Interleukin-8 and chemotactic activity of middle ear effusions

The importance of interleukin (IL)-8 in the chemotactic activity of middle ear effusions (MEEs) was evaluated. There was a significantly higher IL-8 concentration in MEEs of children with acute otitis media (AOM)(n = 17; 136 nglmL) than in children with otitis media with effusion (OME) (n = 28; 65 nglmL). The IL-8 concentration in MEEs with bacteria (149 nglmL) was significantly higher than in MEEs without bacteria (66 ng/mL). MEEs from children with AOM and OME had equally higher chemotactic activity than the diluent alone (23.3 % and 24.8%vs. 9.2%).The chemo-tactic activity was not altered by the presence of bacteria nor did it correlate with IL-8 concentration. Fractionation of MEEs by gel chromatography demonstrated that the main chemotactic activity could clearly be separated from the IL-8 activity, thus excluding IL-8 as a main chemotactic component in MEEs. Otitis media with effusion (OME) is a frequent infection in children, and there is growing evidence that bacteria may play a role in the initiation of the inflammatory process leading to OME. It has been suggested that different types of otitis media represent parts of a continuum of a single disease [1]. Neutrophils are th