Immunologic responses of atopic and normal individuals to aerosolized dextran

Abstract

The immunologic response of atopic and normal subjects to an intranasally administered polysaccharide antigen was determined by exposing groups of these individuals to a native dextran at weekly intervals for five months. A pattern of immediate skin reactivity appeared with greater frequency early in the atopic aerosolized group. Almost all subjects regardless of group had small amounts of antibody to dextran prior to intranasal exposure as determined by the bentonite flocculation technique and titers showed a modest increase during the course of immunization. Although the bentonite flocculating antibody appeared to be non-identical with skin-sensitizing antibody, there was a rough correlation between degree of wheal-and-erythema skin reactivity and flocculating antibody in any single subject irrespective of group. These results are similar to those obtained using an aerosolized protein antigen and suggest that the intranasal route of immunization is sufficient for sensitization of atopic as opposed to normal individuals. They further suggest either latent quantitative differences in the immune apparatus of atopic and normal subjects which become manifest by using the intranasal route of immunization or else an enhanced mucosal permeability to inhalant antigens resulting in greater absorption of airborne protein and polysaccharide antigens in such individuals.