablative radiation therapy, is then administered to the patient to destroy the cancerous cells, as well as the healthy cells in the bone marrow.
• Reinfusing harvested stem cells or bone marrow: Harvested stem cells or bone marrow are then transplanted intravenously into the person's bloodstream. The stem cells travel through the body to the bone marrow where they settle and begin to produce new, healthy blood cells.

Immune system may take 1 to 2 years or longer to recover after a transplant

Autolologous Stem Cell Transplant : 3 min