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Serodiagnosis of Helicobacter pylori infection in childhood
J E Thomas1, A M Whatmore, M R Barer
1Department of Child Health, University of Newcastle-upon-Tyne, United Kingdom.
Insights
An enzyme-linked immunosorbent assay (ELISA) using crude antigens effectively detects Helicobacter pylori infection in children with gastrointestinal symptoms. This method is valuable for diagnosing H. pylori in pediatric patients.
Area of Science:
- Pediatric Gastroenterology
- Immunology
- Microbiology
Background:
- Helicobacter pylori infection is a significant cause of upper gastrointestinal symptoms in children.
- Accurate serodiagnostic tools are needed for H. pylori detection in pediatric populations.
- Current diagnostic methods may have limitations in sensitivity or specificity.
Purpose of the Study:
- To evaluate the utility of enzyme-linked immunosorbent assay (ELISA) for detecting Helicobacter pylori antibodies in children.
- To compare the effectiveness of crude antigens versus urease antigen preparations for serodiagnosis.
- To assess the reliability of IgG, IgM, and IgA antibody levels in diagnosing H. pylori infection.
Main Methods:
- Sera from 100 children (6-16 years) with upper gastrointestinal symptoms were tested using ELISA.
- Tests employed crude, loosely cell-associated antigens and partially purified urease antigen.
- Confirmation of H. pylori infection was established by endoscopy, histology, or culture in 20 children.
Main Results:
- Serum anti-H. pylori immunoglobulin G (IgG) levels using crude antigens were significantly elevated in infected children.
- IgM and IgA ELISA results did not effectively differentiate between infected and non-infected children.
- Anti-urease IgG levels were elevated in only 14 infected children; crude antigen IgG showed better diagnostic potential.
Conclusions:
- An IgG ELISA utilizing crude, loosely cell-associated H. pylori antigens is a viable method for serodiagnosis in children.
- This ELISA approach can aid in identifying H. pylori infection in pediatric patients presenting with relevant symptoms.
- Further research may be needed to refine serodiagnostic reagents for improved specificity and reliability.
Abstract:
Sera from 100 children (ages, 6 to 16 years) presenting with upper gastrointestinal symptoms were examined for antibodies to Helicobacter pylori by enzyme-linked immunosorbent assay (ELISA) based on crude, loosely cell-associated antigens and a partially purified urease antigen preparation. All children underwent endoscopy, and 20 children were shown to have H. pylori infection by histology or direct culture. Serum anti-H. pylori immunoglobulin G (IgG) levels (crude antigen) were clearly raised in the infected group, particularly after preabsorption of sera against a Campylobacter jejuni antigen preparation, while IgM and IgA ELISA determinations did not discriminate between infected and H. pylori-negative patients. Only 14 children in the infected group had raised anti-urease IgG levels. Two patients in whom the organism was not demonstrated or cultured had raised specific IgG levels against both crude and urease antigens and pathological features consistent with H. pylori disease. Immunoblotting studies did not reveal any single protein antigen or simple combination of antigens that could be considered as a candidate for a more defined serodiagnostic reagent. Anti-H. pylori antibody determinations (crude antigen) performed on posttreatment samples from children in whom the organism could no longer be demonstrated suggested that sustained IgG levels may not be a reliable index of treatment failure. An IgG ELISA based on crude, loosely cell-associated antigens of H. pylori can be used for the serodiagnosis of H. pylori infection in childhood.