The role of the immune system in the pathogenesis of asthma and an overview of the diagnosis, classification, and current approach to treating the disease.

OBJECTIVE: To describe what is currently known about the role of allergy and immunologically active cells and mediators in the airway inflammation associated with asthma; to review the diagnosis, classification, and treatment of the disease in accordance with current National Asthma Education and Prevention Program guidelines published in 2002; and to discuss therapeutic issues related to asthma management. DATA SOURCES: This article is based on a presentation given by the author at a symposium entitled “New Frontiers in Asthma Management: Biotechnology for Optimal Therapeutic and Economic Outcomes” at the Academy of Managed Care Pharmacy’s 15th Annual Meeting and Showcase in Minneapolis, Minnesota, on April 10, 2003. CONCLUSIONS: Type 2 helper T (Th2) cells, various other cell mediators and cytokines, and immunoglobulin E play important roles in the pathogenesis of asthma. Atopy is an inherited condition characterized by a predominance of Th2 cells and it predisposes to asthma. Objective measures of pulmonary function improve confidence in the diagnosis of asthma and should be used to monitor response to therapy. Asthma severity is often underestimated by patients and physicians, which can lead to inadequate treatment. Inhaled corticosteroids (ICSs) are the preferred maintenance treatment for patients with persistent asthma because these medications are the most potent and effective long-term controller pharmaceutical agents. Addition of a long-acting inhaled beta2-agonist or a leukotriene modifier to ICS therapy provides added benefit to patients with moderate or severe persistent asthma inadequately controlled by corticosteroids. Choosing an appropriate delivery system for inhaled drug therapies can affect patient adherence and the effectiveness of therapy.