If you're going to get stem cells from another person, your doctors will want to find a donor whose stem cells match yours as closely as possible.
A close match can reduce the risk that your immune system will attack the donor cells. A close match also reduces the risk that cells from the donor's marrow or blood will attack your body.
People having stem cell transplants are matched with donors through a test called HLA tissue typing. HLAs are proteins found on the surface of white blood cells. Your immune system uses HLAs to tell which cells belong to you and which don't.
Because HLA markers are inherited, an identical twin is the best donor match. Brothers or sisters also can be good matches. However, many people don't have a good match in their families.
If no matching donor is found in your family, the search widens to include people outside the family. Millions of volunteer donors are registered with the National Marrow Donor Program. Your doctors will look for:
People who provide their own stem cells for later use don't need to go through HLA matching.
You also will need other medical tests and exams before a stem cell transplant. Your doctors will want to make sure you're healthy enough to have a transplant.
They also will want to find out whether you have any medical problems that could cause complications after the transplant.
Before a stem cell transplant, you might have blood tests to check for HIV, herpes, pregnancy, and other conditions. These tests help your doctors learn about your overall health.
A chest x ray creates a picture of the structures in your chest, such as your heart and lungs. The test can show whether your heart is enlarged or whether your lungs have extra blood flow or extra fluid.
Lung function tests can show whether you have a lung infection or disease. They also show how well your blood is able to carry oxygen throughout your body.
These tests provide detailed images of your body. They're used to see whether you have any tumors in your bones that might complicate a transplant.
Your doctor may recommend a complete dental exam to check for problems that might cause an infection after your transplant.
An EKG detects and records your heart's electrical activity. Echo uses sound waves to create a moving picture of your heart. The picture shows how well your heart is working and its size and shape.
A bone marrow biopsy helps show whether your bone marrow is making enough healthy blood cells. If you're being treated for a blood cancer, this test shows whether your cancer is inactive.
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Blood and Marrow Stem Cell Transplant, visit www.clinicaltrials.gov.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.