Endotoxin and tumor necrosis factor-alpha in middle ear effusions in relation to upper airway infection

Objectives/Hypothesis: This study was performed to elucidate the role of en dotoxin and tumor necrosis factor-or (TNF-alpha) in the middle ear effusion s (MEEs) of children with otitis media with effusion (OME) in relation to t he chronicity of the disease and the presence of upper respiratory tract in fection (URTI), Study Design: In a retrospective study 140 MEEs were collec ted from 101 children between 2 and 12 years of age, and evaluated for the cytokine TNF-alpha and the lipopolysaccharide endotoxin, The amounts were q uantified and correlated with the type of MEE, OME duration, and the presen ce of URTI, Methods: Endotoxin levels were measured using a limulus amebocy te lysate assay and TNF-alpha levels were measured with an enzyme-linked im munosorbent assay (ELISA). Means of the different variables were compared u sing the one-way ANOVA least significance difference test with P <.05 Resul ts: In MEEs classified as mucopurulent (22.8%) both endotoxin and TNF-alpha levels (11.9 +/- 3 ng/mg total protein and 61.1 +/- 21 pg/mg total protein , respectively) were significantly higher compared with serous- (23.6%) or mucoid- (53.6%) type effusions, Fifty-five percent of the children who were classified as having chronic OME also had significantly higher amounts of endotoxin and TNF-alpha. The majority of the children (61%) had no URTI, al though children with URTI (36%) did also have significantly higher levels o f endotoxin and TNF-alpha in their middle ears. Conclusions: These results indicate that there is a strong correlation between the endotoxin and the T NF-alpha concentration in the middle ear and the type of MEE, the presence of URTI, and the chronicity of the disease.