Immunological probes in cardiovascular disease.

The immune system has long been recognised as playing a central role in the organism's defence against infectious diseases and possibly the development of neoplasia. The active stimulation of the immune system by immunisation and the passive administration of antitoxins have a venerable history in medicine. Yet the concept that antibodies may be used to modify physiological or pharmacological effects or may act as diagnostic agents in the living organisms has only recently come to be recognised. Advances, both in an understanding of the structural chemistry of the antibody molecule and in the ability to culture antibody-producing cells, now permit the selection and production of homogeneous antibodies and their smaller fragments in quantity by means other than conventional immunisation. These innovations will allow the development of a new pharmacology based on the remarkable resolving power of the antibody combining site. Antibodies or their fragments are shown to inhibit the pressor action of renin, to neutralise the pharmacological actions of digitalis, to block the beta-adrenergic receptor, and to detect and image myocardial infarcts.