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Plasma anti-pneumococcal antibody activity of the IgG class and subclasses in otitis prone children
Insights
Children with recurrent otitis media have lower levels of key pneumococcal antibodies, specifically IgG2, compared to healthy peers and adults. This suggests an impaired immune response in otitis-prone children.
Area of Science:
- Immunology
- Pediatrics
- Infectious Diseases
Background:
- Recurrent otitis media is common in young children.
- Pneumococcal antibodies are crucial for protection against Streptococcus pneumoniae, a common cause of otitis media.
- Understanding antibody subclass responses is important for evaluating immune function.
Purpose of the Study:
- To compare plasma anti-pneumococcal polysaccharide antibody activity in otitis-prone children versus controls.
- To analyze the IgG subclass distribution of these antibodies.
- To investigate potential immune deficiencies in otitis-prone children.
Main Methods:
- Enzyme immunoassay was used to measure antibody activity against pneumococcal serotypes 3, 6a, and 23.
- IgG subclass-specific monoclonal antibodies were employed for detailed analysis.
- Samples were collected from 15 otitis-prone children (30 months old), age-matched controls, and adults.
Main Results:
- Adults had the highest antibody concentrations, predominantly IgG2.
- Children showed higher IgG1 levels than adults.
- Healthy children had higher IgG1 and IgG2 than otitis-prone children, especially for serotype 6a.
Conclusions:
- Pneumococcal antibody activity is primarily associated with the IgG2 subclass in adults.
- Children's sera contain both IgG1 and IgG2 subclasses.
- Otitis-prone children exhibit reduced IgG1 and IgG2 antibody levels, suggesting an impaired humoral immune response.
Abstract:
Plasma anti-pneumococcal polysaccharide antibody activity (serotypes 3, 6a and 23) was determined in samples from 15 otitis prone children, at 30 months of age, and compared with age matched control children and adults. A recently developed enzyme immunoassay, using IgG subclass specific monoclonal antibodies for analysis of pneumococcal antibody activity of different IgG subclasses was employed. Adult sera always contained the highest antibody concentrations, almost exclusively of the IgG2 subclass. Children, on the other hand, had higher amounts of IgG1, significantly exceeding those of the adults, healthy children having higher IgG1, as well as IgG2 values than otitis prone children. The most significant differences were seen with type 6a, less so with type 23 antibodies. No differences in IgG1 anti-type 3 pneumococcal activity were observed between the children and the adults. These findings support the concept that pneumococcal antibody activity is confined to IgG2 and, in addition, it was found that sera from children contain antibodies of both IgG1 and IgG2 subclasses.