Immune dysregulation as a cause for allergic asthma

Allergic asthma is being increasingly understood as a disease caused by Th2-mediated immune responses to inhaled allergens. Most individuals fail to respond to allergens with a Th2 response, and thus, allergic asthma can be considered the result of an abnormally regulated or dysregulated immune response. The prevalence of asthma has risen precipitously in urbanized cultures, as contrasted with third world countries. This observation underlies the heightened efforts in the past few years of basic and applied research efforts to gain a better understanding of both normal and dysregulated immunity to antigens introduced via the airways. This review focuses on recent human studies into the immune dysregulation that results in the asthma phenotype, but also cites selected relevant papers from research with experimental animals.