THE EFFECT OF GRANULOCYTOPENIA ON EXPERIMENTAL TUBERCULIN FEVER.

The febrile responses of hypersensitive, granulocytopenic and hypersensitive, non-granulocytopenic animals to specific antigen have been compared with the following results: 1. Hypersensitive animals, whether granulocytopenic or not, had an equal febrile response when challenged with specific antigen. 2. Hypersensitive animals with agranulocytosis developed fever when challenged with specific antigen. 3. Serum from granulocytopenic, antigen-challenged, hypersensitive donors contained a pyrogenic factor as potent in normal recipients as was serum from non-granulocytopenic, hypersensitive donors. It is suggested therefore that the granulocyte is not the source of endogenous serum pyrogen in the fever of delayed hypersensitivity and is not necessary for the febrile response of the hypersensitive animal to specific antigen.