[Manifestation of immunologic origin produced by toxic compounds].

Toxic agents may induce immunological manifestations by interfering with either non specific or specific pathways of immunity. The interference with the specific pathways may result in stimulatory (autoimmunity or hypersensitivity) or suppressive reactions. Mechanisms responsible for autoimmunity of hypersensitivity are now better understood. Hypersensitive reaction may be the consequence of the recognition by T cells of the xenobiotic presented by MHC class II molecules. Mechanisms leading to autoimmune reaction probably differ according to the nature of the drug. Thus drugs metabolized by liver enzymes could induce autoimmune hepatitis as a consequence of the binding of a reactive metabolite to the enzyme, thus rendered immunogenic. Other drugs like thiol or metal-containing chemicals could be responsible for autoimmunity reaction by interacting with molecules involved in T-B lymphocyte cooperation. The knowledge of the involved mechanisms should allow to develop predictive assays.