Generally antigen antibody interaction is beneficial to the host. It enhances humoral immune response of the host. Binding of antibodies to toxic molecules neutralizes their toxic effect and protects the host from the adverse effect of toxins.
Through activation of compliment enzymes and phagocytic cells Ag – Ab complex helps the host in removal of pathogens from the body. In certain conditions such as auto immune diseases Ag – Ab works in a negative manner and cause problem to the host