BASIC ASPECTS OF IMMUNOMODULATION THROUGH PASSIVE-IMMUNIZATION - PHARMACOKINETICS AND BIOAVAILABILITY OF ANTIBODIES

The efficacy of immunomodulation through passive immunization is deter mined by the affinity, specificity and isotype of the antibodies used, the bioavailability of these antibodies after injection, the antigen concentration and the available time span for the actual antibody-anti gen interaction. Bioavailability is largely determined by the pharmaco kinetics of the antibodies (i.e., biodistribution and catabolism). Whe n using heterologous antibodies, the induced anti-antibody response af fects the pharmacokinetics of the antibodies and might largely reduce the efficacy of the pursued immunomodulation, especially after repeate d administration of these antibodies. The availability of generically modified whole antibodies with prolonged serum half-life next to whole antibodies and their Fab' and F(ab')(2) fragments will improve the po tential of immunomodulation through passive immunization,