For those interested in the transfusion details, I received 4 units of irradiated, leukocyte-reduced CMV-negative platelets that were collected by apheresis. This is probably more than you'll ever want to know about platelets, but here's what I found out about all that:
- Unlike red blood cells, platelets can only be stored for a few days, so the blood bank is constantly in need of them.
- Platelets can be extracted from whole blood donations, or they can be collected directly from the donor using apheresis. Apheresis is a process where just one blood component is extracted while the rest of the blood is circulated back to the donor. The benefit of apheresis is that someone can donate up to 2 units of platelets per donation this way, whereas it would take 4 full donations of whole blood to make 1 unit of platelets. A donor can also donate platelets up to twice a week compared with a whole blood donation in which they have to wait 3-4 months between donations.
- A small number of white blood cells (those that fight infection) are always present in platelet donations. Normally the body's immune system immediately kills off these donor white blood cells, but for a person with a weakened immune system there is a small risk that these white blood cells could actually overpower the body's own immune system (called graft versus host disease). Irradiation is used to render these stray white cells ineffective. They don't go away, they just don't work anymore. So, platelets are almost always irradiated for patients suffering from low white blood counts.
- Leukocyte-reduced means that the platelets were filtered even further to reduce any white blood cells present in the donation. Leukocyte comes from the greek words leukos (white) and kytos (cell).
- Cytomegalovirus, or CMV, is a very common virus present in over half of the US population. After a CMV infection, the virus normally lies dormant and doesn't present a problem anymore. However, it can be reactivated in people with weakened immune systems and can pose serious problems. CMV-negative means that the platelets tested negative for this virus.
- 4 units of platelets were given for my transfusion. I found that during my marrow transplant, I'll need 120 units of platelets. Wow.
- The threshold of thrombocytopenia (low platelets) when spontaneous bleeding might occur is a platelet count less than 5,000 - 10,000. I don't know why, but gruesome images from my favorite horror movies always pop into my head when I hear the term "spontaneous bleeding". Anyway, the recommended trigger is when it falls below 10,000. Mine was at 8,000, so my doctor consulted with the MDS specialist at the SCCA to confirm we should do a transfusion.
- 4 units of platelets for a 200 lb person should increase the counts by 22,000.
I also found out that the Puget Sound Blood Center has this to say about platelet donations:
If I've joined the National Marrow Donor Program Registry, is there something I can do now to help marrow transplant patients?So there you go. Here's the FAQ. http://www.psbc.org/programs/platelets_fact_sheet.pdf
Yes. Become a platelet donor. Platelet donors offer immediate support to patients with cancer, leukemia and others who may need a marrow or blood stem cell transplant.
And here's what a bag o' platelets looks like:
And here's what I look like getting 'em :)