title: Endotoxin and tumor necrosis factor-alpha in middle ear effusions in relation to upper airway infection.
abstract: OBJECTIVE
  This study was performed to elucidate the role of endotoxin and tumor necrosis factor-alpha (TNF-alpha) in the middle ear effusions (MEEs) of children with otitis media with effusion (OME) in relation to the chronicity of the disease and the presence of upper respiratory tract infection (URTI).
  
  
  METHODS
  In a retrospective study 140 MEEs were collected from 101 children between 2 and 12 years of age, and evaluated for the cytokine TNF-alpha and the lipopolysaccharide endotoxin. The amounts were quantified and correlated with the type of MEE, OME duration, and the presence of URTI.
  
  
  METHODS
  Endotoxin levels were measured using a limulus amebocyte lysate assay and TNF-alpha levels were measured with an enzyme-linked immunosorbent assay (ELISA). Means of the different variables were compared using the one-way ANOVA least significance difference test with P<.05.
  
  
  RESULTS
  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, although children with URTI (36%) did also have significantly higher levels of endotoxin and TNF-alpha in their middle ears.
  
  
  CONCLUSIONS
  These results indicate that there is a strong correlation between the endotoxin and the TNF-alpha concentration in the middle ear and the type of MEE, the presence of URTI, and the chronicity of the disease.
authors.affiliation: Department of Otorhinolaryngology, Leiden University Medical Center, The Netherlands. M.J.Nell@Ent.Medfac.LeidenUniv.NL
authors.forename: M J
authors.initials: MJ
authors.lastname: Nell
authors.forename: J J
authors.initials: JJ
authors.lastname: Grote
mesh_terms: D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D004731:Endotoxins / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010034:Otitis Media with Effusion / Q000150:complications / Q000378:metabolism*; D012141:Respiratory Tract Infections / Q000150:complications / Q000378:metabolism*; D012189:Retrospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
chemical_list: D004731:Endotoxins; D014409:Tumor Necrosis Factor-alpha