Vulnerability and immune response. An overview.

A summary of the scope and mechanisms of the immune response is given and the hypothesis is put forth that, from the immunologic point of view, infections and neoplasms are the result of deficient recognition or arousal of effective defense systems against a foreign invader. An overview is provided of animal and human natural history, epidemiological, or experimental studies relating psychosocial variables to host defenses against infectious and neoplastic disorders; these studies implicate the involvement and competency of the immune system. An exploratory study is reported examining the relationship of a depressive reaction in 7 human subjects to the immune function of polymorphonuclear neutrophils. The 3 most depressed and/or hostile subjects showed significant inhibition of normal (chemiluminescence) immune response of polymorphonuclear neutrophils as compared to nondepressed healthy subjects. This inhibition of the immune response could not be attributed to the effects of pharmacologic agents, plasma cortisol levels, or differences in circadian rhythm.