Potentiation of the reaginic (IgE) antibody response to ovalbumin in the guinea pig with a soluble metabolic product from Ascaris suum

A soluble antigen, the ACF antigen, obtained from cultures of larvae of Ascaris suum was able to potentiate the reaginic response to an unrelated antigen in the guinea pig. When the ACF antigen was administered at the same time or 4 days after ovalbumin, there was a weak primary response and a strong statistically significant secondary IgE response, compared with animals immunized only with ovalbumin. This potential response was not observed when the ACF antigen was presented 10 days before or 8 or 12 days after the ovalbumin.