Current Issue

2016, Volume 26, Number 2

Helicobacter pylori Serologic Testing to Be Discontinued

By William G. Finn, M.D., Medical Director, Warde Medical Laboratory

Helicobacter pylori  symptomThe serologic evaluation for IgG antibodies to Helicobacter pylori (H. pylori) has come under increased scrutiny in the last several years. Evidence is mounting that when non-invasive testing is indicated for detection of H. pylori infection, the urea breath test (UBT) and the H. pylori stool antigen test (SAT) provide superior performance characteristics for the documentation of infection (1-3). Although the UBT and SAT may be affected by previous proton pump inhibitor (PPI) or antimicrobial therapy, they likely have sensitivity, specificity, and positive predictive value (PPV) well in excess of 90% for the detection of active H. pylori infection (1). On the other hand, serologic screening for H. pylori infection has cited sensitivity in the range of 76 to 84%, with specificity in the range of 79 to 90% (1, 4, 5). While the prevalence of H. pylori infection worldwide is high—likely in the range of 50%-- prevalence in the United States and other developed nations is lower. At prevalence rates of 20 to 30% (as is the case for many regions of the US), there is evidence that the positive predictive value of H. pylori serologic testing may dip to about 50%, substantially limiting its clinical utility (1, 5). Furthermore, serologic testing cannot be used to monitor disease after therapy, since IgG antibodies may persist for many years following the eradication of infection (1-3).

For the last decade or so, both the American Gastroenterology Association (AGA) and the American College of Gastroenterology (ACG) have recommended either the UBT or SAT as an initial step in the workup of possible H. pylori infection. (1,3) Current diagnostic algorithms for the non-invasive assessment of patients for possible H. pylori infection no longer include serologic evaluation (6). In the face of accumulating evidence on this topic, large national reference laboratories such as Quest Diagnostics, Mayo Medical Laboratories, and ARUP no longer offer H. pylori serologic testing on their test menus, and many insurance companies no longer cover patients’ costs for this testing.

In light of an emerging consensus that serologic testing for H. pylori is not clinically useful, Warde Medical Laboratory will discontinue its H. pylori IgG antibody assay effective September 1, 2016. For the initial non-invasive (non-endoscopic) workup of H. pylori, either the UBT or the SAT is now recommended. For best results from these assays, the use of PPIs, bismuth-containing compounds, or antibiotics should be discontinued for two weeks prior to testing. Additional information on ordering and collection requirements for these tests may be obtained by contacting Warde client services at 800-760-9969.


References

  1. Chey WD, Wong BC, Practice Parameters Committee of the American College of G. American College of Gastroenterology guideline on the management of Helicobacter pylori infection. Am J Gastroenterol. 2007;102(8):1808-25.
  2. Malfertheiner P, Megraud F, O'Morain CA, et al. Management of Helicobacter pylori infection--the Maastricht IV/ Florence Consensus Report. Gut. 2012;61(5):646-64.
  3. Talley NJ, Vakil NB, Moayyedi P. American gastroenterological association technical review on the evaluation of dyspepsia. Gastroenterology. 2005;129(5):1756-80.
  4. Theel ES. Helicobacter pylori infection: serologic testing not recommended. Mayo Medical Laboratories Communique. 2016.
  5. Theel ES, Johnson RD, Plumhoff E, Hanson CA. Use of the Optum Labs Data Warehouse to assess test ordering patterns for diagnosis of Helicobacter pylori infection in the United States. J Clin Microbiol. 2015;53(4):1358-60.
  6. Talley NJ, Ford AC. Functional Dyspepsia. N Engl J Med. 2015;373(19):1853-63.