Genome screen and candidate gene studies in parasitized populations

The immunoglobulin E (IgE) antibody system is important in the genesis of a sthma, but it appears to have originally evolved for defence against parasi te infection. In order to study how IgE contributes to asthma, there are ad vantages in studying parasitized populations. Firstly, the IgE system can b e studied when it is operating in a more natural state, and this could allo w new insight into basic immune function. Secondly, the genetic susceptibil ity to produce high levels of IEE is more likely to be expressed, as the mo st intense IgE responses in nature are those found in the presence of paras itic infection. These more intense IgE responses should facilitate finding new 'asthma genes', assist in investigating how the DNA variations in candi date genes affect gene function and provide the possibility of developing n ew approaches to the treatment of asthma.