Extracellular release of peroxidase from eosinophils by interaction with immune complexes.

Much peroxidase is released from eosinophils that ingest complexes formed of human immunoglobulins with specific rabbit antibody. The complex formed of IgE with rabbit antibody, was particularly effective. The amount and rate of release of peroxidase was closely related to the amounts of complex ingested by the eosinophils, and degree of lysis of the cell granules. It is proposed that eosinophils attracted to an allergic lesion ingest complexes of IgE, show lysis of granules with release of peroxidase, and that the peroxidase reduces the allergic reaction.