HALF-LIFE OF POLYREACTIVE ANTIBODIES

Monoclonal polyreactive antibodies bind to a variety of self and forei gn antigens. In contrast, monoclonal monoreactive antibodies bind to a single or restricted number of known antigens. The rate at which poly reactive antibodies are removed from the circulation compared to monor eactive antibodies has not been determined. In the present experiments , human monoclonal polyreactive and monoreactive antibodies of differe nt isotypes were injected intravenously into mice and the clearance fr om the circulation was determined. The half-life of polyreactive IgM, IgA, and IgG antibodies was 8.0, 8.2, and 9.8 hr, respectively, compar ed to 35.4, 26.6, and 280 hr for monoreactive IgM, IgA, and IgG antibo dies, respectively. Examination of tissue sections from animals given intravenous antibody showed substantial deposition of polyreactive, bu t not monoreactive, antibodies in several organs, the liver being the principal site of deposition. It is concluded that polyreactive antibo dies are cleared from the circulation substantially faster than monore active antibodies.