[Histamine and immune reactions. 1. Histamine receptor-bearing lymphocytes]

Literature review. Mast cells and basophils are included not only in anaphylactic but also in complement activating and cell-mediated immune reactions. A histamine release can be induced via the IgE mechanism, the anaphylatoxins, the histamine releasing activity, and by other reactions. Histamine and several other mediators induce a local inflammation reaction either by a direct action on their target cells or indirectly by the activation of other humoral and/or cellular effector systems. Histamine influences several immune reactions. Here, its influence on histamine receptor-bearing lymphocytes is discussed more in detail. Using in vitro test systems, it has been shown that histamine has a dual effect, it induces a suppression when applied in higher concentrations, while low concentrations are stimulating. In vivo, histamine receptor-bearing lymphocytes have suppressive functions, mediated by H2 receptors. Some preliminary evidence for the inclusion on histamine in the immunoreagulation of patients with several diseases is presented.