ROLE OF THE COMPLEMENT-SYSTEM IN PULMONARY DISORDERS

Immune injury in the lung is classically divided into types I-IV hyper sensitivity, with the complement system being involved in types II and III hypersensitivity. Anaphylaxis and asthma are generally considered prototypes of type I hypersensitivity and hypersensitivity pneumoniti s as an example of type III hypersensitivity in the lung. However, in asthma, for example, increasing evidence indicates that in addition to mast cells, T lymphocytes play an important role. Therefore, consider ing asthma as strictly a type I mediated reaction is too simplistic. T his report will review the evidence regarding the involvement of the c omplement system and complement activation products in anaphylaxis, as thma and immune complex disease in various experimental models of pulm onary disease. Identification of the mediators responsible for the sym ptoms may suggest rational targets for the continued development of ef fective therapy to combat immune injury in the lung. (C) 1997 Elsevier Science B.V.