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Bacterial antigens and neutrophil granule proteins in middle ear effusions
M B Miller1, P J Koltai, S V Hetherington
1Department of Surgery, Albany, Medical College, NY 12208.
Abstract:
Otitis media with effusion is a significant cause of hearing loss in young children. We hypothesized that persistent bacterial antigens in middle ear effusions (MEEs) might act as chronic inflammatory stimuli causing release of neutrophil proteins. Concentrations of neutrophil lactoferrin and a 37-kd cationic bactericidal protein (CAP 37) were measured in 47 MEEs collected from 27 children at the time of tympanostomy tube placement. Antigens of Streptococcus pneumoniae were detected by latex particle agglutination and those of Haemophilus influenzae by dot-blot assay. Bacterial antigens were detectable in 24 (51%) of MEEs: S pneumoniae in 10 (21%), H influenzae in 12 (26%), and both antigens in 2 (4%). Concentrations of lactoferrin and CAP 37 in H influenzae antigen-positive MEEs were significantly higher than in either S pneumoniae antigen-positive or antigen-negative MEEs. We conclude that H influenzae antigen causes a greater middle-ear inflammatory response, as judged by neutrophil products, than does S pneumoniae antigen.
Insights
Haemophilus influenzae antigens in middle ear effusions trigger a stronger inflammatory response in children than Streptococcus pneumoniae antigens. This finding is crucial for understanding chronic otitis media with effusion and related hearing loss.
Area of Science:
- Otolaryngology
- Pediatric Infectious Diseases
- Immunology
Background:
- Otitis media with effusion (OME) is a primary cause of hearing loss in young children.
- Persistent bacterial antigens in middle ear effusions (MEEs) may chronically stimulate inflammation, leading to neutrophil protein release.
Purpose of the Study:
- To investigate the association between bacterial antigens in MEEs and neutrophil protein concentrations.
- To compare the inflammatory response elicited by Streptococcus pneumoniae and Haemophilus influenzae antigens in OME.
Main Methods:
- Collected 47 MEEs from 27 children undergoing tympanostomy tube placement.
- Detected S. pneumoniae and H. influenzae antigens using latex particle agglutination and dot-blot assays, respectively.
- Quantified neutrophil lactoferrin and cationic bactericidal protein (CAP 37) concentrations in MEEs.
Main Results:
- Bacterial antigens were detected in 51% of MEEs (S. pneumoniae: 21%, H. influenzae: 26%, both: 4%).
- MEEs positive for H. influenzae antigens showed significantly higher concentrations of lactoferrin and CAP 37 compared to S. pneumoniae-positive or antigen-negative MEEs.
- This indicates a more pronounced inflammatory response to H. influenzae.
Conclusions:
- H. influenzae antigen elicits a greater middle ear inflammatory response, indicated by neutrophil products, than S. pneumoniae antigen.
- Findings suggest differential inflammatory potential of common OME pathogens, impacting treatment strategies.