CYTOPHILIC ANTIBODY IN GUINEA-PIGS WITH DELAYED-TYPE HYPERSENSITIVITY.

Cytophilic antibody has been demonstrated in the serum of guinea-pigs injected with sheep red cells mixed with Freund's complete adjuvant. Sheep red cells adhered, in the absence of serum, to normal guinea-pig macrophages which had been treated in vitro with such serum. Treatment of polymorphs and lymphocytes with the antiserum did not confer on them this capacity to adsorb sheep red cells. The animals immunized with sheep red cells and complete adjuvant, when skin tested with an extract of sheep red cells, showed strong delayed-type reactions. Cytophilic antibody was not detectable in the serum of the majority of guinea-pigs which received sheep red cells mixed with incomplete adjuvant. Skin tests in these animals produced strong Arthus reactions but no delayed reactions. Titres of haemagglutinating antibodies were similar whether the adjuvant was complete or incomplete.