We have long known that immunoglobulin E (IgE) plays a pivotal in the deveiopment ef the most common forms of as'thma. There is, for example, a strong correlation between serum IgE levels and the risk of developing asthma. As well, there is a strong correlation between the density of IgE receptors and the severity of ast.hma, Until recently, it has not beefi posslble to translate this awareness into an intervention to treat asthma effectively.