Neuroimmunology and inflammation: implications for therapy of allergic and autoimmune diseases.

OBJECTIVES To review concepts of neuroendocrinoimmunology and provide an overview of the role of immune dysregulation, stress, and the understanding of the pathogenesis and treatment of allergic and autoimmune diseases. DATA SOURCES Articles include original research papers, review articles, and references identified from the bibliographies of pertinent articles. RESULTS Neuroendocrine hormones triggered during stress may lead to immune dysregulation or altered or amplified cytokine production, resulting in atopic, autoimmune diseases or decreased host defense. Various types of transmitter substances of the neuroendocrine-immune (NEI) network include epinephrine, norepinephrine, acetylcholine, substance P, vasoactive intestinal peptide, glucagon, insulin, cytokines, growth factors, and numerous other mediators. The stress response and induction of a dysregulation of cytokine balance can trigger the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. Disorders in which abnormalities in immune function are mediated by the NEI network include allergic diseases: allergic rhinitis, atopic dermatitis, and gastro-intestinal allergies and asthma through overproduction of neuropeptides and cytokines. The multiple roles of Th2 cells in maintaining allergic inflammation and altering the balance between Th1 and Th2 responses are important mechanisms for allergic inflammation and tissue damage. In addition, several autoimmune diseases mediated by NEI network such as rheumatoid arthritis, systemic lupus erythematosus, and diabetes mellitus can be attributable to immune dysregulation. CONCLUSIONS Understanding the NEI network will contribute to novel treatments for immediate and late allergic reactions. Chronic stress or depression could lead to decreased host defenses, decreased response to vaccines, viral susceptibility, or malignancy. Treatment of allergic, autoimmune diseases and asthma should include stress management and behavioral intervention to prevent stress-related immune imbalances.