Mammalian red blood cells are used to safely and rapidly neutralize and/or clear antigens or immunogens from the circulatory system by binding to the RBC a monoclonal antibody specific for a receptor (CR1) on the RBC, which monoclonal antibody is chemically bound to a second Mab specific for the antigen to be cleared from the circulatory system. These chemically cross-linked monoclonal antibody heteropolymers may be injected directly into the patient's circulatory system. Alternatively, red blood cells, extracted from the patient or provided by a suitable donor, are bound to the Mab complex and returned to the system.