Edit: Whoever it is, thank you very much for the silver! This the first award I’ve recieved on Reddit! I love you!
Edit: Whoever gave me the gold… You’re a legend! You’re a fucking legend!! Thanks a lot Redditor!! It means a lot!
In: Biology
There are lots of different blood groups, ABO and Rhesus D are the most commonly known. Your red blood cells which carry oxygen have little markers all over them called antigens. A group A person’s red cells have A antigens, a group B person’s red cells have B antigens, a group AB person’s red cells have A and B antigens and a group O person has neither A or B antigens. People will naturally have antibodies in their plasma (the liquid part of blood) which are produced by white cells (the immune cells that protect the body) to the antigens that they don’t have. So Group A will have Anti-B antibodies, Group B will have Anti-A antibodies, Group O will have Anti-A and Anti-B antibodies and Group AB will not have either Anti-A or Anti-B antibodies. These antibodies when they detect antigens that they are specific for will stimulate the immune response to destroy these cells. That’s why if you give a Group O person Group A red cells their immune system will attack the new cells that their immune system recognises as foreign and they will have a transfusion reaction which can be fatal. Transfusing people red cells from the same ABO group as they are prevents the persons immune system from realising that these new cells introduced are foreign, preventing a reaction.
Rhesus D and also Kell are the two most immunogenic antigens of all the other blood group families. Immunogenic means the most likely antigens the person’s immune system receiving foreign red cells will recognise as foreign and create antibodies against if the individual receiving the red cells doesn’t have these antigens on their own red cells. Antigens being recognised as foreign and the immune system creating antibodies is known as sensitisation. This is typically not dangerous the first time as is the case with allergies. The first attack by the body is weak because its ‘defenses’ weren’t ready. The second time the person is exposed to the foreign antigen the immune system will rapidly spring into action to destroy the foreign cells causing a more serious transfusion reaction that can be life threatening. As a general policy people who are rhesus D negative are only given Rhesus D negative units to prevent sensitisation and women of child bearing years and children are always given Kell negative units also to prevent sensitisation. Any unit of red cells will always have these 3 pieces of information on them; ABO group, Rhesus family status and Kell type.
Latest Answers