[Common and contradictory aspects of inflammatory reactions and pathogenic immune reactions]

Some basic features of the reciprocal relationship between inflammation and the pathogenic immune reactions are presented. Inflammation as a non-specific defense reaction is described first followed by presentation of the fundamental mechanisms of immunity corresponding to specific defense reactions. Immune reactions may, in certain circumstances, have a pathogenic effect leading naturally to pathogenic immune reactions. The mechanisms of this process are explained in detail. Macrophages play an important connecting link between inflammation and pathogenic immune reactions. The majority of specifically triggered pathologic immune reactions produce an inflammatory picture illustrating the relationship between the two processes. Humoral reactions controlled by B-lymphocytes manifest themselves as acute inflammation; cell-mediated processes controlled by T-lymphocytes appear as chronic inflammation with granuloma formation. Granuloma formation is specific to the immune reaction rather than to a given causal agent. Inflammation and pathologic immune reactions have different origins. The process of immune reaction is initiated by a specific phase characterized by the struggle between antigen and sensitized lymphocytes. Lymphocytes and plasma cells appear in the course of prolonged inflammatory processes for reasons which are not now known.