ABOtyyppi

ABOtyyppi refers to the human blood group system, the most important of the 30 known human blood group systems. It is based on the presence or absence of antigens A and B on the surface of red blood cells. Individuals have one of four basic blood groups: A, B, AB, or O. Blood group A has the A antigen, blood group B has the B antigen, blood group AB has both A and B antigens, and blood group O has neither.

In addition to these antigens, the ABO system also involves antibodies in the plasma. Individuals with blood group A have anti-B antibodies, those with blood group B have anti-A antibodies, those with blood group AB have neither anti-A nor anti-B antibodies, and those with blood group O have both anti-A and anti-B antibodies. This antibody presence is crucial for blood transfusions.

When transfusing blood, it is vital to match the ABO type of the donor and recipient to avoid a transfusion reaction. A recipient will react against any antigens present on the donor's red blood cells that they do not have, as their plasma contains corresponding antibodies. For instance, a person with blood group A cannot receive blood from a person with blood group B because their anti-B antibodies would attack the B antigens on the donor's red blood cells.

Blood group O is often considered the universal red blood cell donor because their red blood cells lack both A and B antigens, and thus are less likely to be attacked by antibodies in a recipient's plasma. Conversely, blood group AB is considered the universal plasma donor because their plasma lacks both anti-A and anti-B antibodies. The ABO blood group is inherited from parents.