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Immune complexes in the middle ear fluid and adenoid tissue in chronic secretory otitis media
Abstract:
Specimens of middle ear effusion and adenoid tissue were studied for bacteria and pneumococcal capsular antigen in 107 patients with secretory otitis media. 120 of 163 middle ear effusion samples (73.6%) were negative on bacterial culture. Hemophilus influenzae was present in 9.2% and Streptococcus pneumoniae in 1.8%. Hemophilus influenzae was cultured from 44.8% and Streptococcus pneumoniae from 35.5% of 107 adenoid tissue specimens. Free pneumococcal capsular antigen was demonstrated in 10.4% of the middle ear fluids and this figure rose to 23% when antigen was liberated from the immune complexes by heating. The corresponding figures for adenoid tissue suspension were 27.1% and 39%. The adenoid tissue or the lymphoid tissue of the entire oropharynx could act as the source of antigen which could maintain immune complex disease in some patients suffering from secretory otitis media.
Insights
In secretory otitis media patients, adenoid tissue frequently harbors bacteria like Hemophilus influenzae and Streptococcus pneumoniae. This tissue may also be a source of pneumococcal antigen, potentially driving immune complex disease.
Area of Science:
- Otolaryngology
- Microbiology
- Immunology
Background:
- Secretory otitis media (SOM) is a common condition, particularly in children, characterized by fluid in the middle ear.
- The etiology of SOM is multifactorial, involving bacterial infections and inflammatory processes.
- The role of adenoid tissue and bacterial/antigen presence in the pathogenesis of SOM requires further elucidation.
Purpose of the Study:
- To investigate the presence and types of bacteria in middle ear effusion (MEE) and adenoid tissue of patients with SOM.
- To detect pneumococcal capsular antigen in MEE and adenoid tissue.
- To explore the potential role of adenoid tissue as a source of antigen in maintaining immune complex disease in SOM.
Main Methods:
- Bacterial cultures were performed on 163 MEE samples and 107 adenoid tissue specimens from patients with SOM.
- Pneumococcal capsular antigen detection in MEE and adenoid tissue suspensions, including assays with antigen liberation from immune complexes.
- Quantitative analysis of bacterial and antigen presence in relation to clinical presentation.
Main Results:
- A high percentage (73.6%) of MEE samples were culture-negative for bacteria.
- Hemophilus influenzae and Streptococcus pneumoniae were more prevalent in adenoid tissue (44.8% and 35.5%, respectively) than in MEE (9.2% and 1.8%, respectively).
- Pneumococcal capsular antigen was detected in both MEE (10.4-23%) and adenoid tissue (27.1-39%), with higher rates after immune complex dissociation.
Conclusions:
- Adenoid tissue is a significant reservoir for bacteria implicated in SOM, particularly Hemophilus influenzae and Streptococcus pneumoniae.
- The presence of pneumococcal capsular antigen in adenoid tissue suggests it may serve as a persistent source of antigens.
- Adenoid tissue or oropharyngeal lymphoid tissue could contribute to the chronicity of SOM by maintaining immune complex-mediated inflammation.