Possible role of endotoxin and tumor necrosis factor-alpha in maintaining chronicity of otitis media with effusion in children

ABSTRACT

In this study, endotoxin, a lipopolysaccharide complex present on the outer surface of Gram-negative bacteria, was demonstrated with a substantial level in MEEs from children with chronic otitis media with effusion [OME]. Being a potent inflammatory mediator, it promotes the release of cytokine 1 TNF-alpha, which was also detected in MEEs from children with chronic OME. Forty samples from 20 children with chronic OMEs were aspirated during the introduction of tympanostomy tubes. The samples were studied for culture and Gram stain to detect viable bacteria, assayed for endotoxin utilizing limulus assay and TNF-alpha level utilizing ELISA. The results showed that 33 out of the 40 specimens exhibited an endotoxin activity ranging from 13 to 445 ng/ml and 27 out of the specimens showed TNF-alpha ranging from 2 to 97 pg/ml TP; the levels were higher among specimens with positive H. Influenza culture. Substantial levels of both endotoxin and TNF- alpha were also detected among specimens growing S. Pneum and culture negative specimens, suggesting the possibility of previously existing Gram-negative bacteria nonviable at the time of culture. Thus, it was hypothesized that the persistence of endotoxin and TNF-alpha, in spite of the non-existing viable bacteria, might play a role in sustaining the chronicity of OME in children