Course of IL-1β, IL-6, IL-8, and TNF-α in the Middle Ear Fluid of the Guinea Pig Otitis Media Model Induced by Nonviable Haemophilus Influenzae

Abstract

To characterize the local response in acute otitis media, courses of interleukin (IL)–1β, IL-6, IL-8, and tumor necrosis factor (TNF) α in middle ear fluid (MEF) of the guinea pig otitis media model induced by nonviable Haemophilus influenzae were investigated with enzyme-linked immunosorbent assay (ELISA) kits. The IL-1β concentration in H influenzae–inoculated ears peaked 24 hours after inoculation. The IL-8 concentration was significantly higher in H influenzae–inoculated ears than in controls 48 and 96 hours after inoculation. The TNF-α concentration in H influenzae–inoculated 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-1β and TNF-α were produced by middle ear mucosa in the early stage of the experiment by stimulation of bacterial inoculation, which caused subsequent inflammatory cell accumulation, and that IL-8 and TNF-α were produced in the late stage by accumulating inflammatory cells.