> I was told over the weekend by my uncle, who is a nurse, that the official American Red Cross recommendation is that you shouldn't give blood or any portion thereof -- plasma, platelets, whatever -- more often than every 54 days and that doing so can cause some pretty screwy problems. Can anyone confirm or deny?

I don't donate platelets with the Red Cross (they're the ones who discouraged me from doing so for reasons unknown), but I do donate at the City of Hope, a renown hospital for treatin cancer and critically ill patients. I once donated on a Wednesday, that Saturday, and the following Wednesday because my platelets so closely matched one of their patients. I promise, I felt fine. That's part of the reason they only take components of blood -- so you can donate those components specifically more often.

"Platelets are collected from healthy donors by platelepheresis. During platelepheresis, specially designed blood cell separators collect one-tenth of the donor's circulating platelets. Platelet donations can be given every 48 hours."