Abrogation of type II collagen-induced arthritis in rats by psychological stress.

This study shows that psychological stress, produced either by exposure to a predator or by movement and handling, can profoundly suppress the clinical and histologic manifestations of collagen-induced arthritis. In addition, stress can dissociate the development of humoral and cellular sensitivity to collagen from the occurrence of arthritis. Thus stress modalities provide a means of acquiring additional insights into the pathogenesis of collagen-induced arthritis in rats. Such studies may lead to a further understanding of the relationship between emotional states and the functioning of the immunologic system. This study further illustrates the need to identify and control for the effects of stress in animal studies of immunopathology. Finally, the therapeutic implications of this study for autoimmune diseases would appear self-evident (Fig. 7).