The inventors of the present invention discovered that the loss, from blood plasma, of antigens containing two or more antigen-binding units is accelerated by forming a large immune complex containing two molecules or more of an antigen-binding molecule (for example an antibody), and an antigen having two or more antigen-binding units (epitopes). Moreover, the inventors discovered that the present invention can be achieved by further accelerating the loss of antigens by using the aforementioned characteristic and by using an antigen-binding molecule exerting ion-dependent antigen-binding activity.
