Canine reaginic antibody. Characterization of the spontaneous anti-ragweed and induced anti-dinitrophenyl reaginic antibodies of the atopic dog.

Anti-2,4-dinitrophenyl reaginic antibody has been induced in the atopic dog and compared with anti-ragweed reaginic antibody of spontaneous canine atopic hypersensitivity. Immunization of an atopic dog with ragweed hypersensitivity with dinitrophenylated ragweed pollen produced a high and sustained level of canine reaginic anti-DNP antibody. The induced and spontaneous forms of canine reaginic antibodies were shown to be identical in heat lability, sulfhydryl sensitivity, molecular size, charge, in their ability to remain fixed at passively-sensitized dermal sites for a prolonged period, and in their capacity to sensitized homologous white blood cells from normal donors for an immunospecific release of histamine. The induced anti-DNP and spontaneous anti-ragweed reaginic antibodies were physically separated and immunochemically differentiated from six other classes of canine immunoglobulins: γ2a, γ2b, γ2c, γ1, γA and γM, and shown to be members of a distinct class of canine immunoglobulins analogous to human γE (IgE). A high incidence of spontaneous atopic hypersensitivity has been observed in the progeny of the atopic dog.