Laboratory Studies
The European Society for Paediatric Gastroenterology Hepatology and Nutrition/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition made the following recommendations in 2017 for the Management of Helicobacter pylori in Children and Adolescents [31] :
1. The primary goal of clinical investigation of gastrointestinal symptoms should be to determine the underlying cause of the symptoms and not solely the presence of H pylori infection.
2a. Additional biopsies for rapid urease test and culture should only be taken during endoscopy if treatment is to be offered upon confirmation of infection.
2b. If H pylori infection is an incidental finding at endoscopy, treatment may be considered after a thorough discussion of the risks and benefits of treatment with the patient and or parents.
2c. The guidelines do not recommend a ‘‘test and treat’’ strategy for pediatric H pylori infection.
3. Testing for H pylori should be performed in children with gastric or duodenal ulcers. If H pylori infection is identified, then treatment should be advised and eradication be confirmed.
4. Diagnostic testing for H pylori infection in children with functional abdominal pain is not recommended.
5a. Diagnostic testing for H pylori infection as part of the initial investigation in children with iron deficiency anemia is not recommended.
5b. Testing for H pylori during upper endoscopy may be considered for children with refractory iron deficiency anemia in which other causes have been ruled out.
6. Noninvasive diagnostic testing for H pylori infection may be considered when investigating causes of chronic immune thrombocytopenic purpura.
7. Diagnostic testing for H pylori infection when investigating causes of short stature is not recommended.
8. Wait at least 2 weeks after stopping proton pump inhibitor and 4 weeks after stopping antibiotics before testing for H pylori.
9a. Diagnosis of H pylori infection should be based on either (a) histopathology (H pylori–positive gastritis) plus at least 1 other positive biopsy-based test or (b) positive culture.
9b. During upper endoscopy, at least 6 gastric biopsies should be taken for the diagnosis of H pylori infection.
10. Using antibody-based tests (IgG, IgA) for H pylori in serum, whole blood, urine, and saliva in the clinical setting is not recommended.
Imaging Studies
See the list below:
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Imaging studies are not helpful in the diagnosis of H pylori infection. They may be useful in patients with complicated disease (eg, ulcer disease, gastric cancer, MALToma).
Other Tests
See the list below:
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Urea breath test: The patient ingests a test meal that contains urea labeled with carbon-13 (13 C), which is a nonradioactive isotope. H pylori urease activity produces labeled13 C dioxide that can be detected in exhaled air. A positive result confirms urease activity and H pylori infection. This test is very specific and sensitive in patients older than 6 years. Its most useful application is to verify H pylori eradication after treatment. Experience in children 5 years or younger, particularly in infants, is relatively limited and needs further validation.
Procedures
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Upper endoscopy (EGD) is the procedure of choice for detecting gastritis, duodenitis, and PUD in the pediatric population.
EGD allows for direct visualization of the mucosa; for localization of the source of bleeding; for the detection of H pylori by means of biopsy, culture, and cytology analysis; and for DNA testing by using PCR.
In addition, a quick test based on detection of urease activity (a highly specific marker of H pylori) can be performed. The test, termed the Campylobacter -like organism (CLO) test allows for a diagnosis of H pylori infection within 24 hours.
Two modified, rapid urease test kits are now commercially available and are reported to have better accuracy, a shorter reaction time, and better cost-effectiveness than those of the CLO test.
In children, endoscopy may reveal a nodular appearance in the gastric antrum resulting from lymphoid hyperplasia. [32] However, only approximately 50% of affected children have endoscopic evidence of changes of H pylori gastritis.
The gross appearance of an active ulcer is a round or oval, punched-out lesion with a smooth, white base and with surrounding mucosa that is red and edematous. In H pylori infection, the most common location for ulceration is the duodenal bulb.
Biopsy specimens obtained in the prepyloric antrum have the highest yield in H pylori infection. Tissue specimens are often also obtained from the body and the transition zones of the stomach, particularly if the patient has recently taken acid-suppressing medication.
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Endoscopic biopsy is indicated for the following reasons:
Histologic examination of gastric tissue
Rapid urease testing (eg, CLO test)
Culture of organisms
PCR testing to identify H pylori DNA
Histologic Findings
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Histologic findings include a superficial infiltrate with substantial numbers of plasma cells and lymphocytes within the gastric mucosa and organisms visible on Giemsa, Diff-Quick, or hematoxylin and eosin staining. Sensitive staining for small numbers of bacteria is possible using silver stains such as Genta or Warthin-Starry.
Staging
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Although a staging system for the H pylori infection has not been established, several steps in disease progression are well described.
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The first step is chronic gastritis, which is followed by the second step, atrophic gastritis. The third step is intestinal metaplasia, which may evolve into dysplasia. The last step in this process is gastric adenocarcinoma.
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This process is very slow (ie, decades) and may stop at any step because gastric cancers probably require several other factors to develop, not only an H pylori infection.
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Helicobacter pylori infection revealed by endoscopy (nodular gastropathy).
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Helicobacter pylori–associated peptic ulcer in the duodenal bulb.
