Blood Types
Although everyone’s blood looks alike, it is inherently different determined by the presence of certain molecules on the surface of the red blood cells. The discovery made by scientist Karl Landsteiner in 1901 which classified blood into “types”, set in motion the wheels of modern transfusion medicine. These blood types are classified as A, B, AB, and O, known as the ABO system. Each type is also classified by an Rh factor, positive (+) or negative (-). When a transfusion is necessary, the donor’s blood must be compatible to the patient’s in order to avoid reactions, complications such as kidney damage, or even death.
- GROUP A: Has A antigen on the red cells and anti-B antibodies in the plasma.
- GROUP B: Has B antigen on the red cells and anti-A antibodies in the plasma.
- GROUP AB: Has both A and B antigens on the red cells and neither anti-A or anti-B in the plasma.
- GROUP O: Has no A or B antigens on the red cells and both anti-A and anti-B antibodies in the plasma.
In an emergency, anyone can receive type O-negative red blood cells and type AB individuals can receive any ABO red blood cells. Therefore, anyone with type O-negative blood is considered a “universal donor” and those with type AB are referred to as “universal recipients”. The plasma from an AB donor can be transfused to anyone regardless of their blood type.
It is a general misconception that if one has a more “common” blood type, such as O-positive or A-positive, their blood is not readily needed. In fact, it is in high demand because more patients in the hospitals are likely to have those blood types. Although the local hospitals and INBC are in close communication, it is not possible to always know the patient demand for blood products. A sudden trauma injury can not be anticipated and therefore it is imperative to keep the blood supply at a sufficient level at all times.
