The Use of Helicobacter pylori Serology in Diagnosis and Treatment Monitoring

Abstract

The main problem when serology is used for diagnosis of H. pylori infection is to define the cut-off level. It is therefore of the greatest importance to define a proper “gold standard” for the presence and absence of H. pylori and to define a proper test population for this evaluation. The tests available for diagnosis of H. pylori and thus for definition of the “golden standard” are: (a) culture of H. pylori from endoscopic biopsies, (b) observation of Helicobacter-like organisms (HLO) by microscopy in histological preparation of biopsies, (c) urea breath test (¹⁴C and ¹³C), (d) urease activity in biopsies (the rapid urease test), and (e) polymerase chain reaction (PCR) for detection of H. pylori DNA in biopsies. All these tests, except PCR, have no or very few false-positive results whereas, the frequence of false-negative results are more uncertain depending on the intensity of the infection and the patchiness of the bacteria in the stomach allowing sampling errors. PCR has no or extremely few false-negative results, but only very little contamination of the material with H. pylori can cause false-positive results. In general it is accepted that at the least culture and preferably also microscopy of sections are necessary for an acceptable “gold standard,” but it is clear that the more tests that are included the more rehable is the “gold standard.”