Special Donation Procedures

Plateletpheresis

In plateletpheresis, a donor gives only platelets rather than whole blood. Whole blood is drawn from the donor, and a machine that separates the blood into its components selectively removes the platelets and returns the rest of the blood to the donor. Because donors get most of their blood back, they can safely give 8 to 10 times as many platelets during one of these procedures as they would give in a single donation of whole blood. Collecting platelets from a donor takes about 1 to 2 hours, compared with collecting whole blood, which takes about 10 minutes.

Autologous Transfusion

In an autologous transfusion, the donor is the recipient of his own blood. For example, in the weeks before undergoing surgery, a person may donate several units of blood to be transfused if needed during or after the operation. Or, during surgery, if a person is bleeding, the blood can be collected and given back. An autologous transfusion is the safest type of blood transfusion, because it eliminates the risk of incompatibility and blood-borne disease.

Directed or Designated Donation

Family members or friends can donate blood specifically for one another if the recipient's and donor's blood types and Rh factors are compatible. For some recipients, knowing who donated the blood is comforting, although a donation from a family member or friend is not necessarily safer than one from an unrelated person. Blood from a family member is treated with radiation to prevent graft-versus-host disease, which, although rare, occurs more often when the recipient and donor are related.

Stem Cell Pheresis

In stem cell pheresis, a donor gives only stem cells rather than whole blood. Prior to the donation procedure, the donor receives an injection of a special type of protein (growth factor) that stimulates the bone marrow to release stem cells into the bloodstream. Whole blood is drawn from the donor, and a machine that separates the blood into its components selectively removes the stem cells and returns the rest of the blood to the donor.

See the sidebar Controlling Diseases by Purifying the Blood.