What are Stem Cell Transplants?

By Dr. Ananya Mandal, MDReviewed by Sally Robertson, B.Sc.

Stem cells are very early, undifferentiated forms of cells that can develop into specialized blood cells. Stem cells can also quickly multiply to produce more stem cells.

One of the main sites where stem cells are found is within the shafts of long bones inside a tissue called bone marrow. This spongy tissue contains special stem cells that produce red blood cells, which carry oxygen in the blood, white blood cells, which help fight off infection, and platelets, which are responsible for regulating bleeding and clotting functions.

What is a stem cell transplant?

A stem cell transplant or a bone marrow transplant is essentially the infusion or injection of healthy stem cells to replenish the blood in cases where stem cells are diseased or damaged. For this process, stem cells from healthy blood or bone marrow are injected or infused through a catheter into the patient’s vein. The transplanted cells then find their way to the bone marrow, where they start producing supplies of healthy blood cells. It may take a few weeks for the healthy blood cells to be produced and for blood counts to start to normalize.

Stem cell transplants are useful in several conditions including:

• Leukemias or cancer of the white blood cells

• Lymphomas especially Non-Hodgkin’s lymphomas or cancer of the lymphatic system

• Severe aplastic anemia where there is a complete failure of the bone marrow

• Other cancers such as multiple myeloma and other diseases such as sickle cell anemia

Types of stem cell transplants

There are three basic types of stem cell transplants, which are named according to the donor from which the cells for the transplant are obtained from.

• An autologous stem cell transplant uses stem cells taken from the patient’s own body

• An allogenic transplant uses cells obtained from a tissue-matched individual who may be related or unrelated to the patient.

• A synergenic transplant uses cells obtained from an identical sibling.

References

• http://www.nhs.uk/Conditions/Bone-marrow-transplant/Pages/Introduction.asp
• https://www.nhsbt.nhs.uk/
• http://www.england.nhs.uk/wp-content/uploads/2013/04/b04-p-a.pdf
• http://www.cancer.org/acs/groups/cid/documents/webcontent/003215-pdf.pdf
• https://www.lls.org/
• https://www.ebmt.org/
• https://www.cdc.gov/