What is the bone marrow?

Blood cells are made in the bone marrow. The marrow is a spongy tissue within the bone of the hips, legs, breastbone and skull.

What is blood?

Blood is made up of many different parts. White blood cells fight infections. Red blood cells carry oxygen and nutrients to the body. Platelets are part of the clotting cascade and help stop bleeding. Plasma contains additional clotting components.

What is a transplant?

There are many different kinds of transplants. However, they all share common features. One of the major side effects of chemotherapy and radiation is damage to healthy bone marrow. Even with "normal" doses of chemotherapy most patients experience lowering of their blood counts. With low blood counts patients become at risk for infections, fatigue, and bleeding.

Although normal doses of chemotherapy may shrink some types of cancer, frequently cancer remains. If normal doses shrink cancer, it is hoped that larger doses will rid the body of cancer. A transplant is a technique that allows doctors to give larger doses of chemotherapy and radiation.

During a transplant patients receive high doses of chemotherapy and/or radiation. The purpose of this treatment is to rid the body of cancer or the blood disease. However, this high dose treatment also damages the healthy (non-diseased) bone marrow. Next, new stem cells or marrow is infused to replace the damaged marrow.

What are the kinds of transplant?

After the high-dose treatment the bone marrow is severely damaged. The transplant contains new cells capable of restoring marrow function and making blood. There are several types of transplants that are named by the type of cell used to replace the damaged marrow:

1. ALLOGENEIC: In an allogeneic transplant the new marrow comes from a brother, sister, or family member. This "donor" must share certain tissue qualities to allow the new marrow to grow in the patient.

2. AUTOLOGOUS: In an autologous transplant the new marrow comes from the patient themselves. The marrow (or stem cells) are first collected and stored in the freezer. After the patient receives the high-dose treatment, the stored marrow is thawed and given back to the patient.

3. UNRELATED: A unrelated marrow transplant is similar to an allogeneic transplant in that after high-dose treatment is given, new marrow is used replace and restart blood making. However, this marrow transplant uses cells donated by a volunteer unrelated individual rather than a family member. The National Marrow Donor Program assists in locating and recruiting volunteer donors for patients without tissue matched related donors.

4. BONE MARROW TRANSPLANT: The cells used to restore blood making function can be obtained by collecting cells from the bone marrow of the hip bones. The bone marrow donor can be a relative (allogeneic), the patient (autologous) or and an unrelated individual.

5. STEM CELL TRANSPLANT (Also called peripheral blood stem cell transplant). The cells used to restore blood-making function can be obtained by collecting cells from the peripheral circulating blood. The blood stem cell donor can be a relative (allogeneic), the patient (autologous) or and an unrelated individual.

6. CORD BLOOD STEM CELL TRANSPLANT. The cells used to restore blood-making function can be obtained by collecting cells from the umbilical cord of a newborn baby. The cord blood donor can be a relative (allogeneic), the patient (autologous) or and an unrelated individual.