Summary: | <p>Abstract</p> <p>Background</p> <p>Interleukin 8 (IL8) belongs to the family of chemokines. It mediates the activation and migration of neutrophils from peripheral blood into tissue and hereby plays a pivotal role in the initiation of inflammation. Thus it is important in inflammatory lung diseases like bronchial asthma or severe infections by Respiratory Syncytial Virus (RSV). IL8 acts through binding to the IL8-Receptor alpha (IL8RA). For both genes association with asthma has been described. In addition, <it>IL8 </it>has been found in association with RSV bronchiolitis. The aim of our study was to test both genes for association with asthma and severe RSV infections. In addition we were interested in whether a common genetic background of both diseases exists in regards to these genes.</p> <p>Methods</p> <p>We genotyped the two <it>IL8 </it>promotor polymorphisms -251A/T and -781C/T and the three amino acid variants M31R, S276T and R335C in <it>IL8RA </it>on 322 children with asthma, 131 infants with severe RSV associated diseases and 270 controls. Statistical analyses made use of the Armitage's trend test for single polymorphisms and FAMHAP for calculations of haplotypes.</p> <p>Results</p> <p>We found association of the <it>IL8 </it>polymorphism -781C/T as well as <it>IL8 </it>haplotypes with asthma (p = 0.011 and p = 0.036, respectively). In addition, direct comparison of the asthmatic population with the RSV population revealed significant differences, both for -781C/T alone (p = 0.034) and <it>IL8 </it>haplotypes (p = 0.005). The amino acid variants in IL8RA were evenly distributed in between all three populations.</p> <p>Conclusion</p> <p>We conclude from our data that <it>IL8 </it>might play a role in the genetic predisposition to asthma and that these effects are different or even opposite to the effects on severe RSV diseases. Furthermore, IL8RA is unlikely to play a major role in the genetics of either disease.</p>
|