Final answer:
Binding of TTG to anti-TTG antibodies forms a complex that prompts an autoimmune response and may lead to disease, similar to how blood transfusion reactions involve antibody-antigen binding and complement activation.
Step-by-step explanation:
When TTG (tissue transglutaminase) is bound to an anti-TTG antibody, a complex is formed that is typically targeted by the immune system. This interaction can trigger autoimmune responses, as seen in celiac disease where anti-TTG antibodies signal an abnormal immune response against this enzymatic protein that normally contributes to cellular repair processes. The presence of such autoantibodies is an indication of an autoimmune disorder, and their detection is used for diagnostic purposes in medical practice.
For instance, when applied to blood transfusion reactions, similar principles apply. Anti-A or Anti-B antibodies may bind to incompatible blood type antigens on red blood cells, leading to agglutination and activation of the complement cascade, causing hemolysis. In autoimmune diseases, autoantibodies bind to self-antigens, leading to chronic conditions such as rheumatic fever or type 1 diabetes.