EBM Consult

Lab Test: Helicobacter Pylori Antibody

    Lab Test
    • Helicobacter Pylori Antibody (H-Pylori Antibody)
    Description
    • Detection of helicobacter pylori in serum for the evaluation and management of gastrointestinal disorders.
    Reference Range
    • Negative
    • IgM: 
      • ≤30 U/mL (negative)
      • 30.01-39.99 U/mL (equivocal)
      • ≥40 U/mL (positive)
    • IgG
      • <0.75 (negative)
      • 0.75-0.99 (equivocal)
      • ≥1 (positive)
    Indications & Uses
    • Suspected Helicobacter pylori associated gastric cancer - Helicobacter pylori antibody titers are associated with the development of gastric cancer. 
    • Suspected Helicobacter pylori gastritis - a drop in antibody levels of 20% to 50% from baseline is suggestive of cure.  However, because levels drop slowly and inconsistently, Helicobacter pylori-specific antibody tests are not useful for monitoring response to treatment or for measuring reinfection rates.  Levels should be limited to establishing an initial diagnosis. False results - false negative serology results for Helicobacter pylori have been correlated with chronic atrophic gastritis in the elderly. Because serologic assay cutoff values may be different in children, cut-off values may require a downward adjustment in pediatric patients to avoid false negatives. 
    • Suspected Helicobacter pylori peptic ulcer disease - Helicobacter pylori eradication leads to a substantial reduction in type B gastritis and a lower duodenal ulcer relapse rate.
    Clinical Application
    • H. pylori, is a gram negative bacterium that infects the mucus overlying the gastric mucosa in the stomach.  Its presence creates a risk factor for gastric and duodenal ulcers, chronic gastritis, or even ulcerative esophagitis.  It is also a class I gastric carcinogen.
    • Approximately 10% of healthy persons younger than 30 years of age have H. pylori without disease or symptoms due to colonization, which can increase with age, with people older than age 60 years having rates at a percentage similar to their age.
    • Testing should only be performed on symptomatic patients.
    • It is the least sensitive of the H. pylori tests.  The antibodies can be detected with use of a small amount of blood obtained by fingerstick.  Serologic testing is often used several months after treatment to document eradication of H. pylori infection.  
    • The enzyme-linked immunosorbent assay (ELISA) must be locally validated because of regional variability in antibody levels. 
    • Increased levels may indicate:
      • Acute and chronic gastritis, recurrent duodenal ulcer, gastric ulcer, gastric carcinoma.
    Related Tests
    • Gastrin - this test is a measure of serum gastrin.  This hormone stimulates gastric acid secretion.  The initial symptoms may be similar to those of chronic H. pylori infection.
    • Esophagogastroduodenoscopy - this endoscopic procedure is used to directly biopsy the gastric mucosa for definitive H. pylori identification.
    Drug-Lab Interactions
    • The concomitant use of a proton pump inhibitor, such as Prilosec, Nexium, Prevacid, or Protonix will inhibit urea absorption and diminish the sensitivity of the testing method.
    Test Tube Needed
    • ELISA:  marble top tube
    Procedure
    • Collect a venous blood sample according to the protocol of the laboratory performing the test. 
    • Enzyme-linked immunosorbent assay (ELISA): collect specimen in marble-top tube. 
    • Rapid antibody serology test:  draw fingerstick specimen into glass or plastic capillary tube. 
    • Apply pressure or a pressure dressing to the venipuncture site and assess the site for bleeding.
    What To Tell Patient Before & After
    • Explain the procedure to the patient.
    • Tell the patient that no fating is required.
    References
    • LaGow B et al., eds. PDR Lab Advisor. A Comprehensive Point-of-Care Guide for Over 600 Lab Tests.  First ed. Montvale, NJ: Thomson PDR; 2007.
    • Pagana K, Pagana TJ eds. Mosby's Manual of Diagnostic and Laboratory Tests. 5th Ed.  St. Louis, Missouri. 2014.

MESH Terms & Keywords

  • Helicobacter, Pylori, Antibody, H-Pylori