Biodynamics of antigen-antibody reaction in vivo

The success of the toxin neutralization by a specific antibody in a living system depends on multiple factors. First, the type of the actual available antibody structures (immunoglobulin G, Fab(2) or Fab fragments) must be se lected according to the toxin molecular weight: Fab is adapted to the neutr alization of haptens, IgG and Fab(2) to macromolecular toxins. Other factor s involved in the success of immunotherapy are issued from the pharmacokine tic properties of th toxin: non reversible binding to the receptor, intrace llular distribution of a macromolecular toxin are disadvantageous. Finally, the selection of the antibody dose according to its association constant v alue for the toxin allows to administer the optimal capacity of immunoneutr alization. The control of all these factors inserted in the biodynamics of the living system contributes to the success of immunotherapy.