AB Positive Blood

How to Share AB Positive Blood

4 percent of people are AB positive. Type AB plasma can be transfused to patients of all other blood types.

Men and never pregnant women or HLA negative donors are asked to donate:

  • Platelets and plasma,
  • Platelets,
  • Single red blood cells and double plasma (RBCP) or
  • Whole-blood

Previous pregnant women or HLA positive donors are asked to donate: 

  • Whole-blood

Schedule a blood donation today!


Frequently Asked Questions

What is HLA?

The human leukocyte antigen (HLA) is a protein that is responsible for the regulation of the immune system in humans. 

Why can’t previously pregnant females donate platelets or plasma?

Research has shown that between 10 to 20 percent of women who have been pregnant have Human Leukocyte Antibodies in their bodies, which can be harmful to recipients of donated platelets or plasma.

HLAs are not harmful to the women who carry them, but studies have shown they can lead to a condition known as Transfusion Related Acute Lung Injury (TRALI) in some recipients. TRALI is the largest cause of transfusion-related complications in the United States.

Anyone who tests positive for HLA will be called and informed by mail. And since the antibodies are only present in plasma and platelets donations, women who have been pregnant are still eligible to make either whole-blood or double-red-cell donations.

For more information, please call the STBTC donor advocate nurses at 210-731-5555, extension 2243.

What is an RBCP donation?

This is a donation in which a concentration of a single red blood cells and a double dose of plasma (RBCP) will be collected. This type of donation is crucial in treating burn patients or patients facing certain types of surgeries which require plasma and/or red blood cells. 

The RBCP donation process is faster than a dual red cell donation and only 15 minutes longer than a whole blood donation.

What does this mean to me as a donor?

1. You may be asked to change your whole blood donation to a platelet or plasma donation, because currently patients have a greater need for these components. 

2. By making an appointment to donate, you can be sure that your generous donation is the one most needed by hospital patients. 

Learn more about donating blood.

The Donation Process

Types of Donations


Share Your Type

Click below to learn about another blood type.


Anyone who is 16 years old weighing 120 pounds (with parental consent form), or at least 17 years old weighing 110 pounds and in good general health can donate blood. Donors must present photo ID, last four digits of their Social Security number and their birth date.