H. pylori Testing

H. pylori Testing

Recent guidelines for testing strategies issued by the American Gastroenterology Association and American College of Gastroenterology do not recommend the use of serology for the diagnosis of active H. pylori infection. For these reasons, serological testing for H. pylori has been discontinued at ARUP Laboratories to facilitate physician use of the recommended test methods only.

Why serological testing is not recommended

Serological testing has remained the test of choice for many physicians. Conventional wisdom held that when negative, serological testing provided strong evidence against infection. The relative insensitivity of H. pylori serology has called this belief into question. The major underlying concerns with H. pylori serological testing are:

  • IgG serological results do not provide a diagnosis of current infection.
  • IgG could signal patient was exposed or previously infected.
  • IgG positive results may lead to unnecessary therapy.
  • IgM is of limited benefit, since most symptoms associated with H. pylori are attributable to the chronic inflammatory process.
  • IgM subclass of immunoglobulin is usually absent in a true infection.
  • IgA testing has been used in conjunction with IgG testing in the hope that a positive test would provide evidence of active infection. However, the results of these serologic tests do not correlate with stool antigen testing results.
  • IgA testing is not valid in IgA-deficient individuals.

References

  • Couturier, MR. The evolving challenges of Helicobacter pylori disease, diagnostics, and treatment, part I. ClinMicrobiol 2013;35(3):19–24.
  • Couturier, MR. The evolving challenges of Helicobacter pylori disease, diagnostics, and treatment, part II. Clin Microbiol 2013;35(4):27–30.

Diagnosis of H. pylori

There are various diagnostic tests available for the detection of H. pylori. They can be divided into two broad categories: invasive tests that require esophagogastroduodenoscopy (EGD) and noninvasive tests that do not require EGD. The most common invasive test is an endoscopy with antral biopsy.

  • Invasive testing—recommended for adults >55 years of age who exhibit alarm symptoms, including but not limited to: gastrointestinal bleeding, unexplained iron-deficiency anemia, unexplained weight loss, and a family history of upper gastrointestinal cancer.
  • Noninvasive testing—urea breath test and stool antigen are recommended for adults <55 years of age who do not have alarm symptoms.

Additional Information