Interleukin-6 and tumour necrosis factor alpha synthesized by cholesteatoma cells affect mucociliary function in the Eustachian tube

The aims of this study were to investigate the possible synthesis of IL-6 a nd TNF-alpha by cholesteatoma cells in culture and the effect of IL-6 and T NF-alpha produced by cultured cholesteatoma cells on the function of the mu cociliary system in the tubotympanum. Cholesteatoma cells were collected fr om 10 patients, and the medium supernatants in which cholesteatoma cells or normal human epidermoid cells had been cultured for 48 h were collected. T he concentrations of IL-6 and TNF-alpha in the supernatants were measured b y enzyme-linked immunosorbent assays. The effect of the culture supernatant s on ciliary activity was examined using an ill vitro experimental system. The supernatants were injected into the tympanic cavities of guinea pigs, a nd mucociliary clearance time of the Eustachian tube was determined accordi ng to our dye transport technique 24 h after the intratympanic injection. H uman cholesteatoma cells produced larger amounts of IL-6 and TNF-alpha than normal human epidermoid cells. The supernatants of cholesteatoma cells com promised ciliary activity and mucociliary clearance of the Eustachian tube in the guinea pigs. The effects of the supernatants of cholesteatoma cells on the ciliary activity and mucociliary clearance were correlated with the concentration of IL-6 and TNF-alpha in the supernatants. In conclusion. cho lesteatoma cells can produce IL-6 and TNF-alpha, which are able to compromi se the mucociliary Function in the tubotympanum IL-6 and TNF-alpha produced in middle ear cholesteatoma might aggravate the disease by the wide range of their biological activities on the mucociliary system, the proliferation of cholesteatoma cells and the bone metabolism.