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The agglutinating antibody response in the duodenum of infants with enteropathogenic Escherichia coli gastroenteritis
Insights
Infants with enteropathogenic Escherichia coli gastroenteritis mount a specific antibody response in the gut, primarily immunoglobulin A (IgA). This intestinal immune response, crucial for fighting E. coli infections, shows strain-specific changes over time.
Area of Science:
- Immunology
- Pediatrics
- Microbiology
Background:
- Enteropathogenic Escherichia coli (EPEC) gastroenteritis is a significant cause of infant illness.
- Understanding the host immune response is critical for managing EPEC infections.
Purpose of the Study:
- To investigate the antibody response in duodenal fluid and serum of infants with EPEC gastroenteritis.
- To characterize the immunoglobulin class and specificity of these antibodies.
Main Methods:
- Serial measurement of agglutinating antibodies in duodenal fluid and serum from 15 infants.
- Analysis of immunoglobulin (Ig) class (IgA, IgM) and antibody cross-reactivity with different E. coli strains.
Main Results:
- Peak duodenal antibody levels occurred 8-18 days post-symptom onset, primarily as IgA, with early IgM noted in younger infants.
- Antibody cross-reactivity decreased over time.
- Serum antibody responses were inconsistent and poorly correlated with intestinal antibody levels.
Conclusions:
- Infants mount a localized IgA-dominant antibody response in the gut against EPEC.
- The variability in serum antibody response may be linked to host factors or bacterial invasiveness.
Abstract:
The agglutinating antibody response in duodenal fluid and serum was measured serially in 15 infants with enteropathogenic Escherichia coli gastroenteritis. Peak levels of duodenal agglutinins were recorded 8-18 days after the onset of symptoms, and the titres fell within the next 7-14 days. The immunoglobulin (Ig) class of these antibodies was mainly IgA, but IgM antibodies were detected early in the response, especially in the younger infants. Late antibodies showed less cross-reactions with other strains of E. coli than did early antibodies. Serum antibody responses were detected in eight infants, but they correlated poorly with the titres of intestinal antibodies. No rise in serum antibodies was detected in six infants. It is not known whether these differences are host-derived, or whether they are the result of the invasive properties of some of the infecting organisms.