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Tumor necrosis factor in middle ear effusions
1Department of Otolaryngology, Kaplan Hospital, Rehovot, Israel.
Abstract:
The presence of tumor necrosis factor (TNF) was determined in middle ear effusions from 27 ears of children with chronic otitis media with effusion. Cytotoxic activity was assessed by quantitation of target (HeLa) cell death after incubation with the aspirate. Moderate cytotoxic activity was found in 17 of 27 samples (mean cell death of 53% and 32% at 1:2 and 1:4 dilutions, respectively). In ten (37%) of the middle ear effusion aspirates no cytotoxic activity was detected. To confirm that cytotoxicity was due to TNF, 13 of the samples with cytotoxic activity were incubated with a monoclonal anti-TNF antibody and retested. Cytotoxicity was blocked by the anti-TNF antibodies in all cases. Tumor necrosis factor, derived most probably from macrophages or mast cells in the middle ear, may mediate various pathologic processes associated with otitis media, such as generation of mucoid effusion, fibroblast proliferation, and bone resorption.
Insights
Tumor necrosis factor (TNF) was detected in middle ear fluid of children with chronic otitis media with effusion. This inflammatory cytokine likely contributes to the condition's pathological processes.
Area of Science:
- Otolaryngology
- Immunology
- Cell Biology
Background:
- Chronic otitis media with effusion (COME) is a common pediatric condition.
- The role of specific inflammatory mediators in COME pathogenesis is not fully understood.
Purpose of the Study:
- To investigate the presence and activity of tumor necrosis factor (TNF) in middle ear effusions from children with COME.
- To determine if TNF contributes to the cytotoxic effects observed in these effusions.
Main Methods:
- Middle ear effusion samples were collected from 27 children with COME.
- Cytotoxic activity was assessed using HeLa cells and quantified by cell death.
- The role of TNF was confirmed by blocking experiments using anti-TNF antibodies.
Main Results:
- Cytotoxic activity, indicative of TNF, was found in 17 out of 27 (63%) middle ear effusion samples.
- The mean cell death was 53% at 1:2 dilution and 32% at 1:4 dilution.
- Anti-TNF antibodies completely blocked the observed cytotoxicity in all tested samples.
Conclusions:
- Tumor necrosis factor (TNF) is present and biologically active in middle ear effusions of children with COME.
- TNF may play a significant role in mediating COME pathology, including effusion generation, fibroblast proliferation, and bone resorption.