The American Red Cross informed me that A+ blood is especially suited
to and needed for platelet donations.  I have now read this in several
places (see, e.g., http://www.bbsbrc.org/donation_types.htm).  Why is
it, exactly, that A+ blood is more needed and/or better suited to
plateletpheresis than other blood types (except, perhaps, for AB)?

Hi mikunifan,

  Blood banking is one of the most complicated things to understand,
after quantum physics!


  A positive (Called simply ?A pos? in the hospital) blood is not
better suited for plateletpheresis than other group and type blood.
It?s simply the most common type after O pos! This got me thinking
however, as I did some blood banking years ago, so I called the very
busy blood bank at Mayo Clinic, Rochester, Minnesota. One of the
knowledgeable blood bankers there told me there is no reason that A
pos blood is better suited for plateletpheresis and wondered why this
was stated on the Red Cross site. Actually, the Red Cross site you
cited states: ?Donors with A+ blood are especially needed to donate
platelets.? Certainly this is because of need, and not suitability of
pheresis. Neither myself nor the Mayo blood bankers could come up with
a reason for the Red Cross statement.

 Looking at the compatibility chart on the following site, you can
easily see that people with AB pos blood can receive blood/platelets
of any group and type! However, there are fewer people with this group
and type. A pos is the second most common group and type, yet can
receive only Apos or neg, and O pos or neg. Folks with O ps can
receive O pos or O neg blood/platelets.
http://www.utahblood.org/facts/abosystem.htm


  While blood groups, such as A, B, AB, and O are commonly called
blood types, but the correct name is ?Group? . Blood type technically
refers the Rh factor, negative or positive. For example, A neg (A-)
blood is correctly called ?Group A, type Rh negative?

  Most hospitals transfuse group specific platelets to patients, in
other words, A pos platelets to an A pos patient. If group specific is
unavailable, another group is used, following a compatibility chart.
The amount of red blood cells present in a unit of platelets is
usually insufficient to cause a transfusion reaction. Giving Rh
positive platelets CAN cause antibodies to be produced in an Rh
negative person though. This is only important in women through their
childbearing years, and not at all in men or post-menopausal women.
http://www.psbc.org/medical/transfusion/scenarios/scenario_02/_frm/frm_17_compatibility.htm
http://www.cbbsweb.org/enf/plttx_aboincompat.html


More interesting blood banking information:

AABB is the best source of information on group and type questions.
All hospital blood banks follow  AABB standards.
http://www.aabb.org/

http://www.mayoclinic.org/donateblood/know.html

http://www.utahblood.org/facts/platelets.htm

http://www.bloodbankofalaska.org/donating/apheresis.html

http://www.newenglandblood.org/medical/type.htm

If you have any further questions, please request an Answer
Clarification, before rating, and I will respond as soon as possible.

Regards, crabcakes