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Endotoxin and tumor necrosis factor-alpha in middle ear effusions in relation to upper airway infection
1Department of Otorhinolaryngology, Leiden University Medical Center, The Netherlands. M.J.Nell@Ent.Medfac.LeidenUniv.NL
Objectives/Hypothesis:
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).
Study Design:
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.
Insights
Endotoxin and tumor necrosis factor-alpha (TNF-alpha) are elevated in middle ear effusions (MEEs) of children with otitis media with effusion (OME). Higher levels correlate with mucopurulent MEEs, chronic OME, and upper respiratory tract infections (URTIs).
Area of Science:
- Otolaryngology
- Immunology
- Pediatrics
Background:
- Otitis media with effusion (OME) is common in children.
- Middle ear effusions (MEEs) can be serous, mucoid, or mucopurulent.
- The role of inflammatory mediators in OME pathogenesis is not fully understood.
Purpose of the Study:
- To investigate the levels of endotoxin and tumor necrosis factor-alpha (TNF-alpha) in MEEs.
- To correlate these levels with OME characteristics like effusion type, chronicity, and concurrent upper respiratory tract infections (URTIs).
Main Methods:
- Retrospective analysis of 140 MEEs from 101 children (2-12 years).
- Quantification of endotoxin using limulus amebocyte lysate assay.
- Measurement of TNF-alpha via ELISA.
- Statistical comparison using one-way ANOVA.
Main Results:
- Significantly higher endotoxin and TNF-alpha levels were found in mucopurulent MEEs compared to serous or mucoid types.
- Children with chronic OME showed elevated endotoxin and TNF-alpha.
- Higher levels of both mediators were observed in children with concurrent URTIs.
Conclusions:
- Endotoxin and TNF-alpha concentrations in MEEs are strongly associated with effusion type.
- These inflammatory markers correlate with the chronicity of OME.
- The presence of URTI is linked to increased endotoxin and TNF-alpha levels in MEEs.