Early effect of ultrarush venom immunotherapy on the IgG antibody response

Abstract

During the initial phase of ultrarush VIT, a change in IgG specificity, i.e., a change in the set of epitopes dominantly recognized by IgG on wasp-venom antigens, occurred concomitantly with early clinical tolerance and was already detectable a few hours after the onset of treatment. Although it may be an epiphenomenon, this change represents the earliest humoral modification described so far during this procedure. The mechanism is unknown, but it appears to be a selective depletion of the highest avidity antibody fraction by the venom injected in large doses at this stage of therapy. Finally, our data now show the previously documented association between a particular IgG specificity and the clinical status (allergy vs tolerance) to be true also with ultrarush VIT, a model in which the clinical ability to display allergic symptoms is rapidly reversed.