Eosinophilia

Abstract

Summary Isolated human basophils sensitized in vitro by IgE antibody, and challenged by antigen in the absence of complement, release a substance that attracts eosinophils but not neutrophils. The anaphylactic release of the eosinophilotropic substance is accompanied by morphological changes in the basophils and release of histamine and presumptive SRS‐A. The anaphylactic eosinophilotropic substance differs from that formed in fresh serum by antigen‐antibody complexes. Human IgG, aggregated chemically or with antigen, induces formation of anaphylatoxin and substances attracting both eosinophils and neutrophils. IgE, similarly aggregated, does not. Damaged basophils or neutrophils incubated in serum containing complement, confer on the serum activity attracting neutrophils and eosinophils. The suspensions of the three types of polymorphonuclear leucocytes used in these tests were 92‐97% pure, prepared by the techniques of Day.