If you are planning to donate blood and bone marrow, you've agreed to allow doctors to draw blood stem cells from your blood or bone marrow for transplantation. Blood stem cells are the cells that make all of the body's blood cells. They form and mature in the bone marrow, and are then released into the bloodstream. Although they're called "stem cells," these cells aren't the same as the embryonic stem cells studied in therapeutic cloning and other types of research.

In the past, surgery to draw marrow from the bone was the only way to collect blood stem cells. Today, however, it's more common to collect blood stem cells directly from the blood. This is called peripheral blood stem cell (PBSC) donation.

Blood stem cells can also be collected from umbilical cord blood at birth. However, only a small amount of blood can be retrieved from the umbilical cord, so this type of transplant is generally reserved for children and small adults.

Every year, more than 10,000 people in the U.S. are diagnosed with life-threatening diseases, such as leukemia or lymphoma, for which a stem cell transplant is the best or the only treatment. Donated blood stem cells are needed for these transplantations.

You might be considering donating blood or bone marrow because someone in your family needs a stem cell transplant and doctors think you might be a match for that person. Or perhaps you want to help someone else — maybe even someone you don't know — who's waiting for a stem cell transplant.

Bone marrow donation

The most serious risk associated with donating bone marrow involves the use and effects of anesthesia during surgery. After the surgery, you might feel tired or weak and have trouble walking for a few days. The area where the bone marrow was taken out might feel sore for a few days. You can take a pain reliever for the discomfort. You'll likely be able to get back to your normal routine within a couple of days, but it may take a couple of weeks before you feel fully recovered.

Peripheral blood stem cell donation

The risks of this type of stem cell donation are minimal. Before the donation, you'll get injections of a medicine that increases the number of stem cells in your blood. This medicine can cause side effects, such as bone pain, muscle aches, headache, fatigue, nausea and vomiting. These usually disappear within a couple of days after you stop the injections. You can take a pain reliever for the discomfort. If that doesn't help, your doctor can prescribe another pain medicine for you.

For the donation you'll have a catheter (thin, plastic tube) placed in a vein in your arm. If the veins in your arms are too small or have thin walls, you may need to have a catheter put in a larger vein in your neck, chest or groin. This rarely causes side effects, but complications that can occur include air trapped between your lungs and your chest wall (pneumothorax), bleeding, and infection. During the donation, you might feel lightheaded or have chills, numbness or tingling around the mouth, and cramping in your hands. These will go away after the donation.

If you want to donate stem cells, you can talk to your doctor or contact the National Marrow Donor Program, a federally funded nonprofit organization that keeps a database of volunteers who are willing to donate.

If you decide to donate, the process and possible risks of donating will be explained to you. You will then be asked to sign a consent form. You can choose to sign or not. You won't be pressured to sign the form.

After you agree to be a donor, you'll have a test called human leukocyte antigen (HLA) typing. HLAs are proteins found in most cells in your body. This test helps match up donors and recipients. A close match increases the chances that the transplant will be a success.

If you sign up with a donor registry, you may or may not be matched with someone who needs a blood stem cell transplant. However, if HLA typing shows that you're a match, you'll undergo additional tests to make sure you don't have any genetic or infectious diseases that can be passed to the transplant recipient. Your doctor will also ask about your health and your family history to make sure that donation will be safe for you.

A donor registry may ask you to make a financial contribution to cover the cost of screening and adding you to the registry, but this is usually voluntary. If you're identified as a match for someone who needs a transplant, the costs related to collecting stem cells for donation will be paid by that person or by his or her health insurance.

Bone marrow donation

Collecting stem cells from bone marrow is a type of surgery and is done in the operating room. You will be given anesthesia for the procedure. Needles will be inserted through the skin and into the bone to draw the marrow out of the bone. This process usually takes one to two hours.

After the bone marrow is collected, you will be taken to the recovery room while the anesthesia wears off. You may then be taken to a hospital room where the nursing staff can keep an eye on you. When you're fully alert and able to eat and drink, you'll be released from the hospital.

Peripheral blood stem cell donation

If blood stem cells are going to be collected directly from your blood, you will be given injections of a medication to stimulate production of blood stem cells so that more of them are circulating in your bloodstream. The medication is usually started several days before you're going to donate.

During the donation, blood is taken out through a catheter in a vein in your arm. The blood is sent through a machine that takes out the stem cells. The rest of the blood is then returned to you through a vein in your other arm. This process is called apheresis. It takes two to six hours and is done as an outpatient procedure. You'll typically undergo two to four apheresis sessions, depending on how many blood stem cells are needed.

After the procedure

Recovery times vary depending on the individual and type of donation. But most blood stem cell donors are able to return to their usual activities within a few days to a week after donation.

May 30, 2014