What is Anti-Kell?

Q: I am a 64 years old female. What is Anti-Kell? I had a blood transfusion and just received a card telling me if I need a blood transfusion, I need to let them know.

A:Our red blood cells (and some tissues) have got substances called antigens on their surface and the ability to form these antigens is governed by genes inherited from parents. These antigens may be proteins, carbohydrates or other complex chemicals. The presence of these antigens has given rise to blood group systems. Currently about 30 different blood group systems are known in humans but the ones of clinical significance are the ABO system, Rh system, Kell, MNS, Lewis etc. The importance of blood group systems lies in transfusion and transplant medicine as we can receive blood (or organ) from only an individual whose blood group matches ours. In case of mismatch, the bodys immune system recognises the foreign antigen and fights it leading to disease states.The Kell blood group is one of the major antigenic systems in human red blood cells and is important in transfusion medicine because the antibodies can cause severe reactions to transfusion of incompatible blood. Initially four antigens were described in this system: K or K1 (Kell) and k or K2 (cellano), and Kpa and Kpb. At present it comprises 22 blood group antigens with some showing a distinct racial prevalence (K antigen is more frequently found in Northern Europeans, the Jsa antigen is most frequently found in those of African descent and the Kpc antigen has been more frequently found in the Japanese). Kell allo-immunisation can be caused following transfusion with Kell-positive blood i.e. individuals lacking a specific Kell antigen may develop antibodies against Kell antigens when transfused with blood containing that antigen. Subsequent blood transfusions may be marked by destruction of the new cells by these antibodies. People without Kell antigens (K0), must be transfused with blood from donors who are also K0 to prevent haemolysis. Autoimmune haemolytic anaemia (AIHA) occurs when the body produces an antibody against a blood group antigen on its own red blood cells. The antibodies lead to destruction of the red blood cells with resulting anaemia. It is important for you to contact the transfusion centre and talk to them as they will be able to explain your blood group findings to you.