摘要AIM: To estimate the test characteristics of Helicobacter pylori (H pylori) serology and of C14-urea breath test (C14-UBT) in two different peptic ulcer populations and in community controls. Second, the aim was to explore the association between the level of Hpylori IgG antibodies and severity of inflammation as to active peptic ulceration in the same populations.METHODS: Vagotomized (n = 83), medically treated peptic ulcer patients (n = 73) and one reference group of community controls (n = 88) were gastroscoped.H pylori status was determined by histology, bacterial growth, C14-UBT and serology. Based on the updated Sydney System, cumulative scores from biopsies from the prepyloruos, incisura angularis, corpus and fundus were calculated.RESULTS: The prevalence of Hpylori infection varied from 70% to 79%. The C14-UBT had high accuracy compared to the serology test. The sensitivity of the serology test was good, but the specificity was low (41%-71%). The association between H pylori IgG antibodies and scores of gastric mucosal inflammation and current or previous peptic ulcer were weak.CONCLUSION: The accuracy of C14-UBT to diagnose Hpylori infection was good, and the clinical utility of a negative H pylori serology test was substantial, while the gain in clinical information of a positive test was meagre. Positive H pylori titres could not distinguish between subjects with or those without active peptic ulceration.