Antibodies to self antigens are a common feature of normal B cell function. And of course, antibodies to self antigens are a cardinal feature of some autoimmune diseases such as Graves Disease, Lupus, Myasthenia Gravis. What's the difference? read more
Antibody affinity: Low and high in the case of normal and pathogenic anti-self antibodies, respectively. Each of these differences is a key component that helps shape the difference in outcome, benign when it's part of normal B cell function and pathogenic when it's not. Thus, anti-self antibodies made by 'innate' B cells are considered normal. read more
Depending on the context immune cells recognize the antigen, the body may learn to recognize the antigen as "self" and leave it alone, or "non-self" but safe, such as food stuffs, or "non-self" and dangerous, in which case an immune response is mounted against anything bearing that particular antigen. read more
Immune tolerance requires that cells producing antibody against self antigens be eliminated at some stage. Hence people of blood group O, lacking blood-group antigens A and B, will not have become tolerant to them, and will have antibody-producing cells capable of producing antibodies against them, should they encounter them in an incorrect blood transfusion. read more