The H. Pylori Breath Test: Surrogate Marker for Peptic Ulcer Disease in Dyspeptic Patients
ABSTRACT & COMMENTARY
Synopsis: A positive Helicobacter pylori test is a powerful predictor of the presence of underlying ulcer disease in dyspeptic patients.
Source: McColl KEL, et al. Gut 1997;40:302-306.
In this paper, Mccoll et al set out to assess the value of the C14 urea breath test as a predictor for peptic ulcer disease in patients presenting with dyspepsia. A total of 327 consecutive patients referred for investigation of dyspepsia had a C14 urea breath test performed before endoscopy. Patients were not included if they had previously confirmed ulcer disease, previous gastric surgery, or were taking non-steroidal anti-inflammatory drugs. Of the 182 patients with a positive C14 urea breath test, duodenal and/or gastric ulcers were present in 45% and erosive duodenitis in a further 2%. Esophagitis was present in 12% of the breath test-positive patients, and two-thirds of the esophagitis patients had coexistent ulcer disease. The prevalence of ulcer disease in the Helicobacter pylori-positive dyspeptic patients was independently related to smoking and previous investigation status. If previously uninvestigated, the prevalence of ulcers was 67% in smokers and 46% in nonsmokers. If previous upper gastrointestinal investigations were negative, the prevalence of ulcers was 52% in smokers and 28% in nonsmokers. Of the 136 patients with a negative breath test, only 5% had peptic ulcers. The most frequent endoscopic finding in these H. pylori-negative subjects was esophagitis, being present in 17%. The authors conclude that this study demonstrated that a positive H. pylori test is a powerful predictor of the presence of underlying ulcer disease in dyspeptic patients, especially of smokers, and that a negative H. pylori test is a powerful predictor of the absence of ulcer disease. It also indicates that a negative upper gastrointestinal investigation does not preclude subsequent presentation with ulcer disease.
COMMENT BY EAMONN M.M. QUIGLEY, MD
Dyspepsia remains a major clinical challenge for the primary care physician, general internist, and specialist. In the current medical/economic climate, particular emphasis is being placed on cost-effective approaches to the assessment and management of this patient group. The cost-effectiveness of endoscopy, in particular, has been questioned and compared with such cheaper strategies as H. pylori serology, for example. A major limitation to Helicobacter serology is that the antibody can remain positive for months or even years in some patients following effective eradication. It is not, therefore, a useful test for following patients with H. pylori infection after therapy. The H. pylori breath test has recently been released in the United States and offers the possibility of accuracy in both the diagnosis and follow-up of H. pylori infection. This study now places the H. pylori breath test in perspective in the clinical assessment of patients with dyspepsia. As acknowledged by the authors, this study needs to be placed in context. It was performed in Glasgow, in the west of Scotland, where the prevalence of H. pylori infection is 66% and the prevalence of peptic ulcer disease twice that of the rest of the United Kingdom. These high prevalence rates for both peptic ulcer and H. pylori infection will tend, of course, to bias the results toward the test in question. Nevertheless, what I found most impressive about this test was the ability of a negative test to virtually exclude peptic ulcer disease. Thus, among the 136 patients with a negative test, only 2% had a duodenal ulcer and 3% a gastric ulcer. A positive test was not as helpful, in that, even among those who had prior negative investigations, 28% of nonsmokers and 53% of smokers were found, on endoscopy, to have peptic ulcer disease. The test could not, of course, predict the presence of esophagitis, a common finding in both H. pylori-positive and -negative groups. Of note, also in this study, there is a strong correlation between the presence of peptic ulcer disease and smokingan independent risk factor for ulcer disease. What is missing from this study, however, is a comparison of the breath test with serology. Given the simplicity of the latter, it would be most interesting to see what the diagnostic advantage of the breath test was over the serological test. From these and other studies, one can conclude that non-invasive testing for H. pylori will become a standard component of the evaluation of dyspeptic patients and will help to select patients for endoscopy, and thereby improve its cost-effectiveness.
1. Patel P, et al. Lancet 1995;346:1315-1318.
2. Mendall MA, et al. Euro J Gastroenterol Hepatol 1992;24:713-717.