Course of IL-1 beta, IL-6, IL-8, and TNF-alpha in the middle ear fluid of the guinea pig otitis media model induced by nonviable Haemophilus influenzae

To characterize the local response in acute otitis media, courses of interl eukin (IL)-1 beta, IL-6, IL-8, and tumor necrosis factor (TNF) alpha in mid dle ear fluid (MEF) of the guinea pig otitis media model induced by nonviab le Haemophilus influenzae were investigated with enzyme-linked immunosorben t assay (ELISA) kits. The IL-1 beta concentration in H influenzae-inoculate d ears peaked 24 hours after inoculation. The IL-8 concentration was signif icantly higher in H influenzae-inoculated ears than in controls 48 and 96 h ours after inoculation. The TNF-alpha concentration in H influenzae-inocula ted ears had an initial peak 6 hours after inoculation and had significant late increases 48 and 96 hours after inoculation. The results suggest that IL-1 beta and TNF-alpha were produced by middle ear mucosa in the early sta ge of the experiment by stimulation of bacterial inoculation, which caused subsequent inflammatory cell accumulation, and that IL-8 and TNF-alpha were produced in the late stage by accumulating inflammatory cells.