Talk about timing! Our class just got a presentation and tour of Michigan Blood in Grand Rapids Thursday, including a presentation on the Marrow Registry. One thing y'all might be interested to know: most requested donations now are
not marrow donations, but peripheral blood stem cell (PBSC) donations. If I recall correctly, marrow donations account for only one in five requests, these days.
PBSC donation is through a non-surgical procedure known as apheresis. It's essentially a blood donation, except that blood components not required for a procedure are actually returned to the patient.
In this case, the desired component is blood stem cells. These aren't normally found in peripheral blood (which is any blood outside the bone marrow), so a series of injections are required for five days prior to donation to coax more out. Then, the donor's blood is removed and passed through a machine that extracts the stem cells and returns the rest of the blood to the donor, typically through a second needle in the other arm.
It's a time-consuming process; about four hours, according to our guide. Donors may also experience headaches, or bone or muscle aches for several days prior to donations, side effects related to the movement of more stem cells from the marrow to the peripheral blood. On the up side, it doesn't require penetration of the pelvic bone, as a marrow transplant does. It is a bit more complicated than a regular blood donation, and the need for a needle in each arm is certainly inconvenient. Some apheresis machines are now able to perform the withdrawl and return process through a single needle, but I'm not sure if this method has been adapted for PBSC donation yet.
Anyone interested in learning more might like to check out the National Marrow Donor Program at http://www.marrow.org/Home.aspx. The donations FAQ is especially informative: http://www.marrow.org/Registry_Members/Donation/Donation_FAQ...