The most likely cause of immediate hemolytic transfusion reaction is due to antibodies of which system?

Question

Quizplus · Accepted Answer

ABO antibodies are naturally occurring, meaning that people have these antibodies in their blood even if they have never been transfused before. If someone receives blood from a donor with an incompatible ABO blood type, their antibodies will attack the donor's red blood cells, leading to an immediate hemolytic transfusion reaction. This is why ABO blood typing is always done prior to a blood transfusion.

The Most Likely Cause of Immediate Hemolytic Transfusion Reaction Is