Abstract
Background: β2-Adrenergic agonists are the most potent agents clinically used in inhibiting and preventing the immediate response to bronchoconstricting agents and in inhibiting mast cell mediator release. This raises the possibility that an abnormality in β-adrenergic receptor function or circulating catecholamine levels could contribute to airway hyperresponsiveness. Objective: To link interleukin 13 (IL-13) to the pathogenesis of asthma. Methods: Almost 4 decades ago, Andor Szentivanyi published a β-adrenergic theory of atopic abnormality in bronchial asthma. He proposed 9 characteristics to define bronchial asthma. Because he published these 9 tenets of the β-adrenergic blockade theory of asthma in 1968, it is appropriate and important to evaluate their relevance in light of advances in pharmacology, inflammation, and immunology. Results: We describe the effects of the allergic reaction on β-adrenergic responses and airway responsiveness. Both IL-1β and tumor necrosis factor α have been detected in increased amounts in bronchial lavage fluids in allergic airway inflammation. Both IL-13 and the proinflammatory cytokines IL-1β and tumor necrosis factor α have been demonstrated in airway smooth muscle to cause a decreased relaxation response to β-adrenergic agonist. However, IL-13 has been shown to be necessary and sufficient to produce the characteristics of asthma. Conclusion: The decreased adrenergic bronchodilator activity and associated hypersensitivity to mediators put forth by Szentivanyi can be elicited with IL-13 and support its role in the pathogenesis of asthma.