Just 1 in 25 donors have AB blood making it our rarest ABO group.
In addition to it being the rarest blood group, AB red cells can only be transfused to patients with AB blood. This combination of factors results in AB being the least requested blood type by hospitals, so ensuring a close balance between collections and hospital requests is important.
Group AB donors are extremely important in helping to produce fresh frozen plasma, used to treat patients who have suffered severe blood loss. AB plasma has no anti-A or anti-B antibodies and that’s significant. Not having these antibodies means that plasma from AB donors can be used to treat patients from all ABO groups
Whilst demand for AB positive red cells is at its lowest level for over a decade, demand for this blood group’s plasma remains.
Fresh frozen plasma is only produced from male donations. This is because female donors – especially those who have been pregnant - can develop antibodies that whilst no danger to themselves, can prove life threatening to patients transfused with their plasma.
We can generally meet the demand for frozen plasma and the majority of red cells from our male donors, which is good news. To avoid wastage whilst ensuring the correct balance of plasma and red cells from this group, we encourage our male donors to donate as frequently as possible, but ask that female donors wait to donate until contacted directly by NHSBT.
There are occasions at particular times of the year when demand for AB positive rises. During these times we contact our female donors directly and rely on their support to ensure patients continue to receive the blood and blood products they require.
AB negative is the rarest blood type accounting for just 1% of the donor population. As it is so rare it can be difficult to find new donors and even harder to ensure we always collect enough.
Due to the scarcity of donations, the red cells of this group have a greater importance than the plasma. AB negative red cells also have the benefit of being compatible with AB positive patients and for these reasons we ask all AB negative donors, whether male or female, to donate as frequently as possible.
Other blood groups