Pathogenesis

Abstract

In general, immunopathologic lesions may arise from hypersensitivity reactions or from immunotoxic interaction. The contact of the sensitizing agent with the corresponding humoral antibody or sensitized cell constitutes a trigger mechanism which may activate the complement system and probably induces the release of mediators such as histamines, serotonin, or bradykinin-like substances. As a result, increased permeability, edema, Chemotaxis of leukocytes, and tissue necrosis take place in the host tissue. On the other hand, the formation of a macromolecular aggregate of the immune complex type may act as a foreign body, thus attracting leukocytes or causing disturbances in the nutrition of the tissue. Interaction between antibodies and sensitized cells may produce a synergistic or antagonistic effect. The possibility of this interaction depends on the accessibility of the target cell to the immune agent, which in turn depends on the vascular and tissue permeability. As regards the mechanism of the production of allergic orchitis, there is no agreement yet about the role of cellular immunity or of the different humoral antibodies in this characteristic immunotoxic reaction.