A bone marrow transplant delivers healthy bone marrow stem cells into the patient. It replaces bone marrow that is either not working properly or has been destroyed (ablated) by chemotherapy or radiation.

Bone marrow is the soft, fatty tissue inside your bones. Stem cells are immature cells in the bone marrow. Some stem cells grow into different parts of your blood. These parts are:

• Red blood cells (which carry oxygen to your tissues)
• White blood cells (which fight infection)
• Platelets (which help your blood clot)

In a bone marrow transplant, you will receive healthy stem cells after your own bone marrow has been destroyed.

There are three kinds of bone marrow transplants:

• Autologous bone marrow transplant. "Auto" means "self." Stem cells are taken from the patient before the patient gets chemotherapy or radiation treatment. When chemotherapy or radiation is done, the patient gets their stem cells back. This is called a "rescue" transplant.
• Allogeneic bone marrow transplant. "Allo" means "other." Stem cells come from another person, who is called a donor. Donor stem cells come from the donor’s bone marrow or their blood. Most times, a donor must have the same genetic typing as the patient, so that their blood "matches" the patient’s. Special blood tests will tell whether a possible donor is a good match for the patient. A patient’s brothers and sisters have the highest chance of being a good match, but sometimes parents and children of the patient and other relatives may be matches. Donors who are not related to the patient may be found through national bone marrow registries. These are lists of people who have offered to be donors.
• Umbilical cord blood transplant. Stem cells are taken from an umbilical cord right after delivery of an infant. The stem cells are tested, typed, counted, and frozen until they are needed for a transplant.

Most patients get high doses of chemotherapy, radiation, or both, before the bone marrow transplant. This is called ablative (or myeloablative) treatment. It kills any cancer cells that might remain, and it makes room in the bone marrow for the new stem cells to grow.

Today, some patients are getting less chemotherapy and radiation before their transplant. This is called a reduced intensity (nonmyeloablative) or "mini" transplant.

After the patient gets chemotherapy and radiation, a doctor will do the stem cell transplant. The patient gets the stem cells through a tube called a central venous catheter. The cells go right into the bloodstream.

This delivery of cells is called an infusion. It may take up to several hours. It is not surgery. It is similar to a blood transfusion. The stem cells find their way into the bone marrow, where they may begin reproducing and making healthy new blood cells.

Donors must have minor surgery to collect their bone marrow and stem cells. They will be unconscious and pain-free (under general anesthesia) while their bone marrow is removed from their hip bone.

When receiving stem cells, a patient may have these symptoms:

• Pain
• Chills
• Fever
• Hives
• Chest pain
• Drop in blood pressure
• Shortness of breath
• Nausea
• Flushing
• Headache
• Funny taste in the mouth

Bone marrow or stem cell transplant may be recommended for:

• Certain cancers, such as leukemia, lymphoma, and multiple myeloma
• Illnesses where the bone marrow does not produce the right kind of or enough cells. Some of these are:
  • Sickle cell anemia
  • Aplastic anemia
  • Thalassemia
  • Congenital neutropenia
  • Severe immunodeficiency syndromes
• Rescue transplant to replace bone marrow, when treatment for cancer has destroyed a patient’s bone marrow