Blood Type Basics
Jan 28, 2019
We've all got blood running through our veins, and while it might look the same to the naked eye, it's actually different from person to person. Each blood type or "group" has a specific set of inherited antigenic substances, such as proteins, glycoproteins, carbohydrates, and glycolipids, which make it unique. If bloods of different groups mix (during transfusions or otherwise), these antigens can trigger a person's immune system to attack and reject the new "invading" blood, causing sickness or even death. In 1900 and 1901, Karl Landsteiner at the University of Vienna was attempting to uncover the cause of these failed transfusions and ended up discovering the common blood types we know today - a discovery that eventually earned him the Nobel Prize.
THE ABO BLOOD GROUP SYSTEMThis system is the most important blood group system used in human blood transfusion. It identifies four different common blood types that are determined by the presence or absence of certain antigens.
- Group A contains only the A antigen on red blood cells with the B antibody in the plasma.
- Group B contains only the B antigen on red blood cells with the A antibody in the plasma.
- Group AB contains both A and B antigens on red blood cells with neither A nor B antibodies in the plasma.
- Group O contains neither A nor B antigens on red blood cells but does contain both A and B antibodies in the plasma.
BLOOD GROUP COMPATIBILITY AND UNIVERSAL DONORS AND RECIPIENTSIt probably goes without saying, but physicians must be extremely careful when finding compatible blood types for transfusions. The list below explains which blood types are capable of cross-matching with other types.
- Group A can donate red blood cells to groups A and AB.
- Group B can donate red blood cells to groups B and AB.
- Group AB is the universal recipient, able to receive blood from all groups. However, they can only donate to other AB recipients.
- Group O is the universal donor, able to donate to all other groups. However, they can only receive from other O donors.