Optimal antibody-receptor ratio in anaphylactic-sensitization.

The antigen-induced release of histamine from guinea pig and monkey lung fragments sensitized in vitro with hyperimmune rabbit antibody and human reaginic serum, respectively, was studied. When the amounts of whole antiserum, gamma-globulin fraction, or purified antibody were increased over the optimum in passive anaphylactic sensitization, the subsequent histamine release was reduced in spite of the fact that proportionately greater amounts of antigen were added to the system. The observed inhibition by higher antibody concentrations might be due to a reduction in cell-stimulating capacity of the antigen-antibody-receptor complex caused by inappropriate ratios among any of these three components.