Alloimmunization Theory

Alloimmunization occurs when the immune system encounters foreign antigens from another individual of the same species, such as during pregnancy or blood transfusions. The immune system recognizes these antigens as threats and produces antibodies against them. In pregnancy, if a mother is exposed to fetal blood group antigens that differ from her own, her immune system may create antibodies that can cross the placenta and harm the fetus. This immune response can lead to conditions like hemolytic disease of the newborn, causing anemia or other complications. Essentially, alloimmunization is the body reacting defensively to foreign biological markers introduced from another individual.